gpt-5.6-luna — API, Pricing & Context Window | Vivgrid

gpt-5.6-luna is the fast, low-cost model in OpenAI's gpt-5.6 family. Unlike earlier small models, it keeps the family's 1.05M-token context window, making it the cheapest way to run long-context agents at scale.

On Vivgrid, gpt-5.6-luna is served through a single OpenAI-compatible endpoint with geo-distributed acceleration across AMER and EMEA, reachable with the same unified key as the rest of the catalog.

Specifications

Pricing

Pricing in USD per 1M tokens, matching the provider's rates.

Quick start

Call gpt-5.6-luna through Vivgrid's unified, OpenAI-compatible endpoint. Get an API key from the Vivgrid Console.

curl https://api.vivgrid.com/v1/chat/completions \
  -H "Authorization: Bearer $VIVGRID_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "gpt-5.6-luna",
    "messages": [
      { "role": "user", "content": "Say hello in English, Chinese and Spanish." }
    ],
    "stream": true
  }'

Requests beyond 272K input tokens are billed at the long-context rate: $2.00 input / $0.20 cached input / $9.00 output per 1M tokens.

Ideal use cases

• High-volume agent and content pipelines where cost dominates
• Long-context retrieval, summarization, and classification
• Fast interactive assistants and chat products
• Fallback or draft model alongside gpt-5.6-sol / terra

Related models

• gpt-5.6-terra — the balanced gpt-5.6 model
• gpt-5.6-sol — the flagship gpt-5.6 model
• gpt-5.4-mini — the prior-generation light model