| Filename | Latest commit message | Latest commit date |
|---|---|---|
c345078867`post_message_with_max_sse_event_size` turns a 401 or 403 carrying a
`WWW-Authenticate` header into `StreamableHttpError::AuthRequired` /
`InsufficientScope`. `get_stream_with_max_sse_event_size`, in the same file,
handles only 405 and then falls through to `error_for_status()?`, so the same
challenge becomes an opaque `StreamableHttpError::Client`.
That matters because `AuthClient::get_stream` routes through
`call_reacting_to_challenges`, whose whole purpose is to catch `AuthRequired`,
run `try_refresh_or_reauth()`, and retry once. It never sees that variant from
this path, so an expired token on the standalone SSE stream is never refreshed —
the stream just fails, while the identical expiry on `post_message` recovers
silently.
Copies the two blocks verbatim from `post_message` in the same file.
`unix_socket.rs` already does the same thing in its own `get_stream`.
Adds four tests against an axum mock server: a 401 with a challenge maps to
`AuthRequired`, a 403 maps to `InsufficientScope` with the scope extracted, a
401 *without* a challenge is still not `AuthRequired`, and 405 keeps reporting
`ServerDoesNotSupportSse`. The first two fail before this change with
`Err(Client(reqwest::Error { kind: Status(401, None) }))`; the last two pass
either way and exist to catch an over-broad fix.
|
||
| .. | ||
| 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 | |
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:
(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.