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OpenAI · Language model

GPT-5.6 Luna

openai/gpt-5.6-luna
  • Language
Released Jul 9, 2026

GPT-5.6 Luna is a fast, cost-efficient model in OpenAI's GPT-5.6 series. It is suited for high-volume, latency-sensitive tasks such as chat, classification, and lightweight agentic workflows, providing capable reasoning for...

Specifications

Context window
1,050,000 tokens
Max output
128,000 tokens
Input
file, image, text
Output
text
Reasoning effort
max, xhigh, high, medium, low, none
Tokenizer
GPT
Knowledge cutoff
2026-02-16
Moderation
provider-moderated

Supported parameters

Accepted by the model and forwarded as-is by the gateway.

  • max_completion_tokens
  • max_tokens
  • reasoning
  • reasoning_effort
  • response_format
  • seed
  • structured_outputs
  • tool_choice
  • tools

Use it

POST /api/v1/chat/completions · MCP chat · full reference

curl https://omnirail.org/api/v1/chat/completions \
  -H "Authorization: Bearer $OMNIRAIL_KEY" -H "Content-Type: application/json" \
  -d '{"model":"openai/gpt-5.6-luna","messages":[{"role":"user","content":"Hello"}],"max_tokens":300}'