Releases: modelcontextprotocol/python-sdk
Releases · modelcontextprotocol/python-sdk
v1.6.0
What's Changed
- Fix #201: Move incoming message stream from BaseSession to ServerSession by @dsp-ant in #325
- default log level info by @barnuri in #366
- ci: test multiple python versions by @Kludex in #345
- Add mkdocs by @Kludex in #367
- Fix #355: Fix type error with lifespan context by @dsp-ant in #368
- refactor: Make types.py strictly typechecked. by @dsp-ant in #336
- Fix typo in starlette import in README by @conorbranagan in #374
- Fixes to stdio_client to support Windows more robustly by @saqadri in #372
- Fix/base64 handling (Issue #342) by @evalstate in #343
New Contributors
- @barnuri made their first contribution in #366
- @conorbranagan made their first contribution in #374
- @saqadri made their first contribution in #372
- @evalstate made their first contribution in #343
Full Changelog: v1.5.0...v1.6.0
Contributors
conorbranagan, evalstate, and 4 other contributors
Assets 2
v1.5.0
What's Changed
- Strict types on the client side by @Kludex in #285
- lint docs examples by @samuelcolvin in #286
- Avoid double JSON encoding/decoding by @Kludex in #287
- Improve readability of CLI help option by @Kludex in #295
- Option to mount SSE server to existing ASGI server by @comfuture in #312
- Add callback for logging message notification to client by @ihrpr in #314
- add
cwdtoStdioServerParametersby @samuelcolvin in #292 - docs(examples): fixing the prompts example by @Niraj-Fonseka in #318
- Add strict mode to pyright by @Kludex in #315
- Enhancement: make stderr of server subprocess configurable by @sheffler in #191
- Update init.py by @arthrod in #335
- Update types.py by @NinoRisteski in #243
- enable custom path of sse server by @elsejj in #246
- Use default environment even when
envis provided by @maxguru in #327
New Contributors
- @samuelcolvin made their first contribution in #286
- @comfuture made their first contribution in #312
- @ihrpr made their first contribution in #314
- @Niraj-Fonseka made their first contribution in #318
- @arthrod made their first contribution in #335
- @NinoRisteski made their first contribution in #243
- @elsejj made their first contribution in #246
- @maxguru made their first contribution in #327
Full Changelog: v1.4.1...v1.4.2
Contributors
sheffler, comfuture, and 8 other contributors
Assets 2
v1.4.1
Contributors
john0312 and Kludex
Assets 2
v1.4.0
What's Changed
- Update URL validation to allow file and other nonstandard schemas by @hmwildermuth in #207
- Add client handling for sampling, list roots, ping by @jerome3o-anthropic in #218
- Updated typing on request context for the server to use server session by @jerome3o-anthropic in #217
- Fix #177: Returning multiple tool results by @dsp-ant in #222
- Use proper generic for Context by @Kludex in #245
- Drop
AbstractAsyncContextManagerfor proper type hint toBaseSessionby @Kludex in #257 - Add ServerSessionT type var to Context by @Kludex in #271
- Create Client websocket.py by @calclavia in #179
- Close unclosed resources in the whole project by @Kludex in #267
- Add support for Linux configuration path in get_claude_config_path by @emsi in #270
- Release on GitHub release by @Kludex in #276
- Changed default log level to error by @Michaelzag in #258
- refactor: reorganize message handling for better type safety and clarity by @dsp-ant in #239
New Contributors
- @hmwildermuth made their first contribution in #207
- @Kludex made their first contribution in #245
- @calclavia made their first contribution in #179
- @emsi made their first contribution in #270
- @Michaelzag made their first contribution in #258
Full Changelog: v1.3.0...v1.4.0
Contributors
emsi, calclavia, and 5 other contributors
Assets 2
v1.3.0
Python SDK 1.3.0 - 2025-02-20
Breaking Changes
- Context API Changes: The Context logging methods (info, debug, warning, error) are now async and must be awaited. (#172)
New Features
Lifespan Support
Added comprehensive server lifecycle management through the lifespan API:
@dataclass
class AppContext:
db: Database
@asynccontextmanager
async def app_lifespan(server: FastMCP) -> AsyncIterator[AppContext]:
try:
await db.connect()
yield AppContext(db=db)
finally:
await db.disconnect()
mcp = FastMCP("My App", lifespan=app_lifespan)
@mcp.tool()
def query_db(ctx: Context) -> str:
db = ctx.request_context.lifespan_context["db"]
return db.query()(#203)
Async Resources
Added support for async resource functions in FastMCP:
@mcp.resource("users://{user_id}")
async def get_user(user_id: str) -> str:
async with client.session() as session:
response = await session.get(f"/users/{user_id}")
return await response.text()(#157)
