# API rate limits and 429 errors

> Each API key can make 300 requests a minute. Every response tells you how many are left, and a 429 tells you how long to wait.

Source: https://signwith.co/docs/api/rate-limits · Updated 2026-10-02

## The limit

Each API key may make **300 requests per minute**, counted in fixed one-minute windows. Every authenticated response includes three headers:

| Header | Meaning | Example |
| --- | --- | --- |
| `RateLimit-Limit` | Requests allowed per window | `300` |
| `RateLimit-Remaining` | Requests left in the current window | `287` |
| `RateLimit-Reset` | Seconds until the window resets | `42` |

Over the limit, the API returns `429` with code `rate_limited` and a `Retry-After` header: the number of seconds to wait.

## Waiting and retrying

Read `Retry-After`, wait that long, then send the same request again. For a `POST`, keep the same `Idempotency-Key` so the retry can't do anything twice.

```js
async function signwith(url, options = {}) {
  for (let attempt = 0; attempt < 5; attempt++) {
    const response = await fetch(url, {
      ...options,
      headers: { Authorization: `Bearer ${process.env.SIGNWITH_API_KEY}`, ...options.headers },
    })
    if (response.status !== 429) return response
    const seconds = Number(response.headers.get('Retry-After')) || 60
    await new Promise((resolve) => setTimeout(resolve, seconds * 1000))
  }
  throw new Error('Still rate limited after 5 attempts')
}
```

If you send documents in bulk, watch `RateLimit-Remaining` and slow down before it reaches zero.

## Other limits

Two endpoints have their own limits on top of the per-minute one:

- **Reminders:** [`POST /signature_requests/{id}/remind`](https://signwith.co/docs/api/signature-requests#remind-waiting-signers) works at most once an hour per signature request. Sooner, it returns `429 remind_too_soon`, with `Retry-After` set to the seconds left.
- **Resending one signer's link:** [`PATCH /signers/{id}`](https://signwith.co/docs/api/signers#update-a-signer) with `resend: true` emails a signer at most once every 10 minutes. Sooner, it returns `429 remind_too_soon` with `Retry-After`.
- **Feedback:** [`POST /feedback`](https://signwith.co/docs/api/feedback#send-feedback-to-the-signwith-team) accepts 20 messages per user per clock hour, then returns `429 rate_limited` with `Retry-After` set to the seconds until the next hour.

Webhooks don't count against your limit: SignWith calls you. Using webhooks instead of polling is the easiest way to stay well under it. See [webhooks](https://signwith.co/docs/api/webhooks).