Call a tool by name. This is the public API for executing tools. By default, middleware is applied. Args: name: The tool

List all enabled tools from providers. Overrides Provider.list_tools() to add enabled filtering, auth filtering, and middleware execu

Return the value for `key`, or `default` when it is not set.

Create a Tool from a function.

Add a server-level transform. Server-level transforms are applied after all providers are aggregated. They transform tools, resources

Mount another FastMCP server on this server with an optional namespace. Mounting establishes a dynamic connection between servers. When a cli

List all enabled resources from providers. Overrides Provider.list_resources() to add visibility filtering, auth filtering, and middl

Add a provider for dynamic tools, resources, and prompts. Providers are queried in registration order. The first provider to return a

Send a `DEBUG`-level message to the connected MCP Client. Messages sent to Clients are also logged to the `fastmcp.server.context.to_client`

Enter the server lifespan (Docket backend + worker) for the block.

Register a server extension (SEP-2133). An extension contributes a negotiated capability, additive request methods, a `tools/call` in

Store `value` under `key` in this session (read-modify-write). Preserves the creation marker: only the user-state sub-dict is touched.

Get a logger nested under FastMCP namespace. Args: name: the name of the logger, which will be prefixed with 'FastMCP.' Returns:

Disable components matching all specified criteria. Adds a visibility transform that marks matching components as disabled. Component

List all enabled prompts from providers. Overrides Provider.list_prompts() to add visibility filtering, auth filtering, and middlewar

Convert JSON schema to appropriate Python type with validation. Args: schema: A JSON Schema dictionary defining the type structure and va

Read a resource by URI. This is the public API for reading resources. By default, middleware is applied. Checks concrete resources fi

Run an opted-in `tools/call` through the interceptor and return its task.

Generate a test JWT token using symmetric key for testing purposes. Args: subject: Subject claim (usually user ID)

Create a Starlette app using the specified HTTP transport. Args: path: The path for the HTTP endpoint middleware: A l

List all enabled resource templates from providers. Overrides Provider.list_resource_templates() to add visibility filtering, auth fi

Create a FastMCP proxy server for the given target. This is the recommended way to create a proxy server. For lower-level control, use `FastM

Return the serialized snapshot a stored value holds.

Get a prompt by name, filtering disabled prompts. Overrides Provider.get_prompt() to add visibility filtering after all transforms (i

Look up a cached verification result. Returns: ``(True, AccessToken)`` on a cache hit, ``(False, None)`` on a miss or

Send a `WARNING`-level message to the connected MCP Client. Messages sent to Clients are also logged to the `fastmcp.server.context.to_client

Create a test access token.

Poll `tasks/get` until the task reaches one of `target_states`.

Delegate route creation to the server.

Get a tool by name, filtering disabled tools. Overrides Provider.get_tool() to filter disabled tools after all transforms (including

Reset all state for next test.

Mock token verification.

Format the universal name for a backend tool: ``<hash>_<local_name>``.

Encode cursor state to an opaque string.

Decode cursor from an opaque string. Raises: ValueError: If the cursor is invalid or malformed.

Compress and optimize a JSON schema for MCP compatibility. Args: schema: The schema to compress prune_params: List of parame

Override to preserve _backend_name when name changes.

Combines parameter and request body schemas into a single schema. Handles parameter name collisions by adding location suffixes. Also ret

POST a jwt-bearer grant to the proxy's /token endpoint via an ASGI app. When ``register`` is True the standard test client is registered first; p

Return the stored form of a serialized snapshot.

Check if a version matches this spec. Args: version: The version to check, or None for unversioned. match_none: Wheth

Set the access token in the auth context var.

Render a prompt by name. This is the public API for rendering prompts. By default, middleware is applied. Use get_prompt() to retriev

Mint a fake ID-JAG JWT with full control over header and claims. `client_id` and `resource` default to values matching the standard test clie

Send a `ERROR`-level message to the connected MCP Client. Messages sent to Clients are also logged to the `fastmcp.server.context.to_client`

Convert an OpenAPI schema to JSON Schema format. This is a clean, systematic approach that: 1. Removes OpenAPI-specific fields 2. Co

Create a copy of the component.

The accepted elicitation will contain the response data

Render the prompt with arguments. Subclasses must implement this method. Return one of: - str: Wrapped as single user Message

Get the FastMCP access token from the current context. This function first tries to get the token from the current HTTP request's scope, whic

Send a cancellation notification for an in-progress request.

Require all of the given OAuth scopes.

Start a FastMCP server on a real port as an asyncio task. This runs a real uvicorn server in the current process, bound to a real TCP port,

Enable components matching all specified criteria. Adds a visibility transform that marks matching components as enabled. Later trans

Create a mock tool for testing.

Run auth checks with AND logic, stopping at the first failure.

Add a tool to the server. The tool function can optionally request a Context object by adding a parameter with the Context type annot

Parse scopes from environment variables or settings values. Accepts either a JSON array string, a comma- or space-separated string, a list of

TypeAdapters are heavy objects, and in an application context we'd typically create them once in a global scope and reuse them as often as po

Extract information from a FastMCP instance into a dataclass. This function automatically detects whether the instance is FastMCP v1.x or v2.x

Securely check if a URI matches an allowed pattern with wildcard support. This function parses both the URI and pattern as URLs, comparing each

Add two numbers.

Create a resource from the template with the given parameters. The base implementation does not support background tasks. Use Functio

Find an available port by letting the OS assign one.

Send a `INFO`-level message to the connected MCP Client. Messages sent to Clients are also logged to the `fastmcp.server.context.to_client` l

Check if the client is currently connected.

Convert the FastMCP tool to an MCP tool.

Return an instance of the StreamableHTTP server app. Args: server: The FastMCP server instance streamable_http_path: Path for Str

Submit a task and wait for it to reach a terminal state.

Import a Python file as a module. If the file is part of a package (directory has __init__.py), imports it as a proper package member (relati

Check if component is enabled. Returns True if: - No visibility mark exists (default is enabled) - Visibility mark is True Returns F

Send a log message to the client. Messages sent to Clients are also logged to the `fastmcp.server.context.to_client` logger with a level of `

Temporarily override FastMCP setting values. Args: **kwargs: The settings to override, including nested settings. Example: