Connect atbridge.ai to Codex CLI

The OpenAI Codex CLI reaches atbridge.ai over MCP. Register atbridge.ai once and Codex can search, draft, and file mail from your terminal.

If you haven’t installed atbridge.ai yet, start with Install atbridge.ai. New to how this works? See How your AI connects.

İpucu

This page is for driving Thunderbird from Codex in your own terminal. If you want to chat inside Thunderbird instead, the atbridge AI Chat can use your existing ChatGPT subscription through the Codex CLI connector — no MCP setup needed. See Bring your own model.

The one-click way

In Thunderbird, open the atbridge.ai extension’s Settings → Connect your AI (MCP). Next to OpenAI Codex CLI, hit Set up. Tick “Allow writes” first if you want the AI to send / draft / edit mail (it’s read-only by default).

Or from a terminal:

atbridge mcp setup --client codex
# add --allow-writes to unlock send / draft / edit

Or add it by hand

Codex keeps its configuration in TOML, and its own CLI writes it for you:

codex mcp add atbridge -- atbridge mcp

To let the AI send / draft / edit mail (read-only otherwise), pass the write flag as an environment variable:

codex mcp add atbridge --env ATBRIDGE_ALLOW_WRITES=1 -- atbridge mcp

Either command writes an entry into your Codex config:

macOS / Linux

~/.codex/config.toml

Windows

%USERPROFILE%\.codex\config.toml

config.toml

[mcp_servers.atbridge]
command = "atbridge"
args = ["mcp"]

[mcp_servers.atbridge.env]
ATBRIDGE_ALLOW_WRITES = "1"

Dikkat

The server name must be atbridge — plain letters, numbers, - and _ only. Codex rejects a dotted name like atbridge.ai with “invalid server name”. This is the one client where the entry isn’t called atbridge.ai.

Check it landed with:

codex mcp list

Try it

Codex reads its config on every run, so there’s nothing to restart. Start codex and ask:

List the 5 most recent emails in my Thunderbird inbox.

If you see a list, you’re done.

Not

atbridge must be on your PATH. If the tools don’t appear, use the absolute path as the command (codex mcp add atbridge -- /full/path/to/atbridge mcp) — the same fix as for Claude Desktop. The bridge only answers while Thunderbird is running.

Where to go next

• Try a recipe