diff --git a/core/basepage.php b/core/basepage.php
index 1d7ae666..6b3aaa69 100644
--- a/core/basepage.php
+++ b/core/basepage.php
@@ -496,6 +496,9 @@ class BasePage
         return ["script.js"];
     }
 
+    /**
+     * @return array{0: NavLink[], 1: NavLink[]}
+     */
     protected function get_nav_links(): array
     {
         $pnbe = send_event(new PageNavBuildingEvent());
@@ -641,6 +644,7 @@ class BasePage
 
 class PageNavBuildingEvent extends Event
 {
+    /** @var NavLink[] */
     public array $links = [];
 
     public function add_nav_link(string $name, Link $link, string $desc, ?bool $active = null, int $order = 50): void
@@ -653,6 +657,7 @@ class PageSubNavBuildingEvent extends Event
 {
     public string $parent;
 
+    /** @var NavLink[] */
     public array $links = [];
 
     public function __construct(string $parent)
@@ -704,6 +709,9 @@ class NavLink
         }
     }
 
+    /**
+     * @param string[] $pages_matched
+     */
     public static function is_active(array $pages_matched, string $url = null): bool
     {
         /**
diff --git a/core/cacheengine.php b/core/cacheengine.php
index 147af159..b6e2b0b3 100644
--- a/core/cacheengine.php
+++ b/core/cacheengine.php
@@ -67,6 +67,11 @@ class EventTracingCache implements CacheInterface
         return $val;
     }
 
+    /**
+     * @param string[] $keys
+     * @param mixed $default
+     * @return mixed[]
+     */
     public function getMultiple($keys, $default = null)
     {
         $this->tracer->begin("Cache Get Multiple", ["keys" => $keys]);
@@ -75,6 +80,9 @@ class EventTracingCache implements CacheInterface
         return $val;
     }
 
+    /**
+     * @param array<string, mixed> $values
+     */
     public function setMultiple($values, $ttl = null)
     {
         $this->tracer->begin("Cache Set Multiple", ["keys" => array_keys($values)]);
@@ -83,6 +91,9 @@ class EventTracingCache implements CacheInterface
         return $val;
     }
 
+    /**
+     * @param string[] $keys
+     */
     public function deleteMultiple($keys)
     {
         $this->tracer->begin("Cache Delete Multiple", ["keys" => $keys]);
diff --git a/core/command_builder.php b/core/command_builder.php
index 4908a492..22b02742 100644
--- a/core/command_builder.php
+++ b/core/command_builder.php
@@ -10,7 +10,9 @@ namespace Shimmie2;
 class CommandBuilder
 {
     private string $executable;
+    /** @var string[] */
     private array $args = [];
+    /** @var string[] */
     public array $output;
 
     public function __construct(string $executable)
diff --git a/core/config.php b/core/config.php
index e403435a..8f930e0e 100644
--- a/core/config.php
+++ b/core/config.php
@@ -41,6 +41,8 @@ interface Config
 
     /**
      * Set a configuration option to a new value, regardless of what the value is at the moment.
+     *
+     * @param mixed[] $value
      */
     public function set_array(string $name, array $value): void;
     //@} /*--------------------------------------------------------------------------------------------*/
@@ -93,6 +95,8 @@ interface Config
      * This has the advantage that the values will show up in the "advanced" setup
      * page where they can be modified, while calling get_* with a "default"
      * parameter won't show up.
+     *
+     * @param mixed[] $value
      */
     public function set_default_array(string $name, array $value): void;
     //@} /*--------------------------------------------------------------------------------------------*/
@@ -120,6 +124,9 @@ interface Config
 
     /**
      * Pick a value out of the table by name, cast to the appropriate data type.
+     *
+     * @param mixed[] $default
+     * @return mixed[]
      */
     public function get_array(string $name, ?array $default = []): ?array;
     //@} /*--------------------------------------------------------------------------------------------*/
@@ -134,6 +141,7 @@ interface Config
  */
 abstract class BaseConfig implements Config
 {
+    /** @var array<string, mixed> */
     public array $values = [];
 
     public function set_int(string $name, ?int $value): void
@@ -205,16 +213,31 @@ abstract class BaseConfig implements Config
         }
     }
 
+    /**
+     * @template T of int|null
+     * @param T $default
+     * @return T|int
+     */
     public function get_int(string $name, ?int $default = null): ?int
     {
         return (int)($this->get($name, $default));
     }
 
+    /**
+     * @template T of float|null
+     * @param T $default
+     * @return T|float
+     */
     public function get_float(string $name, ?float $default = null): ?float
     {
         return (float)($this->get($name, $default));
     }
 
+    /**
+     * @template T of string|null
+     * @param T $default
+     * @return T|string
+     */
     public function get_string(string $name, ?string $default = null): ?string
     {
         $val = $this->get($name, $default);
@@ -224,17 +247,34 @@ abstract class BaseConfig implements Config
         return $val;
     }
 
+    /**
+     * @template T of bool|null
+     * @param T $default
+     * @return T|bool
+     */
     public function get_bool(string $name, ?bool $default = null): ?bool
     {
         return bool_escape($this->get($name, $default));
     }
 
-    public function get_array(string $name, ?array $default = []): ?array
+    /**
+     * @template T of array<string>|null
+     * @param T $default
+     * @return T|array<string>
+     */
+    public function get_array(string $name, ?array $default = null): ?array
     {
-        return explode(",", $this->get($name, ""));
+        $val = $this->get($name);
+        if(is_null($val)) {
+            return $default;
+        }
+        if(empty($val)) {
+            return [];
+        }
+        return explode(",", $val);
     }
 
-    private function get(string $name, $default = null): mixed
+    private function get(string $name, mixed $default = null): mixed
     {
         if (isset($this->values[$name])) {
             return $this->values[$name];
diff --git a/core/database.php b/core/database.php
index f034752d..d9b1e60b 100644
--- a/core/database.php
+++ b/core/database.php
@@ -19,8 +19,12 @@ enum DatabaseDriverID: string
 class DatabaseException extends SCoreException
 {
     public string $query;
+    /** @var array<string, mixed> */
     public array $args;
 
+    /**
+     * @param array<string, mixed> $args
+     */
     public function __construct(string $msg, string $query, array $args)
     {
         parent::__construct($msg);
@@ -32,6 +36,8 @@ class DatabaseException extends SCoreException
 
 /**
  * A class for controlled database access
+ *
+ * @phpstan-type QueryArgs array<string, string|int|bool|null>
  */
 class Database
 {
@@ -52,6 +58,7 @@ class Database
      * How many queries this DB object has run
      */
     public int $query_count = 0;
+    /** @var string[] */
     public array $queries = [];
 
     public function __construct(string $dsn)
@@ -162,13 +169,15 @@ class Database
         return $this->get_engine()->get_version($this->get_db());
     }
 
+    /**
+     * @param QueryArgs $args
+     */
     private function count_time(string $method, float $start, string $query, ?array $args): void
     {
         global $_tracer, $tracer_enabled;
         $dur = ftime() - $start;
         // trim whitespace
-        $query = preg_replace('/[\n\t ]/m', ' ', $query);
-        $query = preg_replace('/  +/m', ' ', $query);
+        $query = preg_replace('/[\n\t ]+/m', ' ', $query);
         $query = trim($query);
         if ($tracer_enabled) {
             $_tracer->complete($start * 1000000, $dur * 1000000, "DB Query", ["query" => $query, "args" => $args, "method" => $method]);
@@ -188,6 +197,9 @@ class Database
         $this->get_engine()->notify($this->get_db(), $channel, $data);
     }
 
+    /**
+     * @param QueryArgs $args
+     */
     public function _execute(string $query, array $args = []): PDOStatement
     {
         try {
@@ -203,6 +215,8 @@ class Database
 
     /**
      * Execute an SQL query with no return
+     *
+     * @param QueryArgs $args
      */
     public function execute(string $query, array $args = []): PDOStatement
     {
@@ -214,6 +228,9 @@ class Database
 
     /**
      * Execute an SQL query and return a 2D array.
+     *
+     * @param QueryArgs $args
+     * @return array<array<string, mixed>>
      */
     public function get_all(string $query, array $args = []): array
     {
@@ -225,6 +242,8 @@ class Database
 
     /**
      * Execute an SQL query and return a iterable object for use with generators.
+     *
+     * @param QueryArgs $args
      */
     public function get_all_iterable(string $query, array $args = []): PDOStatement
     {
@@ -236,6 +255,9 @@ class Database
 
     /**
      * Execute an SQL query and return a single row.
+     *
+     * @param QueryArgs $args
+     * @return array<string, mixed>
      */
     public function get_row(string $query, array $args = []): ?array
     {
@@ -247,6 +269,9 @@ class Database
 
     /**
      * Execute an SQL query and return the first column of each row.
+     *
+     * @param QueryArgs $args
+     * @return array<mixed>
      */
     public function get_col(string $query, array $args = []): array
     {
@@ -258,6 +283,8 @@ class Database
 
     /**
      * Execute an SQL query and return the first column of each row as a single iterable object.
+     *
+     * @param QueryArgs $args
      */
     public function get_col_iterable(string $query, array $args = []): \Generator
     {
@@ -271,6 +298,9 @@ class Database
 
     /**
      * Execute an SQL query and return the the first column => the second column.
+     *
+     * @param QueryArgs $args
+     * @return array<string, mixed>
      */
     public function get_pairs(string $query, array $args = []): array
     {
@@ -283,6 +313,8 @@ class Database
 
     /**
      * Execute an SQL query and return the the first column => the second column as an iterable object.
+     *
+     * @param QueryArgs $args
      */
     public function get_pairs_iterable(string $query, array $args = []): \Generator
     {
@@ -296,6 +328,8 @@ class Database
 
     /**
      * Execute an SQL query and return a single value, or null.
+     *
+     * @param QueryArgs $args
      */
     public function get_one(string $query, array $args = []): mixed
     {
@@ -307,6 +341,8 @@ class Database
 
     /**
      * Execute an SQL query and returns a bool indicating if any data was returned
+     *
+     * @param QueryArgs $args
      */
     public function exists(string $query, array $args = []): bool
     {
diff --git a/core/dbengine.php b/core/dbengine.php
index 19502551..abd9909a 100644
--- a/core/dbengine.php
+++ b/core/dbengine.php
@@ -129,7 +129,7 @@ class PostgreSQL extends DBEngine
 }
 
 // shimmie functions for export to sqlite
-function _unix_timestamp($date): int
+function _unix_timestamp(string $date): int
 {
     return strtotime($date);
 }
@@ -137,11 +137,11 @@ function _now(): string
 {
     return date("Y-m-d H:i:s");
 }
-function _floor($a): float
+function _floor(float|int $a): float
 {
     return floor($a);
 }
-function _log($a, $b = null): float
+function _log(float $a, ?float $b = null): float
 {
     if (is_null($b)) {
         return log($a);
@@ -149,19 +149,19 @@ function _log($a, $b = null): float
         return log($b, $a);
     }
 }
-function _isnull($a): bool
+function _isnull(mixed $a): bool
 {
     return is_null($a);
 }
-function _md5($a): string
+function _md5(string $a): string
 {
     return md5($a);
 }
-function _concat($a, $b): string
+function _concat(string $a, string $b): string
 {
     return $a . $b;
 }
-function _lower($a): string
+function _lower(string $a): string
 {
     return strtolower($a);
 }
@@ -169,7 +169,7 @@ function _rand(): int
 {
     return rand();
 }
-function _ln($n): float
+function _ln(float $n): float
 {
     return log($n);
 }
diff --git a/core/event.php b/core/event.php
index 93d4eeec..c66b2ac9 100644
--- a/core/event.php
+++ b/core/event.php
@@ -143,6 +143,9 @@ class PageRequestEvent extends Event
      * Many things use these functions
      */
 
+    /**
+     * @return string[]
+     */
     public function get_search_terms(): array
     {
         $search_terms = [];
@@ -172,7 +175,6 @@ class PageRequestEvent extends Event
             $str = $out;
             // end legacy
 
-
             $search_terms = Tag::explode($str);
         }
         return $search_terms;
diff --git a/core/extension.php b/core/extension.php
index 5f54305d..b3431846 100644
--- a/core/extension.php
+++ b/core/extension.php
@@ -22,9 +22,10 @@ abstract class Extension
     protected Themelet $theme;
     public ExtensionInfo $info;
 
+    /** @var string[] */
     private static array $enabled_extensions = [];
 
-    public function __construct($class = null)
+    public function __construct(?string $class = null)
     {
         $class = $class ?? get_called_class();
         $this->theme = $this->get_theme_object($class);
@@ -87,6 +88,9 @@ abstract class Extension
         return in_array($key, self::$enabled_extensions);
     }
 
+    /**
+     * @return string[]
+     */
     public static function get_enabled_extensions(): array
     {
         return self::$enabled_extensions;
@@ -141,8 +145,11 @@ abstract class ExtensionInfo
     public string $name;
     public string $license;
     public string $description;
+    /** @var array<string, string> */
     public array $authors = [];
+    /** @var string[] */
     public array $dependencies = [];
+    /** @var string[] */
     public array $conflicts = [];
     public ExtensionVisibility $visibility = ExtensionVisibility::DEFAULT;
     public ?string $link = null;
@@ -170,8 +177,11 @@ abstract class ExtensionInfo
         return $this->support_info;
     }
 
+    /** @var array<string, ExtensionInfo> */
     private static array $all_info_by_key = [];
+    /** @var array<string, ExtensionInfo> */
     private static array $all_info_by_class = [];
+    /** @var string[] */
     private static array $core_extensions = [];
 
     protected function __construct()
@@ -207,16 +217,25 @@ abstract class ExtensionInfo
         $this->supported = empty($this->support_info);
     }
 
+    /**
+     * @return ExtensionInfo[]
+     */
     public static function get_all(): array
     {
         return array_values(self::$all_info_by_key);
     }
 
+    /**
+     * @return string[]
+     */
     public static function get_all_keys(): array
     {
         return array_keys(self::$all_info_by_key);
     }
 
+    /**
+     * @return string[]
+     */
     public static function get_core_extensions(): array
     {
         return self::$core_extensions;
@@ -285,6 +304,7 @@ abstract class FormatterExtension extends Extension
  */
 abstract class DataHandlerExtension extends Extension
 {
+    /** @var string[] */
     protected array $SUPPORTED_MIME = [];
 
     public function onDataUpload(DataUploadEvent $event): void
@@ -396,6 +416,9 @@ abstract class DataHandlerExtension extends Extension
         return MimeType::matches_array($mime, $this->SUPPORTED_MIME);
     }
 
+    /**
+     * @return string[]
+     */
     public static function get_all_supported_mimes(): array
     {
         $arr = [];
@@ -413,6 +436,9 @@ abstract class DataHandlerExtension extends Extension
         return $arr;
     }
 
+    /**
+     * @return string[]
+     */
     public static function get_all_supported_exts(): array
     {
         $arr = [];
diff --git a/core/imageboard/event.php b/core/imageboard/event.php
index 5011dc1c..f7be1f2b 100644
--- a/core/imageboard/event.php
+++ b/core/imageboard/event.php
@@ -63,7 +63,9 @@ class ImageReplaceEvent extends Event
     ) {
         parent::__construct();
         $this->old_hash = $image->hash;
-        $this->new_hash = md5_file($tmp_filename);
+        $hash = md5_file($tmp_filename);
+        assert($hash !== false, "Failed to hash file $tmp_filename");
+        $this->new_hash = $hash;
     }
 }
 
diff --git a/core/imageboard/image.php b/core/imageboard/image.php
index 92c5afec..0f2415e2 100644
--- a/core/imageboard/image.php
+++ b/core/imageboard/image.php
@@ -23,6 +23,8 @@ enum ImagePropType
  * As of 2.2, this no longer necessarily represents an
  * image per se, but could be a video, sound file, or any
  * other supported upload type.
+ *
+ * @implements \ArrayAccess<string, mixed>
  */
 #[Type(name: "Post")]
 class Image implements \ArrayAccess
@@ -71,6 +73,8 @@ class Image implements \ArrayAccess
     /**
      * One will very rarely construct an image directly, more common
      * would be to use Image::by_id, Image::by_hash, etc.
+     *
+     * @param array<string|int, mixed>|null $row
      */
     public function __construct(?array $row = null)
     {
@@ -82,6 +86,7 @@ class Image implements \ArrayAccess
                     continue;
                 } elseif(property_exists($this, $name)) {
                     $t = (new \ReflectionProperty($this, $name))->getType();
+                    assert(!is_null($t));
                     if(is_a($t, \ReflectionNamedType::class)) {
                         $this->$name = match($t->getName()) {
                             "int" => is_null($value) ? $value : int_escape((string)$value),
@@ -116,10 +121,12 @@ class Image implements \ArrayAccess
 
     public function offsetExists(mixed $offset): bool
     {
+        assert(is_string($offset));
         return array_key_exists($offset, static::$prop_types);
     }
     public function offsetGet(mixed $offset): mixed
     {
+        assert(is_string($offset));
         if(!$this->offsetExists($offset)) {
             throw new \OutOfBoundsException("Undefined dynamic property: $offset");
         }
@@ -127,16 +134,19 @@ class Image implements \ArrayAccess
     }
     public function offsetSet(mixed $offset, mixed $value): void
     {
+        assert(is_string($offset));
         $this->dynamic_props[$offset] = $value;
     }
     public function offsetUnset(mixed $offset): void
     {
+        assert(is_string($offset));
         unset($this->dynamic_props[$offset]);
     }
 
     #[Field(name: "post_id")]
     public function graphql_oid(): int
     {
+        assert(!is_null($this->id));
         return $this->id;
     }
     #[Field(name: "id")]
@@ -170,6 +180,9 @@ class Image implements \ArrayAccess
         return (is_numberish($id) && strlen($id) != 32) ? Image::by_id((int)$id) : Image::by_hash($id);
     }
 
+    /**
+     * @param string[] $tags
+     */
     public static function by_random(array $tags = [], int $limit_range = 0): ?Image
     {
         $max = Search::count_images($tags);
@@ -234,7 +247,9 @@ class Image implements \ArrayAccess
     #[Field(name: "owner")]
     public function get_owner(): User
     {
-        return User::by_id($this->owner_id);
+        $user = User::by_id($this->owner_id);
+        assert(!is_null($user));
+        return $user;
     }
 
     /**
@@ -457,7 +472,7 @@ class Image implements \ArrayAccess
      * Get the image's mime type.
      */
     #[Field(name: "mime")]
-    public function get_mime(): ?string
+    public function get_mime(): string
     {
         if ($this->mime === MimeType::WEBP && $this->lossless) {
             return MimeType::WEBP_LOSSLESS;
@@ -468,7 +483,7 @@ class Image implements \ArrayAccess
     /**
      * Set the image's mime type.
      */
-    public function set_mime($mime): void
+    public function set_mime(string $mime): void
     {
         $this->mime = $mime;
         $ext = FileExtension::get_for_mime($this->get_mime());
@@ -545,6 +560,8 @@ class Image implements \ArrayAccess
 
     /**
      * Set the tags for this image.
+     *
+     * @param string[] $unfiltered_tags
      */
     public function set_tags(array $unfiltered_tags): void
     {
diff --git a/core/imageboard/misc.php b/core/imageboard/misc.php
index 402c9093..63ea0706 100644
--- a/core/imageboard/misc.php
+++ b/core/imageboard/misc.php
@@ -12,9 +12,10 @@ namespace Shimmie2;
  * Add a directory full of images
  *
  * @param string $base
+ * @param string[] $extra_tags
  * @return UploadResult[]
  */
-function add_dir(string $base, ?array $extra_tags = []): array
+function add_dir(string $base, array $extra_tags = []): array
 {
     global $database;
     $results = [];
@@ -33,6 +34,7 @@ function add_dir(string $base, ?array $extra_tags = []): array
                 ]));
                 $results = [];
                 foreach($dae->images as $image) {
+                    assert(!is_null($image->id));
                     $results[] = new UploadSuccess($filename, $image->id);
                 }
                 return $results;
@@ -59,7 +61,7 @@ function get_file_ext(string $filename): ?string
  * @param int $orig_width
  * @param int $orig_height
  * @param bool $use_dpi_scaling Enables the High-DPI scaling.
- * @return array
+ * @return array{0: int, 1: int}
  */
 function get_thumbnail_size(int $orig_width, int $orig_height, bool $use_dpi_scaling = false): array
 {
@@ -107,6 +109,9 @@ function get_thumbnail_size(int $orig_width, int $orig_height, bool $use_dpi_sca
     }
 }
 
+/**
+ * @return array{0: int, 1: int, 2: float}
+ */
 function get_scaled_by_aspect_ratio(int $original_width, int $original_height, int $max_width, int $max_height): array
 {
     $xscale = ($max_width / $original_width);
@@ -120,7 +125,7 @@ function get_scaled_by_aspect_ratio(int $original_width, int $original_height, i
 /**
  * Fetches the thumbnails height and width settings and applies the High-DPI scaling setting before returning the dimensions.
  *
- * @return array [width, height]
+ * @return array{0: int, 1: int}
  */
 function get_thumbnail_max_size_scaled(): array
 {
@@ -147,7 +152,9 @@ function create_image_thumb(Image $image, string $engine = null): void
 }
 
 
-
+/**
+ * @param array{0: int, 1: int} $tsize
+ */
 function create_scaled_image(
     string $inname,
     string $outname,
diff --git a/core/imageboard/tag.php b/core/imageboard/tag.php
index 9d7de0c4..d5eddd6b 100644
--- a/core/imageboard/tag.php
+++ b/core/imageboard/tag.php
@@ -86,7 +86,8 @@ class TagUsage
  */
 class Tag
 {
-    private static $tag_id_cache = [];
+    /** @var array<string, int> */
+    private static array $tag_id_cache = [];
 
     public static function get_or_create_id(string $tag): int
     {
@@ -196,9 +197,13 @@ class Tag
     public static function sanitize(string $tag): string
     {
         $tag = preg_replace("/\s/", "", $tag);                # whitespace
+        assert($tag !== null);
         $tag = preg_replace('/\x20[\x0e\x0f]/', '', $tag);    # unicode RTL
+        assert($tag !== null);
         $tag = preg_replace("/\.+/", ".", $tag);              # strings of dots?
+        assert($tag !== null);
         $tag = preg_replace("/^(\.+[\/\\\\])+/", "", $tag);   # trailing slashes?
+        assert($tag !== null);
         $tag = trim($tag, ", \t\n\r\0\x0B");
 
         if ($tag == ".") {
@@ -211,6 +216,10 @@ class Tag
         return $tag;
     }
 
+    /**
+     * @param string[] $tags1
+     * @param string[] $tags2
+     */
     public static function compare(array $tags1, array $tags2): bool
     {
         if (count($tags1) !== count($tags2)) {
@@ -225,6 +234,11 @@ class Tag
         return $tags1 == $tags2;
     }
 
+    /**
+     * @param string[] $source
+     * @param string[] $remove
+     * @return string[]
+     */
     public static function get_diff_tags(array $source, array $remove): array
     {
         $before = array_map('strtolower', $source);
@@ -238,6 +252,10 @@ class Tag
         return $after;
     }
 
+    /**
+     * @param string[] $tags
+     * @return string[]
+     */
     public static function sanitize_array(array $tags): array
     {
         global $page;
diff --git a/core/microhtml.php b/core/microhtml.php
index f3eb3681..33fb375c 100644
--- a/core/microhtml.php
+++ b/core/microhtml.php
@@ -46,13 +46,19 @@ function SHM_FORM(string $target, string $method = "POST", bool $multipart = fal
     );
 }
 
-function SHM_SIMPLE_FORM($target, ...$children): HTMLElement
+/**
+ * @param array<string|HTMLElement|null> $children
+ */
+function SHM_SIMPLE_FORM(string $target, ...$children): HTMLElement
 {
     $form = SHM_FORM($target);
     $form->appendChild(emptyHTML(...$children));
     return $form;
 }
 
+/**
+ * @param array<string, mixed> $args
+ */
 function SHM_SUBMIT(string $text, array $args = []): HTMLElement
 {
     $args["type"] = "submit";
@@ -60,6 +66,9 @@ function SHM_SUBMIT(string $text, array $args = []): HTMLElement
     return INPUT($args);
 }
 
+/**
+ * @param array<string, mixed> $args
+ */
 function SHM_A(string $href, string|HTMLElement $text, string $id = "", string $class = "", array $args = []): HTMLElement
 {
     $args["href"] = make_link($href);
@@ -83,7 +92,7 @@ function SHM_COMMAND_EXAMPLE(string $ex, string $desc): HTMLElement
     );
 }
 
-function SHM_USER_FORM(User $duser, string $target, string $title, $body, $foot): HTMLElement
+function SHM_USER_FORM(User $duser, string $target, string $title, HTMLElement $body, HTMLElement|string $foot): HTMLElement
 {
     if (is_string($foot)) {
         $foot = TFOOT(TR(TD(["colspan" => "2"], INPUT(["type" => "submit", "value" => $foot]))));
@@ -106,12 +115,12 @@ function SHM_USER_FORM(User $duser, string $target, string $title, $body, $foot)
  * Generates a <select> element and sets up the given options.
  *
  * @param string $name The name attribute of <select>.
- * @param array $options An array of pairs of parameters for <option> tags. First one is value, second one is text. Example: ('optionA', 'Choose Option A').
- * @param array $selected_options The values of options that should be pre-selected.
+ * @param array<string|int, string> $options An array of pairs of parameters for <option> tags. First one is value, second one is text. Example: ('optionA', 'Choose Option A').
+ * @param array<string> $selected_options The values of options that should be pre-selected.
  * @param bool $required Wether the <select> element is required.
  * @param bool $multiple Wether the <select> element is multiple-choice.
  * @param bool $empty_option Whether the first option should be an empty one.
- * @param array $attrs Additional attributes dict for <select>. Example: ["id"=>"some_id", "class"=>"some_class"].
+ * @param array<string, mixed> $attrs Additional attributes dict for <select>. Example: ["id"=>"some_id", "class"=>"some_class"].
  */
 function SHM_SELECT(string $name, array $options, array $selected_options = [], bool $required = false, bool $multiple = false, bool $empty_option = false, array $attrs = []): HTMLElement
 {
diff --git a/core/polyfills.php b/core/polyfills.php
index e889ecd9..992de6c3 100644
--- a/core/polyfills.php
+++ b/core/polyfills.php
@@ -10,6 +10,9 @@ namespace Shimmie2;
 
 /**
  * Return the unique elements of an array, case insensitively
+ *
+ * @param array<string> $array
+ * @return list<string>
  */
 function array_iunique(array $array): array
 {
@@ -98,6 +101,8 @@ function full_copy(string $source, string $target): void
 
 /**
  * Return a list of all the regular files in a directory and subdirectories
+ *
+ * @return string[]
  */
 function list_files(string $base, string $_sub_dir = ""): array
 {
@@ -203,6 +208,8 @@ if (!function_exists('http_parse_headers')) {
 /**
  * HTTP Headers can sometimes be lowercase which will cause issues.
  * In cases like these, we need to make sure to check for them if the camelcase version does not exist.
+ *
+ * @param array<string, mixed> $headers
  */
 function find_header(array $headers, string $name): ?string
 {
@@ -225,20 +232,22 @@ function find_header(array $headers, string $name): ?string
 if (!function_exists('mb_strlen')) {
     // TODO: we should warn the admin that they are missing multibyte support
     /** @noinspection PhpUnusedParameterInspection */
-    function mb_strlen($str, $encoding): int
+    function mb_strlen(string $str, string $encoding): int
     {
         return strlen($str);
     }
-    function mb_internal_encoding($encoding): void
+    function mb_internal_encoding(string $encoding): void
     {
     }
-    function mb_strtolower($str): string
+    function mb_strtolower(string $str): string
     {
         return strtolower($str);
     }
 }
 
-/** @noinspection PhpUnhandledExceptionInspection */
+/**
+ * @return class-string[]
+ */
 function get_subclasses_of(string $parent): array
 {
     $result = [];
@@ -307,6 +316,8 @@ function get_base_href(): string
 
 /**
  * The opposite of the standard library's parse_url
+ *
+ * @param array<string, string|int> $parsed_url
  */
 function unparse_url(array $parsed_url): string
 {
@@ -376,7 +387,7 @@ function url_escape(?string $input): string
 /**
  * Turn all manner of HTML / INI / JS / DB booleans into a PHP one
  */
-function bool_escape($input): bool
+function bool_escape(mixed $input): bool
 {
     /*
      Sometimes, I don't like PHP -- this, is one of those times...
@@ -634,6 +645,10 @@ function isValidDate(string $date): bool
     return false;
 }
 
+/**
+ * @param array<string, string> $inputs
+ * @return array<string, mixed>
+ */
 function validate_input(array $inputs): array
 {
     $outputs = [];
@@ -754,6 +769,12 @@ function join_path(string ...$paths): string
 
 /**
  * Perform callback on each item returned by an iterator.
+ *
+ * @template T
+ * @template U
+ * @param callable(U):T $callback
+ * @param \iterator<U> $iter
+ * @return \Generator<T>
  */
 function iterator_map(callable $callback, \iterator $iter): \Generator
 {
@@ -764,6 +785,12 @@ function iterator_map(callable $callback, \iterator $iter): \Generator
 
 /**
  * Perform callback on each item returned by an iterator and combine the result into an array.
+ *
+ * @template T
+ * @template U
+ * @param callable(U):T $callback
+ * @param \iterator<U> $iter
+ * @return array<T>
  */
 function iterator_map_to_array(callable $callback, \iterator $iter): array
 {
diff --git a/core/send_event.php b/core/send_event.php
index c791936a..553a4b15 100644
--- a/core/send_event.php
+++ b/core/send_event.php
@@ -75,11 +75,16 @@ function _namespaced_class_name(string $class): string
     return str_replace("Shimmie2\\", "", $class);
 }
 
+/**
+ * Dump the event listeners to a file for faster loading.
+ *
+ * @param array<string, array<int, Extension>> $event_listeners
+ */
 function _dump_event_listeners(array $event_listeners, string $path): void
 {
     $p = "<"."?php\nnamespace Shimmie2;\n";
 
-    foreach (get_subclasses_of("Shimmie2\Extension") as $class) {
+    foreach (get_subclasses_of(Extension::class) as $class) {
         $scn = _namespaced_class_name($class);
         $p .= "\$$scn = new $scn(); ";
     }
diff --git a/core/testcase.php b/core/testcase.php
index 80390104..2dfe126c 100644
--- a/core/testcase.php
+++ b/core/testcase.php
@@ -69,7 +69,11 @@ if(class_exists("\\PHPUnit\\Framework\\TestCase")) {
             $_tracer->flush("data/test-trace.json");
         }
 
-        private static function check_args(?array $args): array
+        /**
+         * @param array<string, mixed> $args
+         * @return array<string, string|mixed[]>
+         */
+        private static function check_args(array $args): array
         {
             if (!$args) {
                 return [];
@@ -84,11 +88,15 @@ if(class_exists("\\PHPUnit\\Framework\\TestCase")) {
             return $args;
         }
 
