GPT-5.6 Mini

OpenAITextReasoningToolsVision

GPT-5.6 Mini: a fast, economical option for high-volume tasks.

Our price
$0.85 / $5.10
input / output per 1M
Official
$1.00 / $6.00
−15% vs official

First request

from openai import OpenAI

client = OpenAI(
    base_url="https://api.altrouter.ai/v1",
    api_key="ar-...",
)

resp = client.chat.completions.create(
    model="gpt-5.6-mini",
    messages=[{"role": "user", "content": "Hello!"}],
)
print(resp.choices[0].message.content)

The interface is OpenAI-compatible: in existing code only the base_url, the key and the model id change — nothing else.

GPT-5.6 Mini against its price neighbours

GPT-5.6 Mini and its closest neighbours by price: prices and parameters from the AltRouter AI catalog
ModelInput / 1MOutput / 1MContext
Gemini 3.8 FlashGoogle$0.64$3.191MOpen
Claude Haiku 4.5Anthropic$0.77$4.00200KOpen
GPT-5.6 Minithis pageOpenAI$0.85$5.10400K
Grok 4.6xAI$1.70$5.10256KOpen
Claude Sonnet 5Anthropic$1.69$8.50200KOpen

Prices and parameters come from the same catalog as the price above; this is not a benchmark, it is comparable billing terms.

Limits

Context is 400K tokens per request, and it holds everything you send: the system prompt, the conversation history and the current question together. Whatever does not fit is not seen by the model — trimming the history is your side of the job, and you pay for exactly what fit.

Supported: a reasoning mode, tool calling, image input.

There is no subscription: every successful request is billed at the price above, and a failed one is not billed at all. That price is already 15% below the vendor's official one — the official price is shown struck through next to it so it can be checked. No OpenAI account of your own is needed: requests go to api.altrouter.ai and we make the upstream call.

Rate limiting is shared across models and counted per key: 600 requests per minute by default, and a 429 with retry-after: 60 above it. An individual key can get its own limit and a spending cap per day, week, month or lifetime in the dashboard.

Full limits and credits

When to pick GPT-5.6 Mini, and when a neighbour

The cheaper neighbour is Claude Haiku 4.5: $0.77 per 1M input tokens against $0.85 for GPT-5.6 Mini. On the same volume the bill comes out 1.1× smaller. Its context is smaller: 200K against 400K — long documents will need splitting. It is the sensible pick where the task is repetitive and high-volume — labelling, classification, short templated answers — the kind of work where quality is bounded by the prompt rather than the model.

The dearer neighbour is Grok 4.6: $1.70 per 1M input tokens, or 2× the price. On catalog parameters it offers the same capabilities and the same order of context, so the premium is only justified if GPT-5.6 Mini falls short on your own task.

Guessing is more expensive than checking: the table above is prices and parameters, not a benchmark, and it cannot tell you which model does better on your own prompt. Switching costs one line — the model id in the request changes, the base_url and the key stay — so running both on your own data takes minutes.

API

OpenAI-compatible chat completions endpoint, with SSE streaming.

POST/v1/chat/completions
Body parameters
modelstringrequired"gpt-5.6-mini"
The model id.
messagesarrayrequired
The conversation: [{ role, content }].
streambooleandefault false
Stream the response over SSE.
reasoning_effortenumlow · medium · high · xhighdefault low
Thinking budget for reasoning models.
web_searchbooleandefault false
Server-side web search - answers with live data.

Structured fields (tools, response_format, stop and more) are in the full parameter reference.

Response
idstring
Completion id.
choicesarray
Completions. Each: index, message { role, content, reasoning_content, tool_calls }, finish_reason.
usageobject
Tokens: prompt_tokens, completion_tokens, total_tokens.
Example
cURLPythonJavaScriptJSON
curl https://api.altrouter.ai/v1/chat/completions \
  -H "Authorization: Bearer ar-..." \
  -H "Content-Type: application/json" \
  -d '{
  "model": "gpt-5.6-mini",
  "messages": [
    {
      "role": "user",
      "content": "Hello!"
    }
  ],
  "reasoning_effort": "low"
}'
Errors
400Invalid request.
401Missing or invalid API key.
402Insufficient credits, or the key’s spending cap is exhausted.
404Model not found.
429Rate limit exceeded.

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