Build servers from anything

🔌 Components no longer have to live in one file with one server. FileSystemProvider discovers tools from directories with hot-reload. OpenAPIProvider wraps REST APIs. ProxyProvider proxies remote MCP servers. SkillsProvider delivers agent skills as resources. Write your own provider for whatever source makes sense. Compose multiple providers into one server, share one across many, or chain them with transforms that rename, namespace, filter, version, and secure components as they flow to clients. ResourcesAsTools and PromptsAsTools expose non-tool components to tool-only clients.

Ship to production

🔐 Component versioning: serve @tool(version="2.0") alongside older versions from one codebase. Granular authorization on individual components with async auth checks, server-wide policies via AuthMiddleware, and scope-based access control. OAuth gets CIMD, Static Client Registration, Azure OBO via dependency injection, JWT audience validation, and confused-deputy protections. OpenTelemetry tracing with MCP semantic conventions. Response size limiting. Background tasks with distributed Redis notification and ctx.elicit() relay. Security fixes include dropping diskcache (CVE-2025-69872) and upgrading python-multipart and protobuf for additional CVEs.

Adapt per session

💾 Session state persists across requests via ctx.set_state() / ctx.get_state(). ctx.enable_components() and ctx.disable_components() let servers adapt dynamically per client — show admin tools after authentication, progressively reveal capabilities, or scope access by role.

Develop faster

⚡ --reload auto-restarts on file changes. Standalone decorators return the original function, so decorated tools stay callable in tests and non-MCP contexts. Sync functions auto-dispatch to a threadpool. Tool timeouts, MCP-compliant pagination, composable lifespans, PingMiddleware for keepalive, and concurrent tool execution when the LLM returns multiple calls in one response.

Use FastMCP as a CLI

🖥️ fastmcp list and fastmcp call query and invoke tools on any server from a terminal. fastmcp discover scans your editor configs (Claude Desktop, Cursor, Goose, Gemini CLI) and finds configured servers by name. fastmcp generate-cli writes a standalone typed CLI where every tool is a subcommand. fastmcp install registers your server with Claude Desktop, Cursor, or Goose in one command.

Build apps (3.1 preview)

📱 Spec-level support for MCP Apps is in: ui:// resource scheme, typed UI metadata via AppConfig, extension negotiation, and runtime detection. The full Apps experience lands in 3.1.

If you hit 3.0 because you didn't pin your dependencies and something breaks — the upgrade guides will get you sorted. We minimized breaking changes, but a major version is a major version.

pip install fastmcp -U

📖 Documentation 🚀 Upgrade from FastMCP v2 🔀 Upgrade from MCP Python SDK 📰 What's New in FastMCP 3.0

What's Changed

New Features 🎉

• Refactor resource behavior and add meta support by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2611
• Refactor prompt behavior and add meta support by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2610
• feat: Provider abstraction for dynamic MCP components by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2622
• Unify component storage in LocalProvider by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2680
• Introduce ResourceResult as canonical resource return type by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2734
• Introduce Message and PromptResult as canonical prompt types by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2738
• Add --reload flag for auto-restart on file changes by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2816
• Add FileSystemProvider for filesystem-based component discovery by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2823
• Add standalone decorators and eliminate fastmcp.fs module by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2832
• Add authorization checks to components and servers by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2855
• Decorators return functions instead of component objects by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2856
• Add transform system for modifying components in provider chains by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2836
• Add OpenTelemetry tracing support by @chrisguidry in https://github.com/PrefectHQ/fastmcp/pull/2869
• Add component versioning and VersionFilter transform by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2894
• Add version discovery and calling a certain version for components by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2897
• Refactor visibility to mark-based enabled system by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2912
• Add session-specific visibility control via Context by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2917
• Add Skills Provider for exposing agent skills as MCP resources by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2944
• Add MCP Apps Phase 1 — SDK compatibility (SEP-1865) by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/3009
• Add fastmcp list and fastmcp call CLI commands by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/3054
• Add fastmcp generate-cli command by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/3065
• Add CIMD (Client ID Metadata Document) support for OAuth by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2871

