resource-templates.md

Resource Templates

Resource templates are dynamic resources that use parameterized URIs with variables. They follow all the same rules as static resources (URI schemas, return values, MIME types, etc.) but accept {variable} placeholders in the URI.

Only simple RFC 6570 variable expansion is supported — {var}, one path segment each. Operators such as {+var}, {#var}, {/path}, {?query} and explode ({list*}) are not parsed, and a variable's value cannot contain /.

use Mcp\Capability\Attribute\McpResourceTemplate;

class UserProvider
{
    /**
     * Retrieves user profile information by ID.
     */
    #[McpResourceTemplate(
        uriTemplate: 'user://{userId}/profile/{section}',
        name: 'user_profile',
        description: 'User profile data by section',
        mimeType: 'application/json'
    )]
    public function getUserProfile(string $userId, string $section): array
    {
        return $this->users[$userId][$section] ?? throw new \InvalidArgumentException("Profile section not found");
    }
}

Parameters

• uriTemplate (required): URI with {variables}. Must start with a scheme (file://, user://, …) and contain at least one variable.
• name (optional): Short resource template identifier. Defaults to method name if not provided.
• title (optional): Human-readable display title shown in client UI. Distinct from name.
• description (optional): Template description. Falls back to the docblock (summary plus long description).
• mimeType (optional): MIME type of the resource content.
• annotations (optional): Additional metadata.
• meta (optional): Arbitrary key-value pairs for custom metadata.

Variable Rules

1. Variable names must match exactly between URI template and method parameters — they are bound by name, so the parameter order is free
2. All variables are required - no optional parameters supported
3. Type hints work normally - parameters can be typed (string, int, etc.)

Example mapping: user://123/profile/settings → getUserProfile("123", "settings")