#rate-limiting 4 articles

• Retry-After does not survive CORS — a header you send and the client reads can still arrive as nullgotchas / azure-functionsA cross-origin response exposes only the headers named in Access-Control-Expose-Headers plus a short safelist, so an API that sends Retry-After and a client that reads it still meet at null — both ends look right and a…
• Azure OpenAI 429 on a single request is a TPM ceiling, not a busy service — measure size, not frequencygotchas / azure-functionsOne request whose prompt exceeds the deployment's TPM allowance can never fit the window, so retrying is futile — a sub-second rejection means "over the ceiling", not "busy"; separate the two with a small/large request…
• Per-IP rate limit counts the capability probe — corporate NAT kills the feature silentlygotchas / azure-functionsCorporate NAT makes per-IP per-company; metered probes silently hide the feature
• The best-known public API may be the worst one — measure before you build on itgotchas / azure-functionsThe best-known free API returned 404/502/timeout on 7 of 8 live calls while the test suite stayed green; probe latency and status on real data, then cache successes (never failures) and honour Retry-After — a Function…