Breaking Change
ELI5 — The Vibe Check
A Breaking Change is a modification to your API or library that will BREAK existing code that uses it. If you rename a function, remove a parameter, or change a response format, anyone using the old version will need to update their code. Breaking changes require a major version bump and a big warning in the changelog.
Real Talk
A breaking change (breaking API change) is a modification that is not backward-compatible, requiring consumers to update their code to continue working. In SemVer, breaking changes must increment the MAJOR version. Examples include removing endpoints, changing required parameter types, or modifying response schemas.
When You'll Hear This
"That's a breaking change — bump the major version and document it clearly." / "We try to avoid breaking changes in our public API — they cause pain for all our integrators."
Related Terms
API (Application Programming Interface)
An API is like a menu at a restaurant. The kitchen (server) can do a bunch of things, but you can only order what's on the menu.
Changelog
A Changelog is a file (usually CHANGELOG.md) that records what changed in each version of your software.
Release
A release is an official versioned snapshot of your software that you hand to the world.
Semantic Versioning (SemVer)
Semantic versioning uses three numbers — MAJOR.MINOR.PATCH — where each number means something. PATCH (1.0.1) = bug fix. MINOR (1.1.