Reference
API reference
Every endpoint, field, header, status and example of the Base Eleven API, from the OpenAPI 3.1 document the gateway is tested against.
Base Eleven's models are fictional and its API returns simulated responses. Usage, credits and billing run for real, in test mode.
Base URL https://api.baseeleven.dev/v1. Send your key in x-api-key or as Authorization: Bearer <key>; the quickstart shows a first call. The try-it panel below sends real calls with your key, metered like any other.
Limits by model
The document states these as conditions on MessagesRequest, which not every viewer shows: max_tokens runs from 1 to the model’s maximum, and input tokens plus max_tokens may not exceed its context. The first entry of messages is always the user’s turn.
| Model | API id | Highest max_tokens | Context tokens |
|---|---|---|---|
| Eleven Lite | eleven-lite | 1,024 | 32,000 |
| Eleven Max | eleven-max | 4,096 | 128,000 |