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Filename Latest commit message Latest commit date
Nick Cooper 697c497724
 fix: allow concurrent streamable http requests (#1186) 
* fix: allow concurrent streamable http requests

* fix: keep streamable http recovery responsive

Keep cancellation and replies available while old session POSTs finish.
Bound the wait for old POSTs and the replacement initialization handshake.
Do not retry interrupted POSTs because the server may have processed them.

Add regressions for recovery, queued cancellation, control timeouts, and
server replies needed by active requests.

* fix: preserve response and cancellation ordering

* refactor: clarify streamable http control flow

* fix: match stream responses against pending request ids

Match responses against all pending requests before removing a stream
registration. Keep distinct numeric and string ids separate while preserving
the existing fallback for servers that stringify numeric ids.

Add a mixed-id regression and keep a separate registration owner alive in
the abandoned-cancellation test.

* feat: make streamable http control timeouts configurable
2026-08-24 22:43:35 +09:00
..
src fix: allow concurrent streamable http requests (#1186) 2026-08-24 22:43:35 +09:00
tests fix: allow concurrent streamable http requests (#1186) 2026-08-24 22:43:35 +09:00
build.rs chore: add pre-commit hook for conventional commit verification (#619) 2026-01-14 16:01:28 -05:00
Cargo.toml fix: allow concurrent streamable http requests (#1186) 2026-08-24 22:43:35 +09:00
CHANGELOG.md chore: release v3.1.4 (#1185) 2026-08-20 12:40:17 +09:00
README.md docs: prepare for stable 3.0 release (#1073) 2026-07-28 15:09:56 -04:00

README.md

rmcp

Crates.io Documentation

The official Rust SDK for the Model Context Protocol. Build MCP servers that expose tools, resources, and prompts to AI assistants — or build clients that connect to them.

For getting started, usage guides, and full MCP feature documentation (resources, prompts, sampling, roots, logging, completions, subscriptions, etc.), see the main README.

Feature Flags

Feature Description Default
server Server functionality and the tool system ✅
client Client functionality
macros #[tool] / #[prompt] macros (re-exports rmcp-macros) ✅
schemars JSON Schema generation for tool definitions
auth OAuth 2.0 authentication support
elicitation Elicitation support

Transport features

Feature Description
transport-io Server-side stdio transport
transport-child-process Client-side stdio transport (spawns a child process)
transport-async-rw Generic async read/write transport
transport-streamable-http-client Streamable HTTP client (transport-agnostic)
transport-streamable-http-client-reqwest Streamable HTTP client with default reqwest backend
transport-streamable-http-server Streamable HTTP server transport

TLS backend options (for HTTP transports)

Feature Description
reqwest Uses rustls — pure Rust TLS (recommended default)
reqwest-native-tls Uses platform-native TLS (OpenSSL / Secure Transport / SChannel)
reqwest-tls-no-provider Uses rustls without a default crypto provider (bring your own)

Transports

The transport layer is pluggable. Two built-in pairs cover the most common cases:

Client Server
stdio TokioChildProcess stdio
Streamable HTTP StreamableHttpClientTransport StreamableHttpService

Any type that implements the Transport trait can be used. The IntoTransport helper trait provides automatic conversions from:

  1. (Sink, Stream) or a combined Sink + Stream
  2. (AsyncRead, AsyncWrite) or a combined AsyncRead + AsyncWrite
  3. A Worker implementation
  4. A Transport implementation directly

License

This project is licensed under the terms specified in the repository's LICENSE file.