gpt-5.6-luna
Auto-routeropenai/gpt-5.6-luna
Context
1.1M
Max output
128K
Input / 1M
$0.20
Output / 1M
$1.20
Cached / 1M
Free
Cutoff
Feb 2026
About this model
GPT-5.6 Luna is OpenAI's fastest and most affordable model in the GPT-5.6 family. Built for high-volume, latency-sensitive workloads like chat, classification, and lightweight agentic tasks, it delivers strong reasoning at the lowest cost in the lineup — with a 1M+ token context window and 128K max output.
Best suited for
- High-volume chat & customer support — fast, low-cost responses for user-facing chatbots and support assistants at scale
- Classification & routing — intent detection, sentiment analysis, content moderation, ticket triage, and query routing pipelines
- Data extraction & structuring — pulling structured JSON from documents, emails, forms, and unstructured text
- Lightweight agentic workflows — quick tool-calling steps, sub-agent tasks, and orchestration steps that don't need deep reasoning
- Summarization at scale — condensing conversations, documents, and logs in bulk, aided by the 1M+ token context window
- Autocomplete & real-time assistance — latency-sensitive features like suggestions, rewriting, and inline completions
- Cost-optimized fallbacks — a default cheap tier in multi-model routing, escalating to Terra/Sol only when tasks demand it
Built-in tools
Hosted by the gateway — enable them per request without wiring your own endpoint.
Capabilities
Vision
Accepts images alongside text in the same message.
Files
Accepts file attachments — PDFs, transcripts, spreadsheets.
Tools
Native function calling, so agents can invoke your endpoints.
System prompt
Honours a dedicated system role, separate from the user turn.
Reasoning
Emits a separate thinking pass before the answer.
Supported parameters
max_tokensControls the creativity of responses. Higher values (e.g., 0.7) increase creativity; lower values (e.g., 0.2) make responses more predictable.
toolsLists tool definitions or capabilities available to the model.
tool_choiceDecides whether to use tools or just the model for generating responses.
response_typeparallel_tool_callsreasoningverbositystreamSends the response in real-time as it's being generated.
Use this model
OpenAI-SDK compatible, with gateway fallback and routing across providers.
Other Openai models
| Model | Context | Max output | Input | Output | Capabilities |
|---|---|---|---|---|---|
| gpt-4o Chat | — | 16K | $2.50 | $10.00 | Vision, Tools, System prompt |
| gpt-4o-mini Chat | 128K | 8K | $0.15 | $0.60 | Vision, Files, Tools, System prompt |
| gpt-4.1 Chat | 1.0M | 33K | $2.00 | $8.00 | Vision, Files, Tools, System prompt |
| gpt-4.1-mini Chat | 1.0M | 33K | $0.40 | $1.60 | Vision, Files, Tools, System prompt |
| gpt-4.1-nano Chat | 1.0M | 33K | $0.10 | $0.40 | Vision, Files, Tools, System prompt |
| gpt-5 Chat | 400K | 128K | $1.25 | $10.00 | Vision, Files, Tools, System prompt, Reasoning |
| gpt-5-mini Chat | 400K | 128K | $0.25 | $2.00 | Vision, Files, Tools, System prompt, Reasoning |
| gpt-5-nano Chat | 400K | 128K | $0.05 | $0.40 | Vision, Files, Tools, System prompt, Reasoning |
| gpt-5.1 Chat | 400K | 128K | $1.25 | $10.00 | Vision, Files, Tools, System prompt, Reasoning |
| gpt-5.2 Chat | 400K | 128K | $1.75 | $14.00 | Vision, Files, Tools, System prompt, Reasoning |
| gpt-5.5 Chat | 1.1M | 200K | $5.00 | $30.00 | Vision, Files, Tools, System prompt, Reasoning |
| gpt-5.4-mini Chat | 400K | 128K | $0.75 | $4.50 | Vision, Files, Tools, System prompt, Reasoning |
| gpt-5.4-nano Chat | 400K | 128K | $0.20 | $1.25 | Vision, Files, Tools, System prompt, Reasoning |
| gpt-5.4 Chat | 600K | 200K | $2.25 | $18.00 | Vision, Files, Tools, System prompt, Reasoning |
| gpt-5.5-pro Chat | 400K | 128K | $30.00 | $180.00 | Vision, Files, Tools, System prompt, Reasoning |
| gpt-5.6-sol Chat | 1.1M | 128K | $5.00 | $30.00 | Vision, Files, Tools, System prompt, Reasoning |
| gpt-5.6-terra Chat | 1.1M | 128K | $2.00 | $12.00 | Vision, Files, Tools, System prompt, Reasoning |
| gpt-5.3-codex Chat | 400K | — | $1.75 | $14.00 | Vision, Tools, System prompt |
| gpt-6-astra Chat | 1.1M | — | $10.00 | $50.00 | Vision, Files, Tools, System prompt |
| gpt-4o-2024-08-06 Completion | 128K | 16K | $2.50 | $10.00 | Vision, Tools, System prompt |
| gpt-4o-mini-2024-07-18 Completion | 128K | 8K | $0.15 | $0.60 | Vision, Tools, System prompt |
| o1 Reasoning | 200K | 100K | $15.00 | $60.00 | Vision, Files, Tools, System prompt, Reasoning |
| o3-mini Reasoning | 200K | 100K | $1.10 | $4.40 | Files, Tools, System prompt, Reasoning |
| o4-mini Reasoning | 200K | 100K | $1.10 | $4.40 | Vision, Files, Tools, System prompt, Reasoning |
| gpt-image-1.5 Image | — | — | — | — | Vision |
| gpt-image-1 Image | — | — | — | — | Vision |
| gpt-image-1-mini Image | — | — | — | — | Vision |
| gpt-image-2-2026-04-21 Image | 400K | 228K | $8.00 | — | Vision, Files, Tools, System prompt, Reasoning |
Pricing & provider details
Openai
openai/gpt-5.6-luna
- Input · per 1M
- $0.20
- Output · per 1M
- $1.20
- Cached input · per 1M
- Free
- Context window
- 1,050,000 tokens
- Max output
- 128,000 tokens
- Knowledge cutoff
- Feb 2026
- Auto-router
- Supported
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