* feat!: add MRTR behavior support
* feat: harden SEP-2322 MRTR support
* ci: diff public API only on features common to base and head
cargo public-api builds both revisions with the same feature set, so a
feature introduced (or removed) by a PR broke the build of the other
revision. Restrict the all-features diff to features present in both the
base and head revisions.
* docs(server): document Err vs Ok(CallToolResult::error) visibility contract
The MCP spec separates two failure modes that surface very differently in
clients:
- Err(ErrorData) is a JSON-RPC protocol error. Most MCP clients render
it opaquely ("Tool result missing due to internal error") - the
caller does not see the message text.
- Ok(CallToolResult::error(content)) is a tool-level error. Clients
render the content; the caller reads the message.
The right shape for "the tool didn't work" is the latter, but Err is
what most handlers reach for because it looks like the natural Rust
return value. This commit adds rustdoc on both ServerHandler::call_tool
and CallToolResult::error pointing handlers at the correct shape, with
a worked example showing protocol errors (-32602 invalid_params) vs
tool errors (empty result, downstream failure).
This is the docs half of the visibility-contract ask. A follow-up may
introduce a typed ToolOutcome sum type to enforce the distinction at
compile time; this PR is the lower-risk version that unblocks the
class immediately.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
* docs: update crates/rmcp/src/handler/server.rs
* docs: update crates/rmcp/src/model.rs
---------
Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Co-authored-by: Dale Seo <5466341+DaleSeo@users.noreply.github.com>
* feat: implement SEP-2164 resource not found errors
* test: update protocol version utility expectations
* feat: gate not-found code at server boundary
---------
Co-authored-by: Michael Neale <michael.neale@gmail.com>
* feat: implement SEP-1319 Decouple Request Payload from RPC Methods
* test: update tests
* fix: update handler trait methods to use new types
* fix: update examples
* fix: correct deprecation version
* fix: update wrapper macros to use new *Params type names
* feat!: implement ServerHandler for Box<H> and Arc<H> where H is a ServerHandler
* feat!: implement ClientHandler for Box<H> and Arc<H> where H is a ClientHandler
* test: test Box and Arc have blanket implementations for handler traits
* refactor: deduplicate blanket implementations with macros
#580 and #556 introduced support for custom notifications,
so this PR takes the next logical step and adds support for custom requests:
- Introduces `CustomRequest` and `CustomResult` model types, wires them into the client/server
request and result unions, and allows `ClientRequest::method()` to return the dynamic method
name.
- Implements serde and meta handling for `CustomRequest` so `_meta` is carried through
extensions; adds default `on_custom_request` handlers that return `METHOD_NOT_FOUND` unless
overridden.
- Updates JSON schema fixtures to include the new request/result shapes and `EmptyObject`
strictness.
- Adds tests for custom request roundtrips and end-to-end client↔server handling.
- Focused integration test in `crates/rmcp/tests/test_custom_request.rs`.
For additional testing, I used this locally to update Codex to use a custom
request instead of a custom notification so that it gets an "ack" from the MCP
server to ensure it has processed the update before sending more messages:
https://github.com/openai/codex/pull/8142.
https://github.com/modelcontextprotocol/rust-sdk/pull/556 introduced support for
custom client notifications, so this PR makes the complementary change, adding
support for custom server notifications.
MCP clients, particularly ones that offer "experimental" capabilities,
may wish to handle custom server notifications that are not part of the
standard MCP specification. This change introduces a new
`CustomServerNotification` type that allows a client to process
such custom notifications.
- introduces `CustomServerNotification` to carry arbitrary methods/params while
still preserving meta/extensions; wires it into the `ServerNotification` union
and `serde` so `params` can be decoded with `params_as`
- allows client handlers to receive custom notifications via a new
`on_custom_notification` hook
- adds integration coverage that sends a custom server notification end-to-end
and asserts the client sees the method and payload
Test:
```shell
cargo test -p rmcp --features client test_custom_server_notification_reaches_client
```
MCP servers, particularly ones that offer "experimental" capabilities,
may wish to handle custom client notifications that are not part of the
standard MCP specification. This change introduces a new
`CustomClientNotification` type that allows a server to process
such custom notifications.
- introduces `CustomClientNotification` to carry arbitrary methods/params while
still preserving meta/extensions; wires it into the `ClientNotification` union
and `serde` so `params` can be decoded with `params_as`
- allows server handlers to receive custom notifications via a new
`on_custom_notification` hook
- adds integration coverage that sends a custom client notification end-to-end
and asserts the server sees the method and payload
Test:
```shell
cargo test -p rmcp --features client test_custom_client_notification_reaches_server
```
* feat: implement MCP completion specification 2025-06-18
Complete implementation of MCP completion specification with performance optimizations:
Core Features:
- Add CompletionContext for context-aware completion with previously resolved arguments
- Implement CompletionProvider trait with async support and dyn compatibility
- Create DefaultCompletionProvider with optimized fuzzy matching algorithm
- Add comprehensive validation and helper methods to CompletionInfo
- Update ServerHandler to handle completion/complete requests
- Add client convenience methods for prompt and resource completion
Performance Optimizations:
- Zero-allocation fuzzy matching using index-based scoring
- Top-k selection with select_nth_unstable instead of full sorting
- Pre-allocated vectors to avoid reallocations during matching
- Char-based case-insensitive matching to minimize string operations
- 5-8x performance improvement for large candidate sets
API Design:
- Context-aware completion supporting multi-argument scenarios
- Type-safe validation with MAX_VALUES limit (100 per MCP spec)
- Helper methods: with_all_values, with_pagination, validate
- Reference convenience methods: for_prompt, for_resource
- Client methods: complete_prompt_argument, complete_resource_argument
Testing:
- 17 comprehensive tests covering all functionality
- Schema compliance tests for MCP 2025-06-18 specification
- Performance tests with <100ms target for 1000 candidates
- Edge case and validation tests
Schema Updates:
- Add CompletionContext to JSON schema
- Update CompleteRequestParam with optional context field
- Maintain backward compatibility with existing API
* test: add comprehensive fuzzy matching tests for completion
Add three new test cases to enhance coverage of fuzzy matching algorithm:
- test_fuzzy_matching_with_typos_and_missing_chars: Tests subsequence matching
with real-world scenarios including abbreviated patterns, case-insensitive
matching, and complex file/package name completion
- test_fuzzy_matching_scoring_priority: Validates scoring system prioritizes
exact matches > prefix matches > substring matches > subsequence matches
- test_fuzzy_matching_edge_cases: Covers boundary conditions including
single character queries, oversized queries, and repeated characters
These tests ensure robust fuzzy search functionality for MCP completion
specification implementation with proper handling of user typos and
incomplete input patterns.
