Codex CLI Setup

Codex CLI has no usable pre-prompt hook, so recall works through a rule the model follows rather than an injection it cannot miss. The plugin installs the rule and the MCP config together.

Prerequisites

Node.js 18+
A Nexus-Catalyst account with an active subscription or trial — start a 14-day trial, or use your invitation if you have one
A Plugin API key from Account → API Keys

Install

npm install -g @nexus-catalyst/codex-plugin
export NC_PLUGIN_API_KEY="your-plugin-key"
nc-codex install
nc-codex status

Add the export to your shell profile (~/.zshrc, ~/.bashrc) so it survives new sessions.

What it installs

Two things, and it is worth knowing which is which:

An AGENTS.md recall rule — tells the model to call recall_context when a session starts
MCP server config — so the tools exist to be called

Neither fires on its own the way a hook does. If recall is inconsistent, that is the rule not being followed, not a broken connection.

Commands

nc-codex install      # Add the AGENTS.md rule and MCP config
nc-codex uninstall    # Remove them, leaving other config intact
nc-codex status       # Check installation state and API key

Make recall reliable

Add the Agent instruction set to your AGENTS.md alongside the rule the plugin installs. It is more explicit about when to recall and when to store, and it is the difference between memory that mostly works and memory you can rely on.

Troubleshooting

`nc-codex status` reports no API key

NC_PLUGIN_API_KEY is not set in the shell you are running Codex from. Check with echo $NC_PLUGIN_API_KEY.

The model never calls `recall_context`

Confirm AGENTS.md carries the rule, then add the full instruction set above. A rule in a file the model is not reading does nothing.

Tools fail with 401

Your OAuth session expired. Re-authenticate against the MCP server.

Need help? Common Issues · support@nexus-catalyst.com