API Integration Patterns

Connecting to External APIs

n8n's HTTP Request node connects to any REST API. Configure: method, URL, headers, body, authentication, and response parsing.

Authentication Patterns

API Key — pass in a header (Authorization: Bearer {key}) or query parameter. Store keys in n8n credentials, never hardcode.

OAuth 2.0 — n8n handles the OAuth flow for supported integrations. For custom OAuth, use the OAuth2 credential type.

HMAC — generate a signature from request contents. Used by Stripe, GitHub webhooks. Implement in a Function node.

Pagination

Most APIs paginate large result sets. Common patterns:

Offset pagination — ?page=2&limit=50. Loop until results < page size.

Cursor pagination — ?cursor=abc123. Loop until cursor is null.

Link header — response includes a Link: <url>; rel="next" header. Follow until no "next" link.

Build the pagination loop in a Function node with recursive calls or use n8n's built-in Split In Batches node.

Rate Limit Handling

APIs throttle requests. Handle rate limits:

1. Check for 429 status code
2. Read the Retry-After header
3. Wait for the specified duration
4. Retry the request

Some APIs use soft limits (headers warning you're approaching limits) — monitor these proactively.

The Resilient API Client Pattern

async function callWithRetry(url, options, maxRetries = 3) {
  for (let attempt = 0; attempt <= maxRetries; attempt++) {
    const response = await fetch(url, options);
    if (response.ok) return response.json();
    if (response.status === 429) {
      const wait = parseInt(response.headers.get('Retry-After') || '60');
      await sleep(wait * 1000);
      continue;
    }
    if (attempt === maxRetries) throw new Error(`Failed: ${response.status}`);
  }
}