How to Test Third-Party Integrations in Vibecoded Apps

Verify that all API keys, secrets, and webhook URLs are correctly configured for your environment. AI-generated code frequently has development credentials hardcoded or environment variables that are not set in production. Check that no API keys are exposed in client-side JavaScript by inspecting the page source and JavaScript bundles.

Test the initial connection to each third-party service. Call each API endpoint and verify you receive a valid response, not an authentication error. Many vibecoded apps ship with expired trial API keys or keys with insufficient permissions. Also verify that your app handles configuration errors gracefully — a missing API key should produce a clear error log, not a crash.

Simulate each third-party service being unavailable by blocking its domain in your hosts file or using a mock server that returns errors. Verify that your app degrades gracefully: if the analytics service is down, the app should still work. If the payment service is down, the user should see a clear message and be able to try again later.

Test rate limiting by sending requests rapidly to third-party APIs and verifying your app handles 429 responses. AI-generated code almost never implements retry logic with exponential backoff, causing cascading failures when a service returns rate limit errors. Also test timeout handling — if an external API takes 30 seconds to respond, your app should not hang.

When your app syncs data with external services, test that the data stays consistent. Create a user in your app and verify they appear correctly in your email marketing tool, analytics platform, and CRM. Update or delete the user and verify those changes propagate. AI-generated sync logic often handles creation but not updates or deletions.

Test webhook processing from each third-party service. Use the service's webhook testing tools to send sample events and verify your app processes them correctly. Test with duplicate events (which happen in production), out-of-order events, and events for resources that do not exist in your app. Many vibecoded webhook handlers crash on unexpected event types instead of ignoring them.