API reference
Limits
Rate limits, request sizes and timeouts.
Rate limits
| Scope | Limit |
|---|---|
| Requests per account | 60 per minute |
| Concurrent requests per account | 4 |
| Concurrent requests per model | 1, shared by all customers |
Each model serves one request at a time and keeps no queue. A request that arrives while the model is busy gets 429 with x-lyber-admission: not-admitted and Retry-After: 5. Nothing was started or charged, so wait and send it again.
Request size
| Limit | Value |
|---|---|
| Request body | 16 MiB |
messages and tools as JSON | 8 MiB |
| Messages per request | 4,096 |
| Tools per request | 32 |
| Context | 1,048,576 tokens, input and output together |
| Output | 32,768 tokens (MiniMax M3.1 Flash), 262,144 tokens (DeepSeek V4.1 Flash 1017) |
Timeouts
| Limit | Value |
|---|---|
| Uploading the request body | 15 seconds |
| Generating the response | 180 seconds |
A request that runs past its time limit returns 504 upstream_timeout, or ends a stream without [DONE]. Very long outputs can take longer than that; set max_tokens to what you need.