API reference · Headers
Response headers.
The API keeps its header surface small and stable: which model served you, where your request window stands, and — when you're asked to slow down — exactly how long to wait.
On every response
| Header | Example | Meaning |
|---|---|---|
x1-model | lx1-gpt-oss-120b | The model that served this request — always the catalog id you asked for. |
x-ratelimit-limit-requests | 1000 | Your plan's requests-per-minute limit. |
x-ratelimit-remaining-requests | 997 | Requests left in the current window. |
x-ratelimit-reset-requests | 42 | Seconds until the window fully resets. |
x1-allowance-limit | 200.00 | Your plan's monthly included usage, measured in list-price USD. |
x1-allowance-remaining | 142.3120 | Included usage left this month (USD). When it reaches zero, requests return 429 allowance_exhausted until reset or upgrade. |
x1-allowance-reset | 1209600s | Seconds until the monthly allowance resets. |
x1-model: lx1-gpt-oss-120b
x-ratelimit-limit-requests: 1000
x-ratelimit-remaining-requests: 997
x-ratelimit-reset-requests: 42
x1-allowance-limit: 200.00
x1-allowance-remaining: 142.3120
x1-allowance-reset: 1209600sThe x-ratelimit-* trio lets a client pace itself instead of discovering the limit by hitting it — throttle proactively as remaining approaches zero. Per-plan limits are published on Plans & limits.
On 429 responses
| Header | Example | Meaning |
|---|---|---|
retry-after | 12 | Seconds to wait before retrying. Present on every 429 — a short pause on a rate limit, the seconds to month-end on an exhausted allowance. |
x1-allowance | exhausted | Present only when the 429 is the monthly allowance (type allowance_exhausted), so clients can tell it apart from a transient rate limit without parsing the body. |
Honor it exactly; the value is computed, not a guess. The retry recipe (and which statuses to retry at all) is on Errors.
Note
This is the complete customer-visible header surface. Anything else you may observe is not part of the API contract and can change without notice — build only against the headers on this page.