pi-codex-fast

Fast Mode extension for pi that toggles OpenAI/Codex priority service tier for configured models.

Requires pi 0.74.0 or newer.

Install

pi install npm:pi-codex-fast

Try it temporarily without installing:

pi -e npm:pi-codex-fast

Or test from a local checkout:

pi -e ./

Usage

The extension adds the /fast command:

/fast          Toggle Fast Mode on/off
/fast on       Enable Fast Mode
/fast off      Disable Fast Mode
/fast toggle   Toggle Fast Mode on/off
/fast status   Show current status
/fast style    Cycle the footer status style

When enabled, requests for configured OpenAI/OpenAI Codex models use serviceTier: "priority".

How it works

pi-codex-fast registers provider wrappers for pi's OpenAI Responses and OpenAI Codex Responses APIs.

For configured models, the wrapper calls the native provider streamer with serviceTier: "priority". For all other models, providers, or disabled Fast Mode, it falls through to pi's normal simple streamers unchanged.

The extension intentionally does not use the before_provider_request hook to patch request payloads. That preserves pi's native provider flow, including pi's built-in usage and cost calculation.

Configuration

On first load, the extension creates:

~/.pi/agent/extensions/pi-codex-fast.json

If PI_CODING_AGENT_DIR is set, the config is created under that agent directory instead.

Default config:

{
  "enabled": false,
  "models": ["openai/gpt-5.4", "openai/gpt-5.5", "openai-codex/gpt-5.4", "openai-codex/gpt-5.5"]
}

Optional fields such as style are resolved internally and only written when changed via /fast style.

Model entries may be provider-qualified, for example openai/gpt-5.5, or bare model IDs, for example gpt-5.5.

License

MIT