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API Documentation

OnChange REST API

Programmatic access to your monitors, changes, and notifications. Build dashboards, automate workflows, and integrate OnChange into your toolchain.

Authentication

External integrations should pass an API key in theX-API-Keyheader. Signed Bearer tokens are used by the web app. Generate or rotate your API key in dashboard settings.

Base URL

All API endpoints use the base URLhttps://onchange.app/apiand return JSON responses. Rate limited to 120 requests per minute per user.

Pagination

List endpoints support page-based pagination usingpageandper_pagequery parameters. Default is 20; monitor lists allow up to 500.

Example request
curl https://onchange.app/api/monitors \
  -H "X-API-Key: oc_live_abc123..." \
  -H "Content-Type: application/json"

Interactive API Explorer

Try any endpoint live. Enter your API key and send requests directly from this page.

Authentication

Add your API key to try endpoints live. Find it in Settings → API Key.

Monitors

Changes

Timeline & Values

Crawl

Alert Rules

Accessibility

Reports

Status Pages

Export

User

Error codes

CodeMeaning
200Success
201Created
400Bad request - invalid parameters
401Unauthorized - invalid or missing API key
403Forbidden - insufficient permissions
404Not found
429Rate limited - too many requests
500Internal server error

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