Unfix

Unfix is an independent verifier that tests and validates bug fixes for C, C++ and firmware.

Unfix is an independent verifier for bug fixes in C, C++, and firmware, including code written by AI coding agents. It reproduces the bug on a base version, applies the patch, runs reference tests with sanitizers, and removes the fix to confirm the bug returns. It provides a deterministic verdict of VERIFIED, REJECTED, or NOT VERIFIABLE, along with an anti-masking scan to flag disabled sanitizers or weakened assertions. Built for C/C++ and embedded teams, it runs locally on your machines without an LLM making the final judgment. It integrates with tools like Claude Code and Codex via an MCP tool, GitHub pull requests, the terminal, and hardware rigs like STM32 NUCLEO boards.

Unfix at a glance

Best for: Software engineer
Runs on: Web, Terminal, API, CLI, GitHub check, MCP tool
Pricing: Paid
Released: November 2026
Category: AI coding tool
Website: unfix.dev

Key features

Reproduces bugs on base versions
Applies patches and re-runs tests with sanitizers
Performs revert checks to ensure bugs return
Scans diffs for anti-masking and disabled sanitizers
Flashes and tests real hardware boards
Generates deterministic verdicts
Exports HTML reports and change records

Use it for

Verifying AI-generated C, C++ and firmware bug fixes
Running checks on real hardware and STM32 NUCLEO boards
Checking pull requests for valid bug resolutions
Detecting weakened assertions and disabled sanitizers

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