GPT-5.6 Luna API: Endpoint & 25% Discount
Up to 25%GPT-5.6 Luna is available on LLM.API as an OpenAI-compatible chat endpoint—route Gpt Luna quality through one key with transparent token pricing.
What is GPT-5.6 Luna?
On LLM.API, GPT-5.6 Luna (gpt-5.6-luna) serves as a Gpt Luna conversational model for products that need 1.1M tokens context windows and predictable token pricing. Cost-efficient GPT-5.6 model for fast, high-volume workloads.
Can you self-host GPT-5.6 Luna?
No. We found no public weights for GPT-5.6 Luna on Hugging Face, so there is nothing to download, quantize or serve on your own GPUs: no VRAM budget, no vLLM or GGUF build to plan for. The only way to run it is over an API.
Skip the deploy — use LLM.API as your endpoint
No GPUs, no quantization trade-offs. Same model, OpenAI-compatible, up to 25% below list price.
Providers
LLM.API routes GPT-5.6 Luna to the providers below, with discounted effective rates versus list price.
List price by provider
InputOutputProvider list prices; the LLM.API discount applies on top.
| Provider | Pricing | Context | Capabilities |
|---|---|---|---|
| in $0.2; out $1.2 per 1M tokens | 1.1M tokens | vision, tools, streaming, reasoning, web search, JSON, structured | |
| in $0.2; out $1.2 per 1M tokens | 1.1M tokens | vision, tools, streaming, reasoning, web search, JSON, structured | |
 aws-mantle | in $0.22; out $1.32 per 1M tokens | 1.1M tokens | vision, tools, streaming, reasoning, web search, JSON, structured |
| in $0.2; out $1.2 per 1M tokens | 1.1M tokens | vision, tools, streaming, reasoning, web search, JSON, structured |
Prices and availability from the LLMAPI catalogue, updated nightly. Last updated 11 Oct 2026.
Try this model
Test GPT-5.6 Luna right here — free to start.
Suggestions for your first prompt
Code snippet
Call GPT-5.6 Luna through the OpenAI-compatible API — POST /v1/chat/completions.
Switching from OpenAI? Change 2 lines.
- base_url="https://api.openai.com/v1"
- api_key="YOUR_OPENAI_KEY"
+ base_url="https://api.llmapi.ai/v1"
+ api_key="YOUR_LLMAPI_KEY"Everything else stays the same — SDK, message format, tools, streaming. Set model to gpt-5.6-luna and the call runs unchanged.
curl https://api.llmapi.ai/v1/chat/completions \
-H "Authorization: Bearer $LLMAPI_KEY" \
-H "Content-Type: application/json" \
-d '{
"model": "gpt-5.6-luna",
"messages": [
{"role": "user", "content": "Give me three crisp launch checklist items."}
],
"reasoning_effort": "medium"
}'from openai import OpenAI
client = OpenAI(
api_key="YOUR_LLMAPI_KEY",
base_url="https://api.llmapi.ai/v1",
)
resp = client.chat.completions.create(
model="gpt-5.6-luna",
messages=[
{"role": "system", "content": "You are a precise product assistant."},
{"role": "user", "content": "Give me three crisp launch checklist items."},
],
reasoning_effort="medium",
)
print(resp.choices[0].message.content)import OpenAI from "openai";
const client = new OpenAI({
apiKey: process.env.LLMAPI_KEY,
baseURL: "https://api.llmapi.ai/v1",
});
const resp = await client.chat.completions.create({
model: "gpt-5.6-luna",
messages: [
{ role: "user", content: "Give me three crisp launch checklist items." },
],
});
console.log(resp.choices[0].message.content);stream = client.chat.completions.create(
model="gpt-5.6-luna",
messages=[{"role": "user", "content": "Write a haiku about latency."}],
stream=True,
)
for chunk in stream:
delta = chunk.choices[0].delta.content
if delta:
print(delta, end="", flush=True){
"model": "gpt-5.6-luna",
"messages": [
{"role": "system", "content": "You are a precise product assistant."},
{"role": "user", "content": "Give me three crisp launch checklist items."}
],
"reasoning_effort": "medium"
}ENDPOINTS
Supported endpoints & features
Base URL https://api.llmapi.ai/v1 · model ID gpt-5.6-luna · OpenAI-compatible.
POST /v1/chat/completionsChat Completions — supported
| Feature | Status | How to set it |
|---|---|---|
| Function calling (tools) | Supported | tools, tool_choice |
| Parallel tool calls | Not supported | parallel_tool_calls |
| JSON mode | Supported | response_format: {"type": "json_object"} |
| Structured outputs | Supported | response_format: {"type": "json_schema", …} |
| Streaming | Supported | stream: true |
| Vision (image input) | Supported | image_url content parts |
| Web search | Supported | web_search |
| Reasoning effort | none · low · medium · high · xhigh · max | reasoning_effort: "medium" default medium |
ERRORS
Errors & fallback routing
| Code | What it means | What to do |
|---|---|---|
401 | Missing or invalid API key. | Send Authorization: Bearer YOUR_LLMAPI_KEY and check the key is active. |
429 | Rate limited, or the upstream provider is throttling the request. | Back off and retry with jitter; the gateway also retries the request on another provider where one is available. |
5xx | Upstream provider error or timeout. | Retry; fallback routing sends the retry to the next healthy provider for this model. |
When a provider fails or throttles, the request is routed to the next provider serving this model — the ones listed in the providers table above.
