To ensure system stability and equitable resource distribution, the Google
Health API enforces rate limits on incoming API requests.

While the default quotas are designed to accommodate the vast majority of
standard use cases, applications that exceed these thresholds will be throttled.

## Handle Rate Limit Errors

When your application exceeds an allocated rate limit, the API rejects the
request and returns the error `429 Too Many Requests`. To mitigate the error,
your application should backoff sending requests and implement retry logic
to gracefully handle rate-limiting events.

## Default Limits and Impact Analysis

Rate limits are evaluated across daily, minutely, and per-user intervals. The
impact analysis outlines how these quotas translate to
**Queries Per Second (QPS)**.

| Metric | Default Limit | QPS Impact Analysis |
|---|---|---|
| Per project (daily) | 86.4M requests / day | \~1,000 QPS sustained |
| Per project (minutely) | 120,000 requests / minute | \~2,000 QPS burst |
| Per user (minutely) | 300 requests / minute | **Standard** : 5 QPS per user **Unverified applications**: Max 250 QPS total (capped at 100 users @ 2.5 QPS per user) |

## OAuth token grant rate limits

Google Cloud enforces a rate limit on OAuth token grants to control how quickly your app can onboard or re-authenticate users. If you expect to exceed 10,000 user sign-ups or re-authentications within a 24-hour sliding window, request a higher quota in advance. For more information, see [OAuth application rate limits](https://support.google.com/cloud/answer/9028764).

## Request a Quota Increase

If your application requires higher throughput than the default allocations
provided, you can request an adjustment through the Google Cloud Console. See
[View and manage quotas](https://docs.cloud.google.com/docs/quotas/view-manage).