diff --git a/src/Database/Database.php b/src/Database/Database.php
index 52d2b2761..23eb1e0bc 100644
--- a/src/Database/Database.php
+++ b/src/Database/Database.php
@@ -1141,7 +1141,7 @@ public function skipFilters(callable $callback, ?array $filters = null): mixed
     /**
      * Get instance filters
      *
-     * @return array<string, array{encode: callable, decode: callable}>
+     * @return array<string, array{encode: callable, decode: callable, signature: string}>
      */
     public function getInstanceFilters(): array
     {
diff --git a/tests/unit/CacheKeyTest.php b/tests/unit/CacheKeyTest.php
new file mode 100644
index 000000000..7e5e41d44
--- /dev/null
+++ b/tests/unit/CacheKeyTest.php
@@ -0,0 +1,133 @@
+<?php
+
+namespace Tests\Unit;
+
+use PHPUnit\Framework\TestCase;
+use Utopia\Cache\Adapter\None;
+use Utopia\Cache\Cache;
+use Utopia\Database\Adapter;
+use Utopia\Database\Database;
+
+class CacheKeyTest extends TestCase
+{
+    /**
+     * @param array<string, array{encode: callable, decode: callable}> $instanceFilters
+     */
+    private function createDatabase(array $instanceFilters = []): Database
+    {
+        $adapter = $this->createMock(Adapter::class);
+        $adapter->method('getSupportForHostname')->willReturn(false);
+        $adapter->method('getTenant')->willReturn(null);
+        $adapter->method('getNamespace')->willReturn('test');
+
+        return new Database($adapter, new Cache(new None()), $instanceFilters);
+    }
+
+    private function getHashKey(Database $db, string $collection = 'col', string $docId = 'doc1'): string
+    {
+        [, , $hashKey] = $db->getCacheKeys($collection, $docId);
+        return $hashKey;
+    }
+
+    public function testSameConfigProducesSameCacheKey(): void
+    {
+        $db1 = $this->createDatabase();
+        $db2 = $this->createDatabase();
+
+        $this->assertEquals($this->getHashKey($db1), $this->getHashKey($db2));
+    }
+
+    public function testDifferentSelectsProduceDifferentCacheKeys(): void
+    {
+        $db = $this->createDatabase();
+
+        [, , $hashA] = $db->getCacheKeys('col', 'doc1', ['name']);
+        [, , $hashB] = $db->getCacheKeys('col', 'doc1', ['email']);
+
+        $this->assertNotEquals($hashA, $hashB);
+    }
+
+    public function testSelectOrderDoesNotAffectCacheKey(): void
+    {
+        $db = $this->createDatabase();
+
+        [, , $hashA] = $db->getCacheKeys('col', 'doc1', ['name', 'email']);
+        [, , $hashB] = $db->getCacheKeys('col', 'doc1', ['email', 'name']);
+
+        $this->assertEquals($hashA, $hashB);
+    }
+
+    public function testInstanceFilterOverrideProducesDifferentCacheKey(): void
+    {
+        $noop = function (mixed $value) {
+            return $value;
+        };
+
+        $dbDefault = $this->createDatabase();
+        $dbOverride = $this->createDatabase([
+            'json' => [
+                'encode' => $noop,
+                'decode' => $noop,
+            ],
+        ]);
+
+        $this->assertNotEquals(
+            $this->getHashKey($dbDefault),
+            $this->getHashKey($dbOverride)
+        );
+    }
+
+    public function testDifferentInstanceFilterCallablesProduceDifferentCacheKeys(): void
+    {
+        $noopA = function (mixed $value) {
+            return $value;
+        };
+        $noopB = function (mixed $value) {
+            return $value;
+        };
+
+        $dbA = $this->createDatabase([
+            'myFilter' => [
+                'encode' => $noopA,
+                'decode' => $noopA,
+            ],
+        ]);
+        $dbB = $this->createDatabase([
+            'myFilter' => [
+                'encode' => $noopB,
+                'decode' => $noopB,
+            ],
+        ]);
+
+        $this->assertNotEquals(
+            $this->getHashKey($dbA),
+            $this->getHashKey($dbB)
+        );
+    }
+
+    public function testDisabledFiltersProduceDifferentCacheKey(): void
+    {
+        $db = $this->createDatabase();
+
+        $hashEnabled = $this->getHashKey($db);
+
+        $hashDisabled = $db->skipFilters(function () use ($db) {
+            return $this->getHashKey($db);
+        }, ['json']);
+
+        $this->assertNotEquals($hashEnabled, $hashDisabled);
+    }
+
+    public function testFiltersDisabledEntirelyProducesDifferentCacheKey(): void
+    {
+        $db = $this->createDatabase();
+
+        $hashEnabled = $this->getHashKey($db);
+
+        $db->disableFilters();
+        $hashDisabled = $this->getHashKey($db);
+        $db->enableFilters();
+
+        $this->assertNotEquals($hashEnabled, $hashDisabled);
+    }
+}