+        /**
+         * @param array<string, mixed> $get_args
+         * @param array<string, mixed> $post_args
+         */
         protected static function request(
             string $method,
             string $page_name,
-            ?array $get_args = null,
-            ?array $post_args = null
+            array $get_args = [],
+            array $post_args = []
         ): Page {
             // use a fresh page
             global $page;
@@ -109,14 +117,20 @@ if(class_exists("\\PHPUnit\\Framework\\TestCase")) {
             return $page;
         }
 
-        protected static function get_page(string $page_name, array $args = null): Page
+        /**
+         * @param array<string, mixed> $args
+         */
+        protected static function get_page(string $page_name, array $args = []): Page
         {
-            return self::request("GET", $page_name, $args, null);
+            return self::request("GET", $page_name, $args, []);
         }
 
-        protected static function post_page(string $page_name, array $args = null): Page
+        /**
+         * @param array<string, mixed> $args
+         */
+        protected static function post_page(string $page_name, array $args = []): Page
         {
-            return self::request("POST", $page_name, null, $args);
+            return self::request("POST", $page_name, [], $args);
         }
 
         // page things
diff --git a/core/tests/SearchTest.php b/core/tests/SearchTest.php
index 3e90772c..3054af3e 100644
--- a/core/tests/SearchTest.php
+++ b/core/tests/SearchTest.php
@@ -25,7 +25,9 @@ class SearchTest extends ShimmiePHPUnitTestCase
         $this->assert_search_results(["exclamation%"], [$image_id_2]);
     }
 
-    // base case
+    /**
+     * @return int[]
+     */
     public function testUpload(): array
     {
         $this->log_in_as_user();
@@ -41,8 +43,13 @@ class SearchTest extends ShimmiePHPUnitTestCase
     }
 
 
-    /********************************************************
+    /** ******************************************************
      * Test turning a string into an abstract query
+     *
+     * @param string $tags
+     * @param TagCondition[] $expected_tag_conditions
+     * @param ImgCondition[] $expected_img_conditions
+     * @param string $expected_order
      */
     private function assert_TTC(
         string $tags,
@@ -142,8 +149,16 @@ class SearchTest extends ShimmiePHPUnitTestCase
         );
     }
 
-    /********************************************************
+    /** ******************************************************
      * Test turning an abstract query into SQL + fetching the results
+     *
+     * @param string[] $tcs
+     * @param string[] $ics
+     * @param string $order
+     * @param int $limit
+     * @param int $start
+     * @param int[] $res
+     * @param string[] $path
      */
     private function assert_BSQ(
         array $tcs = [],
@@ -196,7 +211,7 @@ class SearchTest extends ShimmiePHPUnitTestCase
     * No-tag search      *
     * * * * * * * * * * */
     #[Depends('testUpload')]
-    public function testBSQ_NoTags(array $image_ids): void
+    public function testBSQ_NoTags(): void
     {
         $image_ids = $this->testUpload();
         $this->assert_BSQ(
@@ -210,7 +225,7 @@ class SearchTest extends ShimmiePHPUnitTestCase
     * Fast-path search   *
     * * * * * * * * * * */
     #[Depends('testUpload')]
-    public function testBSQ_FastPath_NoResults(array $image_ids): void
+    public function testBSQ_FastPath_NoResults(): void
     {
         $this->testUpload();
         $this->assert_BSQ(
@@ -221,7 +236,7 @@ class SearchTest extends ShimmiePHPUnitTestCase
     }
 
     #[Depends('testUpload')]
-    public function testBSQ_FastPath_OneResult(array $image_ids): void
+    public function testBSQ_FastPath_OneResult(): void
     {
         $image_ids = $this->testUpload();
         $this->assert_BSQ(
@@ -232,7 +247,7 @@ class SearchTest extends ShimmiePHPUnitTestCase
     }
 
     #[Depends('testUpload')]
-    public function testBSQ_FastPath_ManyResults(array $image_ids): void
+    public function testBSQ_FastPath_ManyResults(): void
     {
         $image_ids = $this->testUpload();
         $this->assert_BSQ(
@@ -243,7 +258,7 @@ class SearchTest extends ShimmiePHPUnitTestCase
     }
 
     #[Depends('testUpload')]
-    public function testBSQ_FastPath_WildNoResults(array $image_ids): void
+    public function testBSQ_FastPath_WildNoResults(): void
     {
         $this->testUpload();
         $this->assert_BSQ(
@@ -262,7 +277,7 @@ class SearchTest extends ShimmiePHPUnitTestCase
      * https://github.com/shish/shimmie2/issues/547
      */
     #[Depends('testUpload')]
-    public function testBSQ_FastPath_WildOneResult(array $image_ids): void
+    public function testBSQ_FastPath_WildOneResult(): void
     {
         $image_ids = $this->testUpload();
         $this->assert_BSQ(
@@ -277,7 +292,7 @@ class SearchTest extends ShimmiePHPUnitTestCase
      * when a wildcard matches one image multiple times.
      */
     #[Depends('testUpload')]
-    public function testBSQ_FastPath_WildManyResults(array $image_ids): void
+    public function testBSQ_FastPath_WildManyResults(): void
     {
         $image_ids = $this->testUpload();
         // two images match comp* - one matches it once, one matches it twice
@@ -292,7 +307,7 @@ class SearchTest extends ShimmiePHPUnitTestCase
     * General search     *
     * * * * * * * * * * */
     #[Depends('testUpload')]
-    public function testBSQ_GeneralPath_NoResults(array $image_ids): void
+    public function testBSQ_GeneralPath_NoResults(): void
     {
         $this->testUpload();
         # multiple tags, one of which doesn't exist
@@ -305,7 +320,7 @@ class SearchTest extends ShimmiePHPUnitTestCase
     }
 
     #[Depends('testUpload')]
-    public function testBSQ_GeneralPath_OneResult(array $image_ids): void
+    public function testBSQ_GeneralPath_OneResult(): void
     {
         $image_ids = $this->testUpload();
         $this->assert_BSQ(
@@ -324,7 +339,7 @@ class SearchTest extends ShimmiePHPUnitTestCase
      * https://github.com/shish/shimmie2/issues/547
      */
     #[Depends('testUpload')]
-    public function testBSQ_GeneralPath_WildOneResult(array $image_ids): void
+    public function testBSQ_GeneralPath_WildOneResult(): void
     {
         $image_ids = $this->testUpload();
         $this->assert_BSQ(
@@ -335,7 +350,7 @@ class SearchTest extends ShimmiePHPUnitTestCase
     }
 
     #[Depends('testUpload')]
-    public function testBSQ_GeneralPath_ManyResults(array $image_ids): void
+    public function testBSQ_GeneralPath_ManyResults(): void
     {
         $image_ids = $this->testUpload();
         $this->assert_BSQ(
@@ -346,7 +361,7 @@ class SearchTest extends ShimmiePHPUnitTestCase
     }
 
     #[Depends('testUpload')]
-    public function testBSQ_GeneralPath_WildManyResults(array $image_ids): void
+    public function testBSQ_GeneralPath_WildManyResults(): void
     {
         $image_ids = $this->testUpload();
         $this->assert_BSQ(
@@ -357,7 +372,7 @@ class SearchTest extends ShimmiePHPUnitTestCase
     }
 
     #[Depends('testUpload')]
-    public function testBSQ_GeneralPath_SubtractValidFromResults(array $image_ids): void
+    public function testBSQ_GeneralPath_SubtractValidFromResults(): void
     {
         $image_ids = $this->testUpload();
         $this->assert_BSQ(
@@ -368,7 +383,7 @@ class SearchTest extends ShimmiePHPUnitTestCase
     }
 
     #[Depends('testUpload')]
-    public function testBSQ_GeneralPath_SubtractNotValidFromResults(array $image_ids): void
+    public function testBSQ_GeneralPath_SubtractNotValidFromResults(): void
     {
         $image_ids = $this->testUpload();
         $this->assert_BSQ(
@@ -379,7 +394,7 @@ class SearchTest extends ShimmiePHPUnitTestCase
     }
 
     #[Depends('testUpload')]
-    public function testBSQ_GeneralPath_SubtractValidFromDefault(array $image_ids): void
+    public function testBSQ_GeneralPath_SubtractValidFromDefault(): void
     {
         $image_ids = $this->testUpload();
         // negative tag alone, should remove the image with that tag
@@ -391,7 +406,7 @@ class SearchTest extends ShimmiePHPUnitTestCase
     }
 
     #[Depends('testUpload')]
-    public function testBSQ_GeneralPath_SubtractNotValidFromDefault(array $image_ids): void
+    public function testBSQ_GeneralPath_SubtractNotValidFromDefault(): void
     {
         $image_ids = $this->testUpload();
         // negative that doesn't exist, should return all results
@@ -403,7 +418,7 @@ class SearchTest extends ShimmiePHPUnitTestCase
     }
 
     #[Depends('testUpload')]
-    public function testBSQ_GeneralPath_SubtractMultipleNotValidFromDefault(array $image_ids): void
+    public function testBSQ_GeneralPath_SubtractMultipleNotValidFromDefault(): void
     {
         $image_ids = $this->testUpload();
         // multiple negative tags that don't exist, should return all results
@@ -418,7 +433,7 @@ class SearchTest extends ShimmiePHPUnitTestCase
     * Meta Search        *
     * * * * * * * * * * */
     #[Depends('testUpload')]
-    public function testBSQ_ImgCond_NoResults(array $image_ids): void
+    public function testBSQ_ImgCond_NoResults(): void
     {
         $this->testUpload();
         $this->assert_BSQ(
@@ -434,7 +449,7 @@ class SearchTest extends ShimmiePHPUnitTestCase
     }
 
     #[Depends('testUpload')]
-    public function testBSQ_ImgCond_OneResult(array $image_ids): void
+    public function testBSQ_ImgCond_OneResult(): void
     {
         $image_ids = $this->testUpload();
         $this->assert_BSQ(
@@ -455,7 +470,7 @@ class SearchTest extends ShimmiePHPUnitTestCase
     }
 
     #[Depends('testUpload')]
-    public function testBSQ_ImgCond_ManyResults(array $image_ids): void
+    public function testBSQ_ImgCond_ManyResults(): void
     {
         $image_ids = $this->testUpload();
 
@@ -480,7 +495,7 @@ class SearchTest extends ShimmiePHPUnitTestCase
     * Mixed              *
     * * * * * * * * * * */
     #[Depends('testUpload')]
-    public function testBSQ_TagCondWithImgCond(array $image_ids): void
+    public function testBSQ_TagCondWithImgCond(): void
     {
         $image_ids = $this->testUpload();
         // multiple tags, many results
diff --git a/core/user.php b/core/user.php
index 127ca881..b70357aa 100644
--- a/core/user.php
+++ b/core/user.php
@@ -44,6 +44,7 @@ class User
      * One will very rarely construct a user directly, more common
      * would be to use User::by_id, User::by_session, etc.
      *
+     * @param array<string|int, mixed> $row
      * @throws SCoreException
      */
     public function __construct(array $row)
diff --git a/core/userclass.php b/core/userclass.php
index 2f4789f5..1afa8a37 100644
--- a/core/userclass.php
+++ b/core/userclass.php
@@ -23,8 +23,13 @@ class UserClass
     #[Field]
     public ?string $name = null;
     public ?UserClass $parent = null;
+
+    /** @var array<string, bool> */
     public array $abilities = [];
 
+    /**
+     * @param array<string, bool> $abilities
+     */
     public function __construct(string $name, string $parent = null, array $abilities = [])
     {
         global $_shm_user_classes;
@@ -39,6 +44,9 @@ class UserClass
         $_shm_user_classes[$name] = $this;
     }
 
+    /**
+     * @return string[]
+     */
     #[Field(type: "[Permission!]!")]
     public function permissions(): array
     {
diff --git a/core/util.php b/core/util.php
index dea379f9..961355fa 100644
--- a/core/util.php
+++ b/core/util.php
@@ -285,12 +285,16 @@ function load_balance_url(string $tmpl, string $hash, int $n = 0): string
     return $tmpl;
 }
 
+/**
+ * @return null|array<string, mixed>
+ */
 function fetch_url(string $url, string $mfile): ?array
 {
     global $config;
 
     if ($config->get_string(UploadConfig::TRANSLOAD_ENGINE) === "curl" && function_exists("curl_init")) {
         $ch = curl_init($url);
+        assert($ch !== false);
         $fp = fopen($mfile, "w");
 
         curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
@@ -397,6 +401,9 @@ function path_to_tags(string $path): array
     return $tags;
 }
 
+/**
+ * @return string[]
+ */
 function get_dir_contents(string $dir): array
 {
     assert(!empty($dir));
@@ -442,7 +449,9 @@ function remove_empty_dirs(string $dir): bool
     return $result;
 }
 
-
+/**
+ * @return string[]
+ */
 function get_files_recursively(string $dir): array
 {
     assert(!empty($dir));
@@ -475,6 +484,8 @@ function get_files_recursively(string $dir): array
 
 /**
  * Returns amount of files & total size of dir.
+ *
+ * @return array{"path": string, "total_files": int, "total_mb": string}
  */
 function scan_dir(string $path): array
 {
diff --git a/ext/alias_editor/main.php b/ext/alias_editor/main.php
index 2658733a..97e2b58e 100644
--- a/ext/alias_editor/main.php
+++ b/ext/alias_editor/main.php
@@ -174,6 +174,7 @@ class AliasEditor extends Extension
         $csv = "";
         $aliases = $database->get_pairs("SELECT oldtag, newtag FROM aliases ORDER BY newtag");
         foreach ($aliases as $old => $new) {
+            assert(is_string($new));
             $csv .= "\"$old\",\"$new\"\n";
         }
         return $csv;
diff --git a/ext/approval/main.php b/ext/approval/main.php
index 9417157e..23b83536 100644
--- a/ext/approval/main.php
+++ b/ext/approval/main.php
@@ -174,7 +174,9 @@ class Approval extends Extension
         }
     }
 
-
+    /**
+     * @param string[] $context
+     */
     private function no_approval_query(array $context): bool
     {
         foreach ($context as $term) {
@@ -185,7 +187,7 @@ class Approval extends Extension
         return true;
     }
 
-    public static function approve_image($image_id)
+    public static function approve_image(int $image_id): void
     {
         global $database, $user;
 
@@ -195,7 +197,7 @@ class Approval extends Extension
         );
     }
 
-    public static function disapprove_image($image_id)
+    public static function disapprove_image(int $image_id): void
     {
         global $database;
 
diff --git a/ext/artists/main.php b/ext/artists/main.php
index 807abcfe..2570a612 100644
--- a/ext/artists/main.php
+++ b/ext/artists/main.php
@@ -495,43 +495,52 @@ class Artists extends Extension
         return (int)$database->get_one("SELECT artist_id FROM artist_urls WHERE id = :id", ['id' => $urlID]);
     }
 
-    private function delete_alias(int $aliasID)
+    private function delete_alias(int $aliasID): void
     {
         global $database;
         $database->execute("DELETE FROM artist_alias WHERE id = :id", ['id' => $aliasID]);
     }
 
-    private function delete_url(int $urlID)
+    private function delete_url(int $urlID): void
     {
         global $database;
         $database->execute("DELETE FROM artist_urls WHERE id = :id", ['id' => $urlID]);
     }
 
-    private function delete_member(int $memberID)
+    private function delete_member(int $memberID): void
     {
         global $database;
         $database->execute("DELETE FROM artist_members WHERE id = :id", ['id' => $memberID]);
     }
 
+    /**
+     * @return array<string, mixed>
+     */
     private function get_alias_by_id(int $aliasID): array
     {
         global $database;
         return $database->get_row("SELECT * FROM artist_alias WHERE id = :id", ['id' => $aliasID]);
     }
 
+    /**
+     * @return array<string, mixed>
+     */
     private function get_url_by_id(int $urlID): array
     {
         global $database;
         return $database->get_row("SELECT * FROM artist_urls WHERE id = :id", ['id' => $urlID]);
     }
 
+    /**
+     * @return array<string, mixed>
+     */
     private function get_member_by_id(int $memberID): array
     {
         global $database;
         return $database->get_row("SELECT * FROM artist_members WHERE id = :id", ['id' => $memberID]);
     }
 
-    private function update_artist()
+    private function update_artist(): void
     {
         global $user;
         $inputs = validate_input([
@@ -629,7 +638,7 @@ class Artists extends Extension
         }
     }
 
-    private function update_alias()
+    private function update_alias(): void
     {
         global $user;
         $inputs = validate_input([
@@ -639,7 +648,7 @@ class Artists extends Extension
         $this->save_existing_alias($inputs['aliasID'], $inputs['alias'], $user->id);
     }
 
-    private function save_existing_alias(int $aliasID, string $alias, int $userID)
+    private function save_existing_alias(int $aliasID, string $alias, int $userID): void
     {
         global $database;
         $database->execute(
@@ -648,7 +657,7 @@ class Artists extends Extension
         );
     }
 
-    private function update_url()
+    private function update_url(): void
     {
         global $user;
         $inputs = validate_input([
@@ -658,7 +667,7 @@ class Artists extends Extension
         $this->save_existing_url($inputs['urlID'], $inputs['url'], $user->id);
     }
 
-    private function save_existing_url(int $urlID, string $url, int $userID)
+    private function save_existing_url(int $urlID, string $url, int $userID): void
     {
         global $database;
         $database->execute(
@@ -667,7 +676,7 @@ class Artists extends Extension
         );
     }
 
-    private function update_member()
+    private function update_member(): void
     {
         global $user;
         $inputs = validate_input([
@@ -677,7 +686,7 @@ class Artists extends Extension
         $this->save_existing_member($inputs['memberID'], $inputs['name'], $user->id);
     }
 
-    private function save_existing_member(int $memberID, string $memberName, int $userID)
+    private function save_existing_member(int $memberID, string $memberName, int $userID): void
     {
         global $database;
         $database->execute(
@@ -772,6 +781,9 @@ class Artists extends Extension
         return ($result != 0);
     }
 
+    /**
+     * @return array<string, mixed>
+     */
     private function get_artist(int $artistID): array
     {
         global $database;
@@ -786,6 +798,9 @@ class Artists extends Extension
         return $result;
     }
 
+    /**
+     * @return array<string, mixed>
+     */
     private function get_members(int $artistID): array
     {
         global $database;
@@ -802,6 +817,9 @@ class Artists extends Extension
         return $result;
     }
 
+    /**
+     * @return array<string, mixed>
+     */
     private function get_urls(int $artistID): array
     {
         global $database;
@@ -837,7 +855,7 @@ class Artists extends Extension
         );
     }
 
-    private function delete_artist(int $artistID)
+    private function delete_artist(int $artistID): void
     {
         global $database;
         $database->execute(
@@ -849,7 +867,7 @@ class Artists extends Extension
     /*
     * HERE WE GET THE LIST OF ALL ARTIST WITH PAGINATION
     */
-    private function get_listing(PageRequestEvent $event)
+    private function get_listing(PageRequestEvent $event): void
     {
         global $config, $database;
 
@@ -927,7 +945,7 @@ class Artists extends Extension
                         ON a.id = aa.artist_id
             ");
 
-        $totalPages = ceil($count / $artistsPerPage);
+        $totalPages = (int)ceil($count / $artistsPerPage);
 
         $this->theme->list_artists($listing, $pageNumber + 1, $totalPages);
     }
@@ -935,7 +953,7 @@ class Artists extends Extension
     /*
     * HERE WE ADD AN ALIAS
     */
-    private function add_urls()
+    private function add_urls(): void
     {
         global $user;
         $inputs = validate_input([
@@ -952,7 +970,7 @@ class Artists extends Extension
         }
     }
 
-    private function save_new_url(int $artistID, string $url, int $userID)
+    private function save_new_url(int $artistID, string $url, int $userID): void
     {
         global $database;
 
@@ -962,7 +980,7 @@ class Artists extends Extension
         );
     }
 
-    private function add_alias()
+    private function add_alias(): void
     {
         global $user;
         $inputs = validate_input([
@@ -979,7 +997,7 @@ class Artists extends Extension
         }
     }
 
-    private function save_new_alias(int $artistID, string $alias, int $userID)
+    private function save_new_alias(int $artistID, string $alias, int $userID): void
     {
         global $database;
 
@@ -989,7 +1007,7 @@ class Artists extends Extension
         );
     }
 
-    private function add_members()
+    private function add_members(): void
     {
         global $user;
         $inputs = validate_input([
@@ -1006,7 +1024,7 @@ class Artists extends Extension
         }
     }
 
-    private function save_new_member(int $artistID, string $member, int $userID)
+    private function save_new_member(int $artistID, string $member, int $userID): void
     {
         global $database;
 
@@ -1040,6 +1058,8 @@ class Artists extends Extension
 
     /**
      * HERE WE GET THE INFO OF THE ALIAS
+     *
+     * @return array<string, mixed>
      */
     private function get_alias(int $artistID): array
     {
diff --git a/ext/artists/theme.php b/ext/artists/theme.php
index 12e9e921..8d2531fb 100644
--- a/ext/artists/theme.php
+++ b/ext/artists/theme.php
@@ -9,6 +9,12 @@ use MicroHTML\HTMLElement;
 use function MicroHTML\emptyHTML;
 use function MicroHTML\{INPUT,P};
 
+/**
+ * @phpstan-type ArtistArtist array{id:int,artist_id:int,user_name:string,name:string,notes:string,type:string,posts:int}
+ * @phpstan-type ArtistAlias array{id:int,alias_id:int,alias_name:string,alias:string}
+ * @phpstan-type ArtistMember array{id:int,name:string}
+ * @phpstan-type ArtistUrl array{id:int,url:string}
+ */
 class ArtistsTheme extends Themelet
 {
     public function get_author_editor_html(string $author): HTMLElement
@@ -20,7 +26,7 @@ class ArtistsTheme extends Themelet
         );
     }
 
-    public function sidebar_options(string $mode, ?int $artistID = null, $is_admin = false): void
+    public function sidebar_options(string $mode, ?int $artistID = null, bool $is_admin = false): void
     {
         global $page, $user;
 
@@ -77,7 +83,13 @@ class ArtistsTheme extends Themelet
         }
     }
 
-    public function show_artist_editor($artist, $aliases, $members, $urls)
+    /**
+     * @param ArtistArtist $artist
+     * @param ArtistAlias[] $aliases
+     * @param ArtistMember[] $members
+     * @param ArtistUrl[] $urls
+     */
+    public function show_artist_editor(array $artist, array $aliases, array $members, array $urls): void
     {
         global $user;
 
@@ -137,7 +149,7 @@ class ArtistsTheme extends Themelet
         $page->add_block(new Block("Edit artist", $html, "main", 10));
     }
 
-    public function new_artist_composer()
+    public function new_artist_composer(): void
     {
         global $page, $user;
 
@@ -158,7 +170,10 @@ class ArtistsTheme extends Themelet
         $page->add_block(new Block("Artists", $html, "main", 10));
     }
 
-    public function list_artists($artists, $pageNumber, $totalPages)
+    /**
+    * @param ArtistArtist[] $artists
+    */
+    public function list_artists(array $artists, int $pageNumber, int $totalPages): void
     {
         global $user, $page;
 
@@ -237,7 +252,7 @@ class ArtistsTheme extends Themelet
         $this->display_paginator($page, "artist/list", null, $pageNumber, $totalPages);
     }
 
-    public function show_new_alias_composer($artistID)
+    public function show_new_alias_composer(int $artistID): void
     {
         global $user;
 
@@ -256,7 +271,7 @@ class ArtistsTheme extends Themelet
         $page->add_block(new Block("Artist Aliases", $html, "main", 20));
     }
 
-    public function show_new_member_composer($artistID)
+    public function show_new_member_composer(int $artistID): void
     {
         global $user;
 
@@ -275,7 +290,7 @@ class ArtistsTheme extends Themelet
         $page->add_block(new Block("Artist members", $html, "main", 30));
     }
 
-    public function show_new_url_composer($artistID)
+    public function show_new_url_composer(int $artistID): void
     {
         global $user;
 
@@ -294,7 +309,10 @@ class ArtistsTheme extends Themelet
         $page->add_block(new Block("Artist URLs", $html, "main", 40));
     }
 
-    public function show_alias_editor($alias)
+    /**
+     * @param ArtistAlias $alias
+     */
+    public function show_alias_editor(array $alias): void
     {
         global $user;
 
@@ -312,7 +330,10 @@ class ArtistsTheme extends Themelet
         $page->add_block(new Block("Edit Alias", $html, "main", 10));
     }
 
-    public function show_url_editor($url)
+    /**
+     * @param ArtistUrl $url
+     */
+    public function show_url_editor(array $url): void
     {
         global $user;
 
@@ -330,7 +351,10 @@ class ArtistsTheme extends Themelet
         $page->add_block(new Block("Edit URL", $html, "main", 10));
     }
 
-    public function show_member_editor($member)
+    /**
+     * @param ArtistMember $member
+     */
+    public function show_member_editor(array $member): void
     {
         global $user;
 
@@ -348,7 +372,14 @@ class ArtistsTheme extends Themelet
         $page->add_block(new Block("Edit Member", $html, "main", 10));
     }
 
-    public function show_artist($artist, $aliases, $members, $urls, $images, $userIsLogged, $userIsAdmin)
+    /**
+     * @param ArtistArtist $artist
+     * @param ArtistAlias[] $aliases
+     * @param ArtistMember[] $members
+     * @param ArtistUrl[] $urls
+     * @param Image[] $images
+     */
+    public function show_artist(array $artist, array $aliases, array $members, array $urls, array $images, bool $userIsLogged, bool $userIsAdmin): void
     {
         global $page;
 
@@ -416,6 +447,9 @@ class ArtistsTheme extends Themelet
         $page->add_block(new Block("Artist Posts", $artist_images, "main", 20));
     }
 
+    /**
+     * @param ArtistAlias[] $aliases
+     */
     private function render_aliases(array $aliases, bool $userIsLogged, bool $userIsAdmin): string
     {
         $html = "";
@@ -462,6 +496,9 @@ class ArtistsTheme extends Themelet
         return $html;
     }
 
+    /**
+     * @param ArtistMember[] $members
+     */
     private function render_members(array $members, bool $userIsLogged, bool $userIsAdmin): string
     {
         $html = "";
@@ -506,6 +543,9 @@ class ArtistsTheme extends Themelet
         return $html;
     }
 
+    /**
+     * @param ArtistUrl[] $urls
+     */
     private function render_urls(array $urls, bool $userIsLogged, bool $userIsAdmin): string
     {
         $html = "";
diff --git a/ext/auto_tagger/main.php b/ext/auto_tagger/main.php
index 08c3a52f..39d88d5c 100644
--- a/ext/auto_tagger/main.php
+++ b/ext/auto_tagger/main.php
@@ -186,6 +186,7 @@ class AutoTagger extends Extension
         $csv = "";
         $pairs = $database->get_pairs("SELECT tag, additional_tags FROM auto_tag ORDER BY tag");
         foreach ($pairs as $old => $new) {
+            assert(is_string($new));
             $csv .= "\"$old\",\"$new\"\n";
         }
         return $csv;
@@ -209,7 +210,7 @@ class AutoTagger extends Extension
         return $i;
     }
 
-    private function add_auto_tag(string $tag, string $additional_tags)
+    private function add_auto_tag(string $tag, string $additional_tags): void
     {
         global $database;
         $existing_tags = $database->get_one("SELECT additional_tags FROM auto_tag WHERE LOWER(tag)=LOWER(:tag)", ["tag" => $tag]);
@@ -250,7 +251,7 @@ class AutoTagger extends Extension
         $this->apply_new_auto_tag($tag);
     }
 
-    private function apply_new_auto_tag(string $tag)
+    private function apply_new_auto_tag(string $tag): void
     {
         global $database;
         $tag_id = $database->get_one("SELECT id FROM tags WHERE LOWER(tag) = LOWER(:tag)", ["tag" => $tag]);
@@ -264,7 +265,7 @@ class AutoTagger extends Extension
         }
     }
 
-    private function remove_auto_tag(string $tag)
+    private function remove_auto_tag(string $tag): void
     {
         global $database;
 
@@ -273,6 +274,7 @@ class AutoTagger extends Extension
 
     /**
      * @param string[] $tags_mixed
+     * @return string[]
      */
     private function apply_auto_tags(array $tags_mixed): array
     {
diff --git a/ext/auto_tagger/theme.php b/ext/auto_tagger/theme.php
index a96ab76c..abe99281 100644
--- a/ext/auto_tagger/theme.php
+++ b/ext/auto_tagger/theme.php
@@ -4,6 +4,8 @@ declare(strict_types=1);
 
 namespace Shimmie2;
 
+use MicroHTML\HTMLElement;
+
 class AutoTaggerTheme extends Themelet
 {
     /**
@@ -11,7 +13,7 @@ class AutoTaggerTheme extends Themelet
      *
      * Note: $can_manage = whether things like "add new alias" should be shown
      */
-    public function display_auto_tagtable($table, $paginator): void
+    public function display_auto_tagtable(HTMLElement $table, HTMLElement $paginator): void
     {
         global $page, $user;
 
diff --git a/ext/autocomplete/main.php b/ext/autocomplete/main.php
index b6ddbbec..57571976 100644
--- a/ext/autocomplete/main.php
+++ b/ext/autocomplete/main.php
@@ -27,6 +27,9 @@ class AutoComplete extends Extension
         }
     }
 
+    /**
+     * @return array<string, int>
+     */
     private function complete(string $search, int $limit): array
     {
         global $cache, $database;
diff --git a/ext/ban_words/main.php b/ext/ban_words/main.php
index 94636ea6..d51b479e 100644
--- a/ext/ban_words/main.php
+++ b/ext/ban_words/main.php
@@ -97,6 +97,9 @@ xanax
         }
     }
 
+    /**
+     * @return string[]
+     */
     private function get_words(): array
     {
         global $config;
diff --git a/ext/ban_words/test.php b/ext/ban_words/test.php
index 543d1e3b..cb78fa63 100644
--- a/ext/ban_words/test.php
+++ b/ext/ban_words/test.php
@@ -6,7 +6,7 @@ namespace Shimmie2;
 
 class BanWordsTest extends ShimmiePHPUnitTestCase
 {
-    public function check_blocked($image_id, $words)
+    public function check_blocked(int $image_id, string $words): void
     {
         global $user;
         try {
diff --git a/ext/bbcode/test.php b/ext/bbcode/test.php
index 3eb2c761..79094841 100644
--- a/ext/bbcode/test.php
+++ b/ext/bbcode/test.php
@@ -101,13 +101,13 @@ class BBCodeTest extends ShimmiePHPUnitTestCase
         );
     }
 
-    private function filter($in): string
+    private function filter(string $in): string
     {
         $bb = new BBCode();
         return $bb->_format($in);
     }
 
