Add backwards compatibility support for MCP clients when connecting to SSE-only servers.
When a StreamableHttpTransport receives a 405 Method Not Allowed error, the client now
automatically falls back to SSETransport using the same URL and authentication settings.
This implements the backwards compatibility requirement from the MCP specification:
https://modelcontextprotocol.io/specification/2025-03-26/basic/transports#backwards-compatibility
Key changes:
- Modified Client._context_manager() to detect 405 errors from StreamableHttpTransport
- Automatically retry with SSETransport preserving auth, headers, and timeouts
- Added comprehensive test coverage for fallback behavior
- Non-405 HTTP errors are re-raised without fallback attempt
Fixes#853🤖 Generated with [Claude Code](https://claude.ai/code)
Co-authored-by: William Easton <strawgate@users.noreply.github.com>
* Refactor Client session state with ClientSessionState dataclass
Fixes#1068 by introducing ClientSessionState to encapsulate session management
attributes, simplifying Client.new() and preventing concurrent proxy client
context mixing through client factory pattern.
🤖 Generated with [Claude Code](https://claude.ai/code)
Co-Authored-By: Claude <noreply@anthropic.com>
* Update proxy documentation for new client factory pattern
Documents the new session management behavior, client_factory parameter,
and concurrent operation safety introduced in v2.10.3 to fix#1068.
* Remove deprecation of client parameter and update documentation
- Undeprecated FastMCPProxy client parameter
- Made client_factory the advanced option for custom control
- Added detailed explanation of how client factories work internally
- Removed outdated note about proxy feature limitations
- Removed fabricated Advanced Usage section
* Re-do proxy documentation
* Fix deprecated client parameter to provide session isolation
🤖 Generated with [Claude Code](https://claude.ai/code)
Co-Authored-By: Claude <noreply@anthropic.com>
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Co-authored-by: Claude <noreply@anthropic.com>
Single-element lists like [1] were being incorrectly unwrapped to "1"
in unstructured content while multi-element lists remained as lists.
This created inconsistent behavior where the structure was lost for
single items.
This fix ensures lists always preserve their structure in unstructured
content regardless of length, making behavior consistent and predictable.
Also removes pretty-printing from JSON serialization for more compact
output across tools, prompts, and resources.
Fixes#1064🤖 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>
- 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>
Added comprehensive elicitation support including:
- Client-side handler infrastructure following sampling pattern
- Server-side Context.elicit() method with type safety and validation
- Support for primitive types (str, int, float, bool) with automatic wrapping
- Support for dataclasses and other complex types
- Pattern matching with AcceptedElicitation, DeclinedElicitation, CancelledElicitation
- Comprehensive atomic test coverage for all scenarios
🤖 Generated with [Claude Code](https://claude.ai/code)
Co-Authored-By: Claude <noreply@anthropic.com>