Concurrent Request Handling
Made message handling concurrent, allowing multiple requests to be processed simultaneously. (#206)
Request Cancellation
Added support for canceling in-flight requests and cleaning up resources. (#167)
Server Instructions
Added support for the instructions field in server initialization, allowing servers to provide usage guidance. (#150)
Bug Fixes
- Fixed progress reporting for first tool call by correcting progress_token handling (#176)
- Fixed server crash when using debug logging (#158)
- Fixed resource template handling in FastMCP server (#137)
- Fixed MIME type preservation in resource responses (#170)
- Fixed documentation for environment variables in CLI commands (#149)
- Fixed request ID preservation in JSON-RPC responses (#205)
Dependency Updates
- Relaxed version constraints for better compatibility:
pydantic: Changed from>=2.10.1,<3.0.0to>=2.7.2,<3.0.0pydantic-settings: Changed from>=2.6.1to>=2.5.2uvicorn: Changed from>=0.30to>=0.23.1
(#180)
Examples
- Added a simple chatbot example client to demonstrate SDK usage (#98)
Client Improvements
- Added client support for sampling, list roots, and ping requests (#218)
- Added flexible type system for tool result returns (#222)
Compatibility and Platform Support
- Updated URL validation to allow file and other nonstandard schemas (#68fcf92)
- Force stdin/stdout encoding to UTF-8 for cross-platform compatibility (#d92ee8f)
Internal Improvements
- Improved type annotations for better IDE support (#181)
- Added comprehensive tests for SSE transport (#151)
- Updated types to match 2024-11-05 MCP schema (#165)
- Refactored request and notification handling for better code organization (#166)
New Contributors
- @salman1993 made their first contribution in #150
- @micpst made their first contribution in #158
- @3choff made their first contribution in #98
- @cr7258 made their first contribution in #149
- @sheffler made their first contribution in #172
- @jeremydanielfox made their first contribution in #180
- @zzstoatzz made their first contribution in #181
Full Changelog: v1.2.1...v1.3.0
Contributors
sheffler, jeremydanielfox, and 5 other contributors
Assets 2
v1.3.0rc1
Python SDK 1.3.0 Release Candidate 1
Breaking Changes
- Context API Changes: The Context logging methods (info, debug, warning, error) are now async and must be awaited. (#172)
- Resource Response Format: Standardized resource response format to return both content and MIME type. Method
read_resource()now returns a tuple of(content, mime_type)instead of just content. (#170)
New Features
Lifespan Support
Added comprehensive server lifecycle management through the lifespan API:
@dataclass
class AppContext:
db: Database
@asynccontextmanager
async def app_lifespan(server: FastMCP) -> AsyncIterator[AppContext]:
try:
await db.connect()
yield AppContext(db=db)
finally:
await db.disconnect()
mcp = FastMCP("My App", lifespan=app_lifespan)
@mcp.tool()
def query_db(ctx: Context) -> str:
db = ctx.request_context.lifespan_context["db"]
return db.query()(#203)
Async Resources
Added support for async resource functions in FastMCP:
@mcp.resource("users://{user_id}")
async def get_user(user_id: str) -> str:
async with client.session() as session:
response = await session.get(f"/users/{user_id}")
return await response.text()(#157)
Concurrent Request Handling
Made message handling concurrent, allowing multiple requests to be processed simultaneously. (#206)
Request Cancellation
Added support for canceling in-flight requests and cleaning up resources. (#167)
Server Instructions
Added support for the instructions field in server initialization, allowing servers to provide usage guidance. (#150)
Bug Fixes
- Fixed progress reporting for first tool call by correcting progress_token handling (#176)
- Fixed server crash when using debug logging (#158)
- Fixed resource template handling in FastMCP server (#137)
- Fixed MIME type preservation in resource responses (#170)
- Fixed documentation for environment variables in CLI commands (#149)
- Fixed request ID preservation in JSON-RPC responses (#205)
Dependency Updates
- Relaxed version constraints for better compatibility:
pydantic: Changed from>=2.10.1,<3.0.0to>=2.7.2,<3.0.0pydantic-settings: Changed from>=2.6.1to>=2.5.2uvicorn: Changed from>=0.30to>=0.23.1
(#180)
Examples
- Added a simple chatbot example client to demonstrate SDK usage (#98)
Internal Improvements
v1.2.1
Release Notes
Features
- Added support for async resources
- Added example and test for parameter descriptions in FastMCP tools
Bug Fixes
Contributors
sd2k
Assets 2
v1.2.0
A big thank you to @jlowin for the creation of the fantastic FastMCP, which is now included into the MCP SDK.