-    private function strip($in): string
+    private function strip(string $in): string
     {
         $bb = new BBCode();
         return $bb->strip($in);
diff --git a/ext/blocks/theme.php b/ext/blocks/theme.php
index 7dc73c46..fc225d53 100644
--- a/ext/blocks/theme.php
+++ b/ext/blocks/theme.php
@@ -16,7 +16,10 @@ use function MicroHTML\OPTION;
 
 class BlocksTheme extends Themelet
 {
-    public function display_blocks($blocks): void
+    /**
+     * @param array<array{id:int,title:string,area:string,priority:int,userclass:string,pages:string,content:string}> $blocks
+     */
+    public function display_blocks(array $blocks): void
     {
         global $page;
 
diff --git a/ext/blotter/main.php b/ext/blotter/main.php
index ef8137b8..0a4dc1bb 100644
--- a/ext/blotter/main.php
+++ b/ext/blotter/main.php
@@ -136,7 +136,7 @@ class Blotter extends Extension
         $this->display_blotter();
     }
 
-    private function display_blotter()
+    private function display_blotter(): void
     {
         global $database, $config;
         $limit = $config->get_int("blotter_recent", 5);
diff --git a/ext/blotter/theme.php b/ext/blotter/theme.php
index 7944d895..fb047b5a 100644
--- a/ext/blotter/theme.php
+++ b/ext/blotter/theme.php
@@ -4,9 +4,15 @@ declare(strict_types=1);
 
 namespace Shimmie2;
 
+/**
+ * @phpstan-type BlotterEntry array{id:int,entry_date:string,entry_text:string,important:bool}
+ */
 class BlotterTheme extends Themelet
 {
-    public function display_editor($entries): void
+    /**
+     * @param BlotterEntry[] $entries
+     */
+    public function display_editor(array $entries): void
     {
         global $page;
         $html = $this->get_html_for_blotter_editor($entries);
@@ -16,7 +22,10 @@ class BlotterTheme extends Themelet
         $page->add_block(new Block("Navigation", "<a href='".make_link()."'>Index</a>", "left", 0));
     }
 
-    public function display_blotter_page($entries): void
+    /**
+     * @param BlotterEntry[] $entries
+     */
+    public function display_blotter_page(array $entries): void
     {
         global $page;
         $html = $this->get_html_for_blotter_page($entries);
@@ -25,6 +34,9 @@ class BlotterTheme extends Themelet
         $page->add_block(new Block("Blotter Entries", $html, "main", 10));
     }
 
+    /**
+     * @param BlotterEntry[] $entries
+     */
     public function display_blotter(array $entries): void
     {
         global $page, $config;
@@ -33,6 +45,9 @@ class BlotterTheme extends Themelet
         $page->add_block(new Block(null, $html, $position, 20));
     }
 
+    /**
+     * @param BlotterEntry[] $entries
+     */
     private function get_html_for_blotter_editor(array $entries): string
     {
         global $user;
@@ -104,6 +119,9 @@ class BlotterTheme extends Themelet
         return $html;
     }
 
+    /**
+     * @param BlotterEntry[] $entries
+     */
     private function get_html_for_blotter_page(array $entries): string
     {
         /**
@@ -135,25 +153,27 @@ class BlotterTheme extends Themelet
         return $html;
     }
 
+    /**
+     * @param BlotterEntry[] $entries
+     */
     private function get_html_for_blotter(array $entries): string
     {
         global $config;
         $i_color = $config->get_string("blotter_color", "#FF0000");
         $position = $config->get_string("blotter_position", "subheading");
         $entries_list = "";
-        $num_entries = count($entries);
-        for ($i = 0 ; $i < $num_entries ; $i++) {
+        foreach($entries as $entry) {
             /**
              * Blotter entries
              */
             // Reset variables:
             $i_open = "";
             $i_close = "";
-            //$id = $entries[$i]['id'];
-            $messy_date = $entries[$i]['entry_date'];
+            //$id = $entry['id'];
+            $messy_date = $entry['entry_date'];
             $clean_date = date("m/d/y", strtotime($messy_date));
-            $entry_text = $entries[$i]['entry_text'];
-            if ($entries[$i]['important'] == 'Y') {
+            $entry_text = $entry['entry_text'];
+            if ($entry['important'] == 'Y') {
                 $i_open = "<span style='color: #$i_color'>";
                 $i_close = "</span>";
             }
diff --git a/ext/bulk_actions/main.php b/ext/bulk_actions/main.php
index e141ea34..096cc00d 100644
--- a/ext/bulk_actions/main.php
+++ b/ext/bulk_actions/main.php
@@ -13,10 +13,14 @@ class BulkActionException extends SCoreException
 }
 class BulkActionBlockBuildingEvent extends Event
 {
+    /**
+     * @var array<array{block:string,access_key:?string,confirmation_message:string,action:string,button_text:string,position:int}>
+     */
     public array $actions = [];
+    /** @var string[] */
     public array $search_terms = [];
 
-    public function add_action(string $action, string $button_text, string $access_key = null, string $confirmation_message = "", string $block = "", int $position = 40)
+    public function add_action(string $action, string $button_text, string $access_key = null, string $confirmation_message = "", string $block = "", int $position = 40): void
     {
         if (!empty($access_key)) {
             assert(strlen($access_key) == 1);
@@ -28,13 +32,13 @@ class BulkActionBlockBuildingEvent extends Event
         }
 
         $this->actions[] = [
-                "block" => $block,
-                "access_key" => $access_key,
-                "confirmation_message" => $confirmation_message,
-                "action" => $action,
-                "button_text" => $button_text,
-                "position" => $position
-            ];
+            "block" => $block,
+            "access_key" => $access_key,
+            "confirmation_message" => $confirmation_message,
+            "action" => $action,
+            "button_text" => $button_text,
+            "position" => $position
+        ];
     }
 }
 
@@ -194,29 +198,42 @@ class BulkActions extends Extension
         }
     }
 
+    /**
+     * @param int[] $data
+     * @return \Generator<Image>
+     */
     private function yield_items(array $data): \Generator
     {
         foreach ($data as $id) {
-            if (is_numeric($id)) {
-                $image = Image::by_id($id);
-                if ($image != null) {
-                    yield $image;
-                }
+            $image = Image::by_id($id);
+            if ($image != null) {
+                yield $image;
             }
         }
     }
 
+    /**
+     * @return \Generator<Image>
+     */
     private function yield_search_results(string $query): \Generator
     {
         $tags = Tag::explode($query);
         return Search::find_images_iterable(0, null, $tags);
     }
 
-    private function sort_blocks($a, $b)
+    /**
+     * @param array{position: int} $a
+     * @param array{position: int} $b
+     */
+    private function sort_blocks(array $a, array $b): int
     {
         return $a["position"] - $b["position"];
     }
 
+    /**
+     * @param iterable<Image> $posts
+     * @return array{0: int, 1: int}
+     */
     private function delete_posts(iterable $posts): array
     {
         global $page;
@@ -240,6 +257,9 @@ class BulkActions extends Extension
         return [$total, $size];
     }
 
+    /**
+     * @param iterable<Image> $items
+     */
     private function tag_items(iterable $items, string $tags, bool $replace): int
     {
         $tags = Tag::explode($tags);
@@ -280,6 +300,9 @@ class BulkActions extends Extension
         return $total;
     }
 
+    /**
+     * @param iterable<Image> $items
+     */
     private function set_source(iterable $items, string $source): int
     {
         global $page;
diff --git a/ext/bulk_actions/theme.php b/ext/bulk_actions/theme.php
index bb7afa64..1059b4a0 100644
--- a/ext/bulk_actions/theme.php
+++ b/ext/bulk_actions/theme.php
@@ -6,6 +6,9 @@ namespace Shimmie2;
 
 class BulkActionsTheme extends Themelet
 {
+    /**
+     * @param array<array{block:string,access_key:?string,confirmation_message:string,action:string,button_text:string,position:int}> $actions
+     */
     public function display_selector(Page $page, array $actions, string $query): void
     {
         $body = "<input type='hidden' name='bulk_selected_ids' id='bulk_selected_ids' />
diff --git a/ext/bulk_add_csv/main.php b/ext/bulk_add_csv/main.php
index 94fc5a1d..c1ce0984 100644
--- a/ext/bulk_add_csv/main.php
+++ b/ext/bulk_add_csv/main.php
@@ -50,8 +50,10 @@ class BulkAddCSV extends Extension
 
     /**
      * Generate the necessary DataUploadEvent for a given image and tags.
+     *
+     * @param string[] $tags
      */
-    private function add_image(string $tmpname, string $filename, array $tags, string $source, string $rating, string $thumbfile)
+    private function add_image(string $tmpname, string $filename, array $tags, string $source, string $rating, string $thumbfile): void
     {
         global $database;
         $database->with_savepoint(function () use ($tmpname, $filename, $tags, $source, $rating, $thumbfile) {
@@ -72,7 +74,7 @@ class BulkAddCSV extends Extension
         });
     }
 
-    private function add_csv(string $csvfile)
+    private function add_csv(string $csvfile): void
     {
         if (!file_exists($csvfile)) {
             $this->theme->add_status("Error", "$csvfile not found");
diff --git a/ext/bulk_add_csv/theme.php b/ext/bulk_add_csv/theme.php
index 26b1b50d..a29777f9 100644
--- a/ext/bulk_add_csv/theme.php
+++ b/ext/bulk_add_csv/theme.php
@@ -6,6 +6,7 @@ namespace Shimmie2;
 
 class BulkAddCSVTheme extends Themelet
 {
+    /** @var Block[] */
     private array $messages = [];
 
     /*
@@ -44,7 +45,7 @@ class BulkAddCSVTheme extends Themelet
         $page->add_block(new Block("Bulk Add CSV", $html));
     }
 
-    public function add_status($title, $body)
+    public function add_status(string $title, string $body): void
     {
         $this->messages[] = new Block($title, $body);
     }
diff --git a/ext/bulk_import_export/events.php b/ext/bulk_import_export/events.php
index 89b4b00c..3cbb1b91 100644
--- a/ext/bulk_import_export/events.php
+++ b/ext/bulk_import_export/events.php
@@ -7,6 +7,7 @@ namespace Shimmie2;
 class BulkExportEvent extends Event
 {
     public Image $image;
+    /** @var array<string,mixed> */
     public array $fields = [];
 
     public function __construct(Image $image)
@@ -20,9 +21,13 @@ class BulkExportEvent extends Event
 class BulkImportEvent extends Event
 {
     public Image $image;
+    /** @var array<string,mixed> */
     public array $fields = [];
 
-    public function __construct(Image $image, $fields)
+    /**
+     * @param array<string,mixed> $fields
+     */
+    public function __construct(Image $image, array $fields)
     {
         parent::__construct();
         $this->image = $image;
diff --git a/ext/bulk_import_export/main.php b/ext/bulk_import_export/main.php
index 0248080c..1b7f34fb 100644
--- a/ext/bulk_import_export/main.php
+++ b/ext/bulk_import_export/main.php
@@ -155,6 +155,9 @@ class BulkImportExport extends DataHandlerExtension
         return false;
     }
 
+    /**
+     * @return array<mixed>
+     */
     private function get_export_data(\ZipArchive $zip): ?array
     {
         $info = $zip->getStream(self::EXPORT_INFO_FILE_NAME);
diff --git a/ext/comment/main.php b/ext/comment/main.php
index 284fe2a8..5d05ead2 100644
--- a/ext/comment/main.php
+++ b/ext/comment/main.php
@@ -63,7 +63,10 @@ class Comment
     #[Field]
     public string $posted;
 
-    public function __construct($row)
+    /**
+     * @param array<string,mixed> $row
+     */
+    public function __construct(array $row)
     {
         $this->owner = null;
         $this->owner_id = (int)$row['user_id'];
@@ -96,6 +99,9 @@ class Comment
         return $this->owner;
     }
 
+    /**
+     * @return Comment[]
+     */
     #[Field(extends: "Post", name: "comments", type: "[Comment!]!")]
     public static function get_comments(Image $post): array
     {
@@ -223,7 +229,7 @@ class CommentList extends Extension
         $event->add_disallow("comment");
     }
 
-    private function onPageRequest_add()
+    private function onPageRequest_add(): void
     {
         global $user, $page;
         if (isset($_POST['image_id']) && isset($_POST['comment'])) {
@@ -238,7 +244,7 @@ class CommentList extends Extension
         }
     }
 
-    private function onPageRequest_delete(PageRequestEvent $event)
+    private function onPageRequest_delete(PageRequestEvent $event): void
     {
         global $user, $page;
         if ($user->can(Permissions::DELETE_COMMENT)) {
@@ -254,7 +260,7 @@ class CommentList extends Extension
         }
     }
 
-    private function onPageRequest_bulk_delete()
+    private function onPageRequest_bulk_delete(): void
     {
         global $user, $database, $page;
         if ($user->can(Permissions::DELETE_COMMENT) && !empty($_POST["ip"])) {
@@ -279,7 +285,7 @@ class CommentList extends Extension
         }
     }
 
-    private function onPageRequest_list(PageRequestEvent $event)
+    private function onPageRequest_list(PageRequestEvent $event): void
     {
         global $cache, $config, $database, $user;
 
@@ -332,7 +338,7 @@ class CommentList extends Extension
         $this->theme->display_comment_list($images, $current_page + 1, $total_pages, $user->can(Permissions::CREATE_COMMENT));
     }
 
-    private function onPageRequest_beta_search(PageRequestEvent $event)
+    private function onPageRequest_beta_search(PageRequestEvent $event): void
     {
         $search = $event->get_arg(1);
         $page_num = $event->try_page_num(2);
@@ -448,6 +454,7 @@ class CommentList extends Extension
     }
 
     /**
+     * @param array<string,mixed> $args
      * @return Comment[]
      */
     private static function get_generic_comments(string $query, array $args): array
@@ -603,7 +610,7 @@ class CommentList extends Extension
     }
     // do some checks
 
-    private function add_comment_wrapper(int $image_id, User $user, string $comment)
+    private function add_comment_wrapper(int $image_id, User $user, string $comment): void
     {
         global $database, $page;
 
@@ -628,7 +635,7 @@ class CommentList extends Extension
         log_info("comment", "Comment #$cid added to >>$image_id: $snippet");
     }
 
-    private function comment_checks(int $image_id, User $user, string $comment)
+    private function comment_checks(int $image_id, User $user, string $comment): void
     {
         global $config, $page;
 
diff --git a/ext/comment/theme.php b/ext/comment/theme.php
index ee628315..a79bd759 100644
--- a/ext/comment/theme.php
+++ b/ext/comment/theme.php
@@ -8,10 +8,13 @@ class CommentListTheme extends Themelet
 {
     private bool $show_anon_id = false;
     private int $anon_id = 1;
+    /** @var array<string,int> */
     private array $anon_map = [];
 
     /**
      * Display a page with a list of images, and for each image, the image's comments.
+     *
+     * @param array<array{0: Image, 1: Comment[]}> $images
      */
     public function display_comment_list(array $images, int $page_number, int $total_pages, bool $can_post): void
     {
@@ -164,6 +167,9 @@ class CommentListTheme extends Themelet
         $page->add_block(new Block("Comments", $html, "left", 70, "comment-list-user"));
     }
 
+    /**
+     * @param Comment[] $comments
+     */
     public function display_all_user_comments(array $comments, int $page_number, int $total_pages, User $user): void
     {
         global $page;
diff --git a/ext/cron_uploader/main.php b/ext/cron_uploader/main.php
index 6f2e0de9..201bf0c7 100644
--- a/ext/cron_uploader/main.php
+++ b/ext/cron_uploader/main.php
@@ -139,7 +139,7 @@ class CronUploader extends Extension
         }
     }
 
-    private function restage_folder(string $folder)
+    private function restage_folder(string $folder): void
     {
         global $page;
         if (empty($folder)) {
@@ -196,7 +196,7 @@ class CronUploader extends Extension
         }
     }
 
-    private function clear_folder($folder)
+    private function clear_folder(string $folder): void
     {
         global $page, $user_config;
         $path = join_path($user_config->get_string(CronUploaderConfig::DIR), $folder);
@@ -414,7 +414,7 @@ class CronUploader extends Extension
         }
     }
 
-    private function move_uploaded(string $path, string $filename, string $output_subdir, bool $corrupt = false)
+    private function move_uploaded(string $path, string $filename, string $output_subdir, bool $corrupt = false): void
     {
         global $user_config;
 
@@ -454,6 +454,8 @@ class CronUploader extends Extension
 
     /**
      * Generate the necessary DataUploadEvent for a given image and tags.
+     *
+     * @param string[] $tags
      */
     private function add_image(string $tmpname, string $filename, array $tags): DataUploadEvent
     {
diff --git a/ext/cron_uploader/theme.php b/ext/cron_uploader/theme.php
index 6fe7e5d4..36aec0e1 100644
--- a/ext/cron_uploader/theme.php
+++ b/ext/cron_uploader/theme.php
@@ -17,6 +17,12 @@ use function MicroHTML\emptyHTML;
 
 class CronUploaderTheme extends Themelet
 {
+    /**
+     * @param array{path:string,total_files:int,total_mb:string} $queue_dirinfo
+     * @param array{path:string,total_files:int,total_mb:string} $uploaded_dirinfo
+     * @param array{path:string,total_files:int,total_mb:string} $failed_dirinfo
+     * @param array<array{date_sent:string,message:string}>|null $log_entries
+     */
     public function display_documentation(
         bool $running,
         array $queue_dirinfo,
@@ -25,7 +31,7 @@ class CronUploaderTheme extends Themelet
         string $cron_cmd,
         string $cron_url,
         ?array $log_entries
-    ) {
+    ): void {
         global $page, $config, $user_config;
 
         $info_html = "";
@@ -159,6 +165,9 @@ class CronUploaderTheme extends Themelet
         return (string)$html;
     }
 
+    /**
+     * @param string[] $failed_dirs
+     */
     public function display_form(array $failed_dirs): void
     {
         global $page;
diff --git a/ext/custom_html_headers/main.php b/ext/custom_html_headers/main.php
index 8e73c6d4..87f90033 100644
--- a/ext/custom_html_headers/main.php
+++ b/ext/custom_html_headers/main.php
@@ -38,7 +38,7 @@ class CustomHtmlHeaders extends Extension
         $this->handle_modified_page_title();
     }
 
-    private function handle_custom_html_headers()
+    private function handle_custom_html_headers(): void
     {
         global $config, $page;
 
@@ -48,7 +48,7 @@ class CustomHtmlHeaders extends Extension
         }
     }
 
-    private function handle_modified_page_title()
+    private function handle_modified_page_title(): void
     {
         global $config, $page;
 
diff --git a/ext/emoticons_list/theme.php b/ext/emoticons_list/theme.php
index d53d637f..5d770d70 100644
--- a/ext/emoticons_list/theme.php
+++ b/ext/emoticons_list/theme.php
@@ -6,6 +6,9 @@ namespace Shimmie2;
 
 class EmoticonListTheme extends Themelet
 {
+    /**
+     * @param string[] $list
+     */
     public function display_emotes(array $list): void
     {
         global $page;
diff --git a/ext/et/main.php b/ext/et/main.php
index 5b6cfc57..33db0109 100644
--- a/ext/et/main.php
+++ b/ext/et/main.php
@@ -53,6 +53,8 @@ class ET extends Extension
 
     /**
      * Collect the information and return it in a keyed array.
+     *
+     * @return array<string, mixed>
      */
     private function get_info(): array
     {
@@ -135,6 +137,9 @@ class ET extends Extension
         return $info;
     }
 
+    /**
+     * @param array<string, mixed> $info
+     */
     private function to_yaml(array $info): string
     {
         $data = "";
diff --git a/ext/et/theme.php b/ext/et/theme.php
index 9d908ac6..f877ecb5 100644
--- a/ext/et/theme.php
+++ b/ext/et/theme.php
@@ -13,10 +13,8 @@ class ETTheme extends Themelet
 {
     /*
      * Create a page showing info
-     *
-     * $info = an array of ($name => $value)
      */
-    public function display_info_page($yaml): void
+    public function display_info_page(string $yaml): void
     {
         global $page;
 
@@ -26,7 +24,7 @@ class ETTheme extends Themelet
         $page->add_block(new Block("Information:", $this->build_data_form($yaml)));
     }
 
-    protected function build_data_form($yaml): \MicroHTML\HTMLElement
+    protected function build_data_form(string $yaml): \MicroHTML\HTMLElement
     {
         return FORM(
             ["action" => "https://shimmie.shishnet.org/register.php", "method" => "POST"],
diff --git a/ext/ext_manager/main.php b/ext/ext_manager/main.php
index 1b5ab95c..73b176d1 100644
--- a/ext/ext_manager/main.php
+++ b/ext/ext_manager/main.php
@@ -116,7 +116,10 @@ class ExtManager extends Extension
         return $extensions;
     }
 
-    private function set_things($settings)
+    /**
+     * @param array<string, bool> $settings
+     */
+    private function set_things(array $settings): void
     {
         $core = ExtensionInfo::get_core_extensions();
         $extras = [];
@@ -133,7 +136,7 @@ class ExtManager extends Extension
     /**
      * @param string[] $extras
      */
-    private function write_config(array $extras)
+    private function write_config(array $extras): void
     {
         file_put_contents(
             "data/config/extensions.conf.php",
diff --git a/ext/favorites/main.php b/ext/favorites/main.php
index 43189490..8b83e0ad 100644
--- a/ext/favorites/main.php
+++ b/ext/favorites/main.php
@@ -238,7 +238,7 @@ class Favorites extends Extension
         }
     }
 
-    private function add_vote(int $image_id, int $user_id, bool $do_set)
+    private function add_vote(int $image_id, int $user_id, bool $do_set): void
     {
         global $database;
         if ($do_set) {
diff --git a/ext/favorites/theme.php b/ext/favorites/theme.php
index 0762c208..e9fff045 100644
--- a/ext/favorites/theme.php
+++ b/ext/favorites/theme.php
@@ -22,6 +22,9 @@ class FavoritesTheme extends Themelet
         );
     }
 
+    /**
+     * @param string[] $username_array
+     */
     public function display_people(array $username_array): void
     {
         global $page;
diff --git a/ext/forum/main.php b/ext/forum/main.php
index c65f78fe..4c737c26 100644
--- a/ext/forum/main.php
+++ b/ext/forum/main.php
@@ -206,6 +206,9 @@ class Forum extends Extension
         return (int)ceil($result["count"] / $config->get_int("forumPostsPerPage"));
     }
 
+    /**
+     * @return string[]
+     */
     private function sanity_check_new_thread(): array
     {
         $errors = [];
@@ -226,6 +229,9 @@ class Forum extends Extension
         return $errors;
     }
 
+    /**
+     * @return string[]
+     */
     private function sanity_check_new_post(): array
     {
         $errors = [];
diff --git a/ext/forum/theme.php b/ext/forum/theme.php
index a37e3719..ea7400f8 100644
--- a/ext/forum/theme.php
+++ b/ext/forum/theme.php
@@ -8,9 +8,16 @@ use MicroHTML\HTMLElement;
 
 use function MicroHTML\{INPUT, LABEL, SMALL, TEXTAREA, TR, TD, TABLE, TH, TBODY, THEAD, DIV, A, BR, emptyHTML, SUP, rawHTML};
 
+/**
+ * @phpstan-type Thread array{id:int,title:string,sticky:bool,user_name:string,uptodate:string,response_count:int}
+ * @phpstan-type Post array{id:int,user_name:string,user_class:string,date:string,message:string}
+ */
 class ForumTheme extends Themelet
 {
-    public function display_thread_list(Page $page, $threads, $showAdminOptions, $pageNumber, $totalPages): void
+    /**
+     * @param Thread[] $threads
+     */
+    public function display_thread_list(Page $page, array $threads, bool $showAdminOptions, int $pageNumber, int $totalPages): void
     {
         if (count($threads) == 0) {
             $html = "There are no threads to show.";
@@ -27,7 +34,7 @@ class ForumTheme extends Themelet
 
 
 
-    public function display_new_thread_composer(Page $page, $threadText = null, $threadTitle = null): void
+    public function display_new_thread_composer(Page $page, string $threadText = null, string $threadTitle = null): void
     {
         global $config, $user;
         $max_characters = $config->get_int('forumMaxCharsPerPost');
@@ -73,9 +80,7 @@ class ForumTheme extends Themelet
         $page->add_block(new Block($blockTitle, $html, "main", 120));
     }
 
-
-
-    public function display_new_post_composer(Page $page, $threadID): void
+    public function display_new_post_composer(Page $page, int $threadID): void
     {
         global $config;
 
@@ -108,8 +113,10 @@ class ForumTheme extends Themelet
     }
 
 
-
-    public function display_thread($posts, $showAdminOptions, $threadTitle, $threadID, $pageNumber, $totalPages): void
+    /**
+     * @param array<Post> $posts
+     */
+    public function display_thread(array $posts, bool $showAdminOptions, string $threadTitle, int $threadID, int $pageNumber, int $totalPages): void
     {
         global $config, $page/*, $user*/;
 
@@ -189,13 +196,16 @@ class ForumTheme extends Themelet
         $page->add_block(new Block($threadTitle, $html, "main", 20));
     }
 
-    public function add_actions_block(Page $page, $threadID)
+    public function add_actions_block(Page $page, int $threadID): void
     {
         $html = A(["href" => make_link("forum/nuke/".$threadID)], "Delete this thread and its posts.");
         $page->add_block(new Block("Admin Actions", $html, "main", 140));
     }
 
-    private function make_thread_list($threads, $showAdminOptions): HTMLElement
+    /**
+     * @param Thread[] $threads
+     */
+    private function make_thread_list(array $threads, bool $showAdminOptions): HTMLElement
     {
         global $config;
 
diff --git a/ext/four_oh_four/main.php b/ext/four_oh_four/main.php
index 162d28fc..627e18d3 100644
--- a/ext/four_oh_four/main.php
+++ b/ext/four_oh_four/main.php
@@ -21,7 +21,10 @@ class FourOhFour extends Extension
         }
     }
 
-    private function count_main($blocks): int
+    /**
+     * @param Block[] $blocks
+     */
+    private function count_main(array $blocks): int
     {
         $n = 0;
         foreach ($blocks as $block) {
diff --git a/ext/graphql/main.php b/ext/graphql/main.php
index 66212258..17e92070 100644
--- a/ext/graphql/main.php
+++ b/ext/graphql/main.php
@@ -115,6 +115,9 @@ class GraphQL extends Extension
         }
     }
 
+    /**
+     * @return array{error?:string,results?:array<array{error?:string,image_ids?:int[]}>}
+     */
     private static function handle_uploads(): array
     {
         global $user;
@@ -135,7 +138,7 @@ class GraphQL extends Extension
                 break;
             }
             try {
-                $results[] = self::handle_upload($n, $common_tags, $common_source);
+                $results[] = ["image_ids" => self::handle_upload($n, $common_tags, $common_source)];
             } catch(\Exception $e) {
                 $results[] = ["error" => $e->getMessage()];
             }
@@ -143,10 +146,14 @@ class GraphQL extends Extension
         return ["results" => $results];
     }
 
+    /**
+     * @return int[]
+     */
     private static function handle_upload(int $n, string $common_tags, string $common_source): array
     {
+        global $database;
         if (!empty($_POST["url$n"])) {
-            throw new \Exception("URLs not handled yet");
+            throw new UploadException("URLs not handled yet");
         } else {
             $ec = $_FILES["data$n"]["error"];
             switch($ec) {
@@ -155,9 +162,9 @@ class GraphQL extends Extension
                     $filename = $_FILES["data$n"]["name"];
                     break;
                 case UPLOAD_ERR_INI_SIZE:
-                    return ["error" => "File larger than PHP can handle"];
+                    throw new UploadException("File larger than PHP can handle");
                 default:
-                    return ["error" => "Mystery error: $ec"];
+                    throw new UploadException("Mystery error: $ec");
             }
         }
 
@@ -166,13 +173,15 @@ class GraphQL extends Extension
         if (!empty($_POST["source$n"])) {
             $source = $_POST["source$n"];
         }
-        $event = send_event(new DataUploadEvent($tmpname, [
-            'filename' => $filename,
-            'tags' => Tag::explode($tags),
-            'source' => $source,
-        ]));
+        $event = $database->with_savepoint(function () use ($tmpname, $filename, $tags, $source) {
+            return send_event(new DataUploadEvent($tmpname, [
+                'filename' => $filename,
+                'tags' => Tag::explode($tags),
+                'source' => $source,
+            ]));
+        });
 
-        return ["image_ids" => array_map(fn ($im) => $im->id, $event->images)];
+        return array_map(fn ($im) => $im->id, $event->images);
     }
 
     public function onCliGen(CliGenEvent $event): void
diff --git a/ext/handle_svg/main.php b/ext/handle_svg/main.php
index 5b5d2378..9d9e7120 100644
--- a/ext/handle_svg/main.php
+++ b/ext/handle_svg/main.php
@@ -107,7 +107,10 @@ class MiniSVGParser
         xml_parser_free($xml_parser);
     }
 
-    public function startElement($parser, $name, $attrs): void
+    /**
+     * @param array<string, mixed> $attrs
+     */
+    public function startElement(mixed $parser, string $name, array $attrs): void
     {
         if ($name == "SVG" && $this->xml_depth == 0) {
             $this->width = int_escape($attrs["WIDTH"]);
@@ -116,7 +119,7 @@ class MiniSVGParser
         $this->xml_depth++;
     }
 
-    public function endElement($parser, $name): void
+    public function endElement(mixed $parser, string $name): void
     {
         $this->xml_depth--;
     }
diff --git a/ext/handle_video/main.php b/ext/handle_video/main.php
index 0b294a29..e3f78053 100644
--- a/ext/handle_video/main.php
+++ b/ext/handle_video/main.php
@@ -39,6 +39,9 @@ class VideoFileHandler extends DataHandlerExtension
         );
     }
 
+    /**
+     * @return array<string, string>
+     */
     private function get_options(): array
     {
         $output = [];
diff --git a/ext/help_pages/main.php b/ext/help_pages/main.php
index 4568842c..5eb5e1ac 100644
--- a/ext/help_pages/main.php
+++ b/ext/help_pages/main.php
@@ -6,9 +6,10 @@ namespace Shimmie2;
 
 class HelpPageListBuildingEvent extends Event
 {
+    /** @var array<string,string> */
     public array $pages = [];
 
-    public function add_page(string $key, string $name)
+    public function add_page(string $key, string $name): void
     {
         $this->pages[$key] = $name;
     }
@@ -17,6 +18,7 @@ class HelpPageListBuildingEvent extends Event
 class HelpPageBuildingEvent extends Event
 {
     public string $key;
+    /** @var array<string,array<Block>> */
     public array $blocks = [];
 
     public function __construct(string $key)
@@ -25,7 +27,7 @@ class HelpPageBuildingEvent extends Event
         $this->key = $key;
     }
 
