Understand API usage limits

Rate Limits

Mailpipe enforces rate limits to ensure fair usage and platform stability. Learn about tier limits, response headers, and retry strategies.

Tier Limits

Rate limits vary by subscription tier. All limits are applied per organization.

Tier	Emails / Hour	Emails / Day	Burst Limit
Standard	100	1,000	10 / second
Pro	1,000	50,000	50 / second

Rate Limit Headers

Every API response includes rate limit headers so you can track your usage:

Response Headers

X-RateLimit-Limit: 100
X-RateLimit-Remaining: 87
X-RateLimit-Reset: 2024-01-15T12:00:00Z

X-RateLimit-Limit — Maximum requests allowed in the current window

X-RateLimit-Remaining — Requests remaining in the current window

X-RateLimit-Reset — ISO 8601 timestamp when the window resets

Rate Limit Exceeded (429)

When you exceed your rate limit, the API returns a 429 Too Many Requests response with a Retry-After header.

429 Response

HTTP/1.1 429 Too Many Requests
Retry-After: 3600
X-RateLimit-Limit: 100
X-RateLimit-Remaining: 0
X-RateLimit-Reset: 2024-01-15T13:00:00Z

{
  "error": "Rate limit exceeded: hourly email limit reached"
}

Retry Strategies

Implement exponential backoff with jitter for the best retry behavior:

Node.js

async function sendWithRetry(payload, maxRetries = 3) {
  for (let attempt = 0; attempt < maxRetries; attempt++) {
    const response = await fetch('/api/v1/outbound/{orgId}/send', {
      method: 'POST',
      headers: {
        'Authorization': 'Bearer mp_live_xxx',
        'Content-Type': 'application/json',
      },
      body: JSON.stringify(payload),
    });

    if (response.status !== 429) return response;

    const retryAfter = parseInt(response.headers.get('Retry-After') || '60');
    const jitter = Math.random() * 1000;
    const delay = retryAfter * 1000 + jitter;

    console.log(`Rate limited. Retrying in ${delay / 1000}s...`);
    await new Promise(resolve => setTimeout(resolve, delay));
  }

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

Check Your Quota

You can check your current quota at any time:

cURL

curl "https://api.mailpipe.dev/v1/outbound/{orgId}/send" \
  -H "Authorization: Bearer mp_live_xxx"

Response

{
  "orgId": "org_xxx",
  "tier": "standard",
  "used": 42,
  "remaining": 58,
  "limit": 100,
  "resetsAt": "2024-01-15T13:00:00Z"
}

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