Errors & limits

Dual limits

Burst — short-window requests per minute (abuse / fairness).
Quota — included api_request count per billing period.

Plan numbers (sandbox through enterprise) live on Pricing. Sandbox: 1,000 req/mo, 10/min, hard block at cap.

`429` Too Many Requests

Returned when burst or period quota is exceeded. Prefer respecting Retry-After when present. Paid plans may allow limited overage; sandbox does not.

`402` Payment Required

No active license for vocabulary API use on this key. Confirm the account has a sandbox or paid Lybra plan, then retry.

Pagination

There is no cursor pagination yet. Most list endpoints return the full active corpus. Error-code search accepts limit (default large). Prefer MCP search tools or REST query params when you only need a subset.

Troubleshooting

Symptom	Check
`401`	Key spelling; `Bearer` prefix; key not revoked
`403`	Key has `datasets.read`
`402`	Active license / plan
`429`	Burst vs monthly quota; wait or upgrade
Empty / unexpected codes	Cite live API/MCP results — do not invent codes from training data

Support on paid tiers is described on Pricing.