GPT-6 Luna

POST/v1/responses

GPT-6 Luna is the smallest, fastest tier of OpenAI's GPT-6 reasoning family, described by OpenAI as its most efficient model for focused, high-volume tasks, with text and image input. It was trained with methods similar to GPT-6 Astra to carry much of that model's strengths into a faster tier. Choose it for high-throughput chat, extraction and lightweight agent steps, and move to GPT-6.1 Sol or GPT-6 Astra when work needs deeper reasoning.

Request body

Parameters supported by the OpenAI Responses API. Values, defaults, and limits are read from the model registry.

stringmodelrequired

Model identifier. Set to openai/gpt-6-luna.

Default: openai/gpt-6-luna

string | array<object>inputrequired

Input text or structured content for the response.

Optional<integer>max_tokens

Maximum number of tokens the model may generate in the response.

Maximum: 128000

Optional<number>temperature

Sampling temperature. Lower values are more deterministic; higher values are more creative.

Range: 0 to 2

Default: 1

Optional<boolean>stream

When true, returns incremental Server-Sent Events instead of one completed response.

Default: false

Optional<array>tools

Tool definitions that the model may call during the response.

Optional<string>tool_choice

Controls whether the model may call a tool and, when supported, which tool it must call.

Optional<object>response_format

Controls the response format, including JSON mode or structured JSON output when supported.

Optional<integer>seed

Seed used to make sampling more reproducible when the provider supports it.

Response Schema

Fields returned by the OpenAI Responses API.

stringidrequired

Unique response identifier.

stringmodelrequired

Model that generated the response.

stringobjectrequired

Response object type.

array<object>outputrequired

Generated response output items.

stringstatusrequired

Response lifecycle status.

Optional<object>usage

Token usage when available.

Model capabilities

array<string>capability_tagsrequired

Capabilities declared by the model registry.

Default: chat, vision, reasoning, structured_output, function_calling

integercontext_lengthrequired

Maximum context window accepted by this model.

Default: 1050000 tokens

stringexecution_moderequired

Execution mode declared by the model registry.

Default: sync

curl -X POST https://api.sandbase.ai/v1/responses \
  -H "Authorization: Bearer $SANDBASE_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
  "model": "openai/gpt-6-luna",
  "input": "Describe this product in one sentence."
}'

Response200 OK

{
  "id": "resp_abc123",
  "object": "response",
  "status": "completed",
  "model": "openai/gpt-6-luna",
  "output": [
    {
      "type": "message",
      "content": [
        {
          "type": "output_text",
          "text": "A concise product description."
        }
      ]
    }
  ]
}