GPT-5.6 Sol
Sol is the high-cost flagship candidate in the GPT-5.6 series for people tracking extremely complex tasks. Until its worst-case output cost can be proven, this site publishes the boundary without enabling generation.
Online use is currently unavailable
This page is for reviewing the model's capabilities, use cases, and public references. The model does not appear in the home workbench, and you cannot submit generation tasks with it.
At a glance
What is this model like?
A flagship label does not make a model available or replace a reliable cost limit. Sol's details and alternatives remain visible, but it does not appear in the model selector, accept messages, or charge credits.
Key facts
Quickly assess whether this model fits your use case.
Also known as
The same model may appear under different names across documentation and community discussions; this list keeps them easy to search and compare.
Common questions
These practical questions focus on the task, input conditions, and result requirements you should confirm before choosing.
Selection guide
Use these decision points when choosing a model.
Run representative samples with Claude Opus 4.7 or Claude Sonnet 5 first.
Prepare difficult tests with counterexamples, evidence, and strict formatting requirements.
Base migration on factual accuracy, verifiability, and total rework cost.
Popular comparisons
Compare common alternatives on the same task to clarify differences in inputs, controls, and cost.
Model comparison
Compare the current model with alternatives at a glance.
Practical usage insights
Practical guidance based on public sources, current on-site limits, and representative tasks.
Higher rates demand a complete contract
Measure flagship value by reduced rework
Capabilities
Multi-turn messages
High-effort reasoning
Tool contract
Use cases
Consequential decision memos
Rigorous review
Complex technical plans
Prompt tips
Ask for disconfirming evidence
Separate facts from recommendations
Use one scoring rubric
Why choose it
What to know first
Currently unavailable
This page is for reviewing the model's capabilities, use cases, and public references. The model does not appear in the home workbench, and you cannot submit generation tasks with it. The flagship GPT-5.6 tier for complex reasoning and high-value professional work.
FAQ
Related models
Compare these similar candidates before deciding.
Claude Opus 4.8
Claude Opus 4.8 is designed for high-complexity text analysis and consequential writing. Kyeo AI offers text-only chat with up to 20,000 characters per message and an explicit 4,096-token maximum output.
Claude Sonnet 5
Claude Sonnet 5 is the more balanced Claude candidate in this batch for research, code explanation, and structured writing. Its maximum output on this site is 4,096 tokens.
Claude Opus 5
Claude Opus 5 is a flagship candidate for high-complexity text work. Kyeo AI limits each message to 20,000 characters, includes the 40 most recent submitted messages, and caps output at 4,096 tokens.
Sources
Content is based on model documentation, feature references, and the settings available on Kyeo AI.
GPT-5.6 Sol's message format, four reasoning levels, mutually exclusive tools, and advanced token rates are confirmed. Runtime access remains disabled because a maximum output-usage bound cannot be proven.
Records messaging, reasoning, tool, rate, and preauthorization-block details.