API Changelog Generator

Detect breaking changes in your API before your users do. API Changelog Generator compares OpenAPI specifications or Git commits to automatically generate structured changelogs with severity levels (major/minor/patch). Subscribe to webhook notifications for breaking change alerts.

Why use API Changelog Generator?

Stop manually tracking API changes. This Actor monitors your API specifications and Git repositories to detect breaking changes automatically — removed endpoints, modified parameters, deprecated features. Get instant notifications via webhook when something breaks.

What data does API Changelog Generator return?

Structured diffs with three severity levels:

• MAJING — Breaking changes (removed endpoints, removed required parameters)
• MINOR — Non-breaking modifications (changed descriptions, optional params)
• PATCH — No significant changes detected

Each result includes:

• Endpoint path and method
• Change type (added / removed / modified)
• Breaking status (true/false)
• Detailed description
• Full change details (added/removed parameters)

How to use API Changelog Generator

Compare OpenAPI specs

curl -X POST https://imapp--api-changelog-generator.apify.actor/changelogs/generate/openapi \
  -H "Authorization: Bearer YOUR_APIFY_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{
    "base_spec_url": "https://api.example.com/openapi-v1.json",
    "new_spec": {
      "openapi": "3.0.0",
      "info": {"title": "My API", "version": "2.0"},
      "paths": {
        "/users": {"get": {"summary": "List users"}},
        "/users/{id}": {"get": {"summary": "Get user"}}
      }
    }
  }'

Compare Git commits

curl -X POST https://imapp--api-changelog-generator.apify.actor/changelogs/generate/git \
  -H "Authorization: Bearer YOUR_APIFY_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{
    "repository_url": "org/api-repo",
    "base_commit": "v1.0.0",
    "target_commit": "HEAD"
  }'

Subscribe to breaking change notifications

curl -X POST https://imapp--api-changelog-generator.apify.actor/subscriptions \
  -H "Authorization: Bearer YOUR_APIFY_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{
    "webhook_url": "https://your-app.com/webhooks/changelog",
    "event_types": ["breaking_change"]
  }'

Manage subscriptions

# Get subscription details
curl -H "Authorization: Bearer YOUR_APIFY_TOKEN" \
  https://imapp--api-changelog-generator.apify.actor/subscriptions/{id}

# Delete subscription
curl -X DELETE -H "Authorization: Bearer YOUR_APIFY_TOKEN" \
  https://imapp--api-changelog-generator.apify.actor/subscriptions/{id}

How much does it cost?

$3.00 per 1,000 calls with 100 free calls per month.

Pay only for what you use. No monthly fees, no minimums.

Input and output

Input

Parameter	Type	Required	Description
new_spec	object	Yes (for OpenAPI)	New OpenAPI specification
base_spec_url	string	No	URL to fetch previous spec for diff
repository_url	string	Yes (for Git)	Git repository path
base_commit	string	Yes (for Git)	Starting commit/tag
target_commit	string	No	Ending commit (default: HEAD)

Output

JSON array of ChangelogEntry objects:

[{
  "version": "3.0.0",
  "date": "2026-07-09T16:08:25",
  "severity_level": "minor",
  "changes": [
    {
      "endpoint": "GET /users",
      "change_type": "added",
      "description": "New endpoint 'GET /users' has been added.",
      "breaking": false,
      "details": {}
    }
  ],
  "summary": "Detected 2 changes. Non-breaking."
}]

Features

• Breaking change detection — Automatically identify removed endpoints and parameters
• OpenAPI spec diffing — Compare any two OpenAPI 3.0 specifications
• Git commit comparison — Track changes between repository tags/commits
• Webhook notifications — Subscribe to breaking change alerts
• Structured severity levels — MAJOR/MINOR/PATCH classification
• Pay-per-use pricing — Only pay for what you use
• Standby Mode — Instant response, no cold starts

FAQ

Is there a free tier? Yes, 100 free calls per month.

What OpenAPI versions are supported? OpenAPI 3.0+ (JSON and YAML formats).

Can I monitor private Git repositories? Yes, provide a GitHub token via the Authorization header for private repos.

How are breaking changes detected? Removed endpoints and removed required parameters are flagged as breaking. Added endpoints and optional parameters are non-breaking.

Do I need to host anything? No. This is a fully managed serverless API on the Apify platform.