-    public function add_block(Block $block, int $position = 50)
+    public function add_block(Block $block, int $position = 50): void
     {
         if (!array_key_exists("$position", $this->blocks)) {
             $this->blocks["$position"] = [];
diff --git a/ext/help_pages/theme.php b/ext/help_pages/theme.php
index 60c6a426..0087a4bb 100644
--- a/ext/help_pages/theme.php
+++ b/ext/help_pages/theme.php
@@ -6,6 +6,9 @@ namespace Shimmie2;
 
 class HelpPagesTheme extends Themelet
 {
+    /**
+     * @param array<string,string> $pages
+     */
     public function display_list_page(array $pages): void
     {
         global $page;
diff --git a/ext/home/theme.php b/ext/home/theme.php
index 7e42bc1a..97d33087 100644
--- a/ext/home/theme.php
+++ b/ext/home/theme.php
@@ -29,7 +29,7 @@ EOD
         );
     }
 
-    public function build_body(string $sitename, string $main_links, string $main_text, string $contact_link, $num_comma, string $counter_text): string
+    public function build_body(string $sitename, string $main_links, string $main_text, string $contact_link, string $num_comma, string $counter_text): string
     {
         $main_links_html = empty($main_links) ? "" : "<div class='space' id='links'>$main_links</div>";
         $message_html = empty($main_text) ? "" : "<div class='space' id='message'>$main_text</div>";
diff --git a/ext/image/main.php b/ext/image/main.php
index b90942f0..ec6e4676 100644
--- a/ext/image/main.php
+++ b/ext/image/main.php
@@ -215,7 +215,7 @@ class ImageIO extends Extension
         $event->replace("\\n", "\n");
     }
 
-    private function send_file(int $image_id, string $type)
+    private function send_file(int $image_id, string $type): void
     {
         global $config, $page;
 
diff --git a/ext/image_hash_ban/theme.php b/ext/image_hash_ban/theme.php
index 3671ac0f..e0d5d2c1 100644
--- a/ext/image_hash_ban/theme.php
+++ b/ext/image_hash_ban/theme.php
@@ -4,25 +4,27 @@ declare(strict_types=1);
 
 namespace Shimmie2;
 
-use function MicroHTML\INPUT;
+use MicroHTML\HTMLElement;
+
+use function MicroHTML\{INPUT,emptyHTML};
 
 class ImageBanTheme extends Themelet
 {
     /*
      * Show all the bans
      */
-    public function display_bans(Page $page, $table, $paginator): void
+    public function display_bans(Page $page, HTMLElement $table, HTMLElement $paginator): void
     {
         $page->set_title("Post Bans");
         $page->set_heading("Post Bans");
         $page->add_block(new NavBlock());
-        $page->add_block(new Block("Edit Post Bans", $table . $paginator));
+        $page->add_block(new Block("Edit Post Bans", emptyHTML($table, $paginator)));
     }
 
     /*
      * Display a link to delete an image
      */
-    public function get_buttons_html(Image $image): \MicroHTML\HTMLElement
+    public function get_buttons_html(Image $image): HTMLElement
     {
         return SHM_SIMPLE_FORM(
             "image_hash_ban/add",
diff --git a/ext/image_view_counter/theme.php b/ext/image_view_counter/theme.php
index 5ba94656..485b82b7 100644
--- a/ext/image_view_counter/theme.php
+++ b/ext/image_view_counter/theme.php
@@ -9,7 +9,7 @@ class ImageViewCounterTheme extends Themelet
     /**
      * @param Image[] $images
      */
-    public function view_popular(array $images)
+    public function view_popular(array $images): void
     {
         global $page, $config;
         $pop_images = "";
diff --git a/ext/index/events.php b/ext/index/events.php
index 0c957872..ca94cfed 100644
--- a/ext/index/events.php
+++ b/ext/index/events.php
@@ -21,6 +21,9 @@ class SearchTermParseEvent extends Event
     public array $tag_conditions = [];
     public ?string $order = null;
 
+    /**
+     * @param string[] $context
+     */
     public function __construct(int $id, string $term = null, array $context = [])
     {
         parent::__construct();
@@ -41,17 +44,17 @@ class SearchTermParseEvent extends Event
         $this->context = $context;
     }
 
-    public function add_querylet(Querylet $q)
+    public function add_querylet(Querylet $q): void
     {
         $this->add_img_condition(new ImgCondition($q, $this->positive));
     }
 
-    public function add_img_condition(ImgCondition $c)
+    public function add_img_condition(ImgCondition $c): void
     {
         $this->img_conditions[] = $c;
     }
 
-    public function add_tag_condition(TagCondition $c)
+    public function add_tag_condition(TagCondition $c): void
     {
         $this->tag_conditions[] = $c;
     }
@@ -63,7 +66,9 @@ class SearchTermParseException extends SCoreException
 
 class PostListBuildingEvent extends Event
 {
+    /** @var string[] */
     public array $search_terms = [];
+    /** @var array<int,string> */
     public array $parts = [];
 
     /**
@@ -75,7 +80,7 @@ class PostListBuildingEvent extends Event
         $this->search_terms = $search;
     }
 
-    public function add_control(string $html, int $position = 50)
+    public function add_control(string $html, int $position = 50): void
     {
         while (isset($this->parts[$position])) {
             $position++;
diff --git a/ext/index/theme.php b/ext/index/theme.php
index bc601a3b..5d5a1a8a 100644
--- a/ext/index/theme.php
+++ b/ext/index/theme.php
@@ -13,9 +13,13 @@ class IndexTheme extends Themelet
 {
     protected int $page_number;
     protected int $total_pages;
+    /** @var string[] */
     protected array $search_terms;
 
-    public function set_page(int $page_number, int $total_pages, array $search_terms)
+    /**
+     * @param string[] $search_terms
+     */
+    public function set_page(int $page_number, int $total_pages, array $search_terms): void
     {
         $this->page_number = $page_number;
         $this->total_pages = $total_pages;
@@ -109,7 +113,7 @@ and of course start organising your images :-)
         return $table;
     }
 
-    protected function display_shortwiki(Page $page)
+    protected function display_shortwiki(Page $page): void
     {
         global $config;
 
@@ -141,7 +145,7 @@ and of course start organising your images :-)
     /**
      * @param Image[] $images
      */
-    protected function display_page_header(Page $page, array $images)
+    protected function display_page_header(Page $page, array $images): void
     {
         global $config;
 
@@ -167,7 +171,7 @@ and of course start organising your images :-)
     /**
      * @param Image[] $images
      */
-    protected function display_page_images(Page $page, array $images)
+    protected function display_page_images(Page $page, array $images): void
     {
         if (count($this->search_terms) > 0) {
             if ($this->page_number > 3) {
diff --git a/ext/ipban/main.php b/ext/ipban/main.php
index 1def39ee..96703973 100644
--- a/ext/ipban/main.php
+++ b/ext/ipban/main.php
@@ -130,7 +130,7 @@ class IPBan extends Extension
 
         // Check if our current IP is in either of the ban lists
         $active_ban_id = (
-            $this->find_active_ban($ips, get_real_ip(), $networks)
+            $this->find_active_ban(get_real_ip(), $ips, $networks)
         );
 
         // If an active ban is found, act on it
@@ -355,11 +355,12 @@ class IPBan extends Extension
         }
     }
 
-    public function find_active_ban($ips, $remote, $networks)
+    /**
+     * @param array<string,int> $ips
+     * @param array<string,int> $networks
+     */
+    public function find_active_ban(string $remote, array $ips, array $networks): ?int
     {
-        if (!$remote) {
-            return null;
-        }
         $active_ban_id = null;
         if (isset($ips[$remote])) {
             $active_ban_id = $ips[$remote];
diff --git a/ext/ipban/theme.php b/ext/ipban/theme.php
index 6697a065..16f7dd9a 100644
--- a/ext/ipban/theme.php
+++ b/ext/ipban/theme.php
@@ -4,9 +4,13 @@ declare(strict_types=1);
 
 namespace Shimmie2;
 
+use MicroHTML\HTMLElement;
+
+use function MicroHTML\emptyHTML;
+
 class IPBanTheme extends Themelet
 {
-    public function display_bans(Page $page, $table, $paginator): void
+    public function display_bans(Page $page, HTMLElement $table, HTMLElement $paginator): void
     {
         $html = "
 			<a href='".make_link("ip_ban/list", "r__size=1000000")."'>Show All Active</a> /
diff --git a/ext/link_image/main.php b/ext/link_image/main.php
index 4255a50e..d1b41bba 100644
--- a/ext/link_image/main.php
+++ b/ext/link_image/main.php
@@ -27,6 +27,9 @@ class LinkImage extends Extension
         $config->set_default_string("ext_link-img_text-link_format", '$title - $id ($ext $size $filesize)');
     }
 
+    /**
+     * @return array{thumb_src: string, image_src: string, post_link: string, text_link: string}
+     */
     private function data(Image $image): array
     {
         global $config;
@@ -38,6 +41,7 @@ class LinkImage extends Extension
             'thumb_src' => make_http($image->get_thumb_link()),
             'image_src' => make_http($image->get_image_link()),
             'post_link' => make_http(make_link("post/view/{$image->id}")),
-            'text_link' => $text_link];
+            'text_link' => $text_link
+        ];
     }
 }
diff --git a/ext/link_image/theme.php b/ext/link_image/theme.php
index dfe9e4c7..cffc2278 100644
--- a/ext/link_image/theme.php
+++ b/ext/link_image/theme.php
@@ -6,14 +6,16 @@ namespace Shimmie2;
 
 class LinkImageTheme extends Themelet
 {
-    public function links_block(Page $page, $data)
+    /**
+     * @param array{thumb_src:string,image_src:string,post_link:string,text_link:string} $data
+     */
+    public function links_block(Page $page, array $data): void
     {
         $thumb_src = $data['thumb_src'];
         $image_src = $data['image_src'];
         $post_link = $data['post_link'];
         $text_link = $data['text_link'];
 
-
         $page->add_block(new Block(
             "Link to Post",
             "
@@ -93,7 +95,7 @@ class LinkImageTheme extends Themelet
         return $text;
     }
 
-    protected function link_code(string $label, string $content, $id = null): string
+    protected function link_code(string $label, string $content, string $id): string
     {
         return	"
 			<tr>
diff --git a/ext/link_scan/main.php b/ext/link_scan/main.php
index 00f1ecc0..9b5e7e15 100644
--- a/ext/link_scan/main.php
+++ b/ext/link_scan/main.php
@@ -26,6 +26,9 @@ class LinkScan extends Extension
         }
     }
 
+    /**
+     * @return int[]
+     */
     private function scan(string $text): array
     {
         $ids = [];
diff --git a/ext/livefeed/main.php b/ext/livefeed/main.php
index cf5e8018..3b05ee3a 100644
--- a/ext/livefeed/main.php
+++ b/ext/livefeed/main.php
@@ -48,7 +48,7 @@ class LiveFeed extends Extension
         return 99;
     }
 
-    private function msg(string $data)
+    private function msg(string $data): void
     {
         global $config;
 
diff --git a/ext/log_console/main.php b/ext/log_console/main.php
index 1170becf..09aca5b5 100644
--- a/ext/log_console/main.php
+++ b/ext/log_console/main.php
@@ -48,7 +48,7 @@ class LogConsole extends Extension
         }
     }
 
-    private function log(LogEvent $event)
+    private function log(LogEvent $event): void
     {
         global $config, $user;
         // TODO: colour based on event->priority
diff --git a/ext/log_db/main.php b/ext/log_db/main.php
index e52c4de6..5831d111 100644
--- a/ext/log_db/main.php
+++ b/ext/log_db/main.php
@@ -42,7 +42,7 @@ class ShortDateTimeColumn extends DateTimeColumn
 
 class ActorColumn extends Column
 {
-    public function __construct($name, $title)
+    public function __construct(string $name, string $title)
     {
         parent::__construct($name, $title);
         $this->sortable = false;
@@ -78,6 +78,9 @@ class ActorColumn extends Column
         );
     }
 
+    /**
+     * @return array{0: string, 1: string}
+     */
     public function modify_input_for_read(string|array $input): array
     {
         list($un, $ip) = $input;
@@ -90,7 +93,10 @@ class ActorColumn extends Column
         return [$un, $ip];
     }
 
-    public function display($row): HTMLElement
+    /**
+     * @param array{username: string, address: string} $row
+     */
+    public function display(array $row): HTMLElement
     {
         $ret = emptyHTML();
         if ($row['username'] != "Anonymous") {
@@ -189,7 +195,7 @@ class MessageColumn extends Column
         return SPAN(["style" => "color: $c"], rawHTML($this->scan_entities($row[$this->name])));
     }
 
-    protected function scan_entities(string $line)
+    protected function scan_entities(string $line): string
     {
         $line = preg_replace_callback("/Image #(\d+)/s", [$this, "link_image"], $line);
         $line = preg_replace_callback("/Post #(\d+)/s", [$this, "link_image"], $line);
@@ -197,7 +203,10 @@ class MessageColumn extends Column
         return $line;
     }
 
-    protected function link_image($id)
+    /**
+     * @param array{1: string} $id
+     */
+    protected function link_image(array $id): string
     {
         $iid = int_escape($id[1]);
         return "<a href='".make_link("post/view/$iid")."'>&gt;&gt;$iid</a>";
diff --git a/ext/log_db/theme.php b/ext/log_db/theme.php
index a44c0ed9..f57183cf 100644
--- a/ext/log_db/theme.php
+++ b/ext/log_db/theme.php
@@ -4,14 +4,18 @@ declare(strict_types=1);
 
 namespace Shimmie2;
 
+use MicroHTML\HTMLElement;
+
+use function MicroHTML\emptyHTML;
+
 class LogDatabaseTheme extends Themelet
 {
-    public function display_events($table, $paginator): void
+    public function display_events(HTMLElement $table, HTMLElement $paginator): void
     {
         global $page;
         $page->set_title("Event Log");
         $page->set_heading("Event Log");
         $page->add_block(new NavBlock());
-        $page->add_block(new Block("Events", $table . $paginator));
+        $page->add_block(new Block("Events", emptyHTML($table, $paginator)));
     }
 }
diff --git a/ext/log_logstash/main.php b/ext/log_logstash/main.php
index bb10adf6..a3fb8a75 100644
--- a/ext/log_logstash/main.php
+++ b/ext/log_logstash/main.php
@@ -39,7 +39,10 @@ class LogLogstash extends Extension
         }
     }
 
-    private function send_data($data)
+    /**
+     * @param array<string, mixed> $data
+     */
+    private function send_data(array $data): void
     {
         global $config;
 
diff --git a/ext/log_net/main.php b/ext/log_net/main.php
index e35f8cbf..c237d98f 100644
--- a/ext/log_net/main.php
+++ b/ext/log_net/main.php
@@ -31,7 +31,7 @@ class LogNet extends Extension
         }
     }
 
-    private function msg($data)
+    private function msg(string $data): void
     {
         global $config;
         $host = $config->get_string("log_net_host");
diff --git a/ext/media/main.php b/ext/media/main.php
index 3014e62e..9834ad24 100644
--- a/ext/media/main.php
+++ b/ext/media/main.php
@@ -298,7 +298,7 @@ class Media extends Extension
      * The factor of 2.5 is simply a rough guideline.
      * https://stackoverflow.com/questions/527532/reasonable-php-memory-limit-for-image-resize
      *
-     * @param array $info The output of getimagesize() for the source file in question.
+     * @param array{0:int,1:int,2:int,bits?:int,channels?:int} $info The output of getimagesize() for the source file in question.
      * @return int The number of bytes an image resize operation is estimated to use.
      */
     public static function calc_memory_use(array $info): int
@@ -368,8 +368,10 @@ class Media extends Extension
         return $ok;
     }
 
-
-    public static function get_ffprobe_data($filename): array
+    /**
+     * @return array<string, mixed>
+     */
+    public static function get_ffprobe_data(string $filename): array
     {
         global $config;
 
@@ -410,7 +412,7 @@ class Media extends Extension
         return $ext;
     }
 
-    //    private static function image_save_imagick(Imagick $image, string $path, string $format, int $output_quality = 80, bool $minimize)
+    //    private static function image_save_imagick(Imagick $image, string $path, string $format, int $output_quality = 80, bool $minimize): void
     //    {
     //        switch ($format) {
     //            case FileExtension::PNG:
@@ -638,7 +640,7 @@ class Media extends Extension
      * Performs a resize operation on an image file using GD.
      *
      * @param string $image_filename The source file to be resized.
-     * @param array $info The output of getimagesize() for the source file.
+     * @param array{0:int,1:int,2:int} $info The output of getimagesize() for the source file.
      * @param int $new_width
      * @param int $new_height
      * @param string $output_filename
@@ -658,7 +660,7 @@ class Media extends Extension
         string $resize_type = self::RESIZE_TYPE_FIT,
         int $output_quality = 80,
         bool $allow_upscale = true
-    ) {
+    ): void {
         $width = $info[0];
         $height = $info[1];
 
@@ -785,9 +787,6 @@ class Media extends Extension
                     }
 
                     $background_color = Media::hex_color_allocate($new_image, $alpha_color);
-                    if ($background_color === false) {
-                        throw new ImageTranscodeException("Could not allocate background color");
-                    }
                     if (imagefilledrectangle($new_image, 0, 0, $width, $height, $background_color) === false) {
                         throw new ImageTranscodeException("Could not fill background color");
                     }
@@ -839,7 +838,7 @@ class Media extends Extension
      * Determines the dimensions of a video file using ffmpeg.
      *
      * @param string $filename
-     * @return array [width, height]
+     * @return array{0: int, 1: int}
      */
     public static function video_size(string $filename): array
     {
@@ -939,12 +938,14 @@ class Media extends Extension
         }
     }
 
-    public static function hex_color_allocate($im, $hex)
+    public static function hex_color_allocate(mixed $im, string $hex): int
     {
         $hex = ltrim($hex, '#');
         $a = hexdec(substr($hex, 0, 2));
         $b = hexdec(substr($hex, 2, 2));
         $c = hexdec(substr($hex, 4, 2));
-        return imagecolorallocate($im, $a, $b, $c);
+        $col = imagecolorallocate($im, $a, $b, $c);
+        assert($col !== false);
+        return $col;
     }
 }
diff --git a/ext/mime/file_extension.php b/ext/mime/file_extension.php
index adbe7d0e..2526939e 100644
--- a/ext/mime/file_extension.php
+++ b/ext/mime/file_extension.php
@@ -90,6 +90,8 @@ class FileExtension
 
     /**
      * Returns all the file extension associated with the specified mimetype.
+     *
+     * @return string[]
      */
     public static function get_all_for_mime(string $mime): array
     {
diff --git a/ext/mime/mime_map.php b/ext/mime/mime_map.php
index 37db7fd4..325869eb 100644
--- a/ext/mime/mime_map.php
+++ b/ext/mime/mime_map.php
@@ -235,6 +235,9 @@ class MimeMap
         ],
     ];
 
+    /**
+     * @return array{name: string, ext: string[], mime: string[]}
+     */
     public static function get_for_extension(string $ext): ?array
     {
         $ext = strtolower($ext);
@@ -247,6 +250,9 @@ class MimeMap
         return null;
     }
 
+    /**
+     * @return array{name: string, ext: string[], mime: string[]}
+     */
     public static function get_for_mime(string $mime): ?array
     {
         $mime = strtolower(MimeType::remove_parameters($mime));
diff --git a/ext/mime/mime_type.php b/ext/mime/mime_type.php
index c3e71fd4..1c8af44b 100644
--- a/ext/mime/mime_type.php
+++ b/ext/mime/mime_type.php
@@ -100,6 +100,9 @@ class MimeType
         return $mime;
     }
 
+    /**
+     * @param array<string> $mime_array
+     */
     public static function matches_array(string $mime, array $mime_array, bool $exact = false): bool
     {
         // If there's an exact match, find it and that's it
@@ -151,6 +154,9 @@ class MimeType
     }
 
 
+    /**
+     * @param array<int|null> $comparison
+     */
     private static function compare_file_bytes(string $file_name, array $comparison): bool
     {
         $size = filesize($file_name);
diff --git a/ext/not_a_tag/main.php b/ext/not_a_tag/main.php
index 8caf42ce..fa93f936 100644
--- a/ext/not_a_tag/main.php
+++ b/ext/not_a_tag/main.php
@@ -65,7 +65,7 @@ class NotATag extends Extension
     /**
      * @param string[] $tags_mixed
      */
-    private function scan(array $tags_mixed)
+    private function scan(array $tags_mixed): void
     {
         global $database;
 
@@ -86,6 +86,7 @@ class NotATag extends Extension
 
     /**
      * @param string[] $tags
+     * @return string[]
      */
     private function strip(array $tags): array
     {
diff --git a/ext/not_a_tag/theme.php b/ext/not_a_tag/theme.php
index 1d2a1390..04acdfe4 100644
--- a/ext/not_a_tag/theme.php
+++ b/ext/not_a_tag/theme.php
@@ -4,13 +4,17 @@ declare(strict_types=1);
 
 namespace Shimmie2;
 
+use MicroHTML\HTMLElement;
+
+use function MicroHTML\emptyHTML;
+
 class NotATagTheme extends Themelet
 {
-    public function display_untags(Page $page, $table, $paginator): void
+    public function display_untags(Page $page, HTMLElement $table, HTMLElement $paginator): void
     {
         $page->set_title("UnTags");
         $page->set_heading("UnTags");
         $page->add_block(new NavBlock());
-        $page->add_block(new Block("Edit UnTags", $table . $paginator));
+        $page->add_block(new Block("Edit UnTags", emptyHTML($table, $paginator)));
     }
 }
diff --git a/ext/notes/main.php b/ext/notes/main.php
index 5b174674..905af893 100644
--- a/ext/notes/main.php
+++ b/ext/notes/main.php
@@ -233,6 +233,8 @@ class Notes extends Extension
 
     /**
      * HERE WE GET ALL NOTES FOR DISPLAYED IMAGE.
+     *
+     * @return array<string, mixed>
      */
     private function get_notes(int $imageID): array
     {
@@ -293,7 +295,7 @@ class Notes extends Extension
         return $noteID;
     }
 
-    private function add_note_request()
+    private function add_note_request(): void
     {
         global $database, $user;
 
@@ -312,7 +314,7 @@ class Notes extends Extension
         log_info("notes", "Note requested {$resultID} by {$user->name}");
     }
 
-    private function update_note()
+    private function update_note(): void
     {
         global $database;
 
@@ -331,7 +333,7 @@ class Notes extends Extension
         $this->add_history(1, $note['note_id'], $note['image_id'], $note['x1'], $note['y1'], $note['height'], $note['width'], $note['note']);
     }
 
-    private function delete_note()
+    private function delete_note(): void
     {
         global $user, $database;
 
@@ -344,7 +346,7 @@ class Notes extends Extension
         log_info("notes", "Note deleted {$note["note_id"]} by {$user->name}");
     }
 
-    private function nuke_notes()
+    private function nuke_notes(): void
     {
         global $database, $user;
         $image_id = int_escape($_POST["image_id"]);
@@ -352,7 +354,7 @@ class Notes extends Extension
         log_info("notes", "Notes deleted from {$image_id} by {$user->name}");
     }
 
-    private function nuke_requests()
+    private function nuke_requests(): void
     {
         global $database, $user;
         $image_id = int_escape($_POST["image_id"]);
@@ -362,7 +364,7 @@ class Notes extends Extension
         log_info("notes", "Requests deleted from {$image_id} by {$user->name}");
     }
 
-    private function get_notes_list(PageRequestEvent $event)
+    private function get_notes_list(PageRequestEvent $event): void
     {
         global $database, $config;
 
@@ -380,7 +382,7 @@ class Notes extends Extension
             ['enable' => 1, 'offset' => $pageNumber * $notesPerPage, 'limit' => $notesPerPage]
         );
 
-        $totalPages = ceil($database->get_one("SELECT COUNT(DISTINCT image_id) FROM notes") / $notesPerPage);
+        $totalPages = (int)ceil($database->get_one("SELECT COUNT(DISTINCT image_id) FROM notes") / $notesPerPage);
 
         $images = [];
         while ($row = $result->fetch()) {
@@ -390,7 +392,7 @@ class Notes extends Extension
         $this->theme->display_note_list($images, $pageNumber + 1, $totalPages);
     }
 
-    private function get_notes_requests(PageRequestEvent $event)
+    private function get_notes_requests(PageRequestEvent $event): void
     {
         global $config, $database;
 
@@ -398,10 +400,8 @@ class Notes extends Extension
 
         $requestsPerPage = $config->get_int('notesRequestsPerPage');
 
-
         //$result = $database->get_all("SELECT * FROM pool_images WHERE pool_id=:pool_id", ['pool_id'=>$poolID]);
 
-
         $result = $database->execute(
             "
 				SELECT DISTINCT image_id
@@ -410,7 +410,7 @@ class Notes extends Extension
             ["offset" => $pageNumber * $requestsPerPage, "limit" => $requestsPerPage]
         );
 
-        $totalPages = ceil($database->get_one("SELECT COUNT(*) FROM note_request") / $requestsPerPage);
+        $totalPages = (int)ceil($database->get_one("SELECT COUNT(*) FROM note_request") / $requestsPerPage);
 
         $images = [];
         while ($row = $result->fetch()) {
@@ -420,7 +420,7 @@ class Notes extends Extension
         $this->theme->display_note_requests($images, $pageNumber + 1, $totalPages);
     }
 
-    private function add_history($noteEnable, $noteID, $imageID, $noteX1, $noteY1, $noteHeight, $noteWidth, $noteText)
+    private function add_history(int $noteEnable, int $noteID, int $imageID, int $noteX1, int $noteY1, int $noteHeight, int $noteWidth, string $noteText): void
     {
         global $user, $database;
 
@@ -437,7 +437,7 @@ class Notes extends Extension
         );
     }
 
-    private function get_histories(PageRequestEvent $event)
+    private function get_histories(PageRequestEvent $event): void
     {
         global $config, $database;
 
@@ -455,12 +455,12 @@ class Notes extends Extension
             ['offset' => $pageNumber * $historiesPerPage, 'limit' => $historiesPerPage]
         );
 
-        $totalPages = ceil($database->get_one("SELECT COUNT(*) FROM note_histories") / $historiesPerPage);
+        $totalPages = (int)ceil($database->get_one("SELECT COUNT(*) FROM note_histories") / $historiesPerPage);
 
         $this->theme->display_histories($histories, $pageNumber + 1, $totalPages);
     }
 
-    private function get_history(PageRequestEvent $event)
+    private function get_history(PageRequestEvent $event): void
     {
         global $config, $database;
 
@@ -479,7 +479,7 @@ class Notes extends Extension
             ['note_id' => $noteID, 'offset' => $pageNumber * $historiesPerPage, 'limit' => $historiesPerPage]
         );
 
-        $totalPages = ceil($database->get_one("SELECT COUNT(*) FROM note_histories WHERE note_id = :note_id", ['note_id' => $noteID]) / $historiesPerPage);
+        $totalPages = (int)ceil($database->get_one("SELECT COUNT(*) FROM note_histories WHERE note_id = :note_id", ['note_id' => $noteID]) / $historiesPerPage);
 
         $this->theme->display_history($histories, $pageNumber + 1, $totalPages);
     }
@@ -487,7 +487,7 @@ class Notes extends Extension
     /**
      * HERE GO BACK IN HISTORY AND SET THE OLD NOTE. IF WAS REMOVED WE RE-ADD IT.
      */
-    private function revert_history(int $noteID, int $reviewID)
+    private function revert_history(int $noteID, int $reviewID): void
     {
         global $database;
 
diff --git a/ext/notes/theme.php b/ext/notes/theme.php
index a619ad00..b8adf249 100644
--- a/ext/notes/theme.php
+++ b/ext/notes/theme.php
@@ -8,6 +8,10 @@ use MicroHTML\HTMLElement;
 
 use function MicroHTML\INPUT;
 
+/**
+ * @phpstan-type NoteHistory array{image_id:int,note_id:int,review_id:int,user_name:string,note:string,date:string}
+ * @phpstan-type Note array{id:int,x1:int,y1:int,height:int,width:int,note:string}
+ */
 class NotesTheme extends Themelet
 {
     public function note_button(int $image_id): HTMLElement
@@ -52,6 +56,9 @@ class NotesTheme extends Themelet
     }
 
     // check action POST on form
+    /**
+     * @param Note[] $recovered_notes
+     */
     public function display_note_system(Page $page, int $image_id, array $recovered_notes, bool $adminOptions): void
     {
         $to_json = [];
@@ -73,8 +80,10 @@ class NotesTheme extends Themelet
         </script>");
     }
 
-
-    public function display_note_list($images, $pageNumber, $totalPages): void
+    /**
+     * @param array<array{0:Image}> $images
+     */
+    public function display_note_list(array $images, int $pageNumber, int $totalPages): void
     {
         global $page;
         $pool_images = '';
@@ -94,7 +103,10 @@ class NotesTheme extends Themelet
         $page->add_block(new Block("Notes", $pool_images, "main", 20));
     }
 
-    public function display_note_requests($images, $pageNumber, $totalPages): void
+    /**
+     * @param array<array{0:Image}> $images
+     */
+    public function display_note_requests(array $images, int $pageNumber, int $totalPages): void
     {
         global $page;
 
@@ -115,6 +127,9 @@ class NotesTheme extends Themelet
         $page->add_block(new Block("Note Requests", $pool_images, "main", 20));
     }
 
+    /**
+     * @param NoteHistory[] $histories
+     */
     private function get_history(array $histories): string
     {
         global $user;
@@ -157,7 +172,10 @@ class NotesTheme extends Themelet
         return $html;
     }
 
-    public function display_histories($histories, $pageNumber, $totalPages): void
+    /**
+     * @param NoteHistory[] $histories
+     */
+    public function display_histories(array $histories, int $pageNumber, int $totalPages): void
     {
         global $page;
 
@@ -170,7 +188,10 @@ class NotesTheme extends Themelet
         $this->display_paginator($page, "note/updated", null, $pageNumber, $totalPages);
     }
 
-    public function display_history($histories, $pageNumber, $totalPages): void
+    /**
+     * @param NoteHistory[] $histories
+     */
+    public function display_history(array $histories, int $pageNumber, int $totalPages): void
     {
         global $page;
 
diff --git a/ext/numeric_score/main.php b/ext/numeric_score/main.php
index ac125946..cb6939ec 100644
--- a/ext/numeric_score/main.php
+++ b/ext/numeric_score/main.php
@@ -33,8 +33,8 @@ class NumericScoreVote
     public static function score(Image $post): int
     {
         global $database;
-        if ($post->score ?? null) {
-            return $post->score;
+        if ($post['score'] ?? null) {
+            return $post['score'];
         }
         return $database->get_one(
             "SELECT sum(score) FROM numeric_score_votes WHERE image_id=:image_id",
@@ -42,6 +42,9 @@ class NumericScoreVote
         ) ?? 0;
     }
 
