| Filename | Latest commit message | Latest commit date |
|---|---|---|
3075dc9152* fix(model): deprecate ServerInfo and ClientInfo aliases Those names collide with the protocol's serverInfo/clientInfo fields, which are only Implementation identity. Prefer InitializeResult and InitializeRequestParams. Handler trait signatures, the tool_handler macro output, tests, examples and docs now use the canonical types; the aliases remain as deprecated shims for the rest of 3.x. Fixes #1082 * fix(model): keep public signatures on the deprecated aliases The public API check compares rendered signatures, and rustdoc records a type alias by the name it was written with. Respelling `ServerHandler::get_info`, `ClientHandler::get_info`, `DiscoverResult::from_server_info` and `impl ClientHandler for ClientInfo` onto `InitializeResult`/`InitializeRequestParams` therefore reads as changed public items even though the aliases resolve to those exact types and nothing downstream breaks. Put those four signatures back on the aliases so the published API is byte-identical, and note why at the alias definitions. The deprecation still steers new code, and the macro output, tests, examples and docs keep using the canonical names. * fix(model): migrate leftover ClientInfo test sites Two tests landed on main after the alias deprecation and still named ClientInfo. Clippy -D warnings and the no-local feature test job both failed on them. |
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| .. | ||
| src | ||
| tests | ||
| build.rs | ||
| Cargo.toml | ||
| CHANGELOG.md | ||
| README.md | ||
rmcp
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 | |
auth-enterprise-managed |
EMA/XAA refresh-token and ID-JAG exchanges for registered public and confidential clients (includes auth) |
|
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) |
For enterprise-managed authorization, enable auth-enterprise-managed and a TLS
backend such as reqwest. See the EMA/XAA guide
for client authentication and an MCP connection example.
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:
(Sink, Stream)or a combinedSink + Stream(AsyncRead, AsyncWrite)or a combinedAsyncRead + AsyncWrite- A
Workerimplementation - A
Transportimplementation directly
License
This project is licensed under the terms specified in the repository's LICENSE file.