ft-review-toolkit

A Claude Code plugin for analyzing and migrating CPython C extensions to free-threaded Python (PEP 703).

Make your C extension free-threading safe.

What It Does

• Finds thread-safety bugs in existing C extension code (data races, unprotected shared state, unsafe API usage)
• Plans migrations from GIL-protected to free-threaded code
• Triages ThreadSanitizer reports into actionable findings
• Scores readiness with a quick dashboard

Installation

Install as a Claude Code plugin:

claude plugins add /path/to/ft-review-toolkit/plugins/ft-review-toolkit

Prerequisites

pip install tree-sitter tree-sitter-c
# Optional: pip install tree-sitter-cpp  (for C++ extensions)

Commands

Command	Purpose
/ft-review-toolkit:assess [path]	Quick readiness scorecard
/ft-review-toolkit:explore [path]	Full thread-safety analysis
/ft-review-toolkit:plan [path]	Phased migration plan

Classification System

Tag	Meaning
RACE	Confirmed or highly likely data race
UNSAFE	Operation unsafe without the GIL
PROTECT	Shared state needing protection
MIGRATE	Pattern needing structural changes
SAFE	Confirmed safe pattern

Related Projects

• cext-review-toolkit — C extension correctness analysis
• cpython-review-toolkit — CPython runtime C code analysis
• code-review-toolkit — Python source code analysis

License

MIT