Backwards Compatibility
This release is semver compatible. Existing code will continue to work, unless code relied on re-experts from mcp.server. Version 2.0 of the SDK will remove the use of mcp.server.Server in favour of mcp.server.lowlevel.Server. To stay compatible with upcoming major versions, please change from mcp.server import Server to from mcp.server.lowlevel import Server.
Major Features
FastMCP Integration
- Integrated FastMCP as the recommended high-level server framework
- Added new
mcp.server.fastmcpmodule with simplified decorator-based API - Introduced
FastMCPclass for easier server creation and management - Added comprehensive documentation and examples for FastMCP usage
New CLI Package
- Added new CLI package for improved developer experience
- Introduced
mcp devcommand for local development and testing - Added
mcp installcommand for Claude Desktop integration - Added
mcp runcommand for direct server execution
Improvements
Documentation
- Completely revamped README with new structure and examples
- Added detailed sections on core concepts (Resources, Tools, Prompts)
- Updated documentation to recommend FastMCP as primary API
- Added sections on development workflow and deployment options
- Improved example server documentation
Developer Experience
- Added pre-commit hooks for code quality
- Updated to Pydantic 2.10.0 for improved type checking
- Added uvicorn as a dependency for better server capabilities
Bug Fixes
- Fixed encoding errors in STDIO client (@SecretiveShell)
- Fixed deprecation warnings in core components
- Fixed Pydantic field handling for meta fields
- Fixed type issues throughout the codebase
- Fixed example server READMEs
- Added constructor for McpError to allow setting fields (@allenporter)
Breaking Changes
- Deprecated direct usage of
mcp.serverin favor ofmcp.server.fastmcp - Updated import paths for FastMCP integration
- Changed recommended installation to include CLI features (
pip install "mcp[cli]")
Contributors
Special thanks to all contributors who made this release possible, including:
- @jlowin (FastMCP)
- Oskar Raszkiewicz
- @allenporter
- @SecretiveShell
- @restlessronin
Full Changelog: v1.1.3...v1.2.0
Contributors
jlowin, allenporter, and 2 other contributors
Assets 2
v1.1.3
What's Changed
🐛 Bug Fixes
- Fixed encoding errors in STDIO client (@SecretiveShell)
- Fixed deprecation warnings
- Fixed pydantic Field usage with alias for _meta fields
- Added constructor for McpError to allow setting fields (@allenporter)
✨ Features
- Added version string parameter to Server constructor and initialization options (@restlessronin)
🙌 New Contributors
Thank you for your contributions!
Contributors
allenporter, SecretiveShell, and restlessronin
Assets 2
v1.2.0rc1
MCP Python SDK v1.2.0rc1 Release Notes
Major Features
FastMCP Integration
- Integrated FastMCP as the recommended high-level server framework
- Added new
mcp.server.fastmcpmodule with simplified decorator-based API - Introduced
FastMCPclass for easier server creation and management - Added comprehensive documentation and examples for FastMCP usage
New CLI Package
- Added new CLI package for improved developer experience
- Introduced
mcp devcommand for local development and testing - Added
mcp installcommand for Claude Desktop integration - Added
mcp runcommand for direct server execution
Improvements
Documentation
- Completely revamped README with new structure and examples
- Added detailed sections on core concepts (Resources, Tools, Prompts)
- Updated documentation to recommend FastMCP as primary API
- Added sections on development workflow and deployment options
- Improved example server documentation
Developer Experience
- Added pre-commit hooks for code quality
- Updated to Pydantic 2.10.0 for improved type checking
- Added uvicorn as a dependency for better server capabilities
Bug Fixes
- Fixed deprecation warnings in core components
- Fixed Pydantic field handling for meta fields
- Fixed type issues throughout the codebase
- Fixed example server READMEs
Breaking Changes
- Deprecated direct usage of
mcp.serverin favor ofmcp.server.fastmcp - Updated import paths for FastMCP integration
- Changed recommended installation to include CLI features (
pip install "mcp[cli]")
Contributors
Special thanks to all contributors who made this release possible, including:
- Jeremiah Lowin (FastMCP)
- Oskar Raszkiewicz
Full Changelog: v1.1.2...v1.2.0rc1