# Codex

## What Codex can do

### Write & debug

Generates correct, production-ready code and fixes failing test cases.

### Review diffs

Reads pull request diffs and explains or improves each hunk.

### Run test suites

Executes your test runner and iterates until all assertions pass.

### Multiple models

GPT-6 Astra, GPT-5.6 Sol, DeepSeek V4 Pro, and more — one-word switch.

## Up and running in minutes.

01

Create an account

Sign up for AgentSky and launch it in one click.

02

Choose Codex

Pick Codex and your preferred model. One API key covers Codex and every other agent on AgentSky.

03

Send your first task

Call the API or use the web UI. AgentSky provisions a persistent cloud computer and runs your task.

## Models it runs on

| Model                       | Input  | Output  |
|-----------------------------|--------|---------|
| GPT-5.6 SolDefault          | $5.00  | $30.00  |
| GPT-5.6 Terra               | $2.00  | $12.00  |
| GPT-5.6 Luna                | $0.20  | $1.20   |
| GPT-6 Astra                 | $10.00 | $50.00  |
| DeepSeek V4 Pro             | $1.32  | $3.96   |
| DeepSeek V4.1 Flash         | $0.30  | $1.20   |

## Agent + model guides

- Codex + GPT-5.6 Sol — run this agent and model
- Codex + GPT-5.6 Terra — run this agent and model
- Codex + GPT-5.6 Luna — run this agent and model
- Codex + GPT-6 Astra — run this agent and model
- Codex + DeepSeek V4 Pro — run this agent and model
- Codex + DeepSeek V4.1 Flash — run this agent and model

## Agent + channel

## Use Codex where your team already talks.

## FAQ

### How do I run Codex in the cloud on AgentSky without setting up my own compute instance or server?  
### Which models does Codex on AgentSky support, and why are Claude or Gemini not available?  
### What does Codex cost on AgentSky, and can I use my existing ChatGPT Plus or Pro subscription to eliminate per-token charges?  
### My Codex agent on AgentSky stops partway through a coding task and never finishes — what are the most common causes?  
### If my Codex agent is mid-task and the cloud machine running it is restarted or replaced, will it lose the file edits it made?  
### How do I link my existing ChatGPT subscription to AgentSky so model usage costs nothing when running Codex?