# The API Integration Checklist We Use on Every Project

- **Category:** Web Dev
- **Date:** 2026-01-15
- **Read time:** 4 min

API integrations account for about 40% of our project work. After enough projects, patterns emerge. Here's the checklist we run through before writing integration code.

## Before you write code

- Read the full API docs - not just the endpoint you need, but auth, rate limits, error codes, and webhooks
- Check rate limits - will your usage pattern hit them? Do you need queuing?
- Test the sandbox - never assume the docs are accurate
- Map the data model - how does their data structure map to yours?

## During development

- Centralize API calls - one service layer, not scattered fetch calls
- Handle errors explicitly - every error code gets a specific handler
- Implement retry logic - transient failures happen, use exponential backoff with jitter
- Log everything - request/response pairs, timestamps, correlation IDs

## Before going live

- Test with production-like data - sandbox data is often cleaner than reality
- Set up monitoring - alerts on error rate spikes, latency changes, and auth failures
- Document the integration - what it does, how it's configured, and how to troubleshoot
- Plan for API changes - version your integration layer so upstream changes don't cascade

## The one thing most teams skip

Webhook verification. If the API sends webhooks, verify the signatures. Unverified webhooks are a security hole that's easy to close and dangerous to leave open.