{"record":{"id":"a892d5115c296943","repo":"laravel/framework","slug":"the-cast-object-for-the-attribute-attribute-mus","errorCode":null,"errorMessage":"The cast object for the {$attribute} attribute must implement Stringable.","messagePattern":"The cast object for the (.+?) attribute must implement Stringable\\.","errorType":"exception","errorClass":"InvalidArgumentException","httpStatus":null,"severity":"error","filePath":"src/Illuminate/Database/Eloquent/Concerns/HasAttributes.php","lineNumber":821,"sourceCode":"\n    /**\n     * Ensure that the given casts are strings.\n     *\n     * @param  array  $casts\n     * @return array\n     *\n     * @throws \\InvalidArgumentException\n     */\n    protected function ensureCastsAreStringValues($casts)\n    {\n        foreach ($casts as $attribute => $cast) {\n            $casts[$attribute] = match (true) {\n                is_object($cast) => value(function () use ($cast, $attribute) {\n                    if ($cast instanceof Stringable) {\n                        return (string) $cast;\n                    }\n\n                    throw new InvalidArgumentException(\n                        \"The cast object for the {$attribute} attribute must implement Stringable.\"\n                    );\n                }),\n                is_array($cast) => value(function () use ($cast) {\n                    if (count($cast) === 1) {\n                        return $cast[0];\n                    }\n\n                    [$cast, $arguments] = [array_shift($cast), $cast];\n\n                    return $cast.':'.implode(',', $arguments);\n                }),\n                default => $cast,\n            };\n        }\n\n        return $casts;\n    }","sourceCodeStart":803,"sourceCodeEnd":839,"githubUrl":"https://github.com/laravel/framework/blob/e0f6eb3518ac29fbbca8529e97d0df7fc9f24481/src/Illuminate/Database/Eloquent/Concerns/HasAttributes.php#L803-L839","documentation":"Thrown by ensureCastsAreStringValues() when a cast entry is an object that does not implement Stringable. When casts are merged/resolved, Laravel normalizes each cast to a string form (e.g. 'ClassName:arg1,arg2'); an object that cannot be cast to string via __toString breaks that normalization, so it is rejected with an explicit error.","triggerScenarios":"Assigning a non-Stringable object instance to $casts (e.g. protected $casts = ['data' => new SomeCaster];) where SomeCaster does not implement \\Stringable. Triggered when casts are processed/merged (e.g. via mergeCasts / hasCasts / getCasts).","commonSituations":"Passing a custom caster class instance (instead of its class name) that was not marked Stringable; third-party cast package whose object form predates the Stringable requirement; refactoring casts from strings to object instances during an upgrade.","solutions":["Implement \\Stringable on the caster class and add __toString() returning the cast string (e.g. the class name).","Use the class name string (e.g. SomeCaster::class) in $casts instead of an instance.","If using a class-based cast, register it via the Castable infrastructure or as 'classname:args'."],"exampleFix":"// before\nprotected $casts = [\n    'settings' => new App\\Casts\\SettingsCast, // not Stringable\n];\n\n// after\nclass SettingsCast implements \\Stringable\n{\n    public function __toString(): string\n    {\n        return static::class;\n    }\n}\n\nprotected $casts = [\n    'settings' => new App\\Casts\\SettingsCast,\n];","handlingStrategy":"validation","validationCode":"foreach ((function () { $m = new YourModel; $r = new \\ReflectionObject($m); return $r->getProperty('casts')->getValue($m); })() as $attr => $cast) {\n    if (is_object($cast) && ! ($cast instanceof \\Stringable)) {\n        throw new \\LogicException(\"Cast for {$attr} must implement Stringable\");\n    }\n}","typeGuard":"function castObjectIsStringable(mixed $cast): bool\n{\n    return is_object($cast) && $cast instanceof \\Stringable;\n}","tryCatchPattern":null,"preventionTips":["Prefer class-name strings in $casts over object instances.","If using a caster object, implement \\Stringable with __toString().","Add a boot-time test that iterates $casts and asserts each object entry is Stringable."],"tags":["eloquent","cast","stringable","configuration"],"backgroundTag":null,"analyzedSha":"e0f6eb3518ac29fbbca8529e97d0df7fc9f24481","analyzedAt":"2026-08-11T20:52:37.562Z","contentChangedAt":null,"schemaVersion":2},"datasetVersion":"2026-09-23T08:17:48.524Z"}