Rate limits

Rate limits apply to every endpoint across the WhatsApp, Platform, and Workflows APIs. They are counted per API key, or per IP when no key is present.

Requests per minute

Plan	Requests / minute
Free	100
Legacy	100
Pro	500
Platform	1000
Enterprise	2000

The window is a fixed minute, not a rolling one. A project with no active plan gets the free limit.

Response headers

Every response carries your current state:

X-RateLimit-Limit: 500
X-RateLimit-Remaining: 487

When you exceed the limit, Kapso returns 429 with:

X-RateLimit-Limit: 500
X-RateLimit-Remaining: 0
Retry-After: 60

{
  "error": "Rate limit exceeded",
  "message": "You have exceeded the rate limit. Please try again later."
}

Read X-RateLimit-Remaining and back off before you hit zero, rather than waiting for the 429.

Workflow execution burst limit

Starting workflow executions has a second, tighter limit measured per second and per workflow. It stops a single runaway workflow from consuming your whole per-minute budget.

Plan	Executions / second / workflow
Free	5
Legacy	5
Pro	15
Platform	30
Enterprise	30

Exceeding it returns 429 with its own headers:

X-Burst-RateLimit-Limit: 15
X-Burst-RateLimit-Remaining: 0
Retry-After: 1

Meta’s limits are separate

The WhatsApp API proxies Meta. Meta enforces its own throughput and messaging limits on top of Kapso’s, so a request can pass Kapso’s limit and still be rejected upstream:

{
  "error": "Meta API rate limit exceeded. Retry after 60 seconds"
}

Your WABA messaging tier controls how many business-initiated conversations you can start per day. See Meta’s messaging limits. Broadcasts are not affected by this. Kapso paces them internally to stay within throughput limits, so you do not need to throttle a broadcast yourself.

Handling 429

Retry with exponential backoff, honoring Retry-After:

async function callWithRetry(url: string, options: RequestInit, attempt = 0) {
  const res = await fetch(url, options);

  if (res.status !== 429 || attempt >= 5) return res;

  const wait = Number(res.headers.get('Retry-After') ?? 60) * 1000;
  await new Promise((r) => setTimeout(r, wait * 2 ** attempt));

  return callWithRetry(url, options, attempt + 1);
}

Overview

WhatsApp API

Platform API

Workflows API

Requests per minute

Response headers

Workflow execution burst limit

Meta’s limits are separate

Handling 429

​Requests per minute

​Response headers

​Workflow execution burst limit

​Meta’s limits are separate

​Handling 429

Requests per minute

Response headers

Workflow execution burst limit

Meta’s limits are separate

Handling 429