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Filename Latest commit message Latest commit date
Tyler 64d22def02
 fix: don't respond to unparseable messages (#940) 
* fix: don't respond to unparseable messages

* docs: spell 'unparsable' to satisfy typos linter

* fix: only ignore unparsable JSON, keep protocol errors visible

Classify the serde error in the receive loop: syntax/EOF errors are
unparsable input with no correlatable id (issue #938) and stay silent,
while data errors (valid JSON that doesn't match the message shape) are
real protocol errors and get an error response instead of being dropped.
Add a test covering the protocol-error path.

* fix: respond with Invalid Request for malformed protocol messages

---------

Co-authored-by: tsouth89 <tsouth89@users.noreply.github.com>
2026-07-01 16:01:58 -04:00
..
src fix: don't respond to unparseable messages (#940) 2026-07-01 16:01:58 -04:00
tests feat: add SEP-2575 meta helpers (#942) 2026-07-01 14:40:30 -04:00
build.rs chore: add pre-commit hook for conventional commit verification (#619) 2026-01-14 16:01:28 -05:00
Cargo.toml fix: negotiate protocol version in handler (#930) 2026-06-29 13:29:06 -04:00
CHANGELOG.md chore: release v2.0.0 (#920) 2026-06-29 08:24:11 -04:00
README.md feat: add local feature for !Send tool handler support (#740) 2026-03-11 17:22:56 -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.