+    /**
+     * @return NumericScoreVote[]
+     */
     #[Field(extends: "Post", type: "[NumericScoreVote!]!")]
     public static function votes(Image $post): array
     {
@@ -253,7 +256,7 @@ class NumericScore extends Extension
         $this->delete_votes_by($event->id);
     }
 
-    public function delete_votes_by(int $user_id)
+    public function delete_votes_by(int $user_id): void
     {
         global $database;
 
@@ -405,7 +408,7 @@ class NumericScore extends Extension
         }
     }
 
-    private function add_vote(int $image_id, int $user_id, int $score)
+    private function add_vote(int $image_id, int $user_id, int $score): void
     {
         global $database;
         $database->execute(
diff --git a/ext/numeric_score/theme.php b/ext/numeric_score/theme.php
index 8381a686..318978aa 100644
--- a/ext/numeric_score/theme.php
+++ b/ext/numeric_score/theme.php
@@ -6,7 +6,7 @@ namespace Shimmie2;
 
 class NumericScoreTheme extends Themelet
 {
-    public function get_voter(Image $image)
+    public function get_voter(Image $image): void
     {
         global $user, $page;
         $i_image_id = $image->id;
@@ -55,7 +55,7 @@ class NumericScoreTheme extends Themelet
         $page->add_block(new Block("Post Score", $html, "left", 20));
     }
 
-    public function get_nuller(User $duser)
+    public function get_nuller(User $duser): void
     {
         global $user, $page;
         $html = "
@@ -68,7 +68,11 @@ class NumericScoreTheme extends Themelet
         $page->add_block(new Block("Votes", $html, "main", 80));
     }
 
-    public function view_popular($images, $dte)
+    /**
+     * @param Image[] $images
+     * @param string[] $dte
+     */
+    public function view_popular(array $images, array $dte): void
     {
         global $page, $config;
 
diff --git a/ext/ouroboros_api/main.php b/ext/ouroboros_api/main.php
index 052d07cb..3123e978 100644
--- a/ext/ouroboros_api/main.php
+++ b/ext/ouroboros_api/main.php
@@ -22,6 +22,7 @@ class _SafeOuroborosImage
      * Post Meta
      */
     public ?int $change = null;
+    /** @var array{n:int,s:int,json_class:string} */
     public ?array $created_at = null;
     public ?int $id = null;
     public ?int $parent_id = null;
@@ -103,7 +104,8 @@ class _SafeOuroborosImage
 
 class OuroborosPost extends _SafeOuroborosImage
 {
-    public array $file = [];
+    /** @var array{tmp_name:string,name:string} */
+    public ?array $file = null;
     public bool $is_rating_locked = false;
     public bool $is_note_locked = false;
 
@@ -111,6 +113,8 @@ class OuroborosPost extends _SafeOuroborosImage
      * Initialize an OuroborosPost for creation
      * Mainly just acts as a wrapper and validation layer
      * @noinspection PhpMissingParentConstructorInspection
+     *
+     * @param array<string,mixed> $post
      */
     public function __construct(array $post)
     {
@@ -184,6 +188,9 @@ class _SafeOuroborosTag
     public string $name = '';
     public int $type = 0;
 
+    /**
+     * @param array{id:int,tag:string,count:int} $tag
+     */
     public function __construct(array $tag)
     {
         $this->count = $tag['count'];
@@ -319,7 +326,7 @@ class OuroborosAPI extends Extension
     /**
      * Wrapper for post creation
      */
-    protected function postCreate(OuroborosPost $post, ?string $md5 = '')
+    protected function postCreate(OuroborosPost $post, ?string $md5 = ''): void
     {
         global $config, $database;
         $handler = $config->get_string(ImageConfig::UPLOAD_COLLISION_HANDLER);
@@ -397,7 +404,7 @@ class OuroborosAPI extends Extension
     /**
      * Wrapper for getting a single post
      */
-    protected function postShow(int $id = null)
+    protected function postShow(int $id = null): void
     {
         if (!is_null($id)) {
             $post = new _SafeOuroborosImage(Image::by_id($id));
@@ -411,7 +418,7 @@ class OuroborosAPI extends Extension
      * Wrapper for getting a list of posts
      * @param string[] $tags
      */
-    protected function postIndex(int $limit, int $page, array $tags)
+    protected function postIndex(int $limit, int $page, array $tags): void
     {
         $start = ($page - 1) * $limit;
         $results = Search::find_images(max($start, 0), min($limit, 100), $tags);
@@ -429,7 +436,7 @@ class OuroborosAPI extends Extension
      * Tag
      */
 
-    protected function tagIndex(int $limit, int $page, string $order, int $id, int $after_id, string $name, string $name_pattern)
+    protected function tagIndex(int $limit, int $page, string $order, int $id, int $after_id, string $name, string $name_pattern): void
     {
         global $database, $config;
         $start = ($page - 1) * $limit;
@@ -476,7 +483,7 @@ class OuroborosAPI extends Extension
     /**
      * Sends a simple {success,reason} message to browser
      */
-    private function sendResponse(int $code = 200, string $reason = '', bool $location = false)
+    private function sendResponse(int $code = 200, string $reason = '', bool $location = false): void
     {
         global $page;
         if ($code == 200) {
@@ -529,7 +536,10 @@ class OuroborosAPI extends Extension
         $page->set_data($response);
     }
 
-    private function sendData(string $type = '', array $data = [], int $offset = 0)
+    /**
+     * @param list<_SafeOuroborosTag>|list<_SafeOuroborosImage> $data
+     */
+    private function sendData(string $type = '', array $data = [], int $offset = 0): void
     {
         global $page;
         $response = '';
@@ -539,22 +549,20 @@ class OuroborosAPI extends Extension
             $xml = new \XMLWriter();
             $xml->openMemory();
             $xml->startDocument('1.0', 'utf-8');
-            if (array_key_exists(0, $data)) {
-                $xml->startElement($type . 's');
-                if ($type == 'post') {
-                    $xml->writeAttribute('count', (string)count($data));
-                    $xml->writeAttribute('offset', (string)$offset);
-                }
-                if ($type == 'tag') {
-                    $xml->writeAttribute('type', 'array');
-                }
-                foreach ($data as $item) {
-                    $this->createItemXML($xml, $type, $item);
-                }
-                $xml->endElement();
-            } else {
-                $this->createItemXML($xml, $type, $data);
+
+            $xml->startElement($type . 's');
+            if ($type == 'post') {
+                $xml->writeAttribute('count', (string)count($data));
+                $xml->writeAttribute('offset', (string)$offset);
             }
+            if ($type == 'tag') {
+                $xml->writeAttribute('type', 'array');
+            }
+            foreach ($data as $item) {
+                $this->createItemXML($xml, $type, $item);
+            }
+            $xml->endElement();
+
             $xml->endDocument();
             $response = $xml->outputMemory(true);
             unset($xml);
@@ -562,10 +570,10 @@ class OuroborosAPI extends Extension
         $page->set_data($response);
     }
 
-    private function createItemXML(\XMLWriter $xml, string $type, $item)
+    private function createItemXML(\XMLWriter $xml, string $type, _SafeOuroborosTag|_SafeOuroborosImage $item): void
     {
         $xml->startElement($type);
-        foreach ($item as $key => $val) {
+        foreach (json_decode(json_encode($item)) as $key => $val) {
             if ($key == 'created_at' && $type == 'post') {
                 $xml->writeAttribute($key, $val['s']);
             } else {
@@ -584,7 +592,7 @@ class OuroborosAPI extends Extension
      * Currently checks for either user & session in request or cookies
      * and initializes a global User
      */
-    private function tryAuth()
+    private function tryAuth(): void
     {
         global $config, $user;
 
diff --git a/ext/pm/main.php b/ext/pm/main.php
index aeb19423..4d8bdb4f 100644
--- a/ext/pm/main.php
+++ b/ext/pm/main.php
@@ -70,6 +70,9 @@ class PM
         $this->is_read = $is_read;
     }
 
+    /**
+     * @param array<string, mixed> $row
+     */
     public static function from_row(array $row): PM
     {
         $pm = new PM(
@@ -85,6 +88,9 @@ class PM
         return $pm;
     }
 
+    /**
+     * @return PM[]|null
+     */
     #[Field(extends: "User", name: "private_messages", type: "[PrivateMessage!]")]
     public static function get_pms(User $duser): ?array
     {
@@ -299,7 +305,7 @@ class PrivMsg extends Extension
         log_info("pm", "Sent PM to User #{$event->pm->to_id}");
     }
 
-    private function count_pms(User $user)
+    private function count_pms(User $user): int
     {
         global $database;
 
diff --git a/ext/pm/theme.php b/ext/pm/theme.php
index 26817382..1b9d3924 100644
--- a/ext/pm/theme.php
+++ b/ext/pm/theme.php
@@ -6,7 +6,10 @@ namespace Shimmie2;
 
 class PrivMsgTheme extends Themelet
 {
-    public function display_pms(Page $page, $pms): void
+    /**
+     * @param PM[] $pms
+     */
+    public function display_pms(Page $page, array $pms): void
     {
         global $user;
 
@@ -58,7 +61,7 @@ class PrivMsgTheme extends Themelet
         $page->add_block(new Block("Private Messages", $html, "main", 40, "private-messages"));
     }
 
-    public function display_composer(Page $page, User $from, User $to, $subject = ""): void
+    public function display_composer(Page $page, User $from, User $to, string $subject = ""): void
     {
         global $user;
         $post_url = make_link("pm/send");
diff --git a/ext/pools/main.php b/ext/pools/main.php
index 5308a1fc..22f4b973 100644
--- a/ext/pools/main.php
+++ b/ext/pools/main.php
@@ -26,8 +26,12 @@ class PoolCreationException extends SCoreException
 class PoolAddPostsEvent extends Event
 {
     public int $pool_id;
+    /** @var int[] */
     public array $posts = [];
 
+    /**
+     * @param int[] $posts
+     */
     public function __construct(int $pool_id, array $posts)
     {
         parent::__construct();
@@ -82,6 +86,9 @@ class Pool
     public string $date;
     public int $posts;
 
+    /**
+     * @param array<string,mixed> $row
+     */
     public function __construct(array $row)
     {
         $this->id = (int)$row['id'];
@@ -94,12 +101,15 @@ class Pool
         $this->posts = (int)$row['posts'];
     }
 
+    /**
+     * @param array<string,mixed> $row
+     */
     public static function makePool(array $row): Pool
     {
         return new Pool($row);
     }
 
-    public static function get_pool_id_by_title($poolTitle): ?int
+    public static function get_pool_id_by_title(string $poolTitle): ?int
     {
         global $database;
         $row = $database->get_row("SELECT * FROM pools WHERE title=:title", ["title" => $poolTitle]);
@@ -632,7 +642,7 @@ class Pools extends Extension
         );
     }
 
-    private function list_pools(Page $page, int $pageNumber, $search)
+    private function list_pools(Page $page, int $pageNumber, ?string $search): void
     {
         global $config, $database;
 
@@ -767,46 +777,43 @@ class Pools extends Extension
     /**
      * Gets the previous and next successive images from a pool, given a pool ID and an image ID.
      *
-     * @return int[] Array returning two elements (prev, next) in 1 dimension. Each returns ImageID or NULL if none.
+     * @return array{prev:?int,next:?int} Array returning two elements (prev, next) in 1 dimension. Each returns ImageID or NULL if none.
      */
-    private function get_nav_posts(Pool $pool, int $imageID): ?array
+    private function get_nav_posts(Pool $pool, int $imageID): array
     {
         global $database;
 
-        if (empty($imageID)) {
-            return null;
-        }
-
         return $database->get_row(
             "
-						SELECT (
-							SELECT image_id
-							FROM pool_images
-							WHERE pool_id = :pid
-							AND image_order < (
-								SELECT image_order
-								FROM pool_images
-								WHERE pool_id = :pid
-								AND image_id = :iid
-								LIMIT 1
-							)
-							ORDER BY image_order DESC LIMIT 1
-						) AS prev,
-						(
-							SELECT image_id
-							FROM pool_images
-							WHERE pool_id = :pid
-							AND image_order > (
-								SELECT image_order
-								FROM pool_images
-								WHERE pool_id = :pid
-								AND image_id = :iid
-								LIMIT 1
-							)
-							ORDER BY image_order ASC LIMIT 1
-						) AS next
+                SELECT (
+                    SELECT image_id
+                    FROM pool_images
+                    WHERE pool_id = :pid
+                    AND image_order < (
+                        SELECT image_order
+                        FROM pool_images
+                        WHERE pool_id = :pid
+                        AND image_id = :iid
+                        LIMIT 1
+                    )
+                    ORDER BY image_order DESC LIMIT 1
+                ) AS prev,
+                (
+                    SELECT image_id
+                    FROM pool_images
+                    WHERE pool_id = :pid
+                    AND image_order > (
+                        SELECT image_order
+                        FROM pool_images
+                        WHERE pool_id = :pid
+                        AND image_id = :iid
+                        LIMIT 1
+                    )
+                    ORDER BY image_order ASC LIMIT 1
+                ) AS next
 
-						LIMIT 1",
+                LIMIT 1
+            ",
             ["pid" => $pool->id, "iid" => $imageID]
         );
     }
@@ -814,7 +821,7 @@ class Pools extends Extension
     /**
      * Retrieve all the images in a pool, given a pool ID.
      */
-    private function get_posts(PageRequestEvent $event, int $poolID)
+    private function get_posts(PageRequestEvent $event, int $poolID): void
     {
         global $config, $user, $database;
 
@@ -885,7 +892,7 @@ class Pools extends Extension
      *
      * $action Action=1 (one) MEANS ADDED, Action=0 (zero) MEANS REMOVED
      */
-    private function add_history(int $poolID, int $action, string $images, int $count)
+    private function add_history(int $poolID, int $action, string $images, int $count): void
     {
         global $user, $database;
 
@@ -897,7 +904,7 @@ class Pools extends Extension
         );
     }
 
-    private function get_history(int $pageNumber)
+    private function get_history(int $pageNumber): void
     {
         global $config, $database;
 
@@ -923,7 +930,7 @@ class Pools extends Extension
     /**
      * HERE GO BACK IN HISTORY AND ADD OR REMOVE POSTS TO POOL.
      */
-    private function revert_history(int $historyID)
+    private function revert_history(int $historyID): void
     {
         global $database;
         $status = $database->get_all("SELECT * FROM pool_history WHERE id=:hid", ["hid" => $historyID]);
@@ -1009,7 +1016,7 @@ class Pools extends Extension
         return true;
     }
 
-    private function update_count(int $pool_id)
+    private function update_count(int $pool_id): void
     {
         global $database;
         $database->execute(
diff --git a/ext/pools/test.php b/ext/pools/test.php
index b368a6ac..c4c878a8 100644
--- a/ext/pools/test.php
+++ b/ext/pools/test.php
@@ -31,6 +31,9 @@ class PoolsTest extends ShimmiePHPUnitTestCase
         $this->assert_title("Error");
     }
 
+    /**
+     * @return array{0: int, 1: array{0: int, 1: int}}
+     */
     public function testCreate(): array
     {
         $this->log_in_as_user();
@@ -53,7 +56,7 @@ class PoolsTest extends ShimmiePHPUnitTestCase
     }
 
     #[Depends('testCreate')]
-    public function testOnViewImage($args): void
+    public function testOnViewImage(): void
     {
         [$pool_id, $image_ids] = $this->testCreate();
 
@@ -67,7 +70,7 @@ class PoolsTest extends ShimmiePHPUnitTestCase
     }
 
     #[Depends('testCreate')]
-    public function testSearch($args): void
+    public function testSearch(): void
     {
         [$pool_id, $image_ids] = $this->testCreate();
 
@@ -79,7 +82,7 @@ class PoolsTest extends ShimmiePHPUnitTestCase
     }
 
     #[Depends('testCreate')]
-    public function testList($args): void
+    public function testList(): void
     {
         $this->testCreate();
         $this->get_page("pool/list");
@@ -87,7 +90,7 @@ class PoolsTest extends ShimmiePHPUnitTestCase
     }
 
     #[Depends('testCreate')]
-    public function testView($args): void
+    public function testView(): void
     {
         [$pool_id, $image_ids] = $this->testCreate();
 
@@ -96,7 +99,7 @@ class PoolsTest extends ShimmiePHPUnitTestCase
     }
 
     #[Depends('testCreate')]
-    public function testHistory($args): void
+    public function testHistory(): void
     {
         [$pool_id, $image_ids] = $this->testCreate();
 
@@ -105,7 +108,7 @@ class PoolsTest extends ShimmiePHPUnitTestCase
     }
 
     #[Depends('testCreate')]
-    public function testImport($args): void
+    public function testImport(): void
     {
         [$pool_id, $image_ids] = $this->testCreate();
 
@@ -116,8 +119,11 @@ class PoolsTest extends ShimmiePHPUnitTestCase
         $this->assert_text("Pool");
     }
 
+    /**
+     * @return array{0: int, 1: array{0: int, 1:int}}
+     */
     #[Depends('testCreate')]
-    public function testRemovePosts($args): array
+    public function testRemovePosts(): array
     {
         [$pool_id, $image_ids] = $this->testCreate();
 
@@ -131,9 +137,9 @@ class PoolsTest extends ShimmiePHPUnitTestCase
     }
 
     #[Depends('testRemovePosts')]
-    public function testAddPosts($args): void
+    public function testAddPosts(): void
     {
-        [$pool_id, $image_ids] = $this->testRemovePosts(null);
+        [$pool_id, $image_ids] = $this->testRemovePosts();
 
         $page = $this->post_page("pool/add_posts", [
             "pool_id" => $pool_id,
@@ -142,8 +148,11 @@ class PoolsTest extends ShimmiePHPUnitTestCase
         $this->assertEquals(PageMode::REDIRECT, $page->mode);
     }
 
+    /**
+     * @return array{0: int, 1: array{0: int, 1:int}}
+     */
     #[Depends('testCreate')]
-    public function testEditDescription($args): array
+    public function testEditDescription(): array
     {
         [$pool_id, $image_ids] = $this->testCreate();
 
diff --git a/ext/pools/theme.php b/ext/pools/theme.php
index a007846c..448f067b 100644
--- a/ext/pools/theme.php
+++ b/ext/pools/theme.php
@@ -10,13 +10,18 @@ use function MicroHTML\emptyHTML;
 use function MicroHTML\rawHTML;
 use function MicroHTML\{A,BR,DIV,INPUT,P,SCRIPT,SPAN,TABLE,TBODY,TD,TEXTAREA,TH,THEAD,TR};
 
+/**
+ * @phpstan-type PoolHistory array{id:int,pool_id:int,title:string,user_name:string,action:string,images:string,count:int,date:string}
+ */
 class PoolsTheme extends Themelet
 {
     /**
      * Adds a block to the panel with information on the pool(s) the image is in.
      * $navIDs = Multidimensional array containing pool id, info & nav IDs.
+     *
+     * @param array<int,array{nav:array{prev:?int,next:?int},info:Pool}> $navIDs
      */
-    public function pool_info(array $navIDs)
+    public function pool_info(array $navIDs): void
     {
         global $page;
 
@@ -25,13 +30,11 @@ class PoolsTheme extends Themelet
         foreach ($navIDs as $poolID => $poolInfo) {
             $div = DIV(SHM_A("pool/view/" . $poolID, $poolInfo["info"]->title));
 
-            if (!empty($poolInfo["nav"])) {
-                if (!empty($poolInfo["nav"]["prev"])) {
-                    $div->appendChild(SHM_A("post/view/" . $poolInfo["nav"]["prev"], "Prev", class: "pools_prev_img"));
-                }
-                if (!empty($poolInfo["nav"]["next"])) {
-                    $div->appendChild(SHM_A("post/view/" . $poolInfo["nav"]["next"], "Next", class: "pools_next_img"));
-                }
+            if (!empty($poolInfo["nav"]["prev"])) {
+                $div->appendChild(SHM_A("post/view/" . $poolInfo["nav"]["prev"], "Prev", class: "pools_prev_img"));
+            }
+            if (!empty($poolInfo["nav"]["next"])) {
+                $div->appendChild(SHM_A("post/view/" . $poolInfo["nav"]["next"], "Next", class: "pools_next_img"));
             }
 
             $linksPools->appendChild($div);
@@ -42,6 +45,9 @@ class PoolsTheme extends Themelet
         }
     }
 
+    /**
+     * @param array<int, string> $pools
+     */
     public function get_adder_html(Image $image, array $pools): HTMLElement
     {
         return SHM_SIMPLE_FORM(
@@ -54,8 +60,10 @@ class PoolsTheme extends Themelet
 
     /**
      * HERE WE SHOWS THE LIST OF POOLS.
+     *
+     * @param Pool[] $pools
      */
-    public function list_pools(Page $page, array $pools, string $search, int $pageNumber, int $totalPages)
+    public function list_pools(Page $page, array $pools, string $search, int $pageNumber, int $totalPages): void
     {
         // Build up the list of pools.
         $pool_rows = [];
@@ -95,7 +103,7 @@ class PoolsTheme extends Themelet
     /*
      * HERE WE DISPLAY THE NEW POOL COMPOSER
      */
-    public function new_pool_composer(Page $page)
+    public function new_pool_composer(Page $page): void
     {
         $form = SHM_SIMPLE_FORM("pool/create", TABLE(
             TR(TD("Title:"), TD(INPUT(["type" => "text", "name" => "title"]))),
@@ -108,7 +116,7 @@ class PoolsTheme extends Themelet
         $page->add_block(new Block("Create Pool", $form, position: 20));
     }
 
-    private function display_top(?Pool $pool, string $heading, bool $check_all = false)
+    private function display_top(?Pool $pool, string $heading, bool $check_all = false): void
     {
         global $page, $user;
 
@@ -146,8 +154,10 @@ class PoolsTheme extends Themelet
 
     /**
      * HERE WE DISPLAY THE POOL WITH TITLE DESCRIPTION AND IMAGES WITH PAGINATION.
+     *
+     * @param Image[] $images
      */
-    public function view_pool(Pool $pool, array $images, int $pageNumber, int $totalPages)
+    public function view_pool(Pool $pool, array $images, int $pageNumber, int $totalPages): void
     {
         global $page;
 
@@ -166,7 +176,7 @@ class PoolsTheme extends Themelet
     /**
      * HERE WE DISPLAY THE POOL OPTIONS ON SIDEBAR BUT WE HIDE REMOVE OPTION IF THE USER IS NOT THE OWNER OR ADMIN.
      */
-    public function sidebar_options(Page $page, Pool $pool, bool $check_all)
+    public function sidebar_options(Page $page, Pool $pool, bool $check_all): void
     {
         global $user;
 
@@ -246,8 +256,10 @@ class PoolsTheme extends Themelet
 
     /**
      * HERE WE DISPLAY THE RESULT OF THE SEARCH ON IMPORT.
+     *
+     * @param Image[] $images
      */
-    public function pool_result(Page $page, array $images, Pool $pool)
+    public function pool_result(Page $page, array $images, Pool $pool): void
     {
         $this->display_top($pool, "Importing Posts", true);
 
@@ -283,8 +295,10 @@ class PoolsTheme extends Themelet
     /**
      * HERE WE DISPLAY THE POOL ORDERER.
      * WE LIST ALL IMAGES ON POOL WITHOUT PAGINATION AND WITH A TEXT INPUT TO SET A NUMBER AND CHANGE THE ORDER
+     *
+     * @param Image[] $images
      */
-    public function edit_order(Page $page, Pool $pool, array $images)
+    public function edit_order(Page $page, Pool $pool, array $images): void
     {
         $this->display_top($pool, "Sorting Pool");
 
@@ -293,7 +307,7 @@ class PoolsTheme extends Themelet
             $form->appendChild(SPAN(
                 ["class" => "thumb"],
                 $this->build_thumb_html($image),
-                INPUT(["type" => "number", "name" => "imgs[$i][]", "value" => $image->image_order, "style" => "max-width: 50px;"]),
+                INPUT(["type" => "number", "name" => "imgs[$i][]", "value" => $image['image_order'], "style" => "max-width: 50px;"]),
                 INPUT(["type" => "hidden", "name" => "imgs[$i][]", "value" => $image->id])
             ));
         }
@@ -311,8 +325,10 @@ class PoolsTheme extends Themelet
      *
      * WE LIST ALL IMAGES ON POOL WITHOUT PAGINATION AND WITH
      * A CHECKBOX TO SELECT WHICH IMAGE WE WANT TO REMOVE
+     *
+     * @param Image[] $images
      */
-    public function edit_pool(Page $page, Pool $pool, array $images)
+    public function edit_pool(Page $page, Pool $pool, array $images): void
     {
         $_input_id = INPUT(["type" => "hidden", "name" => "pool_id", "value" => $pool->id]);
 
@@ -347,8 +363,10 @@ class PoolsTheme extends Themelet
 
     /**
      * HERE WE DISPLAY THE HISTORY LIST.
+     *
+     * @param PoolHistory[] $histories
      */
-    public function show_history(array $histories, int $pageNumber, int $totalPages)
+    public function show_history(array $histories, int $pageNumber, int $totalPages): void
     {
         global $page;
 
@@ -397,11 +415,17 @@ class PoolsTheme extends Themelet
         $this->display_paginator($page, "pool/updated", null, $pageNumber, $totalPages);
     }
 
+    /**
+     * @param array<int,string> $options
+     */
     public function get_bulk_pool_selector(array $options): HTMLElement
     {
         return SHM_SELECT("bulk_pool_select", $options, required: true, empty_option: true);
     }
 
+    /**
+     * @param string[] $search_terms
+     */
     public function get_bulk_pool_input(array $search_terms): HTMLElement
     {
         return INPUT(
@@ -410,7 +434,7 @@ class PoolsTheme extends Themelet
                 "name" => "bulk_pool_new",
                 "placeholder" => "New Pool",
                 "required" => "",
-                "value" => implode(" ", $search_terms)
+                "value" => Tag::implode($search_terms)
             ]
         );
     }
diff --git a/ext/post_peek/info.php b/ext/post_peek/info.php
index fa08270f..285b73a3 100644
--- a/ext/post_peek/info.php
+++ b/ext/post_peek/info.php
@@ -11,7 +11,7 @@ class PostPeekInfo extends ExtensionInfo
     public string $key = self::KEY;
     public string $name = "Post Peek";
     public string $url = self::SHIMMIE_URL;
-    public array $authors = ["Matthew Barbour"];
+    public array $authors = ["Matthew Barbour" => "matthew@darkholme.net"];
     public string $license = self::LICENSE_WTFPL;
     public string $description = "Peek at posts";
 }
diff --git a/ext/post_titles/main.php b/ext/post_titles/main.php
index 7f3050bd..d8a66fc3 100644
--- a/ext/post_titles/main.php
+++ b/ext/post_titles/main.php
@@ -88,7 +88,7 @@ class PostTitles extends Extension
         }
     }
 
-    private function set_title(int $image_id, string $title)
+    private function set_title(int $image_id, string $title): void
     {
         global $database;
         $database->execute("UPDATE images SET title=:title WHERE id=:id", ['title' => $title, 'id' => $image_id]);
diff --git a/ext/private_image/main.php b/ext/private_image/main.php
index 24024a6c..81d01836 100644
--- a/ext/private_image/main.php
+++ b/ext/private_image/main.php
@@ -190,7 +190,9 @@ class PrivateImage extends Extension
         }
     }
 
-
+    /**
+     * @param string[] $context
+     */
     private function no_private_query(array $context): bool
     {
         foreach ($context as $term) {
@@ -201,7 +203,7 @@ class PrivateImage extends Extension
         return true;
     }
 
-    public static function privatize_image($image_id)
+    public static function privatize_image(int $image_id): void
     {
         global $database;
 
@@ -211,7 +213,7 @@ class PrivateImage extends Extension
         );
     }
 
-    public static function publicize_image($image_id)
+    public static function publicize_image(int $image_id): void
     {
         global $database;
 
diff --git a/ext/qr_code/theme.php b/ext/qr_code/theme.php
index 857eb89d..4579880c 100644
--- a/ext/qr_code/theme.php
+++ b/ext/qr_code/theme.php
@@ -6,7 +6,7 @@ namespace Shimmie2;
 
 class QRImageTheme extends Themelet
 {
-    public function links_block(string $link)
+    public function links_block(string $link): void
     {
         global $page;
 
diff --git a/ext/random_list/theme.php b/ext/random_list/theme.php
index be0aef7c..bec7a133 100644
--- a/ext/random_list/theme.php
+++ b/ext/random_list/theme.php
@@ -6,12 +6,13 @@ namespace Shimmie2;
 
 class RandomListTheme extends Themelet
 {
+    /** @var string[] */
     protected array $search_terms;
 
     /**
      * @param string[] $search_terms
      */
-    public function set_page(array $search_terms)
+    public function set_page(array $search_terms): void
     {
         $this->search_terms = $search_terms;
     }
@@ -42,6 +43,9 @@ class RandomListTheme extends Themelet
         $page->add_block(new Block("Navigation", $nav, "left", 0));
     }
 
+    /**
+     * @param string[] $search_terms
+     */
     protected function build_navigation(array $search_terms): string
     {
         $h_search_string = html_escape(Tag::implode($search_terms));
diff --git a/ext/rating/main.php b/ext/rating/main.php
index 59fa4393..31b35994 100644
--- a/ext/rating/main.php
+++ b/ext/rating/main.php
@@ -410,6 +410,9 @@ class Ratings extends Extension
         }
     }
 
+    /**
+     * @return ImageRating[]
+     */
     public static function get_sorted_ratings(): array
     {
         global $_shm_ratings;
@@ -421,6 +424,10 @@ class Ratings extends Extension
         return $ratings;
     }
 
+    /**
+     * @param ImageRating[]|null $ratings
+     * @return array<string, string>
+     */
     public static function get_ratings_dict(array $ratings = null): array
     {
         if (!isset($ratings)) {
@@ -464,6 +471,9 @@ class Ratings extends Extension
         return array_intersect($available, $selected);
     }
 
+    /**
+     * @param string[] $privs
+     */
     public static function privs_to_sql(array $privs): string
     {
         $arr = [];
@@ -566,7 +576,7 @@ class Ratings extends Extension
         }
     }
 
-    private function set_rating(int $image_id, string $rating, string $old_rating)
+    private function set_rating(int $image_id, string $rating, string $old_rating): void
     {
         global $database;
         if ($old_rating != $rating) {
diff --git a/ext/rating/theme.php b/ext/rating/theme.php
index 51c3c466..a2b2c5ca 100644
--- a/ext/rating/theme.php
+++ b/ext/rating/theme.php
@@ -11,6 +11,10 @@ use function MicroHTML\{A,P,TABLE,TD,TH,TR};
 
 class RatingsTheme extends Themelet
 {
+    /**
+     * @param array<string, ImageRating> $ratings
+     * @param string[] $selected_options
+     */
     public function get_selection_rater_html(string $name = "rating", array $ratings = [], array $selected_options = []): HTMLElement
     {
         return SHM_SELECT($name, !empty($ratings) ? $ratings : Ratings::get_ratings_dict(), required: true, selected_options: $selected_options);
@@ -25,6 +29,9 @@ class RatingsTheme extends Themelet
         );
     }
 