Enhancements 🔧

• Convert mounted servers to MountedProvider by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2635
• Simplify .key as computed property by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2648
• Refactor MountedProvider into FastMCPProvider + TransformingProvider by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2653
• Enable background task support for custom component subclasses by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2657
• Use CreateTaskResult for background task creation by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2660
• Refactor provider execution: components own their execution by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2663
• Add supports_tasks() method to replace string mode checks by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2664
• Replace type: ignore[attr-defined] with isinstance assertions in tests by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2665
• Add poll_interval to TaskConfig by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2666
• Refactor task module: rename protocol.py to requests.py and reduce redundancy by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2667
• Refactor FastMCPProxy into ProxyProvider by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2669
• Move OpenAPI to providers/openapi submodule by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2672
• Use ergonomic provider initialization pattern by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2675
• Fix ty 0.0.5 type errors by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2676
• Remove execution methods from Provider base class by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2681
• Add type-prefixed keys for globally unique component identification by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2704
• Skip parallel MCP config test on Windows by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2711
• Consolidate notification system with unified API by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2710
• Skip test_multi_client on Windows by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2714
• Parallelize provider operations by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2716
• Consolidate get_* and list* methods into single API by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2719
• Consolidate execution method chains into single public API by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2728
• Add documentation check to required PR workflow by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2730
• Parallelize list_* calls in Provider.get_tasks() by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2731
• Consistent decorator-based MCP handler registration by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2732
• Make ToolResult a BaseModel for serialization support by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2736
• Align prompt handler with resource pattern by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2740
• Update classes to inherit from FastMCPBaseModel instead of BaseModel by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2739
• Convert provider tests to use direct server calls by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2748
• Add explicit task_meta parameter to FastMCP.call_tool() by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2749
• Add task_meta parameter to read_resource() for explicit task control by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2750
• Add task_meta to prompts and centralize fn_key enrichment by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2751
• Remove unused include_tags/exclude_tags settings by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2756
• Parallelize provider access when executing components by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2744
• Add tests for OAuth generator cleanup and use aclosing by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2759
• Deprecate tool_serializer parameter by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2753
• Feature/supabase custom auth route by @EloiZalczer in https://github.com/PrefectHQ/fastmcp/pull/2632
• Add regression tests for caching with mounted server prefixes by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2762
• Update CLI banner with FastMCP 3.0 notice by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2766
• Make FASTMCP_SHOW_SERVER_BANNER apply to all server startup methods by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2771
• Add MCP tool annotations to smart_home example by @bryankthompson in https://github.com/PrefectHQ/fastmcp/pull/2777
• Cherry-pick debug logging for OAuth token expiry to main by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2797
• Turn off negative CLI flags by default by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2801
• Configure ty to fail on warnings by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2804
• Dereference $ref in tool schemas for MCP client compatibility by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2814
• Add v3.0 feature tracking document by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2822
• Remove deprecated WSTransport by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2826
• Add composable lifespans by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2828
• Replace FastMCP.as_proxy() with create_proxy() function by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2829
• Add docs-broken-links command and fix docstring markdown parsing by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2830
• Add PingMiddleware for keepalive connections by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2838
• Add CLI update notifications by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2840
• Add agent skills for testing and code review by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2846
• Add loq pre-commit hook for file size enforcement by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2847
• Add transport property to Context by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2850
• Add loq file size limits and clean up type ignores by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2859
• Run sync tools/resources/prompts in threadpool automatically by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2865
• Add timeout parameter for tool foreground execution by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2872
• Adopt OpenTelemetry MCP semantic conventions by @chrisguidry in https://github.com/PrefectHQ/fastmcp/pull/2886
• Add client_secret_post authentication to IntrospectionTokenVerifier by @shulkx in https://github.com/PrefectHQ/fastmcp/pull/2884
