* Update repository references from jlowin/fastmcp to prefecthq/fastmcp
* Retrigger CI after repo transfer
* chore: Update SDK documentation
* Only run deep triage on bug issues for jlowin
---------
Co-authored-by: marvin-context-protocol[bot] <225465937+marvin-context-protocol[bot]@users.noreply.github.com>
* Reorganize docs navigation and add Apps documentation
Collapse Providers, Transforms, and Deployment under Servers. Add Apps
section with overview and low-level API pages. Add card images to welcome
page and README. Add NEW tags to recent features.
* Fix missing imports in Apps low-level API code examples
* Add `fastmcp generate-cli` command
Connects to any MCP server, reads its tool/resource/prompt schemas,
and writes a standalone Python CLI script with typed subcommands.
* docs: add generate-cli documentation
* docs: add generate-cli documentation; skip Windows executable test
* fix: address PR review feedback
- Sanitize tool and parameter names to valid Python identifiers
- Replace bare except Exception with specific exception types
- Escape server name in generated string literals
- Handle trailing colon edge case in _derive_server_name
- Clarify in docs that generated CLI is a client, not a bundled server
* Fix string escaping issues in generate-cli
- Use single-quoted docstrings to avoid triple-quote escaping issues
- Escape quotes in app_name derived from server_name
- Add tests for descriptions with quotes and server names with quotes
Addresses CodeRabbit review comments about insufficient escaping.
* Implement smart parameter handling for generate-cli
- Simple types (str, int, float, bool): Direct typed flags
- Arrays of simple types (list[str], list[int]): Repeatable flags via cyclopts
- Complex types (objects, nested arrays): Accept JSON strings with parsing
- JSON schema shown in help text for complex parameters
- Proper escaping of newlines and quotes in help text
- Filter out None and empty list defaults when calling tools
This gives typed, discoverable CLIs for common cases while handling
complex schemas via JSON input.
* Update generate-cli docs to explain smart parameter handling
- Document simple types as direct typed flags
- Document arrays of simple types as repeatable flags
- Document complex types as JSON strings with schema in help
- Add examples showing all three patterns
* Fix Codex review issues in generate-cli
High priority fixes:
- Complex type defaults: Serialize dict/list defaults to JSON strings
- List params: Preserve help metadata with Annotated wrapper
- Name collisions: Detect and error on sanitized name conflicts
- JSON parsing: Use isinstance check for safety with defaults
Added tests for:
- Complex types with default values
- Parameter name collision detection
- Updated existing tests to match new format
* Use pydantic_core.to_json for consistency
- Generator now uses pydantic_core.to_json() instead of json.dumps()
- Consistent with rest of fastmcp codebase
- Generated CLI still uses plain json module (standalone script)
* Move local imports to module level in generate-cli
* Handle union item types and Python keyword collisions in generate-cli
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.
Adds opt-in distributed tracing via OpenTelemetry for observability into
FastMCP server and client operations.
Server spans are created for tool calls, resource reads, and prompt
renders with attributes like component key, component type, provider
type, session ID, and auth context. Client spans wrap outgoing calls
with trace context propagation via W3C headers in request meta.
Components provide their own span attributes through a `get_span_attributes()`
method that subclasses override - this lets LocalProvider, FastMCPProvider,
and ProxyProvider each include relevant context (original names, backend URIs).
To enable: configure an OpenTelemetry SDK with a TracerProvider before
importing fastmcp. Traces export to any OTLP-compatible backend.
Closes ENG-2813
🤖 Generated with Claude Code
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
