Modules
The high-level API.
Application-owned state shared across MCP requests.
MCP-facing helpers for the MCP Apps extension.
Declarative auth wrapper and authenticator contract.
RFC 9728 Protected Resource Metadata for an HTTP MCP endpoint.
Normalized authentication result attached to the runtime context.
Hermetic bearer-token authenticator for server-side and local testing.
Component-level authorization checks layered on top of authentication.
Tagged authorization check.
Authorization-only view of the runtime context used by authorization checks.
Handle returned for submitted background tasks.
Connected MCP client.
Context passed to server-initiated client callbacks.
MCP OAuth coordinator for HTTP clients.
Host boundary for interactive OAuth authorization.
Information passed to the host authorization callback.
Host boundary for private_key_jwt client authentication.
Information passed to the host assertion callback.
Host boundary for enterprise identity assertions.
Identity assertion and IdP token-exchange request details.
Information passed to the enterprise identity callback.
Redacted error returned by the MCP OAuth client coordinator.
Storage boundary for MCP OAuth token sets.
Per-client in-memory OAuth token store.
Raised when a connected peer returns a syntactically valid JSON-RPC message that does not satisfy the negotiated MCP method schema.
Opaque handle for an asynchronous connected-client request.
Connected-client handle for one remote MCP task.
Stable, protocol-faithful result returned by FastestMCP.Client.call_tool_result/4.
A server-initiated URL elicitation presented to a connected client.
Runtime-owned mutable component store.
Explicit request context passed to handlers.
Normalized error used by the operation pipeline and transports.
Handler result for a modern MCP multi round-trip request (MRTR).
Friendly interaction helpers built on top of FastestMCP.Context.
Small server lifespan helper for startup and shutdown state.
Built-in middleware constructors.
Bounded, request-scoped tool discovery middleware.
Runtime operation struct passed through middleware and transforms.
Handle for a task owned by the connected MCP peer.
Prompt message helper with content normalization.
Canonical prompt result helper.
Central protocol version and capability helpers. Keep the active MCP protocol baseline in one place so server responses, client handshakes, and tests do not drift.
Normalization and identifiers for MCP extensions.
Shared wrapper for provider-backed component sources.
Optional tools for creating and terminating application sessions.
Request-scoped proxy provider for a remote MCP server.
Immutable snapshot of request metadata exposed through FastestMCP.Context.
Lexical screening policy for decoded resource-template parameters.
Convenience builder for binary resource content.
Resource content helper with MIME and metadata support.
Helper for serving directory listings as JSON resources.
Helper for serving file-backed resources.
Helper for serving HTTP-backed resources.
Canonical resource result helper.
Convenience builder for text resource content.
A client-declared MCP filesystem root.
Elixir-native helpers for MCP sampling.
Compile-once JSON Schema validation for FastestMCP.
An opaque, compiled JSON Schema validator.
A bounded error returned while compiling or validating JSON Schema.
Opt-in HTTPS resolver for remote JSON Schema resources.
Immutable server definition.
Declarative behavior for an executable MCP server extension.
A single request/response method owned by a server extension.
Module-based API for application-owned MCP servers.
Behaviour for session-scoped state backends.
In-memory session-state backend.
Behaviour for background-task storage backends.
ETS-backed in-memory task backend.
Canonical tool result helper.
Embeddable Plug app for FastestMCP's HTTP transport.
JSON-line stdio transport backed by the shared transport engine.
Minimal HTTP transport slice backed by the shared transport engine.
RFC 9728 Protected Resource Metadata plug.