• Add enable_rich_logging setting to disable rich formatting by @strawgate in https://github.com/PrefectHQ/fastmcp/pull/2893
• Rename _fastmcp metadata namespace to fastmcp and make non-optional by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2895
• Refactor FastMCP to inherit from Provider by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2901
• Swap public/private method naming in Provider by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2902
• Add MCP-compliant pagination support by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2903
• Support VersionSpec in enable/disable for range-based filtering by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2914
• Remove sync notification infrastructure by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2915
• Immutable transform wrapping for providers by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2913
• Unify discovery API: deduplicate at protocol layer only by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2919
• Split transports.py into modular structure by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2921
• Move session visibility logic to enabled.py by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2924
• Refactor Client class into mixins and add timeout utilities by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2933
• Refactor OAuthProxy into focused modules by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2935
• Refactor LocalProvider into mixin modules by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2936
• Refactor server.py into mixins by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2939
• Consolidate test fixtures and refactor large test files by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2941
• Refactor transform list methods to pure function pattern by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2942
• Add ResourcesAsTools transform by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2943
• Add PromptsAsTools transform by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2946
• Add client utilities for downloading skills by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2948
• Rename Enabled transform to Visibility by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2950
• Make duplicate bot less aggressive by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2981
• Remove uv lockfile monitoring from Dependabot by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2986
• Run static checks with --upgrade, remove lockfile check by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2988
• Adjust workflow triggers for Marvin by @strawgate in https://github.com/PrefectHQ/fastmcp/pull/3010
• Move tests to a reusable action and enable nightly checks by @strawgate in https://github.com/PrefectHQ/fastmcp/pull/3017
• feat: option to add upstream claims to the FastMCP proxy JWT by @JonasKs in https://github.com/PrefectHQ/fastmcp/pull/2997
• Fix ty 0.0.14 compatibility and upgrade dependencies by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/3027
• fix: automatically include offline_access as a scope in the Azure provider to enable automatic token refreshing by @JonasKs in https://github.com/PrefectHQ/fastmcp/pull/3001
• feat: expand --reload to watch frontend file types by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/3028
• Add fastmcp install stdio command by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/3032
• Update martian-issue-triage.yml for Workflow editing guidance by @strawgate in https://github.com/PrefectHQ/fastmcp/pull/3033
• feat: Goose integration + dedicated install command by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/3040
• [Doc]: fixing spelling issues in multiple files by @didier-durand in https://github.com/PrefectHQ/fastmcp/pull/2996
• Add fastmcp discover and name-based server resolution by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/3055
• feat(context): Add background task support for Context (SEP-1686) by @gfortaine in https://github.com/PrefectHQ/fastmcp/pull/2905
• Add server version to banner by @richardkmichael in https://github.com/PrefectHQ/fastmcp/pull/3076
• Add @handle_tool_errors decorator for standardized error handling by @dgenio in https://github.com/PrefectHQ/fastmcp/pull/2885
• Update Anthropic and OpenAI clients to use Omit instead of NotGiven by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/3088
• Add ResponseLimitingMiddleware for tool response size control by @dgenio in https://github.com/PrefectHQ/fastmcp/pull/3072
• Infer MIME types from OpenAPI response definitions by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/3101
• Remove require_auth in favor of scope-based authorization by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/3103
• generate-cli: auto-generate SKILL.md agent skill by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/3115
• Scope Martian triage to bug-labeled issues for jlowin by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/3124
• Add Azure OBO dependencies, auth token injection, and documentation by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2918
• feat: add Static Client Registration (#3085) by @martimfasantos in https://github.com/PrefectHQ/fastmcp/pull/3086
• Add concurrent tool execution with sequential flag by @strawgate in https://github.com/PrefectHQ/fastmcp/pull/3022
• Add validate_output option for OpenAPI tools by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/3134
• Relay task elicitation through standard MCP protocol by @chrisguidry in https://github.com/PrefectHQ/fastmcp/pull/3136
• Bump py-key-value-aio to >=0.4.0,<0.5.0 by @strawgate in https://github.com/PrefectHQ/fastmcp/pull/3143
• Support async auth checks by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/3152
• Make $ref dereferencing optional via FastMCP(dereference_refs=...) by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/3151
• Expose local_provider property, deprecate FastMCP.remove_tool() by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/3155
• Add helpers for converting FunctionTool and TransformedTool to SamplingTool by @strawgate in https://github.com/PrefectHQ/fastmcp/pull/3062
• Updates to github actions / workflows for claude by @strawgate in https://github.com/PrefectHQ/fastmcp/pull/3157
• Minimize resolved review threads in PRs by @strawgate in https://github.com/PrefectHQ/fastmcp/pull/3200
• Exclude auto-generated python-sdk docs from CodeRabbit reviews by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/3206
• Update repository references for transfer to prefecthq by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/3207
• Fix MDX parsing error and update card images by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/3213