+    /**
+     * @param ImageRating[] $current_ratings
+     */
     public function display_form(array $current_ratings): void
     {
         global $page;
@@ -39,6 +46,9 @@ class RatingsTheme extends Themelet
         $page->add_block(new Block("Update Ratings", SHM_SIMPLE_FORM("admin/update_ratings", $table)));
     }
 
+    /**
+     * @param ImageRating[] $ratings
+     */
     public function get_help_html(array $ratings): HTMLElement
     {
         $rating_rows = [TR(TH("Name"), TH("Search Term"), TH("Abbreviation"))];
diff --git a/ext/relationships/main.php b/ext/relationships/main.php
index b763210e..fd12a064 100644
--- a/ext/relationships/main.php
+++ b/ext/relationships/main.php
@@ -169,6 +169,9 @@ class Relationships extends Extension
         }
     }
 
+    /**
+     * @return Image[]
+     */
     public static function get_children(Image $image, int $omit = null): array
     {
         global $database;
@@ -183,7 +186,7 @@ class Relationships extends Extension
         return $output;
     }
 
-    private function remove_parent(int $imageID)
+    private function remove_parent(int $imageID): void
     {
         global $database;
         $parentID = $database->get_one("SELECT parent_id FROM images WHERE id = :iid", ["iid" => $imageID]);
@@ -194,7 +197,7 @@ class Relationships extends Extension
         }
     }
 
-    private function set_has_children(int $parent_id)
+    private function set_has_children(int $parent_id): void
     {
         global $database;
 
diff --git a/ext/relationships/test.php b/ext/relationships/test.php
index 068b9bc6..e9c1bae0 100644
--- a/ext/relationships/test.php
+++ b/ext/relationships/test.php
@@ -12,6 +12,9 @@ class RelationshipsTest extends ShimmiePHPUnitTestCase
     // Set by box
     //=================================================================
 
+    /**
+     * @return array{0: Image, 1: Image, 2: Image}
+     */
     public function testNoParent(): array
     {
         $this->log_in_as_user();
@@ -34,8 +37,11 @@ class RelationshipsTest extends ShimmiePHPUnitTestCase
         return [$image_1, $image_2, $image_3];
     }
 
+    /**
+     * @return array{0:Image, 1:Image, 2:Image}
+     */
     #[Depends('testNoParent')]
-    public function testSetParent($imgs): array
+    public function testSetParent(): array
     {
         [$image_1, $image_2, $image_3] = $this->testNoParent();
 
@@ -56,10 +62,13 @@ class RelationshipsTest extends ShimmiePHPUnitTestCase
         return [$image_1, $image_2, $image_3];
     }
 
+    /**
+     * @return array{0:Image, 1:Image, 2:Image}
+     */
     #[Depends('testSetParent')]
-    public function testChangeParent($imgs): array
+    public function testChangeParent(): array
     {
-        [$image_1, $image_2, $image_3] = $this->testSetParent(null);
+        [$image_1, $image_2, $image_3] = $this->testSetParent();
         send_event(new ImageRelationshipSetEvent($image_2->id, $image_3->id));
 
         // refresh data from database
@@ -78,9 +87,9 @@ class RelationshipsTest extends ShimmiePHPUnitTestCase
     }
 
     #[Depends('testSetParent')]
-    public function testSearch($imgs): void
+    public function testSearch(): void
     {
-        [$image_1, $image_2, $image_3] = $this->testSetParent(null);
+        [$image_1, $image_2, $image_3] = $this->testSetParent();
 
         $this->assert_search_results(["parent:any"], [$image_2->id]);
         $this->assert_search_results(["parent:none"], [$image_3->id, $image_1->id]);
@@ -91,9 +100,9 @@ class RelationshipsTest extends ShimmiePHPUnitTestCase
     }
 
     #[Depends('testChangeParent')]
-    public function testRemoveParent($imgs): void
+    public function testRemoveParent(): void
     {
-        [$image_1, $image_2, $image_3] = $this->testChangeParent(null);
+        [$image_1, $image_2, $image_3] = $this->testChangeParent();
 
         global $database;
         $database->execute(
@@ -119,6 +128,9 @@ class RelationshipsTest extends ShimmiePHPUnitTestCase
     // Set by tag
     //=================================================================
 
+    /**
+     * @return array{0:Image, 1:Image, 2:Image}
+     */
     public function testSetParentByTagBase(): array
     {
         $this->log_in_as_user();
@@ -140,8 +152,11 @@ class RelationshipsTest extends ShimmiePHPUnitTestCase
         return [$image_1, $image_2, $image_3];
     }
 
+    /**
+     * @return array{0:Image, 1:Image, 2:Image}
+     */
     #[Depends('testSetParentByTagBase')]
-    public function testSetParentByTag($imgs): array
+    public function testSetParentByTag(): array
     {
         [$image_1, $image_2, $image_3] = $this->testSetParentByTagBase();
 
@@ -163,10 +178,13 @@ class RelationshipsTest extends ShimmiePHPUnitTestCase
         return [$image_1, $image_2, $image_3];
     }
 
+    /**
+     * @return array{0:Image, 1:Image, 2:Image}
+     */
     #[Depends('testSetParentByTag')]
-    public function testSetChildByTag($imgs): array
+    public function testSetChildByTag(): array
     {
-        [$image_1, $image_2, $image_3] = $this->testSetParentByTag(null);
+        [$image_1, $image_2, $image_3] = $this->testSetParentByTag();
 
         send_event(new TagSetEvent($image_3, ["pbx", "child:{$image_1->id}"]));
 
@@ -187,10 +205,9 @@ class RelationshipsTest extends ShimmiePHPUnitTestCase
     }
 
     #[Depends('testSetChildByTag')]
-    public function testRemoveParentByTag($imgs): void
+    public function testRemoveParentByTag(): void
     {
-        [$image_1, $image_2, $image_3] = $this->testSetChildByTag(null);
-        assert(!is_null($image_3));
+        [$image_1, $image_2, $image_3] = $this->testSetChildByTag();
 
         // check parent is set
         $this->assertEquals($image_2['parent_id'], $image_1->id);
diff --git a/ext/relationships/theme.php b/ext/relationships/theme.php
index 43bf59e9..d2a61a1b 100644
--- a/ext/relationships/theme.php
+++ b/ext/relationships/theme.php
@@ -10,7 +10,7 @@ use function MicroHTML\{TR, TH, TD, emptyHTML, DIV, INPUT};
 
 class RelationshipsTheme extends Themelet
 {
-    public function relationship_info(Image $image)
+    public function relationship_info(Image $image): void
     {
         global $page, $database;
 
diff --git a/ext/report_image/main.php b/ext/report_image/main.php
index a29e593d..e4fc501a 100644
--- a/ext/report_image/main.php
+++ b/ext/report_image/main.php
@@ -167,7 +167,7 @@ class ReportImage extends Extension
         $sb->add_choice_option("report_image_publicity", $opts, "Show publicly: ");
     }
 
-    public function delete_reports_by(int $user_id)
+    public function delete_reports_by(int $user_id): void
     {
         global $cache, $database;
         $database->execute("DELETE FROM image_reports WHERE reporter_id=:reporter_id", ['reporter_id' => $user_id]);
@@ -210,6 +210,9 @@ class ReportImage extends Extension
         return $reps;
     }
 
+    /**
+     * @return array<array<string, mixed>>
+     */
     public function get_reported_images(): array
     {
         global $database;
diff --git a/ext/report_image/theme.php b/ext/report_image/theme.php
index b8b17372..f82da1dd 100644
--- a/ext/report_image/theme.php
+++ b/ext/report_image/theme.php
@@ -8,6 +8,9 @@ use function MicroHTML\INPUT;
 
 class ReportImageTheme extends Themelet
 {
+    /**
+     * @param array<array{id: int, image: Image, reason: string, reporter_name: string}> $reports
+     */
     public function display_reported_images(Page $page, array $reports): void
     {
         global $config, $user;
@@ -91,7 +94,7 @@ class ReportImageTheme extends Themelet
         $page->add_block(new Block("Report Post", $html, "left"));
     }
 
-    public function get_nuller(User $duser)
+    public function get_nuller(User $duser): void
     {
         global $page;
         $html = (string)SHM_SIMPLE_FORM(
diff --git a/ext/resize/main.php b/ext/resize/main.php
index 92c279f8..e10befee 100644
--- a/ext/resize/main.php
+++ b/ext/resize/main.php
@@ -211,7 +211,7 @@ class ResizeImage extends Extension
         }
     }
 
-    private function can_resize_mime($mime): bool
+    private function can_resize_mime(string $mime): bool
     {
         global $config;
         $engine = $config->get_string(ResizeConfig::ENGINE);
@@ -222,7 +222,7 @@ class ResizeImage extends Extension
 
     // Private functions
     /* ----------------------------- */
-    private function resize_image(Image $image_obj, int $width, int $height)
+    private function resize_image(Image $image_obj, int $width, int $height): void
     {
         global $config;
 
diff --git a/ext/reverse_search_links/main.php b/ext/reverse_search_links/main.php
index 7a58ffa9..92fcfe8d 100644
--- a/ext/reverse_search_links/main.php
+++ b/ext/reverse_search_links/main.php
@@ -31,6 +31,8 @@ class ReverseSearchLinks extends Extension
 
     /**
      * Supported reverse search services
+     *
+     * @var string[]
      */
     protected array $SERVICES = [
         'SauceNAO',
diff --git a/ext/reverse_search_links/theme.php b/ext/reverse_search_links/theme.php
index ffe79d46..dfff6ea7 100644
--- a/ext/reverse_search_links/theme.php
+++ b/ext/reverse_search_links/theme.php
@@ -6,7 +6,7 @@ namespace Shimmie2;
 
 class ReverseSearchLinksTheme extends Themelet
 {
-    public function reverse_search_block(Page $page, Image $image)
+    public function reverse_search_block(Page $page, Image $image): void
     {
         global $config;
 
diff --git a/ext/rotate/main.php b/ext/rotate/main.php
index 1a0c1e01..6da5a429 100644
--- a/ext/rotate/main.php
+++ b/ext/rotate/main.php
@@ -96,7 +96,7 @@ class RotateImage extends Extension
 
     // Private functions
     /* ----------------------------- */
-    private function rotate_image(int $image_id, int $deg)
+    private function rotate_image(int $image_id, int $deg): void
     {
         if (($deg <= -360) || ($deg >= 360)) {
             throw new ImageRotateException("Invalid options for rotation angle. ($deg)");
diff --git a/ext/rss_images/main.php b/ext/rss_images/main.php
index 634b589d..aae332d3 100644
--- a/ext/rss_images/main.php
+++ b/ext/rss_images/main.php
@@ -47,7 +47,11 @@ class RSSImages extends Extension
         $cache->delete("rss-item-image:{$event->image->id}");
     }
 
-    private function do_rss(array $images, array $search_terms, int $page_number)
+    /**
+     * @param Image[] $images
+     * @param string[] $search_terms
+     */
+    private function do_rss(array $images, array $search_terms, int $page_number): void
     {
         global $page;
         global $config;
diff --git a/ext/s3/main.php b/ext/s3/main.php
index b2e385f6..c20c9243 100644
--- a/ext/s3/main.php
+++ b/ext/s3/main.php
@@ -179,7 +179,7 @@ class S3 extends Extension
     }
 
     // utils
-    private function get_client()
+    private function get_client(): ?\Aws\S3\S3Client
     {
         global $config;
         $access_key_id = $config->get_string(S3Config::ACCESS_KEY_ID);
@@ -197,7 +197,7 @@ class S3 extends Extension
         ]);
     }
 
-    private function hash_to_path(string $hash)
+    private function hash_to_path(string $hash): string
     {
         $ha = substr($hash, 0, 2);
         $sh = substr($hash, 2, 2);
@@ -215,6 +215,9 @@ class S3 extends Extension
     }
 
     // underlying s3 interaction functions
+    /**
+     * @param string[]|null $new_tags
+     */
     private function sync_post(Image $image, ?array $new_tags = null, bool $overwrite = true): bool
     {
         global $config;
@@ -254,7 +257,7 @@ class S3 extends Extension
         return true;
     }
 
-    private function remove_file(string $hash)
+    private function remove_file(string $hash): void
     {
         global $config;
         $client = $this->get_client();
@@ -272,7 +275,7 @@ class S3 extends Extension
         }
     }
 
-    private function enqueue(string $hash, string $action)
+    private function enqueue(string $hash, string $action): void
     {
         global $database;
         $database->execute("DELETE FROM s3_sync_queue WHERE hash = :hash", ["hash" => $hash]);
@@ -282,7 +285,7 @@ class S3 extends Extension
         ", ["hash" => $hash, "action" => $action]);
     }
 
-    private function dequeue(string $hash)
+    private function dequeue(string $hash): void
     {
         global $database;
         $database->execute("DELETE FROM s3_sync_queue WHERE hash = :hash", ["hash" => $hash]);
diff --git a/ext/setup/main.php b/ext/setup/main.php
index 63a182b8..54ae1560 100644
--- a/ext/setup/main.php
+++ b/ext/setup/main.php
@@ -71,36 +71,36 @@ class SetupBlock extends Block
         $this->config = $config;
     }
 
-    public function add_label(string $text)
+    public function add_label(string $text): void
     {
         $this->body .= $text;
     }
 
-    public function start_table()
+    public function start_table(): void
     {
         $this->body .= "<table class='form'>";
     }
-    public function end_table()
+    public function end_table(): void
     {
         $this->body .= "</table>";
     }
-    public function start_table_row()
+    public function start_table_row(): void
     {
         $this->body .= "<tr>";
     }
-    public function end_table_row()
+    public function end_table_row(): void
     {
         $this->body .= "</tr>";
     }
-    public function start_table_head()
+    public function start_table_head(): void
     {
         $this->body .= "<thead>";
     }
-    public function end_table_head()
+    public function end_table_head(): void
     {
         $this->body .= "</thead>";
     }
-    public function add_table_header($content, int $colspan = 2)
+    public function add_table_header(string $content, int $colspan = 2): void
     {
         $this->start_table_head();
         $this->start_table_row();
@@ -109,29 +109,29 @@ class SetupBlock extends Block
         $this->end_table_head();
     }
 
-    public function start_table_cell(int $colspan = 1)
+    public function start_table_cell(int $colspan = 1): void
     {
         $this->body .= "<td colspan='$colspan'>";
     }
-    public function end_table_cell()
+    public function end_table_cell(): void
     {
         $this->body .= "</td>";
     }
-    public function add_table_cell($content, int $colspan = 1)
+    public function add_table_cell(string $content, int $colspan = 1): void
     {
         $this->start_table_cell($colspan);
         $this->body .= $content;
         $this->end_table_cell();
     }
-    public function start_table_header_cell(int $colspan = 1, string $align = 'right')
+    public function start_table_header_cell(int $colspan = 1, string $align = 'right'): void
     {
         $this->body .= "<th colspan='$colspan' style='text-align: $align'>";
     }
-    public function end_table_header_cell()
+    public function end_table_header_cell(): void
     {
         $this->body .= "</th>";
     }
-    public function add_table_header_cell($content, int $colspan = 1)
+    public function add_table_header_cell(string $content, int $colspan = 1): void
     {
         $this->start_table_header_cell($colspan);
         $this->body .= $content;
@@ -140,11 +140,11 @@ class SetupBlock extends Block
 
     private function format_option(
         string $name,
-        $html,
+        string $html,
         ?string $label,
         bool $table_row,
         bool $label_row = false
-    ) {
+    ): void {
         if ($table_row) {
             $this->start_table_row();
         }
@@ -176,7 +176,7 @@ class SetupBlock extends Block
         }
     }
 
-    public function add_text_option(string $name, string $label = null, bool $table_row = false)
+    public function add_text_option(string $name, string $label = null, bool $table_row = false): void
     {
         $val = html_escape($this->config->get_string($name));
 
@@ -186,7 +186,7 @@ class SetupBlock extends Block
         $this->format_option($name, $html, $label, $table_row);
     }
 
-    public function add_longtext_option(string $name, string $label = null, bool $table_row = false)
+    public function add_longtext_option(string $name, string $label = null, bool $table_row = false): void
     {
         $val = html_escape($this->config->get_string($name));
 
@@ -197,7 +197,7 @@ class SetupBlock extends Block
         $this->format_option($name, $html, $label, $table_row, true);
     }
 
-    public function add_bool_option(string $name, string $label = null, bool $table_row = false)
+    public function add_bool_option(string $name, string $label = null, bool $table_row = false): void
     {
         $checked = $this->config->get_bool($name) ? " checked" : "";
 
@@ -222,7 +222,7 @@ class SetupBlock extends Block
     //		$this->body .= "<input type='hidden' id='$name' name='$name' value='$val'>";
     //	}
 
-    public function add_int_option(string $name, string $label = null, bool $table_row = false)
+    public function add_int_option(string $name, string $label = null, bool $table_row = false): void
     {
         $val = $this->config->get_int($name);
 
@@ -232,7 +232,7 @@ class SetupBlock extends Block
         $this->format_option($name, $html, $label, $table_row);
     }
 
-    public function add_shorthand_int_option(string $name, string $label = null, bool $table_row = false)
+    public function add_shorthand_int_option(string $name, string $label = null, bool $table_row = false): void
     {
         $val = to_shorthand_int($this->config->get_int($name));
         $html = "<input type='text' id='$name' name='_config_$name' value='$val' size='6'>\n";
@@ -241,7 +241,10 @@ class SetupBlock extends Block
         $this->format_option($name, $html, $label, $table_row);
     }
 
-    public function add_choice_option(string $name, array $options, string $label = null, bool $table_row = false)
+    /**
+     * @param array<string,string|int> $options
+     */
+    public function add_choice_option(string $name, array $options, string $label = null, bool $table_row = false): void
     {
         if (is_int(array_values($options)[0])) {
             $current = $this->config->get_int($name);
@@ -264,7 +267,10 @@ class SetupBlock extends Block
         $this->format_option($name, $html, $label, $table_row);
     }
 
-    public function add_multichoice_option(string $name, array $options, string $label = null, bool $table_row = false)
+    /**
+     * @param array<string,string> $options
+     */
+    public function add_multichoice_option(string $name, array $options, string $label = null, bool $table_row = false): void
     {
         $current = $this->config->get_array($name);
 
@@ -279,12 +285,11 @@ class SetupBlock extends Block
         }
         $html .= "</select>";
         $html .= "<input type='hidden' name='_type_$name' value='array'>\n";
-        $html .= "<!--<br><br><br><br>-->\n"; // setup page auto-layout counts <br> tags
 
         $this->format_option($name, $html, $label, $table_row);
     }
 
-    public function add_color_option(string $name, string $label = null, bool $table_row = false)
+    public function add_color_option(string $name, string $label = null, bool $table_row = false): void
     {
         $val = html_escape($this->config->get_string($name));
 
diff --git a/ext/setup/theme.php b/ext/setup/theme.php
index feee9949..d2a5be1d 100644
--- a/ext/setup/theme.php
+++ b/ext/setup/theme.php
@@ -43,7 +43,10 @@ class SetupTheme extends Themelet
         $page->add_block(new Block("Setup", $table));
     }
 
-    public function display_advanced(Page $page, $options): void
+    /**
+     * @param array<string, mixed> $options
+     */
+    public function display_advanced(Page $page, array $options): void
     {
         $h_rows = "";
         ksort($options);
diff --git a/ext/sitemap/main.php b/ext/sitemap/main.php
index ec035b70..766130d7 100644
--- a/ext/sitemap/main.php
+++ b/ext/sitemap/main.php
@@ -37,7 +37,7 @@ class XMLSitemap extends Extension
     }
 
     // Full sitemap
-    private function handle_full_sitemap()
+    private function handle_full_sitemap(): string
     {
         global $database, $config;
 
@@ -121,7 +121,7 @@ class XMLSitemap extends Extension
     /**
      * Returns true if a new sitemap is needed.
      */
-    private function new_sitemap_needed($cache_path): bool
+    private function new_sitemap_needed(string $cache_path): bool
     {
         if (!file_exists($cache_path)) {
             return true;
diff --git a/ext/source_history/main.php b/ext/source_history/main.php
index 8e8417a3..4f44b562 100644
--- a/ext/source_history/main.php
+++ b/ext/source_history/main.php
@@ -137,7 +137,7 @@ class SourceHistory extends Extension
     /**
      * This function is called when a revert request is received.
      */
-    private function process_revert_request(int $revert_id)
+    private function process_revert_request(int $revert_id): void
     {
         global $page;
 
@@ -180,7 +180,7 @@ class SourceHistory extends Extension
         $page->set_redirect(make_link('post/view/'.$stored_image_id));
     }
 
-    protected function process_bulk_revert_request()
+    protected function process_bulk_revert_request(): void
     {
         if (isset($_POST['revert_name']) && !empty($_POST['revert_name'])) {
             $revert_name = $_POST['revert_name'];
@@ -219,6 +219,9 @@ class SourceHistory extends Extension
         $this->theme->display_revert_ip_results();
     }
 
+    /**
+     * @return array<string, mixed>|null
+     */
     public function get_source_history_from_revert(int $revert_id): ?array
     {
         global $database;
@@ -230,6 +233,9 @@ class SourceHistory extends Extension
         return ($row ? $row : null);
     }
 
+    /**
+     * @return array<string, mixed>
+     */
     public function get_source_history_from_id(int $image_id): array
     {
         global $database;
@@ -244,6 +250,9 @@ class SourceHistory extends Extension
         );
     }
 
+    /**
+     * @return array<string, mixed>
+     */
     public function get_global_source_history(int $page_id): array
     {
         global $database;
@@ -259,7 +268,7 @@ class SourceHistory extends Extension
     /**
      * This function attempts to revert all changes by a given IP within an (optional) timeframe.
      */
-    public function process_revert_all_changes(?string $name, ?string $ip, ?string $date)
+    public function process_revert_all_changes(?string $name, ?string $ip, ?string $date): void
     {
         global $database;
 
@@ -351,7 +360,7 @@ class SourceHistory extends Extension
     /**
      * This function is called just before an images source is changed.
      */
-    private function add_source_history(Image $image, string $source)
+    private function add_source_history(Image $image, string $source): void
     {
         global $database, $config, $user;
 
diff --git a/ext/source_history/theme.php b/ext/source_history/theme.php
index d7558d60..5bb01ba2 100644
--- a/ext/source_history/theme.php
+++ b/ext/source_history/theme.php
@@ -10,10 +10,17 @@ use function MicroHTML\INPUT;
 use function MicroHTML\LABEL;
 use function MicroHTML\rawHTML;
 
+/**
+ * @phpstan-type HistoryEntry array{image_id:int,id:int,source:string,date_set:string,user_id:string,user_ip:string,name:string}
+ */
 class SourceHistoryTheme extends Themelet
 {
+    /** @var string[] */
     private array $messages = [];
 
+    /**
+     * @param HistoryEntry[] $history
+     */
     public function display_history_page(Page $page, int $image_id, array $history): void
     {
         $history_html = $this->history_list($history, true);
@@ -24,6 +31,9 @@ class SourceHistoryTheme extends Themelet
         $page->add_block(new Block("Source History", $history_html, "main", 10));
     }
 
+    /**
+     * @param HistoryEntry[] $history
+     */
     public function display_global_page(Page $page, array $history, int $page_number): void
     {
         $history_html = $this->history_list($history, false);
@@ -78,11 +88,14 @@ class SourceHistoryTheme extends Themelet
         $page->add_block(new Block("Bulk Revert Results", $html));
     }
 
-    public function add_status(string $title, string $body)
+    public function add_status(string $title, string $body): void
     {
         $this->messages[] = '<p><b>'. $title .'</b><br>'. $body .'</p>';
     }
 
+    /**
+     * @param HistoryEntry[] $history
+     */
     protected function history_list(array $history, bool $select_2nd): string
     {
         $history_list = "";
@@ -102,6 +115,9 @@ class SourceHistoryTheme extends Themelet
 		";
     }
 
+    /**
+     * @param HistoryEntry $fields
+     */
     protected function history_entry(array $fields, bool $selected): string
     {
         global $user;
diff --git a/ext/static_files/main.php b/ext/static_files/main.php
index 209f019a..5a7b052d 100644
--- a/ext/static_files/main.php
+++ b/ext/static_files/main.php
@@ -6,6 +6,7 @@ namespace Shimmie2;
 
 class RobotsBuildingEvent extends Event
 {
+    /** @var string[] */
     public array $parts = [
         "User-agent: *",
         // Site is rate limited to 1 request / sec,
@@ -54,7 +55,10 @@ class StaticFiles extends Extension
         }
     }
 
-    private function count_main($blocks): int
+    /**
+     * @param Block[] $blocks
+     */
+    private function count_main(array $blocks): int
     {
         $n = 0;
         foreach ($blocks as $block) {
diff --git a/ext/statsd/main.php b/ext/statsd/main.php
index d0848e6f..d9d45756 100644
--- a/ext/statsd/main.php
+++ b/ext/statsd/main.php
@@ -8,9 +8,10 @@ _d("STATSD_HOST", null);
 
 class StatsDInterface extends Extension
 {
+    /** @var array<string, string> */
     public static array $stats = [];
 
-    private function _stats(string $type)
+    private function _stats(string $type): void
     {
         global $_shm_event_count, $cache, $database, $_shm_load_start;
         $time = ftime() - $_shm_load_start;
@@ -78,7 +79,10 @@ class StatsDInterface extends Extension
         return 99;
     }
 
-    private function send(string $host, array $data, float $sampleRate = 1)
+    /**
+     * @param array<string, string> $data
+     */
+    private function send(string $host, array $data, float $sampleRate = 1): void
     {
         // sampling
         $sampledData = [];
diff --git a/ext/tag_categories/main.php b/ext/tag_categories/main.php
index de9c8479..d932bd1d 100644
--- a/ext/tag_categories/main.php
+++ b/ext/tag_categories/main.php
@@ -67,12 +67,12 @@ class TagCategories extends Extension
 
     public function onPageRequest(PageRequestEvent $event): void
     {
-        global $page, $user;
+        global $database, $page, $user;
 
         if ($event->page_matches("tags/categories")) {
             if ($user->can(Permissions::EDIT_TAG_CATEGORIES)) {
                 $this->page_update();
-                $this->show_tag_categories($page);
+                $this->theme->show_tag_categories($page, $database->get_all('SELECT * FROM image_tag_categories'));
             }
         }
     }
@@ -116,26 +116,26 @@ class TagCategories extends Extension
         }
     }
 
-    public function getDict(): array
+    /**
+     * @return array<string, array{category: string, display_singular: string, display_multiple: string, color: string}>
+     */
+    public function getKeyedDict(): array
     {
         global $database;
-        return $database->get_all('SELECT * FROM image_tag_categories;');
-    }
-
-    public function getKeyedDict($key_with = 'category'): array
-    {
-        $tc_dict = $this->getDict();
+        $tc_dict = $database->get_all('SELECT * FROM image_tag_categories');
         $tc_keyed_dict = [];
 
         foreach ($tc_dict as $row) {
-            $key = $row[$key_with];
-            $tc_keyed_dict[$key] = $row;
+            $tc_keyed_dict[$row['category']] = $row;
         }
 
         return $tc_keyed_dict;
     }
 
-    public function getTagHtml(string $h_tag, $tag_category_dict, string $extra_text = ''): string
+    /**
+     * @param array<string, array{color: string}> $tag_category_dict
+     */
+    public function getTagHtml(string $h_tag, array $tag_category_dict, string $extra_text = ''): string
     {
         $h_tag_no_underscores = str_replace("_", " ", $h_tag);
 
@@ -207,9 +207,4 @@ class TagCategories extends Extension
             );
         }
     }
-
-    public function show_tag_categories($page)
-    {
-        $this->theme->show_tag_categories($page, $this->getDict());
-    }
 }
diff --git a/ext/tag_categories/theme.php b/ext/tag_categories/theme.php
index f47b4ded..59bc79e1 100644
--- a/ext/tag_categories/theme.php
+++ b/ext/tag_categories/theme.php
@@ -6,7 +6,10 @@ namespace Shimmie2;
 
 class TagCategoriesTheme extends Themelet
 {
-    public function show_tag_categories(Page $page, $tc_dict)
+    /**
+     * @param array<array{category: string, display_singular: string, display_multiple: string, color: string}> $tc_dict
+     */
+    public function show_tag_categories(Page $page, array $tc_dict): void
     {
         $tc_block_index = 0;
         $html = '';
diff --git a/ext/tag_edit/main.php b/ext/tag_edit/main.php
index 06485688..caba7468 100644
--- a/ext/tag_edit/main.php
+++ b/ext/tag_edit/main.php
@@ -56,8 +56,11 @@ class TagSetException extends UserErrorException
 class TagSetEvent extends Event
 {
     public Image $image;
+    /** @var string[] */
     public array $old_tags;
+    /** @var string[] */
     public array $new_tags;
+    /** @var string[] */
     public array $metatags;
 
     /**
@@ -323,7 +326,7 @@ class TagEdit extends Extension
         $event->replace('$tags', $tags);
     }
 
-    private function mass_tag_edit(string $search, string $replace, bool $commit)
+    private function mass_tag_edit(string $search, string $replace, bool $commit): void
     {
         global $database, $tracer_enabled, $_tracer;
 
@@ -386,7 +389,7 @@ class TagEdit extends Extension
         }
     }
 
-    private function mass_source_edit(string $tags, string $source)
+    private function mass_source_edit(string $tags, string $source): void
     {
         $tags = Tag::explode($tags);
 
diff --git a/ext/tag_edit/theme.php b/ext/tag_edit/theme.php
index b597c468..8ef6eeac 100644
--- a/ext/tag_edit/theme.php
+++ b/ext/tag_edit/theme.php
@@ -29,7 +29,7 @@ class TagEditTheme extends Themelet
         $page->add_block(new Block("Mass Tag Edit", $html));
     }
 
-    public function mss_html($terms): string
+    public function mss_html(string $terms): string
     {
         $h_terms = html_escape($terms);
         $html = make_form(make_link("tag_edit/mass_source_set"), "POST") . "
diff --git a/ext/tag_history/main.php b/ext/tag_history/main.php
index 867bac17..3758491a 100644
--- a/ext/tag_history/main.php
+++ b/ext/tag_history/main.php
@@ -189,7 +189,7 @@ class TagHistory extends Extension
     /**
      * This function is called when a revert request is received.
      */
-    private function process_revert_request(int $revert_id)
+    private function process_revert_request(int $revert_id): void
     {
         global $page;
 
@@ -229,7 +229,7 @@ class TagHistory extends Extension
         $page->set_redirect(make_link('post/view/'.$stored_image_id));
     }
 
