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Documentation Index

Fetch the complete documentation index at: https://prefetch.mintlify.app/llms.txt

Use this file to discover all available pages before exploring further.

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Overview

Prefetch API enforces three independent limits:
  1. Global rate limit — per IP address, fixed 1-minute window
  2. Per-key rate limit — per API key, sliding 1-minute window
  3. Per-key concurrency limit — max in-flight requests per key at once
When any limit is exceeded, you receive HTTP 429 Too Many Requests.

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Global rate limit

300 requests per minute per IP address, using a fixed 1-minute window. This limit applies before authentication and cannot be configured. It protects the infrastructure from abuse.

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Per-key rate limit

Each API key has a rate_limit_rpm (requests per minute) field, enforced with a sliding 60-second window. When a key’s request rate exceeds this value, requests fail with: 
{
  "success": false,
  "error": "Rate limit exceeded for this API key",
  "meta": { ... }
}
Contact support or manage your key’s rate limit from the dashboard.

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Per-key concurrency limit

Separate from the RPM limit, each key has a maximum number of requests that can be in-flight simultaneously. Exceeding it returns 429 immediately (no queueing). Two headers indicate your current usage:
HeaderDescription
X-Concurrency-LimitMaximum concurrent requests allowed for this key
X-Concurrency-RunningNumber of requests currently in-flight
{
  "success": false,
  "error": "Concurrency limit exceeded for this API key",
  "meta": { ... }
}

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Handling 429 responses

When you receive a 429, implement exponential backoff before retrying: 
async function fetchWithRetry(url, options, maxRetries = 3) {
  for (let attempt = 0; attempt < maxRetries; attempt++) {
    const res = await fetch(url, options);

    if (res.status !== 429) {
      return res;
    }

    const backoffMs = Math.pow(2, attempt) * 1000; // 1s, 2s, 4s
    await new Promise((resolve) => setTimeout(resolve, backoffMs));
  }

  throw new Error("Max retries exceeded");
}

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Tips for staying within limits

  • Batch wisely — use /enrich instead of separate /brand + /company + /classify calls to reduce request count
  • Cache responses — most brand/company data is stable; cache it for hours or days
  • Deduplicate — avoid re-fetching the same domain multiple times in a short window
  • Queue large jobs — if processing many URLs, space requests out over time rather than sending all at once