Fixes 🐞

• Let FastMCPError propagate from dependencies by @chrisguidry in https://github.com/PrefectHQ/fastmcp/pull/2646
• Fix task execution for tools with custom names by @chrisguidry in https://github.com/PrefectHQ/fastmcp/pull/2645
• fix: check the cause of the tool error by @rjolaverria in https://github.com/PrefectHQ/fastmcp/pull/2674
• Bump pydocket to 0.16.3 for task cancellation support by @chrisguidry in https://github.com/PrefectHQ/fastmcp/pull/2683
• Fix uvicorn 0.39+ test timeouts and FastMCPError propagation by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2699
• Fix Prefect website URL in docs footer by @mgoldsborough in https://github.com/PrefectHQ/fastmcp/pull/2701
• Fix: resolve root-level $ref in outputSchema for MCP spec compliance by @majiayu000 in https://github.com/PrefectHQ/fastmcp/pull/2720
• Fix Provider.get_tasks() to include custom component subclasses by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2729
• Fix Proxy provider to return all resource contents by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2742
• Fix prompt return type documentation by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2741
• fix: Client OAuth async_auth_flow() method causing MCP-SDK self.context.lock error. by @lgndluke in https://github.com/PrefectHQ/fastmcp/pull/2644
• Fix rate limit detection during teardown phase by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2757
• fix: set pytest-asyncio default fixture loop scope to function by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2758
• Fix OAuth Proxy resource parameter validation by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2764
• [BugFix] Fix openapi_version Check So 3.1 Is Included by @deeleeramone in https://github.com/PrefectHQ/fastmcp/pull/2768
• Fix titled enum elicitation schema to comply with MCP spec by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2773
• Fix base_url fallback when url is not set by @bhbs in https://github.com/PrefectHQ/fastmcp/pull/2776
• Lazy import DiskStore to avoid sqlite3 dependency on import by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2784
• Fix OAuth token storage TTL calculation by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2796
• Use consistent refresh_ttl for JTI mapping store by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2799
• Return 401 for invalid_grant token errors per MCP spec by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2800
• Fix client hanging on HTTP 4xx/5xx errors by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2803
• Fix unawaited coroutine warning and treat as test error by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2806
• Fix keep_alive passthrough in StdioMCPServer.to_transport() by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2791
• Dereference $ref in tool schemas for MCP client compatibility by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2808
• Prefix Redis keys with docket name for ACL isolation by @chrisguidry in https://github.com/PrefectHQ/fastmcp/pull/2811
• fix smart_home example: HueAttributes schema and deprecated prefix by @zzstoatzz in https://github.com/PrefectHQ/fastmcp/pull/2818
• Fix redirect URI validation docs to match implementation by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2824
• Fix timeout not propagating to proxy clients in multi-server MCPConfig by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2809
• Fix ContextVar propagation for ASGI-mounted servers with tasks by @chrisguidry in https://github.com/PrefectHQ/fastmcp/pull/2844
• Fix HTTP transport timeout defaulting to 5 seconds by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2849
• Fix decorator error messages to link to correct doc pages by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2858
• Fix task capabilities location (issue #2870) by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2875
• Bump the uv group across 1 directory with 2 updates by @dependabot[bot] in https://github.com/PrefectHQ/fastmcp/pull/2890
• Fix FastAPI mounting examples in docs by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2962
• Remove outdated 'FastMCP 3.0 is coming!' CLI banner by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2974
• Pin httpx < 1.0 and simplify beta install docs by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2975
• Add enabled field to ToolTransformConfig by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2991
• fix phue2 import in smart_home example by @zzstoatzz in https://github.com/PrefectHQ/fastmcp/pull/2999
• fix: broaden combine_lifespans type to accept Mapping return types by @aminsamir45 in https://github.com/PrefectHQ/fastmcp/pull/3005
