Connect Pomeroy to Codex

Codex is OpenAI’s agent for the terminal and ChatGPT, and it works with Pomeroy. Pomeroy sets itself up in it with one click. Codex can then read the apps you switched on, and no others.

What Set up does. Pomeroy runs Codex’s own codex mcp add command, which writes to Codex’s configuration file. The CLI, the IDE extension and the ChatGPT desktop app all read that one file, so you set up once. If the codex command is not where Pomeroy can find it, Pomeroy adds the entry to the file itself.

Set up

Install Pomeroy and switch on your apps

Download Pomeroy, drag it into Applications and open it. Switch on the apps you want Codex to reach. Everything starts off, and macOS asks you to approve each app as you switch it on. The full walkthrough.

Install Codex, if you have not

Pomeroy lists the assistants it finds on this Mac, so install Codex first if it is not there. Returning to Pomeroy’s window re-checks.

Press Set up

In Pomeroy’s Assistants pane, find Codex and press Set up. It is safe to press any number of times. It writes the same thing every time, and it never disturbs another server already there.

Pick it up

Quit Codex and open it again. It reads its server list only at launch.

Ask something

In Codex, ask what is on your calendar today. The answer comes from your Mac.

The configuration

You do not need this. Set up writes it for you. It is here so you can see what Pomeroy adds, check it by hand, or set up a second Mac without opening the panel. Goes in ~/.codex/config.toml:

[mcp_servers.pomeroy]
command = "/Applications/Pomeroy.app/Contents/MacOS/pomeroy-mcp"

The command is a single absolute path with no arguments, and it lives inside Pomeroy’s app bundle, so an update never changes it. What the pipe is.

Over the local endpoint

Codex can also reach Pomeroy over the HTTP endpoint instead of the pipe. Use it only for a copy running somewhere that cannot start a program on this Mac, such as a container or a remote workspace. Switch the local address on in Pomeroy’s Connections pane first. Goes in ~/.codex/config.toml:

[mcp_servers.pomeroy]
url = "http://127.0.0.1:13579/mcp"
http_headers = { "Authorization" = "Bearer <the key Pomeroy generates>" }

Pomeroy writes the real token in place of the placeholder when it can reach this assistant’s settings. Otherwise you can read the token under Connections.

How to check it worked

Run codex mcp list in the Terminal and pomeroy is listed. In the ChatGPT app, Settings › MCP servers shows it. If the tools are missing, the cause is almost always that the assistant has not re-read its server list. Troubleshooting.

Worth knowing about Codex

The ChatGPT desktop app has two sides. Its Codex side runs local servers and can use Pomeroy; its chat side is the web assistant and cannot.

What it can reach

Only the apps you switched on, and only through the tools Pomeroy publishes. Codex cannot send mail, send a message, delete anything or edit a contact, because no tool does those things.

What Pomeroy can do

Ten apps, 27 tools, and every refusal.

Permissions

What each toggle grants, and what macOS asks you for.

Other assistants

All 24, and what to do if yours is not listed.