RetryLab

A simple web tool to test how your apps handle API failures and retries.

What does it do?

RetryLab gives you an API endpoint that you can configure to fail in different ways. This helps you test if your application handles errors correctly.

You can make it:

• Fail a specific number of times, then work normally
• Fail randomly (like 30% of requests)
• Return different error codes (404, 500, etc.)
• Add delays to simulate slow networks
• Drop connections or timeout

How to use it

1. Create a session - you get a unique URL
2. Configure how you want it to behave (fail rate, delays, etc.)
3. Point your app to this URL instead of your real API
4. See how your app handles the failures

Example

# test endpoint
GET /api/e/abc-123-def/checkout

# fail twice, then succeed
?fail=2&code=503

# fail 20% of the time with 500ms delay  
?percent=20&latency=500

This is useful for:

• Retry logic in your code
• Circuit breakers
• Error handling
• Monitoring and alerts

Support

Having issues or want to suggest something? Open an issue

RetryLab is actively maintained.