Codex agent in autonomous mode on a server

March 12, 2026

On March 12, a Codex agent was put into autonomous mode on one of the virtual servers in the US and connected to OpenAI with an API key. It took three tries before it produced a simple result: a text file with the greeting Hello World! in the current directory.

The agent kept trying to switch into interactive mode. Creating one small file cost about 10,000 tokens, or roughly 3 cents. After that, the conclusion only got clearer: for ongoing work, Codex is probably better value on subscription than through one-off API use.

A $20 monthly subscription already goes a long way. Over the last six months, the limit was never reached, although nothing especially large was built through Codex either.

The next practical step is straightforward: a small web app for receiving GitHub webhooks, for example when an issue is opened, and then using it to launch the agent. The agent can inspect the task text, route it to work, or reject it outright. With enough funding, that is already enough to build a small automated software agency. In terms of speed, it would not be worse than handling issues manually in Magento. Token usage, though, would be noticeable.