Codex Is Live in Zed

Summary

When we introduced the Agent Client Protocol (ACP) in collaboration with Google's Gemini CLI team, we did not anticipate how much pent-up demand there was for a protocol like this! As of today, Zed supports Codex out-the-box via ACP. You can select it from the New Thread menu, just like Claude Code or Gemini CLI: A walkthrough of OpenAI's Codex in Zed. Like our other ACP integrations, Codex via ACP is strictly about improving UI and keeping you in flow in your IDE of choice; the billing and legal/terms arrangement is directly between you and OpenAI. Zed does not charge for use of external agents like Codex, nor do prompts and code sent via Codex-ACP to OpenAI touch Zed's servers! We've also separately open-sourced the codex-acp adapter so you can use it outside of Zed as well. Every model behaves a bit differently than the others, and the same is true of agents. For example, some agents support switching models in the middle of a conversation, whereas others require sticking with the same model throughout. Some support viewing and resuming past conversations, whereas others have no concept of conversation persistence. ACP is designed to be flexible enough to work with a variety of agent capabilities, but the experience of using them still varies based on the agent's implementation details. A detail that came up when we were building the Codex ACP adapter was that the Codex agent runs terminal commands in its own process, and then streams output bytes from that terminal process to the client. In the past, we've had this reversed: the agent would send the client a request to run a terminal command (e.g. mkdir examples) and then the client would manage the actual running of that command. Naturally, we want to keep the look and feel consistent no matter which agent you're using, but this design difference between Codex and other agents makes certain details unavoidably different. For example, for other agents we can spawn terminals in pseudoterminal (PTY) mode. This mea...