GPT-5.6 Luna in production
What the model is good at.
Multi-step reasoning
Breaks down complex problems into intermediate steps before answering. Relevant for `gpt-5.6-luna` workloads on LLM.API.
Structured outputs
Can produce JSON-friendly or schema-oriented responses when prompted carefully. Grounded in the model's chat role rather than generic chat claims.
Code assistance
Helps write, explain, refactor, and debug application code across common languages.
Multilingual drafting
Drafts and translates professional content across major business languages. Tuned to how teams typically call GPT-5.6 Luna.
Instruction following
Follows detailed system and user instructions with strong adherence to format and tone.
What you get when you call GPT-5.6 Luna through LLM.API.
Unified AI Routing
Reach GPT-5.6 Luna and sibling models through one OpenAI-compatible endpoint.
One endpoint, every model.Cost Control
Production: Compare provider price points and keep spend visible as you scale GPT-5.6 Luna.
More performance, less spend.Reliability Layer
Retry and route across configured providers when a single upstream blips.
Never go dark on users.Observability
Trace prompts, tokens, and errors for GPT-5.6 Luna alongside the rest of your stack.
See every token, everywhere.Drop-in SDKs
Production: Keep using familiar OpenAI client patterns with base URL https://api.llmapi.ai/v1.
Think tasks, not models.Model Breadth
Practical: Swap GPT-5.6 Luna for chat, media, or embedding alternatives without rewriting auth.
Scale from 1 to millions.
When to Use — When NOT to Use
Use it if...
- You want OpenAI-compatible chat completions through a single LLM.API key (GPT-5.6 Luna)
- You need provider failover options exposed for this model id (GPT-5.6 Luna)
- Your prompts benefit from the model's family strengths (reasoning, speed, or cost) (GPT-5.6 Luna)
- You need a general-purpose text model for assistants, agents, or content workflows (GPT-5.6 Luna)
Avoid if...
- Your use case depends on unpublished proprietary benchmarks not listed here
- You need pure embedding, OCR, or media generation instead of chat
- You require on-prem only deployment with no cloud inference
- You need guaranteed real-time hard latency SLAs without benchmarking the provider
BENCHMARKS
GPT-5.6 Luna benchmark scores
Intelligence index
Scale: 0-100 index points
Output speed
Scale: 0-400 tokens per second
Reference price per 1M tokens
Bars compare input and output list prices for this model.
Higher is better. The median covers every model tracked by Artificial Analysis.
Measured throughput; the full dial is 300 tokens per second.
Provider list prices, before the LLM.API discount.
Independent scores published by Artificial Analysis (source). Reference prices are provider list prices, not LLM.API pricing.
COMMUNITY
What developers say about OpenAI models
Summarised from publicly published developer and community reviews of this model family. Opinions are the sources’, not LLM.API’s, and may not be specific to GPT-5.6 Luna.
- Long-horizon coding reports on GPT-6 Astra describe a clear step up over the GPT-5.x line, with the higher reasoning tiers seen as the sweet spot for planning and implementation in large (100K+ LOC) codebases.
- The same field reports note that fast/ultra modes burn quota quickly and that very large refactors still stall, so teams tend to mix a cheap tier for routine calls with a reasoning tier for hard steps.
- Community threads temper the hype: capability gains are acknowledged, but developers still report the usual failure modes on obscure reverse-engineering and modding work.
SOURCES
Frequently Asked Questions
Can I use tools or structured outputs with GPT-5.6 Luna?
Tool and/or structured-output flags appear on one or more providers for this model—confirm in the providers table.
How do I call GPT-5.6 Luna via API?
Send OpenAI-compatible requests to https://api.llmapi.ai/v1 with model "gpt-5.6-luna" and your LLM.API key. See the code snippet on this page.
What modalities does GPT-5.6 Luna support?
GPT-5.6 Luna accepts text, image and produces text according to its architecture metadata on LLM.API.
Does GPT-5.6 Luna support streaming?
Yes—at least one listed provider advertises streaming.
How is GPT-5.6 Luna priced on LLM.API?
Listed pricing metadata shows: In $0.2 / 1M tokens · Out $1.2 / 1M tokens. LLM.API may offer discounted effective rates (illustrative ~30% callout vs list when available).. Confirm live rates in the LLM.API dashboard or docs before production budgeting.
Where is the canonical page for GPT-5.6 Luna?
https://llmapi.ai/models/openai-gpt-5-6-luna/
When should I choose GPT-5.6 Luna?
Your prompts benefit from the model's family strengths (reasoning, speed, or cost) — especially when you specifically need GPT-5.6 Luna.
Is GPT-5.6 Luna a chat model?
Yes—GPT-5.6 Luna is exposed as a chat/completions-style endpoint on LLM.API.
Which providers serve GPT-5.6 Luna?
LLM.API currently lists: aws-mantle, azure, openai. Availability can vary by region and account.
What is the context length for GPT-5.6 Luna?
Reported context for GPT-5.6 Luna is 1.1M tokens. Always verify the active provider row if multiple providers are listed.
What is GPT-5.6 Luna?
Cost-efficient GPT-5.6 model for fast, high-volume workloads. On LLM.API it is addressed as `gpt-5.6-luna`.
What are limitations of GPT-5.6 Luna?
Like other API models, GPT-5.6 Luna can be wrong, incomplete, or uneven on edge cases. Validate outputs for high-stakes use. Media/OCR/STT models additionally depend on input quality.
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