Show HN: Mermaidiff – a sequence diagram of only what a PR changes

Category: devtools

Tags: git, code-review, mermaid, llm-agents, developer-productivity

Score: 6.3/10 (Innovation: 6, Technical: 5, Documentation: 8, Utility: 6)

Mermaidiff is a skill/agent plugin that reads a git diff or PR and produces a Mermaid sequence diagram highlighting only the added, changed, and removed steps, plus a short evidence section. It targets review-time comprehension of behavior changes rather than raw diffs, with a strong no-false-positives constraint and a small evaluation set.

Target audience: backend devs, code reviewers, devops

Repository: https://github.com/osmangoninahid/mermaidiff · Python · MIT · 14 stars

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