Openapi Breaking Change Detection
Spec0
See who an API change breaks. Serve specs to AI agents.
About Spec0
AI coding assistants trust your API specs completely, even when they're out of date. Spec0 keeps every OpenAPI spec in one registry, with owners, versions, and the teams that depend on each API. Breaking changes are flagged on every pull request, before anyone merges. Cursor and Claude Code query Spec0 over MCP and get just the operation they need, about 300 tokens from the latest version, instead of a whole spec pasted into the chat. Your specs stay in your Git repo. Mock servers included. Open-source CLI, free tier.
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1 comment
Hi all, Nakul here. I built spec0. The reason it exists: at every company I've worked at, nobody could tell you what breaks when an API changes. The spec had drifted from what was deployed, the listed owner had moved teams, and the teams depending on it found out from an incident. That was survivable while humans were the ones reading specs, because we work around bad information. Coding agents don't. They take the contract literally and generate a client from it. If you want to look at something without signing up, the public API registry mirrors real public specs and tracks what changed between versions: https://app.spec0.io/registry Curious how your team finds out when an API you depend on has changed. Release notes, an alert, or production?