This release contains a significant refactor of server composition, including the ability to "live" mount local or remote servers and automatically inherit any changes and lifecycle attributes.

There are a number of breaking changes on internal APIs that are unlikely to affect users.

What's Changed

New Features 🎉

• Allow tool manager to store an alternative name for tools by @jlowin in #168
• Add custom key for storing resources by @jlowin in #170
• Generate MCP resources and templates on respective classes by @jlowin in #171
• Create MCP prompts on object; fix issue with forwarding proxy templates by @jlowin in #173
• Move test servers; default SSE to 127.0.0.1 by @jlowin in #182
• Add npx validation by @kongqi404 in #181

Fixes 🐞

• Fix bug with duplicate behavior == ignore by @jlowin in #169

Breaking Changes 🛫

• Refactor MCP composition by @jlowin in #176

Docs 📚

• Improve integration documentation by @jlowin in #184
• Improve documentation by @jlowin in #185

Other Changes 🦾

• Add transport kwargs for mcp.run() and fastmcp run by @jlowin in #161
• Allow resource templates to have optional / excluded arguments by @jlowin in #164
• Update resources.mdx by @jlowin in #165

New Contributors

• @kongqi404 made their first contribution in #181

Full Changelog: v2.1.2...v2.2.0

The main improvement in this release is a fix that allows FastAPI / OpenAPI-generated servers to be mounted as sub-servers.

What's Changed

Fixed 🐛

• Ensure objects are copied properly and test mounting fastapi by @jlowin in #153

Docs 📚

• Fix broken links in docs by @jlowin in #154

Other Changes 🦾

• Update README.md by @jlowin in #149
• Only apply log config to FastMCP loggers by @jlowin in #155
• Update pyproject.toml by @jlowin in #156

Full Changelog: v2.1.1...v2.1.2

FastMCP's docs are now available at gofastmcp.com.

What's Changed

Docs 📚

• Add docs by @jlowin in #136
• Add docs link to readme by @jlowin in #137
• Minor docs updates by @jlowin in #138

Fixes 🐞

• fix branch name in example by @zzstoatzz in #140

Other Changes 🦾

• smart home example by @zzstoatzz in #115
• Remove mac os tests by @jlowin in #142
• Expand support for various method interactions by @jlowin in #143
• Update docs and add_resource_fn by @jlowin in #144
• Update description by @jlowin in #145
• Support openapi 3.0 and 3.1 by @jlowin in #147

Full Changelog: v2.1.0...v2.1.1

The primary motivation for this release is the fix in #128 for Claude desktop compatibility, but the primary new feature of this release is per-object tags. Currently these are for bookkeeping only but will become useful in future releases.

What's Changed

New Features 🎉

• Add tags for all core MCP objects by @jlowin in #121
• Ensure that openapi tags are transferred to MCP objects by @jlowin in #124

Fixes 🐞

• Change default mounted tool separator from / to _ by @jlowin in #128
• Enter mounted app lifespans by @jlowin in #129
• Fix CLI that called mcp instead of fastmcp by @jlowin in #128

Breaking Changes 🛫

• Changed configuration for duplicate resources/tools/prompts by @jlowin in #121
• Improve client return types by @jlowin in #123

Other Changes 🦾

• Add tests for tags in server decorators by @jlowin in #122
• Clean up server tests by @jlowin in #125

Full Changelog: v2.0.0...v2.1.0

What's Changed

New Features 🎉

• Support mounting FastMCP instances as sub-MCPs by @jlowin in #99
• Add in-memory client for calling FastMCP servers (and tests) by @jlowin in #100
• Add MCP proxy server by @jlowin in #105
• Update FastMCP for upstream changes by @jlowin in #107
• Generate FastMCP servers from OpenAPI specs and FastAPI by @jlowin in #110
• Reorganize all client / transports by @jlowin in #111
• Add sampling and roots by @jlowin in #117

Fixes 🐞

• Fix bug with tools that return lists by @jlowin in #116

Other Changes 🦾

• Add back FastMCP CLI by @jlowin in #108
• Update Readme for v2 by @jlowin in #112
• fix deprecation warnings by @zzstoatzz in #113
• Readme by @jlowin in #118
• FastMCP 2.0 by @jlowin in #119

Full Changelog: v1.0...v2.0.0

This release commemorates FastMCP 1.0, which is included in the official Model Context Protocol SDK:

from mcp.server.fastmcp import FastMCP

To the best of my knowledge, v1 is identical to the upstream version included with mcp.

What's Changed

Docs 📚

• Update readme to redirect to the official SDK by @jlowin in #79

Other Changes 🦾

• fix: use Mount instead of Route for SSE message handling by @samihamine in #77

New Contributors

• @samihamine made their first contribution in #77

Full Changelog: v0.4.1...v1.0

What's Changed

Fixes 🐞

• fix: handle strings containing numbers correctly by @sd2k in #63

Docs 📚

• patch: Update pyproject.toml license by @leonkozlowski in #67

Other Changes 🦾

• Avoid new try_eval_type unavailable with older pydantic by @jurasofish in #57
• Decorator typing by @jurasofish in #56

New Contributors

• @leonkozlowski made their first contribution in #67

Full Changelog: v0.4.0...v0.4.1

This is a relatively small release in terms of features, but the version is bumped to 0.4 to reflect that the code is being relicensed from Apache 2.0 to MIT. This is to facilitate FastMCP's inclusion in the official MCP SDK.

What's Changed

New Features 🎉

• Add pyright + tests by @jlowin in #52
• add pgvector memory example by @zzstoatzz in #49

Fixes 🐞

• fix: use stderr for logging by @sd2k in #51

Docs 📚

• Update ai-labeler.yml by @jlowin in #48
• Relicense from Apache 2.0 to MIT by @jlowin in #54

Other Changes 🦾

• fix warning and flake by @zzstoatzz in #47

New Contributors

• @sd2k made their first contribution in #51

Full Changelog: v0.3.5...v0.4.0

This release is highlighted by the ability to handle complex JSON objects as MCP inputs and improved Windows compatibility.

What's Changed

New Features 🎉

• Set up multiple os tests by @jlowin in #44
• Changes to accomodate windows users. by @justjoehere in #42
• Handle complex inputs by @jurasofish in #31

Docs 📚

• Make AI labeler more conservative by @jlowin in #46

Other Changes 🦾

• Additional Windows Fixes for Dev running and for importing modules in a server by @justjoehere in #43

New Contributors

• @justjoehere made their first contribution in #42
• @jurasofish made their first contribution in #31

Full Changelog: v0.3.4...v0.3.5

What's Changed

Fixes 🐞

• Handle missing config file when installing by @jlowin in #37
• Remove BaseURL reference and use AnyURL by @jlowin in #40

Full Changelog: v0.3.3...v0.3.4