Codex (ChatGPT) Setup — Tempreon Docs

Overview

Codex is OpenAI's coding-agent product, available as a Mac app, an IDE extension (VS Code, Cursor, and similar), and a CLI. All three share the same MCP configuration surface — once you connect Tempreon, your Codex session sees your Core Imprint, Knowledge Vault, preferences, and project context, the same intelligence layer your Claude tools use.

Codex supports remote MCP servers over OAuth. There are several equivalent ways to register Tempreon; pick the one that matches your install.

Prerequisites

A current Codex install — Mac app, IDE extension, or CLI (run codex --version to confirm)
A Tempreon account with at least one available Bridge slot (check your Bridges dashboard)
A working default browser on the machine running Codex — the OAuth flow opens one

Step-by-Step Setup

1. Get Your Connection Details

Log into Tempreon and navigate to the Bridges section of your dashboard to find your MCP server URL. The URL ends in /mcp.

2. Add to Your MCP Configuration

Codex reads MCP server configurations from ~/.codex/config.toml (global) or a project-local .codex/config.toml. All three Codex surfaces — Mac app, IDE extension, and CLI — read the same file. Pick whichever method matches your install; the resulting configuration is identical.

Method A — Edit `~/.codex/config.toml` directly (recommended)

This is the most reliable path. Open ~/.codex/config.toml in your editor (create it if it doesn't exist) and add:

[mcp_servers.tempreon]
url = "YOUR_SERVER_URL_FROM_BRIDGES_DASHBOARD"

Save. Fully quit Codex (Cmd-Q on Mac, not just close the window) and reopen. Tempreon will appear in your MCP servers list.

Tip: Use ~/.codex/config.toml to make Tempreon available across every Codex install on this machine. Use a project-local .codex/config.toml to scope it to a single project.

Method B — Codex IDE Extension

In the Codex extension's settings panel, choose MCP settings → Open config.toml. The extension opens the same file as Method A. Add the [mcp_servers.tempreon] block above, save, and reload the extension. The IDE Extension is the most convenient path if you're already working inside VS Code, Cursor, or a similar editor.

Method C — Codex Mac app GUI

In the Mac app, open Settings → MCP servers → Add server and fill in the form. The app writes the same [mcp_servers.tempreon] block to ~/.codex/config.toml for you.

If the Add server form flickers or the OAuth window closes immediately, the form may have failed to persist before triggering OAuth. Fall back to Method A (edit ~/.codex/config.toml directly) — Brandon's verified workaround during the 2026-05-06 validation. The same TOML block applies; the Mac app picks it up on next launch.

3. Authorize the Connection

Once Tempreon is registered (any method), Codex triggers an OAuth flow on first connect. From the CLI you can also kick this off manually:

codex mcp login tempreon

A browser window opens with the Tempreon consent screen. Sign in if prompted, review the requested scopes, and approve. The window closes; Codex stores the access token locally and reuses it on every future session.

4. Verify the Connection

Open the MCP servers list in your Codex surface (Mac app Settings, IDE extension panel, or codex mcp list from the CLI). Tempreon should appear as Connected. Start a new session and ask:

"What Tempreon tools do you have access to?"

If Codex lists Tempreon's tools, the Bridge is working.

Developer-Specific Features

Codex with Tempreon is particularly powerful for developers because:

Architecture decisions persist. Tell Codex to remember a technical decision in one session and it surfaces automatically the next time you're working in the same area — across the Mac app, IDE extension, and CLI.
Project context carries over. Domain-scoped knowledge means Codex knows the difference between your work projects and your personal projects without you re-explaining.
Session bootstrap is automatic. Tempreon surfaces the right context at session start — what you've decided before, who you've talked to, which projects are active — so Codex picks up where the last session left off.
Task management is integrated. Capture tasks from inside the terminal or editor without context-switching to a separate tool.

Try Saying...

"Pull up what I've been working on in [project name]" — Loads project context into the session
"What did I decide about the auth service architecture last week?" — Searches your Knowledge Vault from the terminal or editor
"Save this design note as a spec document" — Stores a file in your File Vault tagged for cross-session retrieval
"What tasks do I have queued for [project]?" — Reads your personal task queue without leaving Codex

Common Issues

Problem	Solution
Mac app's Add server form flickers, OAuth window closes, Tempreon never appears	Use Method A (edit `~/.codex/config.toml` directly). Save, fully Cmd-Q the app, reopen.
OAuth completes but Tempreon disconnects after a few minutes	Connector cache stickiness. Fully delete and re-add the Tempreon connector (not just disconnect/reconnect) to refresh the tool list.
Tools list doesn't update after a Tempreon-side change	Codex caches the tool list per connector. Disconnect, fully restart Codex, re-add as a new connector to bust the cache.
`codex mcp login` reports "unknown command"	Update Codex — older versions had reconnect-loop bugs around v0.125.0.
Browser doesn't open during `codex mcp login`	Codex prints the auth URL on the terminal — copy it into your browser manually.

For more help, see Troubleshooting Connections.