OpenAI GPT 5.6 Luna: AI Large Language Models

Generate text fast with OpenAI's GPT 5.6 Luna. Cost-effective multimodal reasoning for classification and screening. No subscription. GPT 5.6 Luna is OpenAI's fast, cost-effective multimodal reasoning model. Supports mixed text and image inputs, adjustable reasoning effort, and integrated web search tools. Pricing: $2.00/M input tokens, $12.00/M output tokens.

Interactive model controls

GPT 5.6 Luna is OpenAI's fast, cost-effective multimodal reasoning model. Supports mixed text and image inputs, adjustable reasoning effort, and integrated web search tools. Pricing: $2.00/M input tokens, $12.00/M output tokens.

📝

Overview

About this model

GPT 5.6 Luna is OpenAI's fast, cost-effective member of the GPT 5.6 multimodal reasoning family, tuned for high-volume, low-latency workloads. It accepts mixed text and image inputs, supports a system prompt to steer behavior, and can call an integrated web search tool for real-time information. Reasoning depth is adjustable via the reasoning_effort parameter, letting you trade latency for thoroughness on a per-request basis. Luna is the right starting point for automated classification, content screening, and simple extraction pipelines that need to run at scale without the cost of the larger Terra or Sol models.

1High-Volume Automation: Run fast classification, moderation, and screening tasks across large batches at low per-call cost.

2Simple Extraction: Pull structured fields (names, dates, categories) out of unstructured text or scanned documents.

3Chatbot Triage: Route incoming support messages or tickets to the correct queue before escalating to a larger model.

4Quick Multimodal Lookups: Answer straightforward questions about an uploaded image without heavy reasoning overhead.

💰

Pricing & Value

Cost analysis

Provider	Cost	Notes
muapiapp	$2.00/M input, $12.00/M output	Token-based billing. Minimum $0.0002 per call.
Fal.ai	Not available	No dedicated GPT 5.6 Luna endpoint at this time.
Replicate	Not available	No dedicated GPT 5.6 Luna endpoint at this time.

muapiapp$2.00/M input, $12.00/M output

Token-based billing. Minimum $0.0002 per call.

Fal.aiNot available

No dedicated GPT 5.6 Luna endpoint at this time.

ReplicateNot available

No dedicated GPT 5.6 Luna endpoint at this time.

** Competitor pricing is estimated based on similar model architectures and usage tiers.

⚙️

Technical Details

Configuration schema

Parameter	Type	Description	Default
Prompt	string	The user message or instruction.	`Summarize this article in three bullet points.`
Image URL	string	Optional image URL for multimodal requests.	`undefined`
System Prompt	string	Optional system-level instruction to guide model behavior.	`You are an expert tutor.`
Web Search Switch	boolean	Enable web search tool for real-time information retrieval.	`false`
Reasoning Effort	Enum (4 options)	Level of reasoning depth: low, medium, high, or xhigh.	`low`

Promptstring

The user message or instruction.

Default ValueSummarize this article in three bullet points.

Image URLstring

Optional image URL for multimodal requests.

Default Valueundefined

System Promptstring

Optional system-level instruction to guide model behavior.

Default ValueYou are an expert tutor.

Web Search Switchboolean

Enable web search tool for real-time information retrieval.

Default Valuefalse

Reasoning EffortEnum (4 options)

Level of reasoning depth: low, medium, high, or xhigh.

Default Valuelow

📖

Implementation Guide

Developer documentation

Standard (Async)

POST /api/v1/gpt-5-6-luna — returns request_id, poll for result via /api/v1/predictions/{id}/result.

Streaming (SSE)

POST /api/v1/gpt-5-6-luna/stream — returns a live Server-Sent Events stream (Content-Type: text/event-stream). Each chunk has the format data: {"choices":[{"delta":{"content":"text"}}]}, ending with data: [DONE].

cURL Example

curl -X POST "https://api.muapi.ai/api/v1/gpt-5-6-luna" \
  -H "Authorization: Bearer $YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "prompt": "Classify this support ticket as billing, technical, or general.",
    "reasoning_effort": "low"
  }'

❓

Common Questions

Frequently asked

What is GPT 5.6 Luna best used for?

Luna is optimized for speed and efficiency, making it ideal for high-volume automated classification, screening, and simple extraction tasks where low latency and cost matter more than deep reasoning.

How is pricing calculated for GPT 5.6 Luna?

Pricing is token-based at $2.00 per million input tokens and $12.00 per million output tokens, with a minimum charge of $0.0002 per call.

Does GPT 5.6 Luna support multimodal inputs?

Yes, Luna supports mixed text and image (image_url) inputs in a single message.

What is reasoning effort control?

You can control the depth of reasoning by passing a reasoning_effort value of 'low', 'medium', 'high', or 'xhigh'. Higher levels provide more thorough logic but increase latency — Luna is typically run at 'low' for maximum speed.

How do I choose between async and streaming endpoints?

Use the streaming endpoint (/gpt-5-6-luna/stream) for interactive chat interfaces where the user expects real-time feedback. Use the async endpoint (/gpt-5-6-luna) for background tasks, workflows, and automated scripts.

When should I upgrade to Terra or Sol instead of Luna?

Upgrade to Terra for balanced business and analytical tasks, or to Sol for complex math, programming, and scientific reasoning where Luna's speed-optimized responses aren't thorough enough.