* feat: improve completion algorithms, add comprehensive tests and example
- Enhance fuzzy matching algorithm with acronym support for multi-word entries
- Add comprehensive scoring system for better relevance ranking
- Implement multi-level matching: exact, prefix, word prefix, acronym, substring
- Add context-aware completion scoring with proper priority ordering
- Optimize performance through efficient character-by-character matching
- Support case-insensitive acronym matching
- Improve code quality with clippy fixes and async fn syntax
- Add comprehensive test suite covering edge cases and acronym matching
- Create completion example server demonstrating weather-related prompts
* fix(test): typos
* refactor: improve completion API and replace example with SQL query builder
- Remove DefaultCompletionProvider from library core
- Move completion logic to examples following review feedback
- Update CompletionContext.argument_names() to return Iterator for better performance
- Replace tech search example with SQL query builder demonstrating progressive completion
- Add context-aware completion that adapts based on filled arguments
- Use proper Option types for optional SQL fields (columns, where_clause, values)
- Demonstrate real-world value of argument_names() method for dynamic completion flow
The SQL query builder showcases:
• Progressive field availability based on operation type
• Context validation using argument_names()
• Proper Optional field handling
• Smart completion that guides user through multi-step form
* fix: fmt
* feat: add prompt support with typed argument handling
- Implement #[prompt], #[prompt_router], and #[prompt_handler] macros
- Add automatic JSON schema generation from Rust types for arguments
- Support flexible async handler signatures with automatic adaptation
- Create PromptRouter for efficient prompt dispatch
- Include comprehensive tests and example implementation
This enables MCP servers to provide reusable prompt templates that
LLMs can discover and invoke with strongly-typed parameters, similar
to the existing tool system but optimized for prompt use cases.
🤖 Generated with Claude Code
Co-Authored-By: Claude <noreply@anthropic.com>
* refactor: unify parameter handling between tools and prompts
- Replace Arguments<T> with Parameters<T> for consistent API
- Create shared common module for tool/prompt utilities
- Modernize async handling with futures::future::BoxFuture
- Move cached_schema_for_type to common module for reuse
- Update error types from rmcp::Error to rmcp::ErrorData
- Add comprehensive trait implementations for parameter extraction
🤖 Generated with Claude Code
Co-Authored-By: Claude <noreply@anthropic.com>
* refactor: extract Parameters wrapper to shared module and unify trait usage
- Move Parameters type from common.rs to dedicated wrapper/parameters.rs module
- Unify extractor traits by using FromContextPart for both tools and prompts
- Remove duplicate FromToolCallContextPart and FromPromptContextPart traits
- Add structured output support to Json wrapper with IntoCallToolResult impl
- Improve error messages with more descriptive panic for schema serialization
- Update all imports across codebase to use new module path
- Clean up trailing whitespace and formatting inconsistencies
This consolidates parameter extraction logic and reduces code duplication
between tool and prompt handlers while maintaining backward compatibility.
* chore: remove committed .egg-info directory and update gitignore
* docs: fix documentation formatting
* refactor: refactor tool macros and router implementation
- Updated the `#[tool(tool_box)]` macro to `#[tool_router]` across various modules for consistency.
- Enhanced the `Calculator`, `Counter`, and `GenericService` structs to utilize `ToolRouter` for handling tool calls.
- Introduced `Parameters` struct for better parameter handling in tool functions.
- Added new methods for listing tools and calling tools in server handlers.
- Improved test cases to reflect changes in tool routing and parameter handling.
- Updated documentation and examples to align with the new router structure.
* fix: fix fmt and build error
* fix: fix test failure
* docs: documents for macros, fix ci
* fix: fix ci
* fix: fix wrongly replaced documents
* fix: remove useless file
* fix: change the parameter format for tool_router
* fix: update extract_doc_line to handle existing documentation and clean up unused code in server handler
* doc: update document for macro and examples
* doc: update readme and add contribute guide
* fix: fix type
* feat: provide more context information
1. provide context for notification
2. allow extract more info from tool call
3. inject http request part for streamable http server
* docs: add document for getting peer from context
* feat: better http server support
1. allow user get extensions in tool call.
2. allow user serve sse service without initialization.
* fix: fix document test
1. Suppot revision 2025-03-26 data types
2. Support meta, progress tokne, and extensions in request/notification,
3. Remove `Message`, use `JsonRpcMessage` directly
