Completions (legacy).

Endpoint

POST /v1/completions

Authenticate with Authorization: Bearer sdn_.... Any model in the catalog is valid in model.

Request parameters

Parameter	Type	Notes
`model`	string · required	Any catalog id.
`prompt`	string · required	Raw text prompt — no message structure.
`max_tokens`	integer	Output ceiling.
`temperature`	number	Sampling temperature.
`top_p`	number	Nucleus sampling.
`stop`	string \| string[]	Stop sequences.
`stream`	boolean	SSE chunks when true.
`seed` · `frequency_penalty` · `presence_penalty`		Standard sampling knobs, forwarded for models that take them.
`prompt_cache_key`	string	A conversation-stable identity hint used for cache affinity — `user` is accepted as a fallback. See Prompt caching.

A few legacy OpenAI parameters are refused with a 400 rather than silently ignored: n > 1 (multiple choices), echo: true, a non-empty suffix (fill-in-the-middle), and multi-element prompt arrays.

Example

Request

curl https://api.sideren.io/v1/completions \
  -H "authorization: Bearer $SIDEREN_API_KEY" \
  -H "content-type: application/json" \
  -d '{
    "model": "@sdn/gpt-oss-120b",
    "prompt": "The capital of France is",
    "max_tokens": 16
  }'

Response (shape)

{
  "id": "cmpl_...",
  "object": "text_completion",
  "model": "@sdn/gpt-oss-120b",
  "choices": [{
    "index": 0,
    "text": " Paris.",
    "finish_reason": "stop"
  }],
  "usage": { "prompt_tokens": 6, "completion_tokens": 3, "total_tokens": 9 }
}

When to use it

Only when a tool you don’t control requires it. Chat-tuned models expect message structure — the same request through Chat Completions will generally behave better, and tools, vision, and structured output live on the chat surfaces only.

Errors follow the OpenAI shape, like Chat Completions — see Errors.

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Completions (legacy).

Endpoint

Request parameters

Example

When to use it

​Endpoint

​Request parameters

​Example

​When to use it

Endpoint

Request parameters

Example

When to use it