# Codex

Codex works fully with 0bridge: setup, history, resume and agent control. Level: full. Last checked 2026-10-01.

## Set it up

```
npm install -g 0bridge
0b setup
```

By hand: `codex mcp add 0bridge --url https://0bridge.dev/mcp`, and if the sign-in doesn't open, `codex mcp login 0bridge`.

## What works

- **History:** with `0b history on`, Codex CLI and app conversations are collected. `0b history hooks on` adds a Stop hook in `~/.codex/hooks.json` so a conversation uploads as a turn ends. With the [session board](/docs/sessions) on, hooks for a prompt starting, a permission request and the session ending go in too (the events Codex 0.157 lists; not yet seen on a live session, 2026-10-01). Codex may ask you to trust a new hook the first time; approve it in Codex. If hooks aren't turned on in your Codex (no `hooks.json`, no `hooks = true` under `[features]`), 0bridge uses Codex's `notify` setting instead, and only when you haven't set one yourself.
- **Resume into Codex:** `0b resume 0b:k3f9x2 --tool codex` starts Codex with the handoff as its first message. On the machine where the session ran, it offers `codex resume` with the original thread instead. See [Resume anywhere](/docs/resume).
- **Agent control:** `0b agent` starts Codex tasks through `codex app-server`, which Codex marks experimental; 0bridge was written against Codex 0.157 and doesn't check the version, so a newer Codex that changes app-server can break it. If app-server isn't available it falls back to `codex exec`, without approvals relayed: plan and edit modes only. See [Your agents from your phone](/docs/remote-control).
- **Several Codex homes:** history collection also reads the folder `CODEX_HOME` points to, and tags it as that account.

## Cloud agents

`0b project cloud --codex` writes a `.codex/config.toml` entry that reads the token from an environment variable. We haven't verified the field names against Codex cloud, and Codex cloud may remove secrets before the agent runs, so check [Cloud agents](/docs/cloud-agents) before relying on it.