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crates.io · #1877 most downloaded on crates.io
Rust SDK for Model Context Protocol macros library
Last release 2 days ago
05 Oct 2026
Ships fairly regularly
a new release about every 2 weeks
Most releases are documented
notes for 45 of the last 60 stable releases
1 version withdrawn
withdrawn after publishing
2 years old
68 releases · first in 2025
One column per month.
(macros) accept const paths and concat! in tool/prompt descriptions
(macros) accept const paths and concat! in tool/prompt descriptions
(macros) accept const paths and concat! in tool/prompt descriptions
(model) deprecate ServerInfo and ClientInfo aliases
(macros) reject empty tool_router
allow concurrent streamable http requests
Fixed time out auto discovery probe
Fixed time out auto discovery probe
emit cache hints from handler macros
emit cache hints from handler macros
add strict stateless protocol metadata validation
Nothing published for this version
### Other - release stable 3.0.0
### Other - prepare for stable 3.0 release
Nothing published for this version
Nothing published for this version
[breaking] omit resultType for legacy protocol sessions
add client-side TTL-honoring response cache (SEP-2549)
Nothing published for this version
Nothing published for this version
[breaking] align model types with MCP 2025-11-25 spec
deprecate roots, sampling, and logging (SEP-2577)
### Added - add task-based stdio examples
*(docs)* use correct Parameters syntax in tool examples
*(macros)* respect local feature in #[prompt] macro — omit + Send bound
local feature in #[prompt] macro — omit + Send bound (#803)*(macros)* auto-generate get_info and default router
add local feature for !Send tool handler support
*(rmcp-macros)* use re-exported serde_json path in task_handler
*(rmcp-macros)* replace deprecated *Param type aliases with *Params
add McpMux to Built with rmcp section
### Fixed - api ergonomics follow-up
add #[non_exhaustive] and mutation methods to improve compatibility
add trait-based tool declaration
align task response types with MCP spec
*(tasks)* avoid dropping completed task results during collection
added hyper-mcp to the list of built with rmcp
*(task)* add task support (SEP-1686)
merge cached_schema_for_type into schema_for_type
*(meta)* add _meta field to prompts, resources and paginated result
Nothing published for this version
*(shemars)* use JSON Schema 2020-12 as Default Dialect
*(tool)* add _meta to tool definitions
Nothing published for this version
*(doc)* add stakpak-agent to Built with rmcp section
Nothing published for this version
*(macro)* fix visibility attribute's usage of handler macro
Nothing published for this version
generate default schema for tools with no params
*(macros)* support #[doc = include_str!(...)] for macros
*(SEP-973)* add support for icons and websiteUrl across relevant types
Nothing published for this version
*(typo)* correct typo in error message for transport cancellation and field.
*(macros)* Allow macros to work even if Future is not in scope
### Other - add related project rustfs-mcp
Nothing published for this version
Nothing published for this version
[breaking] Add support for Tool.outputSchema and CallToolResult.structuredContent
Nothing published for this version
Fix formatting in crate descriptions in README.md
*(deps)* update darling requirement from 0.20 to 0.21
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