- TransformedTool.run() now returns ToolResult instead of list[ContentBlock]
- forward() and forward_raw() return ToolResult from parent tools
- Transform functions can return ToolResult for full control or any value for auto-wrapping
- Maintains backward compatibility with existing transform functions
🤖 Generated with [Claude Code](https://claude.ai/code)
Co-Authored-By: Claude <noreply@anthropic.com>
- Tools can return StructuredOutput() for explicit structured data
- Tools with output_schema automatically return structured data
- Client hydrates structured responses into typed objects
- Maintains backward compatibility with unstructured-only tools
Because the server now validates inputs, its no longer viable to provide a JSON string where e.g. an array is expected, so we can entirely remove FastMCP's "legacy json parsing" support from 1.x.
This is a breaking change (for legacy opt-in behavior)
Fixes breaking changes from mcp-python-sdk PR #982 which updated
BearerAuthBackend to use TokenVerifier protocol instead of OAuth providers.
Changes:
- Add verify_token() method to BearerAuthProvider implementing TokenVerifier protocol
- Add verify_token() method to InMemoryOAuthProvider implementing TokenVerifier protocol
- Update BearerAuthBackend usage in setup_auth_middleware_and_routes() to pass TokenVerifier
- Add comprehensive unit tests for TokenVerifier implementations
- Add integration tests for BearerAuthBackend with TokenVerifier
- Add tests for HTTP auth setup functions
All existing functionality preserved with full backwards compatibility.
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Co-Authored-By: Claude <noreply@anthropic.com>
Previously, external schema references (URLs) in OpenAPI schemas were
silently passed through and only failed during JSON schema validation
with confusing "failed to match exactly one schema" errors.
This change:
- Detects external references in _replace_ref_with_defs() and raises clear error messages
- Updates exception handlers to propagate external reference errors while preserving other error handling
- Adds comprehensive test coverage for external reference detection
- Provides helpful error messages explaining that FastMCP only supports local schema references
Fixes#926🤖 Generated with [Claude Code](https://claude.ai/code)
Co-Authored-By: Claude <noreply@anthropic.com>
Replace hasattr(param_in, 'value') with isinstance(param_in, Enum)
for more robust enum detection as suggested in review.
🤖 Generated with [Claude Code](https://claude.ai/code)
Co-Authored-By: Claude <noreply@anthropic.com>
Fixes issue where ParameterLocation enum values from openapi_pydantic
were not properly converted to strings, causing validation errors.
🤖 Generated with [Claude Code](https://claude.ai/code)
Co-Authored-By: Claude <noreply@anthropic.com>
Implements comprehensive notification system for tools, resources, and prompts with automatic client updates and flexible message handlers.
🤖 Generated with [Claude Code](https://claude.ai/code)
Co-Authored-By: Claude <noreply@anthropic.com>
Remove redundant `{e}` interpolation from logger.exception() calls.
Since logger.exception() automatically logs the full exception traceback,
including `{e}` in the message causes duplicate error output.
Fixes#936🤖 Generated with [Claude Code](https://claude.ai/code)
Co-Authored-By: Claude <noreply@anthropic.com>
Implements timing, logging, rate limiting, and error handling middleware to showcase
FastMCP's middleware capabilities as a headline feature. Each middleware includes:
- Production-ready implementations with full configurability
- Comprehensive unit and integration tests with real FastMCP servers
- Updated documentation with teaching examples and production usage patterns
🤖 Generated with [Claude Code](https://claude.ai/code)
Co-Authored-By: Claude <noreply@anthropic.com>
- Add pydantic_core.to_json() serialization for non-string prompt arguments
- Update type annotations to accept dict[str, Any] instead of dict[str, str]
- Add focused tests covering specific scenarios:
* Client always serializes non-string args regardless of server types
* Integration with server-side type conversion
* Client serialization error with specific PydanticSerializationError
* Server deserialization error with specific McpError match
This ensures MCP protocol compliance while maintaining developer experience
with typed arguments.
🤖 Generated with [Claude Code](https://claude.ai/code)
Co-Authored-By: Claude <noreply@anthropic.com>
Change from 'Arguments must be strings conforming to this JSON schema'
to 'Provide as a JSON string matching the following schema' for clearer
instruction to LLMs about string format requirements.
🤖 Generated with [Claude Code](https://claude.ai/code)
Co-Authored-By: Claude <noreply@anthropic.com>
- Fix ValueError -> PromptError for consistent error handling
- Add automatic JSON schema descriptions to non-string prompt arguments
- Include comprehensive tests for argument description enhancement
- Verify enhanced descriptions are visible via MCP protocol
This helps developers understand the expected string format for complex
types when calling prompts from MCP clients.
🤖 Generated with [Claude Code](https://claude.ai/code)
Co-Authored-By: Claude <noreply@anthropic.com>
Updated FunctionPrompt.render() to accept dict[str, Any] instead of
dict[str, str | Context] to preserve the developer experience of
passing properly typed arguments while also supporting string-only
arguments from MCP clients.
The _convert_string_arguments method now intelligently handles both
scenarios:
- Already-typed arguments are passed through unchanged
- String arguments are converted to expected types when needed
This maintains backward compatibility while enabling MCP spec compliance.
🤖 Generated with [Claude Code](https://claude.ai/code)
Co-Authored-By: Claude <noreply@anthropic.com>
- Add comprehensive server inspection utility supporting both FastMCP 1.x and 2.x
- Create detailed info dataclasses for tools, prompts, resources, and templates
- Implement CLI command with path:object notation and JSON output
- Add version reporting (fastmcp_version, mcp_version, server_version)
- Include comprehensive unit tests for utilities and CLI
🤖 Generated with [Claude Code](https://claude.ai/code)
Co-Authored-By: Claude <noreply@anthropic.com>
