> ## Documentation Index
> Fetch the complete documentation index at: https://kawax.biz/llms.txt
> Use this file to discover all available pages before exploring further.

# Tools

> Define and handle custom tools in Laravel Copilot SDK, including permissions, invocation metadata, and MCP result conversion.

## Tools

Built-in Copilot CLI tools are enabled by default. The settings here apply to custom tools.

## Basic usage

Set tool definitions in `SessionConfig.tools`.

`Tool::define()` is a helper equivalent to `defineTool` in other language SDKs.
For parameters, you can use Laravel's JSON Schema implementation (also used by Laravel MCP), or pass an array directly.

```php theme={null}
use Illuminate\Support\Facades\Artisan;
use Illuminate\JsonSchema\JsonSchema;
use Revolution\Copilot\Contracts\CopilotSession;
use Revolution\Copilot\Facades\Copilot;
use Revolution\Copilot\Types\SessionConfig;
use Revolution\Copilot\Types\Tool;
use Revolution\Copilot\Types\ToolResultObject;

use function Laravel\Prompts\{info, note, spin, warning};

Artisan::command('copilot:tools', function () {
    $facts = [
        'PHP' => 'A popular general-purpose scripting language that is especially suited to web development.',
        'Laravel' => 'A web application framework with expressive, elegant syntax.',
    ];

    $parameters = JsonSchema::object(
        properties: [
            'topic' => JsonSchema::string()
                ->description('Topic to look up (e.g., "PHP", "Laravel")')
                ->required(),
        ],
    )->toArray();

    $config = new SessionConfig(
        tools: [
            Tool::define(
                name: 'lookup_fact',
                description: 'Returns a fun fact about a given topic.',
                parameters: $parameters,
                handler: function (array $params, array $invocation) use ($facts): ToolResultObject {
                    $topic = $params['topic'] ?? '';

                    $fact = $facts[$topic] ?? null;

                    if (! $fact) {
                        return new ToolResultObject(
                            textResultForLlm: "No fact stored for {$topic}.",
                            resultType: 'failure',
                            sessionLog: "lookup_fact: missing topic {$topic}",
                            toolTelemetry: [],
                        );
                    }

                    return new ToolResultObject(
                        textResultForLlm: $fact,
                        resultType: 'success',
                        sessionLog: "lookup_fact: served {$topic}",
                        toolTelemetry: [],
                    );
                },
                overridesBuiltInTool: false,
                skipPermission: false, // Set to true to execute without a permission prompt
                defer: 'auto', // Controls whether the tool may be deferred (loaded lazily) rather than always pre-loaded. When `"auto"`, the tool can be deferred and surfaced through tool search. When `"never"`, the tool is always pre-loaded. Optional; defaults to `"auto"`.
            ),
        ],
    );

    Copilot::start(function (CopilotSession $session) {
        info('Starting Copilot with tools: '.$session->id());

        $prompt = 'You can call the lookup_fact tool. Use lookup_fact to tell me something about Laravel.';

        warning($prompt);

        $response = spin(
            callback: fn () => $session->sendAndWait($prompt),
            message: 'Copilot thinking...',
        );

        note($response->content());
    }, config: $config);
});
```

## `skipPermission`

When you set `skipPermission: true`, the tool runs without a permission prompt.

```php theme={null}
Tool::define(
    name: 'read_only_lookup',
    description: 'Read-only data lookup.',
    parameters: $parameters,
    handler: fn ($params) => new ToolResultObject(
        textResultForLlm: 'data',
        resultType: 'success',
        sessionLog: 'read_only_lookup',
        toolTelemetry: [],
    ),
    skipPermission: true,
),
```

## `$invocation`

The second argument of the tool handler, `$invocation`, includes:

```php theme={null}
[
    'sessionId'  => '...',
    'toolCallId' => '...',
    'toolName'   => 'lookup_fact',
    'arguments'  => [...], // Tool args (same content as $params)
    // Included only when OpenTelemetry is enabled
    'traceparent' => '...', // W3C Trace Context traceparent
    'tracestate'  => '...', // W3C Trace Context tracestate
]
```

## Protocol details

In Protocol v3 (current default), tool calls are broadcast as session events (`external_tool.requested`) instead of JSON-RPC requests. The SDK handles this internally and responds with the `session.tools.handlePendingToolCall` RPC.

**You do not need to change how you use `SessionConfig`.** Pass definitions in `tools`, and the SDK handles protocol differences.

## Converting MCP `CallToolResult`

To convert an MCP server tool result (`CallToolResult`) into Copilot SDK `ToolResultObject`, use `McpCallToolResult::convert()`.
MCP results contain `content` blocks such as text, image, and resource, but Copilot SDK expects `ToolResultObject`.

```php theme={null}
use Revolution\Copilot\Support\McpCallToolResult;

// MCP CallToolResult format
$mcpResult = [
    'content' => [
        ['type' => 'text', 'text' => 'File contents here'],
        ['type' => 'image', 'data' => 'base64...', 'mimeType' => 'image/png'],
    ],
    'isError' => false,
];

// Convert to Copilot SDK ToolResultObject format
$toolResult = McpCallToolResult::convert($mcpResult);
// $toolResult->textResultForLlm => 'File contents here'
// $toolResult->resultType => 'success'
// $toolResult->binaryResultsForLlm => [['data' => 'base64...', 'mimeType' => 'image/png', 'type' => 'image']]
```

<Info>
  For the latest updates, see the [GitHub repository](https://github.com/invokable/laravel-copilot-sdk).
</Info>


## Related topics

- [Laravel MCP](/en/mcp.md)
- [Laravel AI SDK](/en/ai-sdk.md)
- [Laravel PAO — Agent-Optimized Output for PHP Tools](/en/blog/pao-introduction.md)
- [Session hooks](/en/packages/laravel-copilot-sdk/hooks.md)
- [Streaming events](/en/packages/laravel-copilot-sdk/streaming-events.md)