MCP Panther v2.3.0

Highlights

This release improves reliability for parallel tool calls and significantly enhances the HTTP deployment experience with comprehensive documentation and troubleshooting guidance.

Bug Fixes

Parallel Tool Call Connection Errors (#148)

Resolved intermittent connection errors that could occur when MCP clients (Claude Code, Cursor, etc.) executed multiple tools in parallel:

• Root cause: Each tool call was creating its own HTTP session, which would conflict or close prematurely when multiple tools ran concurrently
• Solution: Implemented persistent HTTP session management using FastMCP's lifespan context
• Result: All tool calls now share connection pools that persist for the server's lifetime

Before: Intermittent errors during parallel execution (would retry successfully):

Error: Connector is closed
Error: Cannot open a client session outside of a context manager

After: Parallel tool calls execute smoothly on the first attempt.

Documentation

Streamable HTTP Deployment (#148)

Rewrote the HTTP deployment documentation with production-ready examples:

• Docker Compose: Added complete docker-compose.yml configuration for easier deployment
• Docker Run: Updated examples with detached mode, restart policies, and logging
• Claude Code HTTP: Added explicit instructions for connecting to HTTP servers (note: uses http:// not https://)
• Troubleshooting: New section covering common issues:
  • Port already in use errors
  • Invalid HTTP request warnings (HTTPS vs HTTP misconfiguration)
  • Container management commands

Claude Code Configuration

Improved readability of Claude Code setup examples with properly formatted multi-line JSON.

Development

Testing Improvements

• Added FastMCP integration tests (tests/panther_mcp_core/test_fastmcp_integration.py)
• Improved test fixtures with shared mocking patterns
• Simplified test utilities

Dependencies

• Updated aiohttp minimum version to >=3.9.0
• Test CI now uses Python 3.12

Migration Guide

For users upgrading from v2.2.x

No breaking changes. This release is fully backward compatible.