• fix: type narrowing for skills resource contents by @strawgate in https://github.com/PrefectHQ/fastmcp/pull/3023
• fix: correctly send resource when exchanging code for the upstream to… by @JonasKs in https://github.com/PrefectHQ/fastmcp/pull/3013
• MCP Apps: structured CSP/permissions types, resource meta propagation fix, QR example by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/3031
• chore: upgrade python-multipart to 0.0.22 (CVE-2026-24486) by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/3042
• chore: upgrade protobuf to 6.33.5 (CVE-2026-0994) by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/3043
• fix: use MCP spec error code -32002 for resource not found by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/3041
• Fix tool_choice reset for structured output sampling by @strawgate in https://github.com/PrefectHQ/fastmcp/pull/3014
• Fix workflow notification URL formatting in upgrade checks by @strawgate in https://github.com/PrefectHQ/fastmcp/pull/3047
• Fix Field() handling in prompts by @strawgate in https://github.com/PrefectHQ/fastmcp/pull/3050
• fix: use SkipJsonSchema to exclude callable fields from JSON schema generation by @strawgate in https://github.com/PrefectHQ/fastmcp/pull/3048
• fix: Preserve metadata in FastMCPProvider component wrappers by @NeelayS in https://github.com/PrefectHQ/fastmcp/pull/3057
• Mock network calls in CLI tests and use MemoryStore for OAuth tests by @strawgate in https://github.com/PrefectHQ/fastmcp/pull/3051
• Remove OpenAPI timeout parameter, make client optional, surface timeout errors by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/3067
• fix: enforce redirect URI validation when allowed_client_redirect_uris is supplied by @nathanwelsh8 in https://github.com/PrefectHQ/fastmcp/pull/3066
• Fix --reload port conflict when using explicit port by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/3070
• Fix compress_schema to preserve additionalProperties: false for MCP compatibility by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/3102
• Fix CIMD redirect allowlist bypass and cache revalidation by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/3098
• Exclude content-type from get_http_headers() to prevent HTTP 415 errors by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/3104
• Updated deprecation URL for V3 by @SrzStephen in https://github.com/PrefectHQ/fastmcp/pull/3108
• Fix Windows test timeouts in OAuth proxy provider tests by @strawgate in https://github.com/PrefectHQ/fastmcp/pull/3123
• Fix session visibility marks leaking across sessions by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/3132
• Fix unhandled exceptions in OpenAPI POST tool calls by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/3133
• feat: distributed notification queue + BLPOP elicitation for background tasks by @gfortaine in https://github.com/PrefectHQ/fastmcp/pull/2906
• fix: snapshot access token for background tasks (#3095) by @gfortaine in https://github.com/PrefectHQ/fastmcp/pull/3138
• Stop duplicating path parameter descriptions into tool prose by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/3149
• fix: guard client pagination loops against misbehaving servers by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/3167
• Fix stale get_* references in docs and examples by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/3168
• Support non-serializable values in Context.set_state by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/3171
• Fix stale request context in StatefulProxyClient handlers by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/3172
• Fix include_tags/exclude_tags ignored without tools in MCPConfig by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/3186
• fix: correct dark mode logo file extension in README by @jfBiswajit in https://github.com/PrefectHQ/fastmcp/pull/3193
• Return 405 for GET SSE on stateless HTTP servers by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/3195
• Fix ty 0.0.17 diagnostics by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/3198
• Drop diskcache dependency (CVE-2025-69872) by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/3185
• Fix confused deputy attack via consent binding cookie by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/3201
• Add JWT audience validation and RFC 8707 warnings to auth providers by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/3204
• Cache OBO credentials on AzureProvider for token reuse by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/3212
• Fix invalid uv add command in upgrade guide by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/3217
• Use standard traceparent/tracestate keys per OTel MCP semconv by @chrisguidry in https://github.com/PrefectHQ/fastmcp/pull/3221

