MCP client that delegates connection management to a Transport instance. The Client class is responsible for MCP protocol logic, while the T

FastMCP server extension implementing SEP-2663 background tasks. Construct with backend/worker configuration; anything omitted falls back to

Intermediate Representation for a single OpenAPI operation.

OAuth provider that presents a DCR-compliant interface while proxying to non-DCR IDPs. Purpose ------- MCP clients expect OAuth providers

A Provider that represents an MCP application. Binds together entry-point tools (``@app.ui``), backend tools (``@app.tool``), and the Prefab

In-memory transport for FastMCP servers. This transport connects directly to a FastMCP server instance in the same Python process. It works w

JWT token verifier supporting both asymmetric (RSA/ECDSA) and symmetric (HMAC) algorithms. This verifier validates JWT tokens using various

Simple static token verifier for testing and development. This verifier validates tokens against a predefined dictionary of valid token

Transport implementation that connects to an MCP server via Streamable HTTP Requests.

Azure (Microsoft Entra) OAuth provider for FastMCP. This provider implements Azure/Microsoft Entra ID authentication using the OAuth Proxy pa

Configuration for transforming a parent tool's argument. This class allows fine-grained control over how individual arguments are transformed

Transform that collapses all tools into discovery + execute meta-tools. Discovery tools are composable via the ``discovery_tools`` parameter.

Specification for filtering components by version. Used by transforms and providers to filter components to a specific version or version ran

Provider for locally-defined components. Supports decorator-based registration (`@provider.tool`, `@provider.resource`, `@provider.prompt`) a

Represents the request body for an HTTP operation in our IR.

AccessToken that includes all JWT claims.

Context passed to auth check callables. Attributes: token: The current access token, or None if unauthenticated. component: The t

Represents a single parameter for an HTTP operation in our IR.

Wrapper for prompt message with auto-serialization. Accepts any content - strings pass through, other types (dict, list, BaseModel) are JSON-

Internal tool registration info.

Authentication provider for resource servers that verify tokens from known authorization servers. This provider composes a TokenVerifier with aut

OAuth client provider for MCP servers with browser-based authentication. This class provides OAuth authentication for FastMCP clients by ope

Context object providing access to MCP capabilities. This provides a cleaner interface to MCP's RequestContext functionality. It gets injecte

Composes an optional auth server with additional token verifiers. Use this when a single server needs to accept tokens from multiple sources.

Provider that creates MCP components from an OpenAPI specification. Components are created eagerly during initialization by parsing the OpenAPI

Configuration for a FastMCP server. This configuration file allows you to specify all settings needed to run a FastMCP server in a declarativ

A proxy client that forwards advanced interactions between a remote MCP server and the proxy's connected clients. Supports forwarding roots, samp

Wrapper for resource content with optional MIME type and metadata. Accepts any value for content - strings and bytes pass through directly, o

Provider that wraps a FastMCP server. This provider enables mounting one FastMCP server onto another, exposing the mounted server's tools, re

Provides a way to transform a tool.

Configuration for Python environment setup.

Sets visibility state on matching components. Does NOT filter inline - just marks components with visibility state. Later transforms in the c

OAuth provider that wraps OAuthProxy to provide configuration via an OIDC configuration URL. This provider makes it easier to add OAuth protectio

OAuth 2.0 Token Introspection verifier (RFC 7662). This verifier validates opaque tokens by calling an OAuth 2.0 token introspection end

Fallback used when MCP dependencies are not installed. Mirrors the real ``mcp.MCPError`` interface — the ``(code, message, data)`` co

UNSAFE: Uses exec() for testing only. Never use in production.

Canonical result type for resource reads. Provides explicit control over resource responses: multiple content items, per-item MIME types, and

Applies tool transformations to modify tool schemas. Wraps ToolTransformConfig to apply argument renames, schema changes, hidden arguments, a

Client for DCR proxy with configurable redirect URI validation. This special client class is critical for the OAuth proxy to work correctly w

Provider that discovers components from the filesystem. Scans a directory for Python files and registers any Tool, Resource, ResourceTemplate

Source for local Python files.

Search transform using regex pattern matching. Tools are matched against their name, description, and parameter information using ``re.search

Error in tool operations.

Transport implementation that connects to an MCP server via Server-Sent Events.

Descope metadata provider for Dynamic Client Registration (DCR). The provider accepts either a resource-specific Descope MCP Server URL such

Middleware that provides consistent error handling and logging. Catches exceptions, logs them appropriately, and converts them to proper MCP

Helper class for returning images from tools.

Provider that exposes a single skill folder as MCP resources. Each skill folder must contain a main file (default: SKILL.md) and may contain

Base class for FastMCP tools, prompts, resources, and resource templates.

Helper class for returning file data from tools.

