Build complete uv run command with environment args and command to execute. Args: command: Command to execute (e.g., ["fastmcp",

Run a `tools/call` with no tasks opt-in (synchronous unless mode=required).

Parse MCP configuration from dictionary format.

Issue a minimal FastMCP access token. FastMCP tokens are reference tokens containing only the minimal claims needed for validation an

Turn CLI inputs into something ``Client()`` accepts. Exactly one of ``server_spec`` or ``command`` should be provided. Resolution order for

Validate redirect URI against proxy patterns and optionally CIMD redirect_uris. For CIMD clients: validates against BOTH the CIMD document's

Extract tool list from a ToolResult's structured content.

Assert that a hook was not called.

Get the current FastMCP Context instance directly.

Get the meta information about the component. Returns a dict that always includes a `fastmcp` key containing: - `tags`: sorted list o

Match URI against template and extract both path and query parameters. Supports RFC 6570 URI templates: - Path params: `{var}`, `{var*}`

Parse a function's docstring into a summary and parameter descriptions. Tries Google, NumPy, and Sphinx parsers in order, using the first one tha

Parses an OpenAPI schema dictionary into a list of HTTPRoute objects using the openapi-pydantic library. Supports both OpenAPI 3.0.x and

Run the tool with arguments. This method is not implemented in the base Tool class and must be implemented by subclasses.

Fetch URL with comprehensive SSRF protection and DNS pinning. Security measures: 1. HTTPS only 2. DNS resolution with IP validation 3

Verify a Clerk OAuth token via introspection and userinfo. Calls the introspection endpoint first to validate the token and retrieve

Set visibility state in component metadata if rule matches. Returns a copy of the component with updated metadata to avoid mutating s

Serve a FastMCP server's HTTP app in-process, with no socket and no uvicorn. This is the fastest way to test a FastMCP server over HTTP. The

Send a tools/call request and return the complete MCP protocol result. This method returns the raw CallToolResult object, which includes an i

Fetch and validate a CIMD document with SSRF protection. Uses ssrf_safe_fetch_response for the HTTP layer, which provides: - HTTPS on

Check if a callable is a coroutine function, unwrapping functools.partial. ``inspect.iscoroutinefunction`` returns ``False`` for ``functools.

Send a ping request.

Set the MCP endpoint path and create JWTIssuer with correct audience. This method is called by get_routes() to configure the resource URL

Set a value in the state store. By default, values are stored in the session-scoped state store and persist across requests within th

Add a tool to this app programmatically. The tool is tagged with this app's name for routing.

Await a coroutine while monitoring the session task for errors. When using HTTP transports, server errors (4xx/5xx) are raised in the

Create a CLIENT span with standard MCP attributes. Automatically records any exception on the span and sets error status.

Coerce a string CLI value according to a JSON-Schema type hint.

Resolve all $ref references in a JSON schema by inlining definitions. This function resolves $ref references that point to $defs, replacing them

Get a value from the state store. Checks request-scoped state first (set with ``serializable=False``), then falls back to the session

Call the `tasks/get` handler within the given auth scope.

Check if this environment config requires uv to set up. Returns: True if any environment settings require uv run

The lowlevel Server the SDK client connects to in-process.

Every tool name the rendered UI would call, in document order.

Assert that a hook was called a specific number of times.

Create a test client for the FastMCP server.

Remove `key` from this session, if present (preserves the marker).

Check if cls is a member of base, even if cls is a type variable. Base can be a type, a UnionType, or an Annotated type. Generic types are n

A guard tool that asks two dependent questions across three rounds. Round 1 (no responses): ask for a destination. Round 2 (destination answe

Validate that a redirect_uri is allowed by the CIMD document. Uses component-level matching (scheme, host, port, path) which correctly

Generate the source for a single ``@call_tool_app.command`` function.

Get the schema for an elicitation response. Args: response_type: The type of the response

Register client and start auth; returns (txn_id, consent_url).

Bind a ``FastMCPRequestContext`` for the duration of a handler. Constructs the wrapper from the SDK's per-request context and sets/resets the

Create an AzureProvider pre-configured for Azure AD B2C. Derives authority host, tenant path, and identifier URI from `tenant_name` a

Check a redirect URI against RFC 7591 / SEP-837 `application_type` rules. `application_type` governs which redirect URIs a Dynamically Registered

Validate a JWT bearer token and return an AccessToken when the token is valid. Parameters: token (str): The JWT bearer t

Store a *successful* verification result. Only successful verifications should be cached. Failures (inactive tokens, missing scopes,

Verify token using custom validation logic. Args: token: The token string to validate Returns: AccessToken i

Extract the primary MIME type from an HTTPRoute's response definitions. Looks for the first successful response (2xx) and returns its content typ

Get auth context for the current request. Returns a tuple of (skip_auth, token) where: - skip_auth=True means auth checks should be skipped (

Return the SHA-256 hex digest of *token*.

Extract a string result from a ToolResult. String results are wrapped in ``{"result": "..."}`` by the structured-output convention.

Create a TransformedTool from a provided tool and this transformation configuration.

Call a tool as a background task and return a `ToolTask` handle immediately. Unlike `client.call_tool` (which polls to completion transparently),

Helper to create a FastMCP server with OpenAPIProvider.

Expand a URI template with parameters — inverse of `match_uri_template`. Supports the same RFC 6570 subset: - Path params: `{var}`, `{var*}`

Generate a SKILL.md file for a generated CLI script.

Delegate well-known route creation to the server. This ensures that server-specific well-known route logic (e.g., OAuthProvider's RFC

Deterministic hex hash for a tool in an app. Same inputs on every replica produce the same output.

Check if the client is currently connected.

The globally unique lookup key for this resource.

Construct the lookup key for this component type. Args: identifier: The raw identifier (name for tools/prompts, uri for resources

Build a minimal SDK ServerRequestContext for direct handler unit tests. The v2 SDK hands handlers a ``ServerRequestContext`` argument. Tests that

Drive the task to completion and return its parsed result. Answers any input prompts through the client's elicitation handler. Raises

Run the FastMCP server asynchronously. Args: transport: Transport protocol to use ("stdio", "http", "sse", or "streamable-http")

Propagate MCP path to the server and all verifiers.

Serialize to JSON for Redis storage.

Extract CSRF token from HTML form.

Return True if the resolved target will use an HTTP-based transport. MCPConfig dicts are excluded because ``MCPConfigTransport`` manages indi

Check if this transform applies to the component. All specified criteria must match (intersection semantics). An empty rule (no crite

Prepare scopes for Azure token refresh. Azure requires fully-qualified scopes and only allows ONE resource per token request (AADSTS2

Replace openapi $ref with jsonschema $defs recursively. Examples: - {"type": "object", "properties": {"$ref": "#/components/schemas/..."

Add a prompt to the server. Args: prompt: A Prompt instance or @prompt-decorated function to add Returns: Th

Assert that a hook was called a specific number of times.

Bind (or clear) the auth context so `get_task_scope` sees a caller.

Generate a CIMD document for hosting. Create a Client ID Metadata Document that you can host at an HTTPS URL. The URL where you host this doc

Drive an httpx auth flow to completion, feeding each yield to responder.

Extract all MCP components from a module. Scans all module attributes for instances of Tool, Resource, ResourceTemplate, or Prompt objects cr

Generate a standalone CLI script from an MCP server. Connects to the server, reads its tools/resources/prompts, and writes a Python script th

Get log lines from a caplog fixture.

Get the current FastMCP server instance directly. In a background-task worker the tasks extension's resolver is consulted first, so a mounted