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Filename Latest commit message Latest commit date
Filinto Duran 00bcf13800
 fix(model): decode metadata-bearing input-required results affecting mrtr (#1097) 
* fix(model): decode metadata-bearing input-required results

  The draft permits every Result, including InputRequiredResult, to carry
  _meta and recommends that servers include
  io.modelcontextprotocol/serverInfo on every response. It also requires
  an InputRequiredResult to contain inputRequests or requestState so the
  client knows what to provide or how to resume the request.

  ServerResult uses untagged deserialization and attempts CallToolResult
  before InputRequiredResult. Because CallToolResult accepts _meta and
  defaults missing content to an empty list, it consumed valid
  input_required results carrying metadata. Unknown inputRequests and
  requestState fields were then discarded, leaving clients without the
  information needed to continue.

  Reject resultType input_required when deserializing CallToolResult so
  Serde proceeds to the InputRequiredResult variant. Add regression
  coverage proving that inputRequests, requestState, and serverInfo
  metadata are preserved.

  Spec:
  41d9e938e9/schema/draft/schema.ts (L137-L151)
  41d9e938e9/schema/draft/schema.ts (L198-L224)
  41d9e938e9/schema/draft/schema.ts (L541-L565)

Signed-off-by: Filinto Duran <1373693+filintod@users.noreply.github.com>

* incorporate feedback - close gap in inputrequired not properly checking that at least one of inputRequest or requestState is present

Signed-off-by: Filinto Duran <1373693+filintod@users.noreply.github.com>

---------

Signed-off-by: Filinto Duran <1373693+filintod@users.noreply.github.com>
2026-07-31 09:23:56 -04:00
..
src fix(model): decode metadata-bearing input-required results affecting mrtr (#1097) 2026-07-31 09:23:56 -04:00
tests fix(model): decode metadata-bearing input-required results affecting mrtr (#1097) 2026-07-31 09:23:56 -04:00
build.rs chore: add pre-commit hook for conventional commit verification (#619) 2026-01-14 16:01:28 -05:00
Cargo.toml feat: classify authorization-required errors (#1056) 2026-07-31 09:00:23 -04:00
CHANGELOG.md chore: release v3.0.1 (#1081) 2026-07-29 16:53:31 -04:00
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.