Codex

Codex reaches the Inbox through MCP and a hook reviews its plans. On Codex 0.149 or newer your reply arrives as its next turn.

Hooks and MCP · Plannotator’s hooks and commands plus the Inbox through MCP

Set it up

Install Plannotator. It turns on Codex hooks and adds the plan review hook.

curl -fsSL https://plannotator.ai/install.sh | bash

You should see Restart Codex Desktop or CLI after installing. and Plan review is configured through the Codex Stop hook.
Open the Inbox. It connects the agents it finds on this computer.

plannotator inbox

You should see The terminal says Connected Codex … to the Inbox. Settings → Agents lists Codex through MCP server.
Restart Codex. Your reply wakes it from Codex 0.149 on.

codex --version

Other ways

Connect the Inbox yourself

This also adds it to the Codex app and the IDE extension. Restart them after.

codex mcp add plannotator-inbox -- plannotator inbox mcp

In the Codex app

Settings → MCP servers → Add server → STDIO with the command plannotator inbox mcp. Then restart.

Plan review hook by hand

Turn hooks on.

~/.codex/config.toml

[features]
hooks = true

Add the Stop hook. Use the full path to plannotator for Codex Desktop.

~/.codex/hooks.json

{ "hooks": { "Stop": [{ "hooks": [{ "type": "command", "command": "plannotator", "timeout": 345600 }] }] } }

On Windows

Install Plannotator from PowerShell. The other steps are the same.

irm https://plannotator.ai/install.ps1 | iex

Check it works

Paste this into Codex.

Send me a test question in the Plannotator Inbox, and read my answer when I tell you I sent it.

You should see A question arrives in the Inbox. Answer it and press Send. The thread reads Queued for Codex; it gets this as its next turn. and Codex picks it up when its turn ends.

Troubleshooting

Your reply isn’t delivered: It needs Codex 0.149 or newer and a codex the Inbox can find on its PATH or in the ChatGPT app. An older Codex reads the reply when it checks the thread.
plannotator inbox says Codex before 0.35 has no codex mcp add: Update Codex or add plannotator-inbox to its config.toml by hand.
Plan review never opens in the Codex app: The app may not see your shell’s PATH. Put the full path to plannotator in hooks.json and restart Codex.
The installer says the Codex hooks file couldn’t be merged: Follow Plan review hook by hand under Other ways.
A codex exec run never got your reply: One-shot runs end before a reply. It stays in the Inbox for a later run to read.
No Send now: Codex takes a reply only as its next turn, so there is no Send now.
Starting Codex from the Inbox says to sign in: Run codex login in a terminal.

codex login
A Codex session the Inbox started says Codex’s turn ended with an error: Codex refused the turn, for example a model your login doesn’t allow or an expired login. The note gives Codex’s own words. Fix that in Codex and reply again.
The Inbox doesn’t open: Read ~/.plannotator/inbox/inbox.log. Stop a stuck Inbox process and run plannotator inbox again.

What works

Inbox tool MCP
Reply wakes it Wakes Codex 0.149+
Start from Inbox Yes
Permission cards Sessions it started

Plan review At the end of a turn
Code review Yes
Annotate Files and last reply
Ask this session No

Plan review doesn’t work on Windows, because Codex hooks are off there.
Starting Codex from the Inbox is macOS and Linux for now.
In a session the Inbox started, a question Codex asks on its own is answered Cancel for now. Questions it sends to the Inbox work.

Examples

Ask Codex for a plan. It opens in Plannotator when the turn ends.
$plannotator-review opens your changes for review.
Pick New Codex session in the Inbox to start one from there.

Every agent Full Codex guide