OpenAPI Changes

The world's most powerful and complete OpenAPI diff tool.

openapi-changes lets you inspect what changed in an OpenAPI specification between two files, between git revisions of the same file, across local git history, or directly from a GitHub-hosted file URL.

It can render the same semantic change model as:

• an interactive terminal UI
• a terminal summary
• a machine-readable JSON report
• a markdown report
• a self-contained offline HTML report

It works well for local exploration, CI/CD checks, release notes, and API review workflows.

How is it the 'most powerful and complete?'?

openapi-changes gives you the power to view all changes between two OpenAPI contracts, and over time in every which way you can possibly think of. Graphs, trees, lists, diffs, JSON, mark down.

Has no network dependencies at all. Runs 100% offline, including the HTML report.

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Install with Homebrew

brew install pb33f/taps/openapi-changes

Install with npm or yarn

npm i -g @pb33f/openapi-changes

If you prefer yarn:

yarn global add @pb33f/openapi-changes

Install with cURL

curl -fsSL https://pb33f.io/openapi-changes/install.sh | sh

Install or run with Docker

docker pull pb33f/openapi-changes

Docker images are available for both linux/amd64 and linux/arm64.

The published image configures Git to trust mounted repositories, so local git-history commands work without requiring extra safe.directory setup inside the container.

To run a command, mount the current working directory into the container:

docker run --rm -v $PWD:/work:rw pb33f/openapi-changes summary . sample-specs/petstorev3.json

To run the interactive console through Docker, allocate a TTY with -it:

docker run --rm -it -v $PWD:/work:rw pb33f/openapi-changes console . path/to/openapi.yaml

Verify the install

Print the installed version:

openapi-changes version

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Summary view

A full terminal UI

Comes in multiple themes! PB33F (Dark), Roger Mode (Light) and Tektronix (Retro Dark)

Powerful HTML report with no rival.

A self-contained, offline HTML report with interactive timeline, change explorer graph, diff views, and more.

Timeline overview with change history chart

Interactive explorer graph

Change report breakdown

Side by side, focused, unified or inline diffing

Roger mode (monochrome light theme)

Tektronix mode (green monochrome)

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Comparing git revisions

Compare a file at different git revisions without checking out branches:

openapi-changes summary HEAD~1:openapi.yaml ./openapi.yaml
openapi-changes html-report main:api/openapi.yaml feature-branch:api/openapi.yaml

The revision:path syntax works with any git ref -- branches, tags, HEAD~N, commit SHAs. The path is relative to the repository root. This works with all commands and supports multi-file specs with $ref references resolved from the same revision.

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Documentation

Quick Start Guide 🚀

Full docs: https://pb33f.io/openapi-changes/

• Installing openapi-changes
• Configuring breaking changes
• Command arguments
• Commands:
  • console
  • summary
  • report
  • markdown-report
  • html-report
  • completion
  • version
• About openapi-changes

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Build from source

openapi-changes currently requires Go 1.25.7+.

git clone https://github.com/pb33f/openapi-changes.git
cd openapi-changes
go build -o bin/openapi-changes .

Or use make:

make

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Command overview

The current command surface is:

• console for the interactive terminal UI
• summary for fast terminal and CI output
• report for machine-readable JSON
• markdown-report for shareable markdown output
• html-report for the interactive offline browser report
• completion for shell completion scripts
• version for raw build version output

Run openapi-changes --help or openapi-changes <command> --help for the live CLI surface.

Terminal themes

The terminal-facing commands support multiple presentation modes:

• --no-color for the light Roger monochrome theme
• --roger-mode as an alias for --no-color
• --tektronix for the green monochrome terminal theme

See the command arguments docs for the full shared flag set.

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Custom breaking rules configuration

openapi-changes supports configurable breaking-change rules via changes-rules.yaml.

Use an explicit config file

openapi-changes summary -c my-rules.yaml old.yaml new.yaml

Or let it auto-discover the default config file

openapi-changes summary old.yaml new.yaml

Default lookup locations:

1. ./changes-rules.yaml
2. ~/.config/changes-rules.yaml

Example

pathItem:
  get:
    removed: false
  post:
    removed: false
  put:
    removed: false
  delete:
    removed: false

schema:
  enum:
    removed: false

parameter:
  required:
    modified: false

Each rule supports:

• added
• modified
• removed

For the full rules reference and more examples, see the configuration docs.

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See the full docs at https://pb33f.io/openapi-changes/