429 — Too Many Requests

Why does this error happen?

• Request pacing, prompt/completion/reasoning tokens, or cached prompt tokens crossed the tier's per-model capacity.
• The effective account, plan, runtime, model, region, or deployment scope may be more restrictive than a headline platform maximum.
• Retries or parallel workers can amplify the condition when they are not bounded or coordinated.

How do you diagnose it?

1. Open xAI Console Rate Limits and compare the exact model's RPS and TPM with aggregate team traffic.
2. Correlate the provider request identifier and UTC timestamp with application logs and metrics without recording secrets.
3. Reproduce with the smallest safe request and verify the exact account, plan, endpoint, region, runtime, or model involved.

How do you fix it?

1. Throttle requests or tokens, back off with jitter, and request or qualify for higher capacity when justified.
2. Retry only when the documented error is temporary; use bounded attempts, jitter, idempotency, and a dead-letter path.
3. Verify recovery with a controlled request, then monitor the same limiter or failure signal under normal traffic.

How do you prevent it from recurring?

Turn the confirmed cause of 429 — Too Many Requests into an observable boundary for Grok / xAI API. Track the relevant request count, token volume, payload size, execution time, connection pressure, billing state, or upstream health before it reaches the documented failure condition. Preserve the platform request ID and timestamp so future incidents can be correlated without logging sensitive payloads.

Test the fix under representative concurrency and failure injection, not only with one successful request. Alert on remaining headroom and repeated retries, and keep the linked limit page and official error source with the runbook so responders can distinguish a configuration problem from temporary service pressure or account state.