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Model detail

GPT-5.6 Sol

Provided by OpenAI
Pay-as-you-go Dynamic pricing 2 tiers

GPT-5.6 Sol is the flagship model in OpenAI's GPT-5.6 series. It is suited for complex reasoning, coding, and agentic workflows, and is particularly strong at command-line and multi-step coding tasks and long-horizon problem solving.

Model specs

Context length
1.05M
Max output
128K
I/O modalities
Text / Image
Released
2026-07

02

API endpoints

One MixRoute gateway, OpenAI-compatible

  • OpenAI-compatible /v1/chat/completions POST

03

Tiered pricing

Unit: /1M Tokens

Tier Input /1M Tokens Output /1M Tokens Cache read /1M Tokens Cache write /1M Tokens
standard Length ≤ 272K $4.0000 $20.0000 $0.4000 $5.0000
long_context Length > 272K $8.0000 $30.0000 $0.8000 $10.0000

05

Selection summary

Quickly judge whether it fits your workload

What is this model good for?

Complex reasoning and multi-step coding tasks to test first

Use GPT-5.6 Sol for complex reasoning, coding, and agent workflows, with the official description highlighting command-line and multi-step coding tasks and long-horizon problem solving. The full specifications and capability list are not published yet, so start with one representative reasoning or coding task and compare results on your own workload.

EX Run one multi-step coding task and one long-horizon reasoning task with model: "gpt-5.6-sol" and compare against your current setup.

What should you check before using it?

Check the 272K pricing tier boundary

Before adopting GPT-5.6 Sol, check the pricing boundary at 272K input tokens: requests at or below that length are billed $4.0000 per 1M input tokens, while longer requests move to the long-context tier at $8.0000. Measure your typical request size and estimate both tiers so the projected cost reflects your real usage.

EX Estimate a 200K-token request at the standard rate and a 300K-token request at the long-context rate before comparing models.

Why use it through MixRoute?

Call it on the OpenAI-compatible endpoint with its model ID

Call GPT-5.6 Sol through MixRoute's OpenAI-compatible endpoint (POST /v1/chat/completions) with the model ID gpt-5.6-sol. Because the endpoint follows the OpenAI request format, you can keep your existing OpenAI-style client, change the model string, and test the same code path against your current setup.

EX Point your existing OpenAI-style client at MixRoute's /v1/chat/completions with model: "gpt-5.6-sol" and rerun your integration tests.

08

Token cost estimator

Live estimate from this page's pricing, not an actual bill

Share of the same prefix read repeatedly, up to 100%

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FAQ

For requests at or below 272K tokens, GPT-5.6 Sol charges $0.4000 per 1M tokens for cached reads instead of $4.0000 for standard input; above 272K, the long-context tier charges $0.8000 cache read versus $8.0000 input. The cache-read price is one tenth of the input price in both tiers. Measure how many input tokens repeat across your requests, then estimate with your own cache-to-input ratio before assuming a budget change.

One endpoint, a testable decision

Test this model and alternate routes with the same request format

Start from a real workload, then let quality, total cost, and failure conditions decide whether to send production traffic.