-    protected function process_bulk_revert_request()
+    protected function process_bulk_revert_request(): void
     {
         if (isset($_POST['revert_name']) && !empty($_POST['revert_name'])) {
             $revert_name = $_POST['revert_name'];
@@ -268,6 +268,9 @@ class TagHistory extends Extension
         $this->theme->display_revert_ip_results();
     }
 
+    /**
+     * @return array<string, mixed>|null
+     */
     public function get_tag_history_from_revert(int $revert_id): ?array
     {
         global $database;
@@ -279,6 +282,9 @@ class TagHistory extends Extension
         return ($row ? $row : null);
     }
 
+    /**
+     * @return array<string, mixed>
+     */
     public function get_tag_history_from_id(int $image_id): array
     {
         global $database;
@@ -293,6 +299,9 @@ class TagHistory extends Extension
         );
     }
 
+    /**
+     * @return array<string, mixed>
+     */
     public function get_global_tag_history(int $page_id): array
     {
         global $database;
@@ -308,7 +317,7 @@ class TagHistory extends Extension
     /**
      * This function attempts to revert all changes by a given IP within an (optional) timeframe.
      */
-    public function process_revert_all_changes(?string $name, ?string $ip, ?string $date)
+    public function process_revert_all_changes(?string $name, ?string $ip, ?string $date): void
     {
         global $database;
 
diff --git a/ext/tag_history/theme.php b/ext/tag_history/theme.php
index 9e869f24..e16e1ca2 100644
--- a/ext/tag_history/theme.php
+++ b/ext/tag_history/theme.php
@@ -11,10 +11,17 @@ use function MicroHTML\LABEL;
 use function MicroHTML\SPAN;
 use function MicroHTML\rawHTML;
 
+/**
+ * @phpstan-type HistoryEntry array{image_id:int,id:int,tags:string,date_set:string,user_id:string,user_ip:string,name:string}
+ */
 class TagHistoryTheme extends Themelet
 {
+    /** @var string[] */
     private array $messages = [];
 
+    /**
+     * @param HistoryEntry[] $history
+     */
     public function display_history_page(Page $page, int $image_id, array $history): void
     {
         $history_html = $this->history_list($history, true);
@@ -25,6 +32,9 @@ class TagHistoryTheme extends Themelet
         $page->add_block(new Block("Tag History", $history_html, "main", 10));
     }
 
+    /**
+     * @param HistoryEntry[] $history
+     */
     public function display_global_page(Page $page, array $history, int $page_number): void
     {
         $history_html = $this->history_list($history, false);
@@ -79,11 +89,14 @@ class TagHistoryTheme extends Themelet
         $page->add_block(new Block("Bulk Revert Results", $html));
     }
 
-    public function add_status(string $title, string $body)
+    public function add_status(string $title, string $body): void
     {
         $this->messages[] = '<p><b>'. $title .'</b><br>'. $body .'</p>';
     }
 
+    /**
+     * @param HistoryEntry[] $history
+     */
     protected function history_list(array $history, bool $select_2nd): string
     {
         $history_list = "";
@@ -103,6 +116,9 @@ class TagHistoryTheme extends Themelet
 		";
     }
 
+    /**
+     * @param HistoryEntry $fields
+     */
     protected function history_entry(array $fields, bool $selected): string
     {
         global $user;
diff --git a/ext/tag_list/main.php b/ext/tag_list/main.php
index 2a8a47d7..589416aa 100644
--- a/ext/tag_list/main.php
+++ b/ext/tag_list/main.php
@@ -11,7 +11,7 @@ class TagList extends Extension
     /** @var TagListTheme */
     protected Themelet $theme;
 
-    private $tagcategories = null;
+    private mixed $tagcategories = null;
 
     public function onInitExt(InitExtEvent $event): void
     {
@@ -152,6 +152,9 @@ class TagList extends Extension
         }
     }
 
+    /**
+     * @return int[]
+     */
     private static function get_omitted_tags(): array
     {
         global $cache, $config, $database;
@@ -452,7 +455,7 @@ class TagList extends Extension
         }
     }
 
-    private function add_split_tags_block(Page $page, Image $image)
+    private function add_split_tags_block(Page $page, Image $image): void
     {
         global $database;
 
@@ -471,7 +474,7 @@ class TagList extends Extension
         }
     }
 
-    private function add_tags_block(Page $page, Image $image)
+    private function add_tags_block(Page $page, Image $image): void
     {
         global $database;
 
@@ -490,7 +493,7 @@ class TagList extends Extension
         }
     }
 
-    private function add_popular_block(Page $page)
+    private function add_popular_block(Page $page): void
     {
         global $cache, $database, $config;
 
@@ -531,7 +534,7 @@ class TagList extends Extension
     /**
      * @param string[] $search
      */
-    private function add_refine_block(Page $page, array $search)
+    private function add_refine_block(Page $page, array $search): void
     {
         global $config;
 
@@ -548,6 +551,10 @@ class TagList extends Extension
         }
     }
 
+    /**
+     * @param string[] $search
+     * @return array<array{tag: string, count: int}>
+     */
     public static function get_related_tags(array $search, int $limit): array
     {
         global $cache, $database;
diff --git a/ext/tag_list/test.php b/ext/tag_list/test.php
index 8d27af0a..a345508d 100644
--- a/ext/tag_list/test.php
+++ b/ext/tag_list/test.php
@@ -6,6 +6,7 @@ namespace Shimmie2;
 
 class TagListTest extends ShimmiePHPUnitTestCase
 {
+    /** @var string[] */
     private array $pages = ["map", "alphabetic", "popularity", "categories"];
 
     public function testTagList(): void
diff --git a/ext/tag_list/theme.php b/ext/tag_list/theme.php
index da0e0bbc..3922ba8e 100644
--- a/ext/tag_list/theme.php
+++ b/ext/tag_list/theme.php
@@ -9,19 +9,19 @@ class TagListTheme extends Themelet
     public string $heading = "";
     public string $list = "";
     public ?string $navigation;
-    private $tagcategories = null;
+    private mixed $tagcategories = null;
 
-    public function set_heading(string $text)
+    public function set_heading(string $text): void
     {
         $this->heading = $text;
     }
 
-    public function set_tag_list(string $list)
+    public function set_tag_list(string $list): void
     {
         $this->list = $list;
     }
 
-    public function set_navigation(string $nav)
+    public function set_navigation(string $nav): void
     {
         $this->navigation = $nav;
     }
@@ -60,13 +60,10 @@ class TagListTheme extends Themelet
 				<tbody>';
     }
 
-    /*
-     * $tag_infos = array(
-     *                 array('tag' => $tag, 'count' => $number_of_uses),
-     *                 ...
-     *              )
+    /**
+     * @param array<array{tag: string, count: int}> $tag_infos
      */
-    public function display_split_related_block(Page $page, $tag_infos): void
+    public function display_split_related_block(Page $page, array $tag_infos): void
     {
         global $config;
 
@@ -124,11 +121,8 @@ class TagListTheme extends Themelet
         }
     }
 
-    /*
-     * $tag_infos = array(
-     *                 array('tag' => $tag, 'count' => $number_of_uses),
-     *                 ...
-     *              )
+    /**
+     * @param array<array{tag: string, count: int}> $tag_infos
      */
     private function get_tag_list_html(array $tag_infos, string $sort): string
     {
@@ -156,13 +150,10 @@ class TagListTheme extends Themelet
         return $main_html;
     }
 
-    /*
-     * $tag_infos = array(
-     *                 array('tag' => $tag, 'count' => $number_of_uses),
-     *                 ...
-     *              )
+    /**
+     * @param array<array{tag: string, count: int}> $tag_infos
      */
-    public function display_related_block(Page $page, $tag_infos, $block_name): void
+    public function display_related_block(Page $page, array $tag_infos, string $block_name): void
     {
         global $config;
 
@@ -174,14 +165,10 @@ class TagListTheme extends Themelet
         $page->add_block(new Block($block_name, $main_html, "left", 10));
     }
 
-
-    /*
-     * $tag_infos = array(
-     *                 array('tag' => $tag, 'count' => $number_of_uses),
-     *                 ...
-     *              )
+    /**
+     * @param array<array{tag: string, count: int}> $tag_infos
      */
-    public function display_popular_block(Page $page, $tag_infos): void
+    public function display_popular_block(Page $page, array $tag_infos): void
     {
         global $config;
 
@@ -194,14 +181,11 @@ class TagListTheme extends Themelet
         $page->add_block(new Block("Popular Tags", $main_html, "left", 60));
     }
 
-    /*
-     * $tag_infos = array(
-     *                 array('tag' => $tag),
-     *                 ...
-     *              )
-     * $search = the current array of tags being searched for
+    /**
+     * @param array<array{tag: string, count: int}> $tag_infos
+     * @param string[] $search
      */
-    public function display_refine_block(Page $page, $tag_infos, $search): void
+    public function display_refine_block(Page $page, array $tag_infos, array $search): void
     {
         global $config;
 
@@ -214,6 +198,11 @@ class TagListTheme extends Themelet
         $page->add_block(new Block("Refine Search", $main_html, "left", 60));
     }
 
+    /**
+     * @param array{tag: string, count: int} $row
+     * @param array<string, array{color: string}> $tag_category_dict
+     * @return array{0: string, 1: string}
+     */
     public function return_tag(array $row, array $tag_category_dict): array
     {
         global $config;
@@ -252,6 +241,9 @@ class TagListTheme extends Themelet
         return [$category, $display_html];
     }
 
+    /**
+     * @param string[] $tags
+     */
     protected function ars(string $tag, array $tags): string
     {
         // FIXME: a better fix would be to make sure the inputs are correct
@@ -266,6 +258,9 @@ class TagListTheme extends Themelet
         return $html;
     }
 
+    /**
+     * @param string[] $tags
+     */
     protected function get_remove_link(array $tags, string $tag): string
     {
         if (!in_array($tag, $tags) && !in_array("-$tag", $tags)) {
@@ -276,6 +271,9 @@ class TagListTheme extends Themelet
         }
     }
 
+    /**
+     * @param string[] $tags
+     */
     protected function get_add_link(array $tags, string $tag): string
     {
         if (in_array($tag, $tags)) {
@@ -286,6 +284,9 @@ class TagListTheme extends Themelet
         }
     }
 
+    /**
+     * @param string[] $tags
+     */
     protected function get_subtract_link(array $tags, string $tag): string
     {
         if (in_array("-$tag", $tags)) {
diff --git a/ext/tagger_xml/main.php b/ext/tagger_xml/main.php
index 038ff251..80faca03 100644
--- a/ext/tagger_xml/main.php
+++ b/ext/tagger_xml/main.php
@@ -97,6 +97,9 @@ class TaggerXML extends Extension
         return $this->list_to_xml($tags, "image", (string)$image_id);
     }
 
+    /**
+     * @param array<string, mixed> $misc
+     */
     private function list_to_xml(\FFSPHP\PDOStatement $tags, string $type, string $query, ?array $misc = []): string
     {
         $props = [
@@ -119,12 +122,12 @@ class TaggerXML extends Extension
         return (string)($list);
     }
 
-    private function count(string $query, $values)
+    /**
+     * @param array<string, string> $values
+     */
+    private function count(string $query, array $values): int
     {
         global $database;
-        return $database->execute(
-            "SELECT COUNT(*) FROM `tags` $query",
-            $values
-        )->fields['COUNT(*)'];
+        return $database->get_one("SELECT COUNT(*) FROM `tags` $query", $values);
     }
 }
diff --git a/ext/tips/main.php b/ext/tips/main.php
index a0e6c01a..6ab89b97 100644
--- a/ext/tips/main.php
+++ b/ext/tips/main.php
@@ -116,7 +116,7 @@ class Tips extends Extension
         }
     }
 
-    private function manageTips()
+    private function manageTips(): void
     {
         $data_href = get_base_href();
         $url = $data_href."/ext/tips/images/";
@@ -145,7 +145,7 @@ class Tips extends Extension
         );
     }
 
-    private function getTip()
+    private function getTip(): void
     {
         global $database;
 
@@ -165,7 +165,7 @@ class Tips extends Extension
         }
     }
 
-    private function getAll()
+    private function getAll(): void
     {
         global $database;
 
@@ -177,7 +177,7 @@ class Tips extends Extension
         $this->theme->showAll($url, $tips);
     }
 
-    private function setStatus(int $tipID)
+    private function setStatus(int $tipID): void
     {
         global $database;
 
diff --git a/ext/tips/theme.php b/ext/tips/theme.php
index c9787b22..01f106e9 100644
--- a/ext/tips/theme.php
+++ b/ext/tips/theme.php
@@ -4,9 +4,15 @@ declare(strict_types=1);
 
 namespace Shimmie2;
 
+/**
+ * @phpstan-type Tip array{id: int, image: string, text: string, enable: bool}
+ */
 class TipsTheme extends Themelet
 {
-    public function manageTips($url, $images)
+    /**
+     * @param string[] $images
+     */
+    public function manageTips(string $url, array $images): void
     {
         global $page;
         $select = "<select name='image'><option value=''>- Select Post -</option>";
@@ -45,7 +51,10 @@ class TipsTheme extends Themelet
         $page->add_block(new Block("Add Tip", $html, "main", 10));
     }
 
-    public function showTip($url, $tip)
+    /**
+     * @param Tip $tip
+     */
+    public function showTip(string $url, array $tip): void
     {
         global $page;
 
@@ -57,7 +66,10 @@ class TipsTheme extends Themelet
         $page->add_block(new Block(null, $html, "subheading", 10));
     }
 
-    public function showAll($url, $tips)
+    /**
+     * @param Tip[] $tips
+     */
+    public function showAll(string $url, array $tips): void
     {
         global $user, $page;
 
diff --git a/ext/transcode/main.php b/ext/transcode/main.php
index 81a075e4..37446fc2 100644
--- a/ext/transcode/main.php
+++ b/ext/transcode/main.php
@@ -83,6 +83,9 @@ class TranscodeImage extends Extension
         $config->set_string(self::get_mapping_name($from_mime), $to_mime);
     }
 
+    /**
+     * @return string[]
+     */
     public static function get_enabled_mimes(): array
     {
         $output = [];
@@ -320,17 +323,18 @@ class TranscodeImage extends Extension
     }
 
 
-    private function can_convert_mime($engine, $mime): bool
+    private function can_convert_mime(string $engine, string $mime): bool
     {
         return MediaEngine::is_input_supported($engine, $mime);
     }
 
-
-    private function get_supported_output_mimes($engine, ?string $omit_mime = null): array
+    /**
+     * @return array<string, string>
+     */
+    private function get_supported_output_mimes(string $engine, ?string $omit_mime = null): array
     {
         $output = [];
 
-
         foreach (self::OUTPUT_MIMES as $key => $value) {
             if ($value == "") {
                 $output[$key] = $value;
@@ -409,9 +413,6 @@ class TranscodeImage extends Extension
                     }
                     try {
                         $background_color = Media::hex_color_allocate($new_image, $config->get_string(TranscodeConfig::ALPHA_COLOR));
-                        if ($background_color === false) {
-                            throw new ImageTranscodeException("Could not allocate background color");
-                        }
                         if (imagefilledrectangle($new_image, 0, 0, $width, $height, $background_color) === false) {
                             throw new ImageTranscodeException("Could not fill background color");
                         }
diff --git a/ext/transcode/theme.php b/ext/transcode/theme.php
index d656181a..10c4c084 100644
--- a/ext/transcode/theme.php
+++ b/ext/transcode/theme.php
@@ -8,8 +8,10 @@ use function MicroHTML\{rawHTML};
 
 class TranscodeImageTheme extends Themelet
 {
-    /*
+    /**
      * Display a link to resize an image
+     *
+     * @param array<string, string> $options
      */
     public function get_transcode_html(Image $image, array $options): \MicroHTML\HTMLElement
     {
@@ -31,6 +33,9 @@ class TranscodeImageTheme extends Themelet
         return rawHTML($html);
     }
 
+    /**
+     * @param array<string, string> $options
+     */
     public function get_transcode_picker_html(array $options): string
     {
         $html = "<select id='transcode_mime'  name='transcode_mime' required='required' >";
diff --git a/ext/transcode_video/main.php b/ext/transcode_video/main.php
index cfa6bccb..713c9822 100644
--- a/ext/transcode_video/main.php
+++ b/ext/transcode_video/main.php
@@ -174,11 +174,13 @@ class TranscodeVideo extends Extension
         }
     }
 
+    /**
+     * @return array<string, string>
+     */
     private static function get_output_options(?string $starting_container = null, ?string $starting_codec = null): array
     {
         $output = ["" => ""];
 
-
         foreach (VideoContainers::ALL as $container) {
             if ($starting_container == $container) {
                 continue;
diff --git a/ext/transcode_video/theme.php b/ext/transcode_video/theme.php
index 4340c6b9..cb74de42 100644
--- a/ext/transcode_video/theme.php
+++ b/ext/transcode_video/theme.php
@@ -8,8 +8,10 @@ use function MicroHTML\{rawHTML};
 
 class TranscodeVideoTheme extends Themelet
 {
-    /*
+    /**
      * Display a link to resize an image
+     *
+     * @param array<string, string> $options
      */
     public function get_transcode_html(Image $image, array $options): \MicroHTML\HTMLElement
     {
@@ -31,6 +33,9 @@ class TranscodeVideoTheme extends Themelet
         return rawHTML($html);
     }
 
+    /**
+     * @param array<string, string> $options
+     */
     public function get_transcode_picker_html(array $options): string
     {
         $html = "<select id='transcode_format'  name='transcode_format' required='required' >";
diff --git a/ext/trash/main.php b/ext/trash/main.php
index 57518cf6..f6e24ac8 100644
--- a/ext/trash/main.php
+++ b/ext/trash/main.php
@@ -135,6 +135,9 @@ class Trash extends Extension
         }
     }
 
+    /**
+     * @param string[] $context
+     */
     private function no_trash_query(array $context): bool
     {
         foreach ($context as $term) {
@@ -145,7 +148,7 @@ class Trash extends Extension
         return true;
     }
 
-    public static function set_trash(int $image_id, bool $trash)
+    public static function set_trash(int $image_id, bool $trash): void
     {
         global $database;
 
diff --git a/ext/upload/main.php b/ext/upload/main.php
index b61b7277..1741d426 100644
--- a/ext/upload/main.php
+++ b/ext/upload/main.php
@@ -23,6 +23,8 @@ class DataUploadEvent extends Event
     /**
      * Some data is being uploaded.
      * This should be caught by a file handler.
+     *
+     * @param array<string, mixed> $metadata
      */
     public function __construct(
         public string $tmpname,
@@ -39,7 +41,7 @@ class DataUploadEvent extends Event
         $metadata['filename'] = substr($metadata['filename'], 0, 255);
     }
 
-    public function set_tmpname(string $tmpname, ?string $mime = null)
+    public function set_tmpname(string $tmpname, ?string $mime = null): void
     {
         assert(is_readable($tmpname));
         $this->tmpname = $tmpname;
@@ -160,6 +162,9 @@ class Upload extends Extension
         $sb->end_table();
     }
 
+    /**
+     * @return array<string, string>
+     */
     private function get_mime_options(): array
     {
         $output = [];
@@ -251,6 +256,9 @@ class Upload extends Extension
         }
     }
 
+    /**
+     * @return string[]
+     */
     private function tags_for_upload_slot(int $id): array
     {
         # merge then explode, not explode then merge - else
@@ -365,6 +373,7 @@ class Upload extends Extension
     }
 
     /**
+     * @param string[] $tags
      * @return UploadResult[]
      */
     private function try_transload(string $url, array $tags, string $source = null): array
diff --git a/ext/user/events.php b/ext/user/events.php
index d4a75de8..a57b047d 100644
--- a/ext/user/events.php
+++ b/ext/user/events.php
@@ -8,6 +8,7 @@ use MicroHTML\HTMLElement;
 
 class UserBlockBuildingEvent extends Event
 {
+    /** @var array<int, array{name: string, link: string}> */
     public array $parts = [];
 
     public function add_link(string|HTMLElement $name, string $link, int $position = 50): void
@@ -21,6 +22,7 @@ class UserBlockBuildingEvent extends Event
 
 class UserOperationsBuildingEvent extends Event
 {
+    /** @var string[] */
     public array $parts = [];
 
     public function __construct(public User $user, public BaseConfig $user_config)
@@ -36,6 +38,7 @@ class UserOperationsBuildingEvent extends Event
 
 class UserPageBuildingEvent extends Event
 {
+    /** @var array<int, string> */
     public array $stats = [];
 
     public function __construct(public User $display_user)
@@ -43,7 +46,7 @@ class UserPageBuildingEvent extends Event
         parent::__construct();
     }
 
-    public function add_stats(string $html, int $position = 50)
+    public function add_stats(string $html, int $position = 50): void
     {
         while (isset($this->stats[$position])) {
             $position++;
diff --git a/ext/user/main.php b/ext/user/main.php
index a9744911..5ec1a3a4 100644
--- a/ext/user/main.php
+++ b/ext/user/main.php
@@ -360,7 +360,8 @@ class UserPage extends Extension
             "user_loginshowprofile",
             [
                 "Return to previous page" => 0, // 0 is default
-                "Send to user profile" => 1],
+                "Send to user profile" => 1,
+            ],
             "On log in/out",
             true
         );
@@ -479,6 +480,9 @@ class UserPage extends Extension
     public const USER_SEARCH_REGEX = "/^(?:poster|user)(!?)[=|:](.*)$/i";
     public const USER_ID_SEARCH_REGEX = "/^(?:poster|user)_id(!?)[=|:]([0-9]+)$/i";
 
+    /**
+     * @param string[] $context
+     */
     public static function has_user_query(array $context): bool
     {
         foreach ($context as $term) {
@@ -761,6 +765,9 @@ class UserPage extends Extension
         }
     }
 
+    /**
+     * @return array<string, int>
+     */
     private function count_upload_ips(User $duser): array
     {
         global $database;
@@ -774,6 +781,9 @@ class UserPage extends Extension
 				ORDER BY max(posted) DESC", ["id" => $duser->id]);
     }
 
+    /**
+     * @return array<string, int>
+     */
     private function count_comment_ips(User $duser): array
     {
         global $database;
@@ -787,6 +797,9 @@ class UserPage extends Extension
 				ORDER BY max(posted) DESC", ["id" => $duser->id]);
     }
 
+    /**
+     * @return array<string, int>
+     */
     private function count_log_ips(User $duser): array
     {
         if (!Extension::is_enabled(LogDatabaseInfo::KEY)) {
diff --git a/ext/user/theme.php b/ext/user/theme.php
index 77996fd1..d492b59e 100644
--- a/ext/user/theme.php
+++ b/ext/user/theme.php
@@ -36,20 +36,26 @@ class UserPageTheme extends Themelet
         ));
     }
 
-    public function display_user_list(Page $page, $table, $paginator): void
+    public function display_user_list(Page $page, HTMLElement $table, HTMLElement $paginator): void
     {
         $page->set_title("User List");
         $page->set_heading("User List");
         $page->add_block(new NavBlock());
-        $page->add_block(new Block("Users", $table . $paginator));
+        $page->add_block(new Block("Users", emptyHTML($table, $paginator)));
     }
 
-    public function display_user_links(Page $page, User $user, $parts): void
+    /**
+     * @param array<int, array{name: string, link: string}> $parts
+     */
+    public function display_user_links(Page $page, User $user, array $parts): void
     {
         # $page->add_block(new Block("User Links", join(", ", $parts), "main", 10));
     }
 
-    public function display_user_block(Page $page, User $user, $parts): void
+    /**
+     * @param array<array{link: string, name: string}> $parts
+     */
+    public function display_user_block(Page $page, User $user, array $parts): void
     {
         $html = emptyHTML('Logged in as ', $user->name);
         foreach ($parts as $part) {
@@ -202,6 +208,9 @@ class UserPageTheme extends Themelet
         return $html;
     }
 
+    /**
+     * @param array<string, int> $ips
+     */
     private function _ip_list(string $name, array $ips): HTMLElement
     {
         $td = TD("$name: ");
@@ -218,6 +227,11 @@ class UserPageTheme extends Themelet
         return $td;
     }
 
+    /**
+     * @param array<string, int> $uploads
+     * @param array<string, int> $comments
+     * @param array<string, int> $events
+     */
     public function display_ip_list(Page $page, array $uploads, array $comments, array $events): void
     {
         $html = TABLE(
@@ -235,10 +249,12 @@ class UserPageTheme extends Themelet
         $page->add_block(new Block("IPs", $html, "main", 70));
     }
 
-    public function display_user_page(User $duser, $stats): void
+    /**
+     * @param string[] $stats
+     */
+    public function display_user_page(User $duser, array $stats): void
     {
         global $page;
-        assert(is_array($stats));
         $stats[] = 'User ID: '.$duser->id;
 
         $page->set_title(html_escape($duser->name)."'s Page");
diff --git a/ext/varnish/main.php b/ext/varnish/main.php
index d6214721..1d201c5c 100644
--- a/ext/varnish/main.php
+++ b/ext/varnish/main.php
@@ -14,7 +14,7 @@ class VarnishPurger extends Extension
         $config->set_default_string('varnish_protocol', 'http');
     }
 
-    private function curl_purge($path)
+    private function curl_purge(string $path): void
     {
         // waiting for curl timeout adds ~5 minutes to unit tests
         if (defined("UNITTEST")) {
diff --git a/ext/view/events/image_admin_block_building_event.php b/ext/view/events/image_admin_block_building_event.php
index 2de8b099..6a79c8d2 100644
--- a/ext/view/events/image_admin_block_building_event.php
+++ b/ext/view/events/image_admin_block_building_event.php
@@ -22,7 +22,7 @@ class ImageAdminBlockBuildingEvent extends Event
         $this->context = $context;
     }
 
-    public function add_part(HTMLElement $html, int $position = 50)
+    public function add_part(HTMLElement $html, int $position = 50): void
     {
         while (isset($this->parts[$position])) {
             $position++;
diff --git a/ext/view/events/image_info_box_building_event.php b/ext/view/events/image_info_box_building_event.php
index db9399e6..de2585da 100644
--- a/ext/view/events/image_info_box_building_event.php
+++ b/ext/view/events/image_info_box_building_event.php
@@ -8,6 +8,7 @@ use MicroHTML\HTMLElement;
 
 class ImageInfoBoxBuildingEvent extends Event
 {
+    /** @var HTMLElement[] */
     public array $parts = [];
     public Image $image;
     public User $user;
@@ -19,7 +20,7 @@ class ImageInfoBoxBuildingEvent extends Event
         $this->user = $user;
     }
 
-    public function add_part(HTMLElement $html, int $position = 50)
+    public function add_part(HTMLElement $html, int $position = 50): void
     {
         while (isset($this->parts[$position])) {
             $position++;
diff --git a/ext/view/theme.php b/ext/view/theme.php
index 027902b5..4e53c5cf 100644
--- a/ext/view/theme.php
+++ b/ext/view/theme.php
@@ -22,10 +22,12 @@ class ViewPostTheme extends Themelet
         $page->add_html_header("<meta property=\"og:url\" content=\"".make_http(make_link("post/view/{$image->id}"))."\">");
     }
 
-    /*
+    /**
      * Build a page showing $image and some info about it
+     *
+     * @param HTMLElement[] $editor_parts
      */
-    public function display_page(Image $image, $editor_parts): void
+    public function display_page(Image $image, array $editor_parts): void
     {
         global $page;
         $page->set_title("Post {$image->id}: ".$image->get_tag_list());
@@ -47,7 +49,7 @@ class ViewPostTheme extends Themelet
     public function display_admin_block(Page $page, array $parts): void
     {
         if (count($parts) > 0) {
-            $page->add_block(new Block("Post Controls", DIV(["class"=>"post_controls"], joinHTML("", $parts)), "left", 50));
+            $page->add_block(new Block("Post Controls", DIV(["class" => "post_controls"], joinHTML("", $parts)), "left", 50));
         }
     }
 
@@ -106,7 +108,10 @@ class ViewPostTheme extends Themelet
         return "$h_pin<br>$h_search";
     }
 
-    protected function build_info(Image $image, $editor_parts): HTMLElement
+    /**
+     * @param HTMLElement[] $editor_parts
+     */
+    protected function build_info(Image $image, array $editor_parts): HTMLElement
     {
         global $user;
 
diff --git a/ext/wiki/main.php b/ext/wiki/main.php
index 3fafd7cf..bb1cb56f 100644
--- a/ext/wiki/main.php
+++ b/ext/wiki/main.php
@@ -67,6 +67,9 @@ class WikiPage
     #[Field]
     public string $body;
 
+    /**
+     * @param array<string, mixed> $row
+     */
     public function __construct(array $row = null)
     {
         //assert(!empty($row));
@@ -314,6 +317,9 @@ class Wiki extends Extension
         return false;
     }
 
+    /**
+     * @return array<array{revision: string, date: string}>
+     */
     public static function get_history(string $title): array
     {
         global $database;
diff --git a/ext/wiki/theme.php b/ext/wiki/theme.php
index 2f6cb5a2..36f83791 100644
--- a/ext/wiki/theme.php
+++ b/ext/wiki/theme.php
@@ -47,6 +47,10 @@ class WikiTheme extends Themelet
         $page->add_block(new Block($title_html, $this->create_display_html($wiki_page)));
     }
 
+    /**
+     * @param array<array{revision: string, date: string}> $history
+     */
+
     public function display_page_history(Page $page, string $title, array $history): void
     {
         $html = "<table class='zebra'>";
diff --git a/ext/word_filter/test.php b/ext/word_filter/test.php
index 6786b192..04eccc25 100644
--- a/ext/word_filter/test.php
+++ b/ext/word_filter/test.php
@@ -13,7 +13,7 @@ class WordFilterTest extends ShimmiePHPUnitTestCase
         $config->set_string("word_filter", "whore,nice lady\na duck,a kitten\n white ,\tspace\ninvalid");
     }
 
-    public function _doThings($in, $out)
+    public function _doThings(string $in, string $out): void
     {
         global $user;
         $this->log_in_as_user();
diff --git a/themes/danbooru/comment.theme.php b/themes/danbooru/comment.theme.php
index 3249679d..5dea15f3 100644
--- a/themes/danbooru/comment.theme.php
+++ b/themes/danbooru/comment.theme.php
@@ -6,6 +6,9 @@ namespace Shimmie2;
 
 class CustomCommentListTheme extends CommentListTheme
 {
+    /**
+     * @param array<array{0: Image, 1: Comment[]}> $images
+     */
     public function display_comment_list(array $images, int $page_number, int $total_pages, bool $can_post): void
     {
         global $config, $page, $user;
@@ -49,7 +52,7 @@ class CustomCommentListTheme extends CommentListTheme
             }
             $p = autodate($image->posted);
 