Breaking Changes 🛫

• Add VisibilityFilter for hierarchical enable/disable by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2708
• Remove automatic environment variable loading from auth providers by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2752
• Make pydocket optional and unify DI systems by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2835
• Add session-scoped state persistence by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2873
• Rename ui= to app= and consolidate ToolUI/ResourceUI into AppConfig by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/3117
• Remove deprecated FastMCP() constructor kwargs by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/3148
• Move fastmcp dev to fastmcp dev inspector by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/3188

Docs 📚

• Undocumented McpError exceptions by @ivanbelenky in https://github.com/PrefectHQ/fastmcp/pull/2656
• docs(server): add http to transport options in run() method docstring by @Ashif4354 in https://github.com/PrefectHQ/fastmcp/pull/2707
• Add v3 breaking changes notice to README by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2712
• Add changelog entries for v2.13.1 through v2.14.1 by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2725
• Reorganize docs around provider architecture by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2723
• Fix documentation to use 'meta' instead of '_meta' for MCP spec field by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2735
• Enhance documentation on tool transformation by @shea-parkes in https://github.com/PrefectHQ/fastmcp/pull/2781
• Add FastMCP 4.0 preview to documentation by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2831
• Add release notes for v2.14.2 and v2.14.3 by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2852
• Add missing 3.0.0 version badges and document tasks extra by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2866
• Add missing v3 features to tracking docs by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2888
• Fix custom provider docs to show correct interface by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2920
• Update v3 features that were missed in PRs by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2947
• Restructure documentation for FastMCP 3.0 by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2951
• Fix broken documentation links by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2952
• Clarify installation for FastMCP 3.0 beta by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2953
• Prepare docs for v3.0 beta release by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2954
• Restructure docs: move transforms to dedicated section by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2956
• Remove unecessary pip warning by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2958
• Update example MCP version in installation docs by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2959
• Update brand images by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2960
• Restructure README and welcome page with motivated narrative by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2963
• Restructure README and docs with motivated narrative by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2964
• Favicon update and Prefect Horizon docs by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2978
• Add dependency injection documentation and DI-style dependencies by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2980
• docs: document expanded reload behavior and restructure beta sections by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/3039
• Add output_schema caveat to response limiting docs by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/3099
• Document token passthrough security in OAuth Proxy docs by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/3100
• Add missing beta2 features to v3 release tracking by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/3105
• Update docs to reference beta 2 by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/3112
• docs: add pre-registered OAuth clients to v3-features by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/3129
• docs: update all references from 3.0.0b2 to 3.0.0rc1 by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/3173
• Document cache key identity behavior by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/3194
• Reorganize docs navigation around Server/Client/Apps pillars by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/3197
• Overhaul v3.0 upgrade guide by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/3205
• Update docs for 3.0 GA release by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/3216
• Add upgrade guides for users coming from the MCP SDK by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/3215
• Update thumbnail background by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/3219
• v3.0.0 release notes, changelog, and README updates by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/3222

