* pin pydantic-monty to 0.0.8
* rename tool/prompt/resource base modules to avoid decorator name shadow
* add sys.modules shims for old submodule import paths
* preserve original module paths in deprecation warnings
* clarify when sys.modules shims can be removed
* Propagate x-fastmcp-wrap-result flag in tool result _meta
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Co-authored-by: Claude <noreply@anthropic.com>
* Skip listTools round-trip when _meta has x-fastmcp-wrap-result
🤖 Generated with Claude Code
Co-authored-by: Claude <noreply@anthropic.com>
* Use namespaced meta key: {"fastmcp": {"wrap_result": true}}
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Co-authored-by: Claude <noreply@anthropic.com>
* Clean up _parse_call_tool_result: hoist cast import, document local CallToolResult import, extract fastmcp_meta
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Co-authored-by: Claude <noreply@anthropic.com>
* Merge _meta in tasks result handler instead of overwriting
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* Preserve type validation in meta-based unwrap path
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* Fix type validation for wrapped task results, guard non-dict meta
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---------
Co-authored-by: Claude <noreply@anthropic.com>
* fix: cache component lists in ProxyProvider to avoid redundant backend connections
Every call_tool through a proxy was triggering _list_tools() to resolve
the tool by name, opening a full MCP session just for the lookup, then
opening a second session for the actual execution. This caches component
lists on the ProxyProvider with a configurable TTL (default 300s),
cutting backend handshakes in half for repeated calls.
* docs: document component caching and session reuse for proxy providers
* fix: add sleep in cache TTL test for Windows clock resolution
* docs: clarify cache scope and dynamic backend guidance
Message.content now accepts ImageContent and AudioContent in addition to
TextContent and EmbeddedResource, matching MCP's ContentBlock type. This
fixes ProxyPrompt.render() silently JSON-serializing image/audio content
instead of preserving it.
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Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Increase performance test threshold from 100ms to 1.0s. Windows CI runners
are slower than Linux, and the 100ms threshold was too tight. The test's
intent is to catch obvious regressions (e.g., accidentally re-introducing
code generation), not to precisely benchmark.
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Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
* fix: restore request context in StatefulProxyClient handlers
StatefulProxyClient reuses sessions across requests, so its receive-loop
task inherits a stale request_ctx ContextVar from the first request.
Server-initiated messages (elicitation, sampling, etc.) that depend on
related_request_id routing get sent to a closed stream and hang forever.
Closes#3169
* chore: Update SDK documentation
---------
Co-authored-by: marvin-context-protocol[bot] <225465937+marvin-context-protocol[bot]@users.noreply.github.com>
Rename Visibility to Enabled, collapse VisibilityRule into the transform,
and move enabled filtering from Provider to Server level so server-level
transforms can override provider-level disables.
Server authors opt-in by setting list_page_size on FastMCP.
Client convenience methods auto-fetch all pages transparently.
Use _mcp methods with cursor parameter for manual pagination.
- get_*() now does aggregation + component auth (raises AuthorizationError)
- Deleted _get_*() overrides - inherited from Provider applies transforms
- Simplified AuthMiddleware to global auth only
- Changed version params to VersionSpec | None (not str | None)
- Updated tests to use _get_*() where visibility filtering is expected
Resolved conflicts to combine Provider inheritance refactor with versioning feature:
- FastMCP now properly inherits from Provider
- get_tool/resource/template/prompt return None instead of raising NotFoundError
- Deduplication uses version_sort_key to keep highest version per name/URI
- _source_* methods eliminated in favor of inherited _* methods
FastMCP now properly inherits from Provider, eliminating ~200 lines of
duplicated _source_* methods. Key changes:
- get_tool/resource/prompt return None instead of raising NotFoundError
- Visibility filter separated from transforms (applied last)
- Nested server middleware runs on both list and execution operations
- Resource auth failure doesn't fall back to templates
- AggregateProvider kept as user-facing utility class
- Fix potential None session_id in span attributes
- Add return type annotation to _get_parent_trace_context
- Fix type checker issue with ClientFactoryT await pattern
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Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
* Consolidate tool transformation logic into TransformingProvider
Tool transformations were previously scattered across LocalProvider,
ProxyProvider, and MCPConfig. This consolidates all transformation
logic into TransformingProvider via with_transforms(tool_transforms={...}).
- Add tool_transforms parameter to TransformingProvider
- Add tool_transforms to Provider.with_transforms()
- Remove transformation storage from LocalProvider and ProxyProvider
- Remove add_tool_transformation() and remove_tool_transformation() from FastMCP
- Add tool_transforms parameter to factory methods (from_openapi, from_fastapi, create_proxy)
- Update tests to use new patterns
* Fix: reject tool lookups by pre-transform name
* Add collision validation for tool_transforms and fix docstring examples
- Validate duplicate target names in tool_transforms raise ValueError
- Fix docstring examples to use arguments/ArgTransformConfig (not args/ArgTransform)
- Add test for collision validation
* Add server-level tool transform APIs and fix task registration
- Add AggregateProvider to present multiple providers as one
- Add _get_root_provider() to apply server-level transforms uniformly
- Fix _docket_lifespan to use root provider (ensures renamed tools
register with correct keys for background execution)
- Add tool_transforms kwarg to __init__ (non-deprecated)
- Add add_tool_transform(), remove_tool_transform(), tool_transforms property
- Deprecate old API names (tool_transformations, add_tool_transformation, etc.)
- Update tests to use new API
* Add graceful degradation for provider errors in AggregateProvider
* Match original behavior: parallel queries with DEBUG logging
* Refactor transforms to middleware-style call_next pattern
Replaces the ad-hoc transformation system with a unified Transform
abstraction using the same call_next pattern as server middleware.
Key changes:
- New src/fastmcp/server/transforms/ module with Transform base class
- Namespace, ToolTransform, Visibility all implement the same interface
- Transforms compose via functools.partial chain building
- Visibility is now just the first transform in provider._transforms
- Server-level transforms apply after provider aggregation
- Task registration now applies full transform chain
Removes TransformingProvider, _BoundTransform, ComponentSource protocol.
User-facing API unchanged: mount(), add_transform(), enable/disable all
work as before.
* Add comprehensive transforms and visibility documentation
New docs/servers/providers/transforms.mdx covering:
- Mental model for middleware-style transform pattern
- Built-in transforms (Namespace, ToolTransform)
- Server vs provider-level transforms and ordering
- Tool modification (immediate vs deferred)
- Custom transform creation
New docs/servers/visibility.mdx covering:
- Enable/disable API for runtime visibility control
- Keys and tags for targeting components
- Allowlist mode with only=True
- Server vs provider visibility layering
Updates existing docs to reference new pages and simplifies
redundant content. Visibility is documented as a user feature,
not as an implementation detail.
* Restructure transforms docs and delete tool-transformation pattern
* Cleanup: simplify get_tasks and remove unused Provider.get_component
* Update loq
* Update loq limits and add loq note to AGENTS.md
* Deprecate add_tool_transformation and tool_transformations param
* Address PR review feedback: remove redundant imports, fix path reference
* Add missing imports to code examples in v3-features.mdx