-            $r = Extension::is_enabled(RatingsInfo::KEY) ? "<b>Rating</b> ".Ratings::rating_to_human($image->rating) : "";
+            $r = Extension::is_enabled(RatingsInfo::KEY) ? "<b>Rating</b> ".Ratings::rating_to_human($image['rating']) : "";
             $comment_html =   "<b>Date</b> $p $s <b>User</b> $un $s $r<br><b>Tags</b> $t<p>&nbsp;";
 
             $comment_count = count($comments);
diff --git a/themes/danbooru/user.theme.php b/themes/danbooru/user.theme.php
index a78bbde2..3772db16 100644
--- a/themes/danbooru/user.theme.php
+++ b/themes/danbooru/user.theme.php
@@ -33,7 +33,10 @@ class CustomUserPageTheme extends UserPageTheme
         $page->add_block(new Block("Login", $html, "main", 90));
     }
 
-    public function display_user_links(Page $page, User $user, $parts): void
+    /**
+     * @param array<int, array{name: string, link: string}> $parts
+     */
+    public function display_user_links(Page $page, User $user, array $parts): void
     {
         // no block in this theme
     }
@@ -42,7 +45,10 @@ class CustomUserPageTheme extends UserPageTheme
         // no block in this theme
     }
 
-    public function display_user_block(Page $page, User $user, $parts): void
+    /**
+     * @param array<array{link: string, name: string}> $parts
+     */
+    public function display_user_block(Page $page, User $user, array $parts): void
     {
         $html = "";
         $blocked = ["Pools", "Pool Changes", "Alias Editor", "My Profile"];
@@ -91,6 +97,11 @@ class CustomUserPageTheme extends UserPageTheme
         $page->add_block(new Block("Signup", $html));
     }
 
+    /**
+     * @param array<string, int> $uploads
+     * @param array<string, int> $comments
+     * @param array<string, int> $events
+     */
     public function display_ip_list(Page $page, array $uploads, array $comments, array $events): void
     {
         $html = "<table id='ip-history' style='width: 400px;'>";
@@ -108,7 +119,10 @@ class CustomUserPageTheme extends UserPageTheme
         $page->add_block(new Block("IPs", $html));
     }
 
-    public function display_user_page(User $duser, $stats): void
+    /**
+     * @param string[] $stats
+     */
+    public function display_user_page(User $duser, array $stats): void
     {
         global $page;
         $page->disable_left();
diff --git a/themes/danbooru/view.theme.php b/themes/danbooru/view.theme.php
index 41127900..eed15aea 100644
--- a/themes/danbooru/view.theme.php
+++ b/themes/danbooru/view.theme.php
@@ -4,9 +4,14 @@ declare(strict_types=1);
 
 namespace Shimmie2;
 
+use MicroHTML\HTMLElement;
+
 class CustomViewPostTheme extends ViewPostTheme
 {
-    public function display_page(Image $image, $editor_parts): void
+    /**
+     * @param HTMLElement[] $editor_parts
+     */
+    public function display_page(Image $image, array $editor_parts): void
     {
         global $page;
         $page->set_heading(html_escape($image->get_tag_list()));
diff --git a/themes/danbooru2/comment.theme.php b/themes/danbooru2/comment.theme.php
index d94709ee..e1b30d5a 100644
--- a/themes/danbooru2/comment.theme.php
+++ b/themes/danbooru2/comment.theme.php
@@ -6,6 +6,9 @@ namespace Shimmie2;
 
 class CustomCommentListTheme extends CommentListTheme
 {
+    /**
+     * @param array<array{0: Image, 1: Comment[]}> $images
+     */
     public function display_comment_list(array $images, int $page_number, int $total_pages, bool $can_post): void
     {
         global $config, $page, $user;
@@ -49,7 +52,7 @@ class CustomCommentListTheme extends CommentListTheme
             }
             $p = autodate($image->posted);
 
-            $r = Extension::is_enabled(RatingsInfo::KEY) ? "<b>Rating</b> ".Ratings::rating_to_human($image->rating) : "";
+            $r = Extension::is_enabled(RatingsInfo::KEY) ? "<b>Rating</b> ".Ratings::rating_to_human($image['rating']) : "";
             $comment_html =   "<b>Date</b> $p $s <b>User</b> $un $s $r<br><b>Tags</b> $t<p>&nbsp;";
 
             $comment_count = count($comments);
diff --git a/themes/danbooru2/user.theme.php b/themes/danbooru2/user.theme.php
index a78bbde2..3772db16 100644
--- a/themes/danbooru2/user.theme.php
+++ b/themes/danbooru2/user.theme.php
@@ -33,7 +33,10 @@ class CustomUserPageTheme extends UserPageTheme
         $page->add_block(new Block("Login", $html, "main", 90));
     }
 
-    public function display_user_links(Page $page, User $user, $parts): void
+    /**
+     * @param array<int, array{name: string, link: string}> $parts
+     */
+    public function display_user_links(Page $page, User $user, array $parts): void
     {
         // no block in this theme
     }
@@ -42,7 +45,10 @@ class CustomUserPageTheme extends UserPageTheme
         // no block in this theme
     }
 
-    public function display_user_block(Page $page, User $user, $parts): void
+    /**
+     * @param array<array{link: string, name: string}> $parts
+     */
+    public function display_user_block(Page $page, User $user, array $parts): void
     {
         $html = "";
         $blocked = ["Pools", "Pool Changes", "Alias Editor", "My Profile"];
@@ -91,6 +97,11 @@ class CustomUserPageTheme extends UserPageTheme
         $page->add_block(new Block("Signup", $html));
     }
 
+    /**
+     * @param array<string, int> $uploads
+     * @param array<string, int> $comments
+     * @param array<string, int> $events
+     */
     public function display_ip_list(Page $page, array $uploads, array $comments, array $events): void
     {
         $html = "<table id='ip-history' style='width: 400px;'>";
@@ -108,7 +119,10 @@ class CustomUserPageTheme extends UserPageTheme
         $page->add_block(new Block("IPs", $html));
     }
 
-    public function display_user_page(User $duser, $stats): void
+    /**
+     * @param string[] $stats
+     */
+    public function display_user_page(User $duser, array $stats): void
     {
         global $page;
         $page->disable_left();
diff --git a/themes/danbooru2/view.theme.php b/themes/danbooru2/view.theme.php
index 0c3726ee..30bb9bd8 100644
--- a/themes/danbooru2/view.theme.php
+++ b/themes/danbooru2/view.theme.php
@@ -4,9 +4,14 @@ declare(strict_types=1);
 
 namespace Shimmie2;
 
+use MicroHTML\HTMLElement;
+
 class CustomViewPostTheme extends ViewPostTheme
 {
-    public function display_page(Image $image, $editor_parts): void
+    /**
+     * @param HTMLElement[] $editor_parts
+     */
+    public function display_page(Image $image, array $editor_parts): void
     {
         global $page;
         $page->set_heading(html_escape($image->get_tag_list()));
diff --git a/themes/futaba/comment.theme.php b/themes/futaba/comment.theme.php
index ec39b18e..3a015f05 100644
--- a/themes/futaba/comment.theme.php
+++ b/themes/futaba/comment.theme.php
@@ -8,6 +8,9 @@ class CustomCommentListTheme extends CommentListTheme
 {
     public int $inner_id = 0;
 
+    /**
+     * @param array<array{0: Image, 1: Comment[]}> $images
+     */
     public function display_comment_list(array $images, int $page_number, int $total_pages, bool $can_post): void
     {
         global $config, $page;
diff --git a/themes/futaba/view.theme.php b/themes/futaba/view.theme.php
index 6370969c..c983f98b 100644
--- a/themes/futaba/view.theme.php
+++ b/themes/futaba/view.theme.php
@@ -4,9 +4,14 @@ declare(strict_types=1);
 
 namespace Shimmie2;
 
+use MicroHTML\HTMLElement;
+
 class CustomViewPostTheme extends ViewPostTheme
 {
-    public function display_page(Image $image, $editor_parts): void
+    /**
+     * @param HTMLElement[] $editor_parts
+     */
+    public function display_page(Image $image, array $editor_parts): void
     {
         global $page;
         $page->set_heading(html_escape($image->get_tag_list()));
diff --git a/themes/lite/user.theme.php b/themes/lite/user.theme.php
index 5ac89f24..8a422abf 100644
--- a/themes/lite/user.theme.php
+++ b/themes/lite/user.theme.php
@@ -33,7 +33,10 @@ class CustomUserPageTheme extends UserPageTheme
         $page->add_block(new Block("Login", $html, "main", 90));
     }
 
-    public function display_user_links(Page $page, User $user, $parts): void
+    /**
+     * @param array<int, array{name: string, link: string}> $parts
+     */
+    public function display_user_links(Page $page, User $user, array $parts): void
     {
         // no block in this theme
     }
@@ -42,7 +45,10 @@ class CustomUserPageTheme extends UserPageTheme
         // no block in this theme
     }
 
-    public function display_user_block(Page $page, User $user, $parts): void
+    /**
+     * @param array<array{link: string, name: string}> $parts
+     */
+    public function display_user_block(Page $page, User $user, array $parts): void
     {
         $html = "";
         $blocked = ["Pools", "Pool Changes", "Alias Editor", "My Profile"];
@@ -63,6 +69,11 @@ class CustomUserPageTheme extends UserPageTheme
         parent::display_signup_page($page);
     }
 
+    /**
+     * @param array<string, int> $uploads
+     * @param array<string, int> $comments
+     * @param array<string, int> $events
+     */
     public function display_ip_list(Page $page, array $uploads, array $comments, array $events): void
     {
         $html = "<table id='ip-history' style='width: 400px;'>";
@@ -80,7 +91,10 @@ class CustomUserPageTheme extends UserPageTheme
         $page->add_block(new Block("IPs", $html));
     }
 
-    public function display_user_page(User $duser, $stats): void
+    /**
+     * @param string[] $stats
+     */
+    public function display_user_page(User $duser, array $stats): void
     {
         global $page;
         $page->disable_left();
diff --git a/themes/lite/view.theme.php b/themes/lite/view.theme.php
index 7163a9b2..467477ea 100644
--- a/themes/lite/view.theme.php
+++ b/themes/lite/view.theme.php
@@ -4,9 +4,14 @@ declare(strict_types=1);
 
 namespace Shimmie2;
 
+use MicroHTML\HTMLElement;
+
 class CustomViewPostTheme extends ViewPostTheme
 {
-    public function display_page(Image $image, $editor_parts): void
+    /**
+     * @param HTMLElement[] $editor_parts
+     */
+    public function display_page(Image $image, array $editor_parts): void
     {
         global $page;
         $page->set_title("Post {$image->id}: ".$image->get_tag_list());
diff --git a/themes/lite/wz_tooltip.js b/themes/lite/wz_tooltip.js
index d45ceb01..8ad5561f 100644
--- a/themes/lite/wz_tooltip.js
+++ b/themes/lite/wz_tooltip.js
@@ -149,13 +149,13 @@ tt_musX, tt_musY,
 tt_over,
 tt_x, tt_y, tt_w, tt_h; // Position, width and height of currently displayed tooltip
 
-function tt_Extension()
+function tt_Extension(): void
 {
 	tt_ExtCmdEnum();
 	tt_aExt[tt_aExt.length] = this;
 	return this;
 }
-function tt_SetTipPos(x, y)
+function tt_SetTipPos(x, y): void
 {
 	var css = tt_aElt[0].style;
 
@@ -173,7 +173,7 @@ function tt_SetTipPos(x, y)
 		}
 	}
 }
-function tt_HideInit()
+function tt_HideInit(): void
 {
 	if(tt_iState)
 	{
@@ -192,7 +192,7 @@ function tt_HideInit()
 		tt_tHide.Timer("tt_Hide();", 1, false);
 	}
 }
-function tt_Hide()
+function tt_Hide(): void
 {
 	if(tt_db && tt_iState)
 	{
@@ -228,45 +228,45 @@ function tt_Hide()
 		}
 	}
 }
-function tt_GetElt(id)
+function tt_GetElt(id): void
 {
 	return(document.getElementById ? document.getElementById(id)
 			: document.all ? document.all[id]
 			: null);
 }
-function tt_GetDivW(el)
+function tt_GetDivW(el): void
 {
 	return(el ? (el.offsetWidth || el.style.pixelWidth || 0) : 0);
 }
-function tt_GetDivH(el)
+function tt_GetDivH(el): void
 {
 	return(el ? (el.offsetHeight || el.style.pixelHeight || 0) : 0);
 }
-function tt_GetScrollX()
+function tt_GetScrollX(): void
 {
 	return(window.pageXOffset || (tt_db ? (tt_db.scrollLeft || 0) : 0));
 }
-function tt_GetScrollY()
+function tt_GetScrollY(): void
 {
 	return(window.pageYOffset || (tt_db ? (tt_db.scrollTop || 0) : 0));
 }
-function tt_GetClientW()
+function tt_GetClientW(): void
 {
 	return tt_GetWndCliSiz("Width");
 }
-function tt_GetClientH()
+function tt_GetClientH(): void
 {
 	return tt_GetWndCliSiz("Height");
 }
-function tt_GetEvtX(e)
+function tt_GetEvtX(e): void
 {
 	return (e ? ((typeof(e.pageX) !== tt_u) ? e.pageX : (e.clientX + tt_GetScrollX())) : 0);
 }
-function tt_GetEvtY(e)
+function tt_GetEvtY(e): void
 {
 	return (e ? ((typeof(e.pageY) !== tt_u) ? e.pageY : (e.clientY + tt_GetScrollY())) : 0);
 }
-function tt_AddEvtFnc(el, sEvt, PFnc)
+function tt_AddEvtFnc(el, sEvt, PFnc): void
 {
 	if(el)
 	{
@@ -277,7 +277,7 @@ function tt_AddEvtFnc(el, sEvt, PFnc)
 		}
 	}
 }
-function tt_RemEvtFnc(el, sEvt, PFnc)
+function tt_RemEvtFnc(el, sEvt, PFnc): void
 {
 	if(el)
 	{
@@ -288,11 +288,11 @@ function tt_RemEvtFnc(el, sEvt, PFnc)
 		}
 	}
 }
-function tt_GetDad(el)
+function tt_GetDad(el): void
 {
 	return(el.parentNode || el.parentElement || el.offsetParent);
 }
-function tt_MovDomNode(el, dadFrom, dadTo)
+function tt_MovDomNode(el, dadFrom, dadTo): void
 {
 	if(dadFrom) {
 		dadFrom.removeChild(el);
@@ -321,7 +321,7 @@ tt_bWait = false,
 tt_u = "undefined";
 
 
-function tt_Init()
+function tt_Init(): void
 {
 	tt_MkCmdEnum();
 	// Send old browsers instantly to hell
@@ -340,7 +340,7 @@ function tt_Init()
 	tt_AddEvtFnc(window, "unload", tt_Hide);
 }
 // Creates command names by translating config variable names to upper case
-function tt_MkCmdEnum()
+function tt_MkCmdEnum(): void
 {
 	var n = 0;
 	for(var i in config) {
@@ -348,7 +348,7 @@ function tt_MkCmdEnum()
 	}
 	tt_aV.length = n;
 }
-function tt_Browser()
+function tt_Browser(): void
 {
 	var n, nv, n6, w3c;
 
@@ -393,7 +393,7 @@ function tt_Browser()
 	tt_db = null;
 	return false;
 }
-function tt_MkMainDiv()
+function tt_MkMainDiv(): void
 {
 	// Create the tooltip DIV
 	if(tt_body.insertAdjacentHTML) {
@@ -407,7 +407,7 @@ function tt_MkMainDiv()
 	tt_db = null;
 	return false;
 }
-function tt_MkMainDivHtm()
+function tt_MkMainDivHtm(): void
 {
 	return(
 		'<div id="WzTtDiV"></div>' +
@@ -415,7 +415,7 @@ function tt_MkMainDivHtm()
 		: '')
 	);
 }
-function tt_MkMainDivDom()
+function tt_MkMainDivDom(): void
 {
 	var el = document.createElement("div");
 	if(el) {
@@ -423,7 +423,7 @@ function tt_MkMainDivDom()
 	}
 	return el;
 }
-function tt_GetMainDivRefs()
+function tt_GetMainDivRefs(): void
 {
 	tt_aElt[0] = tt_GetElt("WzTtDiV");
 	if(tt_ie56 && tt_aElt[0])
@@ -444,14 +444,14 @@ function tt_GetMainDivRefs()
 	}
 	return false;
 }
-function tt_ResetMainDiv()
+function tt_ResetMainDiv(): void
 {
 	tt_SetTipPos(0, 0);
 	tt_aElt[0].innerHTML = "";
 	tt_aElt[0].style.width = "0px";
 	tt_h = 0;
 }
-function tt_IsW3cBox()
+function tt_IsW3cBox(): void
 {
 	var css = tt_aElt[0].style;
 
@@ -461,7 +461,7 @@ function tt_IsW3cBox()
 	css.padding = "0px";
 	tt_ResetMainDiv();
 }
-function tt_OpaSupport()
+function tt_OpaSupport(): void
 {
 	var css = tt_body.style;
 
@@ -474,7 +474,7 @@ function tt_OpaSupport()
 }
 // Ported from http://dean.edwards.name/weblog/2006/06/again/
 // (Dean Edwards et al.)
-function tt_SetOnloadFnc()
+function tt_SetOnloadFnc(): void
 {
 	tt_AddEvtFnc(document, "DOMContentLoaded", tt_HideSrcTags);
 	tt_AddEvtFnc(window, "load", tt_HideSrcTags);
@@ -497,7 +497,7 @@ function tt_SetOnloadFnc()
 				}, 10);
 	}
 }
-function tt_HideSrcTags()
+function tt_HideSrcTags(): void
 {
 	if(!window.tt_HideSrcTags || window.tt_HideSrcTags.done) {
 		return;
@@ -510,7 +510,7 @@ function tt_HideSrcTags()
 				" tooltip configuration to true.", true);
 	}
 }
-function tt_HideSrcTagsRecurs(dad)
+function tt_HideSrcTagsRecurs(dad): void
 {
 	var ovr, asT2t;
 	// Walk the DOM tree for tags that have an onmouseover or onclick attribute
@@ -539,7 +539,7 @@ function tt_HideSrcTagsRecurs(dad)
 	}
 	return true;
 }
-function tt_HideSrcTag(sT2t)
+function tt_HideSrcTag(sT2t): void
 {
 	var id, el;
 
@@ -560,7 +560,7 @@ function tt_HideSrcTag(sT2t)
 	}
 	return true;
 }
-function tt_Tip(arg, t2t)
+function tt_Tip(arg, t2t): void
 {
 	if(!tt_db || (tt_iState & 0x8)) {
 		return;
@@ -590,7 +590,7 @@ function tt_Tip(arg, t2t)
 	tt_ShowInit();
 	tt_Move();
 }
-function tt_ReadCmds(a)
+function tt_ReadCmds(a): void
 {
 	var i;
 
@@ -612,7 +612,7 @@ function tt_ReadCmds(a)
 	tt_Err("Incorrect call of Tip() or TagToTip().\n Each command must be followed by a value.", true);
 	return false;
 }
-function tt_AdaptConfig1()
+function tt_AdaptConfig1(): void
 {
 	tt_ExtCallFncs(0, "LoadConfig");
 	// Inherit unspecified title formattings from body
@@ -654,7 +654,7 @@ function tt_AdaptConfig1()
 		tt_aV[DELAY] = Math.max(tt_aV[DELAY] - tt_aV[FADEIN], 100);
 	}
 }
-function tt_AdaptConfig2()
+function tt_AdaptConfig2(): void
 {
 	if(tt_aV[CENTERMOUSE])
 	{
@@ -663,7 +663,7 @@ function tt_AdaptConfig2()
 	}
 }
 // Expose content globally so extensions can modify it
-function tt_MkTipContent(a)
+function tt_MkTipContent(a): void
 {
 	if(tt_t2t)
 	{
@@ -678,7 +678,7 @@ function tt_MkTipContent(a)
 	}
 	tt_ExtCallFncs(0, "CreateContentString");
 }
-function tt_MkTipSubDivs()
+function tt_MkTipSubDivs(): void
 {
 	var sCss = 'position:relative;margin:0px;padding:0px;border-width:0px;left:0px;top:0px;line-height:normal;width:auto;',
 	sTbTrTd = ' cellspacing="0" cellpadding="0" border="0" style="' + sCss + '"><tbody style="' + sCss + '"><tr><td ';
@@ -717,7 +717,7 @@ function tt_MkTipSubDivs()
 	}
 	tt_ExtCallFncs(0, "SubDivsCreated");
 }
-function tt_GetSubDivRefs()
+function tt_GetSubDivRefs(): void
 {
 	var aId = new Array("WzTiTl", "WzTiTlTb", "WzTiTlI", "WzClOsE", "WzBoDy", "WzBoDyI", "WzTtShDwB", "WzTtShDwR");
 
@@ -725,7 +725,7 @@ function tt_GetSubDivRefs()
 		tt_aElt[i] = tt_GetElt(aId[i - 1]);
 	}
 }
-function tt_FormatTip()
+function tt_FormatTip(): void
 {
 	var css, w, h, pad = tt_aV[PADDING], padT, wBrd = tt_aV[BORDERWIDTH],
 	iOffY, iOffSh, iAdd = (pad + wBrd) << 1;
@@ -863,7 +863,7 @@ function tt_FormatTip()
 	tt_FixSize(iOffY, iOffSh);
 }
 // Fixate the size so it can't dynamically change while the tooltip is moving.
-function tt_FixSize(iOffY, iOffSh)
+function tt_FixSize(iOffY, iOffSh): void
 {
 	var wIn, wOut, h, add, pad = tt_aV[PADDING], wBrd = tt_aV[BORDERWIDTH], i;
 
@@ -910,7 +910,7 @@ function tt_FixSize(iOffY, iOffSh)
 		tt_aElt[i].style.height = tt_h + "px";
 	}
 }
-function tt_DeAlt(el)
+function tt_DeAlt(el): void
 {
 	var aKid;
 
@@ -932,7 +932,7 @@ function tt_DeAlt(el)
 	}
 }
 // This hack removes the native tooltips over links in Opera
-function tt_OpDeHref(el)
+function tt_OpDeHref(el): void
 {
 	if(!tt_op) {
 		return;
@@ -956,7 +956,7 @@ function tt_OpDeHref(el)
 		el = tt_GetDad(el);
 	}
 }
-function tt_OpReHref()
+function tt_OpReHref(): void
 {
 	if(tt_elDeHref)
 	{
@@ -966,7 +966,7 @@ function tt_OpReHref()
 		tt_elDeHref = null;
 	}
 }
-function tt_El2Tip()
+function tt_El2Tip(): void
 {
 	var css = tt_t2t.style;
 
@@ -983,7 +983,7 @@ function tt_El2Tip()
 	css.position = "static";
 	css.left = css.top = css.marginLeft = css.marginTop = "0px";
 }
-function tt_UnEl2Tip()
+function tt_UnEl2Tip(): void
 {
 	// Restore positioning and display
 	var css = tt_t2t.style;
@@ -995,7 +995,7 @@ function tt_UnEl2Tip()
 	css.top = tt_t2t.t_ct;
 	tt_t2tDad = null;
 }
-function tt_OverInit()
+function tt_OverInit(): void
 {
 	if(window.event) {
 		tt_over = window.event.target || window.event.srcElement;
@@ -1005,14 +1005,14 @@ function tt_OverInit()
 	tt_DeAlt(tt_over);
 	tt_OpDeHref(tt_over);
 }
-function tt_ShowInit()
+function tt_ShowInit(): void
 {
 	tt_tShow.Timer("tt_Show()", tt_aV[DELAY], true);
 	if(tt_aV[CLICKCLOSE] || tt_aV[CLICKSTICKY]) {
 		tt_AddEvtFnc(document, "mouseup", tt_OnLClick);
 	}
 }
-function tt_Show()
+function tt_Show(): void
 {
 	var css = tt_aElt[0].style;
 
@@ -1035,7 +1035,7 @@ function tt_Show()
 	}
 	tt_ShowIfrm();
 }
-function tt_ShowIfrm()
+function tt_ShowIfrm(): void
 {
 	if(tt_ie56)
 	{
@@ -1048,7 +1048,7 @@ function tt_ShowIfrm()
 		}
 	}
 }
-function tt_Move(e)
+function tt_Move(e): void
 {
 	if(e) {
 		tt_ovr_ = e.target || e.srcElement;
@@ -1081,7 +1081,7 @@ function tt_Move(e)
 		tt_ExtCallFncs([tt_musX, tt_musY], "MoveAfter");
 	}
 }
-function tt_Pos(iDim)
+function tt_Pos(iDim): void
 {
 	var iX, bJmpMod, cmdAlt, cmdOff, cx, iMax, iScrl, iMus, bJmp;
 
@@ -1140,7 +1140,7 @@ function tt_Pos(iDim)
 	}
 	return iX;
 }
-function tt_PosDef(iDim)
+function tt_PosDef(iDim): void
 {
 	if(iDim) {
 		tt_bJmpVert = tt_aV[ABOVE];
@@ -1150,7 +1150,7 @@ function tt_PosDef(iDim)
 	}
 	return tt_CalcPosDef(iDim);
 }
-function tt_PosAlt(iDim)
+function tt_PosAlt(iDim): void
 {
 	if(iDim) {
 		tt_bJmpVert = !tt_aV[ABOVE];
@@ -1160,11 +1160,11 @@ function tt_PosAlt(iDim)
 	}
 	return tt_CalcPosAlt(iDim);
 }
-function tt_CalcPosDef(iDim)
+function tt_CalcPosDef(iDim): void
 {
 	return iDim ? (tt_musY + tt_aV[OFFSETY]) : (tt_musX + tt_aV[OFFSETX]);
 }
-function tt_CalcPosAlt(iDim)
+function tt_CalcPosAlt(iDim): void
 {
 	var cmdOff = iDim ? OFFSETY : OFFSETX;
 	var dx = tt_aV[cmdOff] - (tt_aV[SHADOW] ? tt_aV[SHADOWWIDTH] : 0);
@@ -1173,7 +1173,7 @@ function tt_CalcPosAlt(iDim)
 	}
 	return((iDim ? (tt_musY - tt_h) : (tt_musX - tt_w)) - dx);
 }
-function tt_PosFix()
+function tt_PosFix(): void
 {
 	var iX, iY;
 
@@ -1209,7 +1209,7 @@ function tt_PosFix()
 	}
 	tt_SetTipPos(iX, iY);
 }
-function tt_Fade(a, now, z, n)
+function tt_Fade(a, now, z, n): void
 {
 	if(n)
 	{
@@ -1226,7 +1226,7 @@ function tt_Fade(a, now, z, n)
 		tt_Hide();
 	}
 }
-function tt_SetTipOpa(opa)
+function tt_SetTipOpa(opa): void
 {
 	// To circumvent the opacity nesting flaws of IE, we set the opacity
 	// for each sub-DIV separately, rather than for the container DIV.
@@ -1241,7 +1241,7 @@ function tt_SetTipOpa(opa)
 		tt_SetOpa(tt_aElt[8], opa);
 	}
 }
-function tt_OnCloseBtnOver(iOver)
+function tt_OnCloseBtnOver(iOver): void
 {
 	var css = tt_aElt[4].style;
 
@@ -1249,7 +1249,7 @@ function tt_OnCloseBtnOver(iOver)
 	css.background = tt_aV[CLOSEBTNCOLORS][iOver];
 	css.color = tt_aV[CLOSEBTNCOLORS][iOver + 1];
 }
-function tt_OnLClick(e)
+function tt_OnLClick(e): void
 {
 	//  Ignore right-clicks
 	e = e || window.event;
@@ -1265,7 +1265,7 @@ function tt_OnLClick(e)
 		}
 	}
 }
-function tt_Int(x)
+function tt_Int(x): void
 {
 	var y;
 
@@ -1285,7 +1285,7 @@ Number.prototype.EndTimer = function()
 		this.value = 0;
 	}
 };
-function tt_GetWndCliSiz(s)
+function tt_GetWndCliSiz(s): void
 {
 	var db, y = window["inner" + s], sC = "client" + s, sN = "number";
 	if(typeof y === sN)
@@ -1310,7 +1310,7 @@ function tt_GetWndCliSiz(s)
 		: document.body[sC]
 	);
 }
-function tt_SetOpa(el, opa)
+function tt_SetOpa(el, opa): void
 {
 	var css = el.style;
 
@@ -1361,7 +1361,7 @@ function tt_SetOpa(el, opa)
 		}
 	}
 }
-function tt_Err(sErr, bIfDebug)
+function tt_Err(sErr, bIfDebug): void
 {
 	if(tt_Debug || !bIfDebug) {
 		alert("Tooltip Script Error Message:\n\n" + sErr);
@@ -1369,7 +1369,7 @@ function tt_Err(sErr, bIfDebug)
 }
 
 //============  EXTENSION (PLUGIN) MANAGER  ===============//
-function tt_ExtCmdEnum()
+function tt_ExtCmdEnum(): void
 {
 	var s;
 
@@ -1384,7 +1384,7 @@ function tt_ExtCmdEnum()
 		}
 	}
 }
-function tt_ExtCallFncs(arg, sFnc)
+function tt_ExtCallFncs(arg, sFnc): void
 {
 	var b = false;
 	for(var i = tt_aExt.length; i;)
diff --git a/themes/rule34v2/index.theme.php b/themes/rule34v2/index.theme.php
index ebbaf1f8..02602f56 100644
--- a/themes/rule34v2/index.theme.php
+++ b/themes/rule34v2/index.theme.php
@@ -6,6 +6,7 @@ namespace Shimmie2;
 
 class CustomIndexTheme extends IndexTheme
 {
+    /** @var string[] */
     public static array $_search_query = [];
 
     // override to add the can-del class, so that thumbnail HTML can be cached
diff --git a/themes/rule34v2/user.theme.php b/themes/rule34v2/user.theme.php
index eee5257d..1c16c0b3 100644
--- a/themes/rule34v2/user.theme.php
+++ b/themes/rule34v2/user.theme.php
@@ -27,7 +27,10 @@ class CustomUserPageTheme extends UserPageTheme
     // (with css media queries deciding which one is visible), and also
     // to switch between new-line and inline display depending on the
     // number of links.
-    public function display_user_block(Page $page, User $user, $parts): void
+    /**
+     * @param array<array{link: string, name: string}> $parts
+     */
+    public function display_user_block(Page $page, User $user, array $parts): void
     {
         $h_name = html_escape($user->name);
         $lines = [];
diff --git a/themes/warm/user.theme.php b/themes/warm/user.theme.php
index 7904a34e..c5239876 100644
--- a/themes/warm/user.theme.php
+++ b/themes/warm/user.theme.php
@@ -6,7 +6,10 @@ namespace Shimmie2;
 
 class CustomUserPageTheme extends UserPageTheme
 {
-    public function display_user_block(Page $page, User $user, $parts): void
+    /**
+     * @param array<array{link: string, name: string}> $parts
+     */
+    public function display_user_block(Page $page, User $user, array $parts): void
     {
         $h_name = html_escape($user->name);
         $html = " | ";