Dependencies 📦

• Bump peter-evans/create-pull-request from 7 to 8 by @dependabot[bot] in https://github.com/PrefectHQ/fastmcp/pull/2623
• Bump ty to 0.0.7+ by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/2737
• Bump the uv group across 1 directory with 4 updates by @dependabot[bot] in https://github.com/PrefectHQ/fastmcp/pull/2891
• Bump ty from 0.0.12 to 0.0.13 by @dependabot[bot] in https://github.com/PrefectHQ/fastmcp/pull/2984
• Bump prek from 0.2.30 to 0.3.0 by @dependabot[bot] in https://github.com/PrefectHQ/fastmcp/pull/2982
• chore(deps): bump cryptography from 46.0.3 to 46.0.5 in /examples/testing_demo in the uv group across 1 directory by @dependabot[bot] in https://github.com/PrefectHQ/fastmcp/pull/3140
• chore(deps): bump cryptography from 46.0.4 to 46.0.5 in the uv group across 1 directory by @dependabot[bot] in https://github.com/PrefectHQ/fastmcp/pull/3147

Other Changes 🦾

• Normalize resource URLs before comparison to support RFC 8707 query parameters by @abhijeethp in https://github.com/PrefectHQ/fastmcp/pull/2967
• Bump pydocket to 0.17.2 (memory leak fix) by @chrisguidry in https://github.com/PrefectHQ/fastmcp/pull/2998
• Add AzureJWTVerifier for Managed Identity token verification by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/3058
• Add release notes for v2.14.4 and v2.14.5 by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/3064
• docs: add v3.0.0rc1 features to v3-features tracking by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/3145
• docs: remove nonexistent MSALApp from rc1 notes by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/3146

New Contributors

• @ivanbelenky made their first contribution in https://github.com/PrefectHQ/fastmcp/pull/2656
• @rjolaverria made their first contribution in https://github.com/PrefectHQ/fastmcp/pull/2674
• @mgoldsborough made their first contribution in https://github.com/PrefectHQ/fastmcp/pull/2701
• @Ashif4354 made their first contribution in https://github.com/PrefectHQ/fastmcp/pull/2707
• @majiayu000 made their first contribution in https://github.com/PrefectHQ/fastmcp/pull/2720
• @lgndluke made their first contribution in https://github.com/PrefectHQ/fastmcp/pull/2644
• @EloiZalczer made their first contribution in https://github.com/PrefectHQ/fastmcp/pull/2632
• @deeleeramone made their first contribution in https://github.com/PrefectHQ/fastmcp/pull/2768
• @shea-parkes made their first contribution in https://github.com/PrefectHQ/fastmcp/pull/2781
• @bryankthompson made their first contribution in https://github.com/PrefectHQ/fastmcp/pull/2777
• @bhbs made their first contribution in https://github.com/PrefectHQ/fastmcp/pull/2776
• @shulkx made their first contribution in https://github.com/PrefectHQ/fastmcp/pull/2884
• @abhijeethp made their first contribution in https://github.com/PrefectHQ/fastmcp/pull/2967
• @aminsamir45 made their first contribution in https://github.com/PrefectHQ/fastmcp/pull/3005
• @JonasKs made their first contribution in https://github.com/PrefectHQ/fastmcp/pull/2997
• @NeelayS made their first contribution in https://github.com/PrefectHQ/fastmcp/pull/3057
• @gfortaine made their first contribution in https://github.com/PrefectHQ/fastmcp/pull/2905
• @nathanwelsh8 made their first contribution in https://github.com/PrefectHQ/fastmcp/pull/3066
• @dgenio made their first contribution in https://github.com/PrefectHQ/fastmcp/pull/2885
• @martimfasantos made their first contribution in https://github.com/PrefectHQ/fastmcp/pull/3086
• @jfBiswajit made their first contribution in https://github.com/PrefectHQ/fastmcp/pull/3193

Full Changelog: https://github.com/PrefectHQ/fastmcp/compare/v2.14.5...v3.0.0