Delimit GitHub Action

Detect breaking API changes on every pull request. Severity-graded PR comments with migration guides. Two lines of YAML. Free.

What It Does

1

Diffs your OpenAPI spec against the base branch

Compares the spec in the PR against the spec on the base branch (main/master). Detects 27 types of changes including endpoint removals, type changes, enum value removals, and new required parameters.

2

Posts a severity-graded PR comment

Every change is classified as breaking or non-breaking, with severity badges. Breaking changes include step-by-step migration guides so developers know exactly what to fix.

3

Blocks merge on breaking changes

Returns exit code 1 when policy violations are found. Combined with branch protection rules, this prevents breaking changes from ever reaching production.

4

Classifies semver impact

Automatically classifies whether the changes require a MAJOR, MINOR, or PATCH version bump so your release process stays consistent.

Two Lines to Get Started

Add this to any workflow file in .github/workflows/

.github/workflows/api-governance.yml
name: API Governance
on:
  pull_request:
    paths:
      - 'api/**'

jobs:
  lint:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: delimit-ai/delimit-action@v1
        with:
          spec: api/openapi.yaml

Or the minimal version if you already have a workflow:

- uses: delimit-ai/delimit-action@v1
  with:
    spec: api/openapi.yaml

Example PR Comment

This is what Delimit posts on your pull request when it detects changes.

D
delimit-botcommented just now
API Governance Report
MAJOR3 breaking changes detected
breakingEndpoint /users was removed
breakingParameter "limit" type changed from integer to string
infoNew endpoint /v2/users was added
Migration Guide
  1. Migrate all /users calls to /v2/users
  2. Update "limit" parameter to send string values

Configuration

InputRequiredDefaultDescription
specYes--Path to your OpenAPI spec file
policyNodefaultPolicy preset: strict, default, or relaxed
base_refNoautoBase branch to compare against
fail_on_breakingNotrueWhether to fail the check on breaking changes
27
change types
17
breaking types
3
policy presets
$0
to start

Add API Governance to Your Repo

Two lines of YAML. No config. No API keys. Breaking changes blocked before merge.