> ## Documentation Index
> Fetch the complete documentation index at: https://docs.cto.new/llms.txt
> Use this file to discover all available pages before exploring further.

# Models

cto works with the best frontier LLMs.

Auto model automatically routes your task to the best frontier LLM, balancing performance, cost, and speed.

cto model support includes:

* Claude Opus 4.8
* GPT-5.5
* Claude Sonnet 4.6
* Gemini 3.5 Flash
* Gemini 3.1 Pro
* GLM 5.1
* GPT 5.3 Codex
* Grok 4.20
* Kimi K2.6
* MiniMax M2.7