Question 1

How do I run Codex in the cloud on AgentSky without setting up my own compute instance or server?

Accepted Answer

Create an AgentSky account and start a Codex agent via the API or web UI. AgentSky provisions a persistent cloud computer, installs the harness, and runs your task. Specify the model (GPT-6 Astra, GPT-5.6 Sol, GPT-5.6 Terra, DeepSeek V4 Pro, or DeepSeek V4 Flash) in the same call.

Question 2

Which models does Codex on AgentSky support, and why are Claude or Gemini not available?

Accepted Answer

Codex uses the OpenAI Responses API exclusively — the standard chat endpoint was dropped per openai/codex#7782 — so a model is only compatible when its provider serves that wire. Today that means GPT-6 Astra, GPT-5.6 Sol, GPT-5.6 Terra, DeepSeek V4 Pro, and DeepSeek V4 Flash. Claude, Gemini, GLM, and Kimi models are not available for Codex because their providers do not offer a Responses endpoint compatible with the Codex client.

Question 3

What does Codex cost on AgentSky, and can I use my existing ChatGPT Plus or Pro subscription to eliminate per-token charges?

Accepted Answer

Connect a ChatGPT plan via `sky auth connect` and eligible model usage is $0. Without a connected subscription, Codex with GPT-5.6 Sol ran 2,188 Playground tasks at a median cost of $1.88 per task and a 90th-percentile cost of $6.40. Current rates are on the pricing page.

Question 4

My Codex agent on AgentSky stops partway through a coding task and never finishes — what are the most common causes?

Accepted Answer

The most common causes are context overflow on large or diffuse codebases, and tool calls that returned a non-zero exit or error that Codex treated as terminal. Check the task log for the last tool call or message before the stop. Keep tasks scoped to a bounded directory or module. Also verify the failing tool call's output in the log — Codex can stop cleanly on a tool error without retrying.

Question 5

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?

Accepted Answer

The workspace persists across ordinary restarts. If the machine is replaced, AgentSky restores the latest durable recovery point, preserving the working directory and recent file state. Work in progress at the exact moment of a hard replacement may replay from the last checkpoint rather than resume mid-step. Committing intermediate results with git adds a durable recovery layer beyond AgentSky's managed checkpoints.

Question 6

How do I link my existing ChatGPT subscription to AgentSky so model usage costs nothing when running Codex?

Accepted Answer

Run `sky auth connect` and complete the OpenAI OAuth flow to link your ChatGPT Plus or Pro account. Once connected, Codex uses your subscription as the model provider and eligible runs cost $0 for model usage. Claude Code with Anthropic models uses the same connect flow with an Anthropic account. Compute, tools, and channel costs are separate from model usage in both cases.

Codex

What Codex can do

Write & debug

Review diffs

Run test suites

Multiple models

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Questions about Codex on AgentSky.

Run Codex in the cloud.