Best practices

Treat 404 and 503 differently

404 is a valid, final answer. 503 is temporary: retry with growing intervals.

Respect Retry-After

On a 429, wait for the time indicated instead of repeating the call in a loop.

Use batches for lists

For hundreds of CPFs, one batch request is simpler and avoids hitting the per-second limit.

Keep only what you need

The data you look up is personal data. Define a purpose, keep it for as short as possible and read the LGPD page.