Stop breaking your
users' code.

A GitHub Action and CLI that diffs your Pull Requests, detects deleted functions and API changes using Abstract Syntax Trees, and warns you before you hit merge.

$ breakguard --repo . --base origin/main
Scanning for downstream breakage risks...
Parsing Abstract Syntax Trees (AST)...
❌ [High] src/api/client.py: Removed public function: execute_query
Migration note: The function 'execute_query' was removed from src/api/client.py. Consumers will break. Check downstream impact.

Error: Overall risk level 'high' exceeds threshold 'high'.

Next-Generation AI Tools

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AST-Based Analysis

Regex isn't enough. We parse Python Abstract Syntax Trees (AST) to detect exactly when parameters are renamed, defaults are removed, or classes are deleted.

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Native GitHub Annotations

Breaking changes magically appear as inline `::error` annotations directly on the exact lines of code inside the GitHub "Files changed" tab.

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Removed public function: send_alert The function 'send_alert' was removed from api.py. Consumers will break.
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Auto-Drafted Releases

Pass `--draft-release` and the tool will automatically draft a beautifully formatted GitHub Release with all the detected breaking changes and migration steps.

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AI Auto-Fix Downstream

Curious who you just broke? BreakGuard uses AI to automatically clone downstream repositories, rewrite their outdated function calls, and open Pull Requests to fix their code for them!

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Visual Dependency Graphs

Instantly generate an interactive Mermaid.js HTML diagram showing exactly which downstream apps you just broke (in red) and which are safe (in green).

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.breakageignore Support

Large monorepo? No problem. Use a `.breakageignore` file to filter out test suites, internal scripts, and private packages using glob patterns.

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Zero Dependencies

Written entirely in Python using only standard libraries. It installs in milliseconds and adds virtually zero overhead to your CI/CD pipeline.