Use XOR with Codex: XOR docs

One command adds XOR to the Codex CLI, the IDE extension and the ChatGPT desktop app.

Add it

Run this in a terminal:

codex mcp add xor --url https://systemofreason.com/mcp

Codex sees that XOR uses sign-in and opens your browser. Enter your email and the code we send you. If it doesn’t open, run codex mcp login xor.

The CLI, the IDE extension and the ChatGPT desktop app share one settings file, so XOR shows up in all three. In the IDE extension, the gear menu’s MCP servers lists it; restart the extension after adding it.

In the settings file

It lands in ~/.codex/config.toml:

[mcp_servers.xor]
url = "https://systemofreason.com/mcp"

With an access key instead

For machines with no browser, use an access key kept in XOR_KEY:

[mcp_servers.xor]
url = "https://systemofreason.com/mcp"
bearer_token_env_var = "XOR_KEY"