GPT-5.6 Sol API

OpenAI GPT-5.6 Sol: flagship GPT-5.6 tier for complex reasoning and coding.

OpenAI·ChatAvailable

from$1.26/ 1M input tokens$1.410% off

Model IDgpt-5.6-sol

reasoningtools1m-context

Input

Text

Output

Chat

Provider

8 providers

Last 7 days · not enough recent requests for stats yet.

GPT-5.6 Sol pricing

Prices are per unit; requests without a provider are routed to the cheapest provider that supports your parameters.

OptionPrice (USD)
All options
$1.26 / 1M input tokens
126 Credits$1.410% off

Try GPT-5.6 Sol before you integrate

Test output quality, compare provider prices and estimate cost before writing any code.

Provider
Chat

Settings

PriceKIE AI
1M input tokens$1.26
1M output tokens$7.56

Credits for max_tokens are held first, then settled to the actual usage.

GPT-5.6 SolAuto (cheapest)
GPT-5.6 Sol

Start a conversation. Replies stream in and are billed by actual token usage.

Enter to send · Shift + Enter for a new line

GPT-5.6 Sol prompt examples

Ready-to-use prompts. Load one into the playground and tweak it.

Source
Scene

21 prompts

Here is our database migration plan. Identify the single riskiest step, explain why, and suggest a safer sequence. <paste plan here>

Explain in one paragraph why this function leaks memory when called in a loop, then show the corrected version. <paste code here>

Read the attached 200-page annual report and list the five findings an investor should care about most, with page references.

GPT-5.6 Sol API reference

Endpoints, request fields and runnable examples for this model.

Base URL

https://01router.com/api/v1
llms.txt

Quick start

Set API_KEY to your project key, then run a sample from your server. Replace example media URLs with your own public URLs.

Auto-routing chooses a provider that supports the request. Select a provider to see its input constraints and pinned request examples.

curl https://01router.com/api/v1/chat/completions \
  -H "Authorization: Bearer $API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "gpt-5.6-sol",
    "messages": [{ "role": "user", "content": "Hello!" }],
    "stream": false
  }'

Endpoints

Only endpoints relevant to this model are listed. Paths below include /api/v1. Click an endpoint to read its usage.

Authentication

Send your API key as a Bearer token. Requests are billed to the key owner's credits.

Authorization: Bearer YOUR_API_KEY
Content-Type: application/json
Get an API key

Input

Send messages directly in the request body. Chat requests do not use an input wrapper.

Request body

NameTypeRequiredDescription
modelstringYes"gpt-5.6-sol"
providerstringNoPin a provider; omit to auto-route to the cheapest. One of: replicate | wavespeed | kie | apimart | evolink | atlascloud | vercel | openrouter
messagesobject[]YesOpenAI-format messages, each with role and content.
streambooleanNotrue returns an SSE stream.
max_tokensintegerNoOutput token cap; credits are pre-held for it (default 4096).

Output

This example uses stream: false. Read the reply from choices[0].message.content. With stream: true, read SSE chunks from choices[].delta until [DONE].

Task completed

{
  "id": "chatcmpl-example",
  "object": "chat.completion",
  "model": "gpt-5.6-sol",
  "choices": [
    {
      "index": 0,
      "message": {
        "role": "assistant",
        "content": "Hello! How can I help?"
      },
      "finish_reason": "stop"
    }
  ],
  "usage": {
    "prompt_tokens": 9,
    "completion_tokens": 8,
    "total_tokens": 17
  }
}

Response fields

NameTypeRequiredDescription
idstringYesChat completion ID
objectstringYeschat.completion
modelstringYesgpt-5.6-sol
choicesobject[]YesReply choices; message.content contains the non-streaming response.
usageobjectNoToken usage: prompt_tokens, completion_tokens and total_tokens. Availability depends on the provider.

Model schema

This public endpoint returns the model parameters and each provider’s supported constraints and prices.

curl "https://01router.com/api/v1/models/gpt-5.6-sol"

Errors

Check the HTTP status and error.message. Fix the request before retrying validation or authentication errors. A failed generation is reported in status and error on the task itself.

{
  "error": {
    "message": "Invalid or missing API key",
    "code": "unauthorized"
  }
}

400Invalid body or parameter value

401Missing or invalid API key

402Not enough credits

404Unknown model or generation

429Too many requests — retry after the given seconds

502Every provider rejected the task (credits refunded)

Auth, routing, billing and error codes are covered in →

Use with AI

Give your coding assistant this model reference: endpoints, input constraints, output fields and request examples in plain text.

Open llms.txt

How does GPT-5.6 Sol compare?

Specs and starting prices side by side. Test with the same prompt before you choose.

GPT-5.6 SolGPT-6 AstraGPT-6 SolGPT-6 Luna
VendorOpenAIOpenAIOpenAIOpenAI
Starting price$1.26 / 1M input tokens$2.52 / 1M input tokens$0.54 / 1M input tokens$0.027 / 1M input tokens
InputTextTextTextText
Provider8 providers7 providers7 providers8 providers

GPT-5.6 Sol API FAQ

How does GPT-5.6 Sol compare with Terra and Luna?

Sol is the strongest GPT-5.6 tier, best for agentic coding, research, long-context analysis and work where quality beats cost. Terra is the everyday default and Luna the cheapest high-volume tier.

What are the limits?

About 1.05M tokens of context and up to 128K output tokens. It accepts text and images (PNG, JPEG, WebP, GIF) and returns text.

Which reasoning settings are supported?

reasoning_effort can be none, low, medium, high or xhigh. Higher levels may need a larger max_tokens, otherwise the visible answer can come back empty.

Does it support tools and structured output?

Yes, function calling, structured JSON output and streaming are supported on our OpenAI-compatible endpoint.

How is it billed on 01router?

Per 1M input and output tokens from the provider's usage. Prompts above roughly 272K tokens are charged at the upstream long-context rate. See the pricing table.

Related models

Other models you can call with the same API key.