Provider that proxies to a remote MCP server via a client factory. This provider fetches components from a remote server and returns Proxy* c

Provider that scans directories and creates a SkillProvider per skill folder. This extends AggregateProvider to combine multiple SkillProviders i

CIMD document per draft-parecki-oauth-client-id-metadata-document. The client metadata document is a JSON document containing OAuth client me

Transport for running Python scripts.

Configuration for MCP background task execution. Controls how a component handles task-augmented requests: - ``forbidden``: Component does n

Filters components by version range. When applied to a provider or server, components within the version range are visible, and unversioned c

UNSAFE: Uses exec() for testing only. Never use in production.

Token verifier for Clerk OAuth tokens. Clerk issues standard OIDC tokens. Verification uses the introspection endpoint (RFC 7662) as the prim

Transform that adds tools for listing and reading resources. Generates two tools: - `list_resources`: Lists all resources and templates -

Helper class for returning audio from tools.

A resource that defers data loading by wrapping a function. The function is only called when the resource is read, allowing for lazy loading

JWT verifier pre-configured for Azure AD / Microsoft Entra ID. Auto-configures JWKS URI, issuer, audience, and scope handling from your Azure

OAuth ``client_credentials`` provider using a client ID and secret. This is the standard machine-to-machine flow: the client exchanges its ``

Represents response information in our IR.

MCP server configuration for stdio transport. This is the canonical configuration format for MCP servers using stdio transport.

Base transport for connecting to an MCP server via subprocess with stdio. This is a base class that can be subclassed for specific command-b

Token verifier with custom validation logic. This verifier delegates token validation to a user-provided callable. By default, it accepts all

Token verifier for Google OAuth tokens. Google OAuth tokens are opaque (not JWTs), so we verify them by calling Google's tokeninfo endpoint w

Configuration for server-side identity assertion (ID-JAG) support. When attached to an :class:`~fastmcp.server.auth.oauth_proxy.OAuthProxy` via t

Keycloak authentication provider using Dynamic Client Registration (DCR). Requires Keycloak 26.6.0 or later, which includes the fix for DCR compa

Progress dependency that works in both server and worker contexts. In a Docket worker, delegates to the execution's Redis-backed progress (ob

Middleware that implements rate limiting to prevent server abuse. Uses a token bucket algorithm by default, allowing for burst traffic while

TTL-based in-memory cache for ``AccessToken`` objects. Features: - SHA-256 hashed cache keys (fixed size, regardless of token length). -

OAuth transaction state for consent flow. Stored server-side to track active authorization flows with client context. Includes CSRF tokens fo

Mapping configuration for HTTP routes to FastMCP component types.

Middleware that provides structured JSON logging for better log analysis. Outputs structured logs that are easier to parse and analyze with log

A class to represent the result of a bulk tool call. It extends CallToolResult to include information about the requested tool call.

A Provider that collects structured input via a Pydantic model. Define a model for the data you need, and ``FormInput`` generates a form from

Token verifier for GitHub OAuth tokens. GitHub OAuth tokens are opaque (not JWTs), so we verify them by calling GitHub's API to check if they

A `ResponseCacheStore` backed by any `AsyncKeyValue` store. Implements the SDK client response cache contract (`get`/`set`/`delete`/ `clear`)

Configuration for MCP App tools and resources. Controls how a tool or resource participates in the MCP Apps extension. On tools, ``resource_u

Minimal async OAuth2 client for upstream token-endpoint interactions. Drop-in replacement for the slice of authlib's `AsyncOAuth2Client` that

A configuration object for MCP Servers that conforms to the canonical MCP configuration format while adding additional fields for enabling FastMCP

Prefixes component names with a namespace. - Tools: name → namespace_name - Prompts: name → namespace_name - Resources: protocol://path →

Middleware that sends periodic pings to keep client connections alive. Starts a background ping task on first message from each session. The task

PropelAuth resource server provider using OAuth 2.1 token introspection. This provider validates access tokens via PropelAuth's introspection end

Security policy applied to extracted resource template parameters. These checks run after a URI has matched a template and its parameter valu

The response caching middleware offers a simple way to cache responses to mcp methods. The Middleware supports cache invalidation via notification

Middleware that implements automatic retry logic for failed requests. Retries requests that fail with transient errors, using exponential bac

Supabase metadata provider for DCR (Dynamic Client Registration). This provider implements Supabase Auth integration using metadata forwarding.

Stored upstream OAuth tokens from identity provider. These tokens are obtained from the upstream provider (Google, GitHub, etc.) and stored i

Auth0 resource server provider for Auth for MCP (DCR/CIMD). FastMCP validates access tokens issued by Auth0 while Auth0 handles OAuth, dynami

Complete Clerk OAuth provider for FastMCP. This provider makes it trivial to add Clerk OAuth protection to any FastMCP server. Provide your C

Complete Google OAuth provider for FastMCP. This provider makes it trivial to add Google OAuth protection to any FastMCP server. Just provide

Transport for connecting to one or more MCP servers defined in an MCPConfig. This transport provides a unified interface to multiple MCP servers