# pi-fast-mode

[简体中文](./README.zh-CN.md)

`pi-fast-mode` asks the **same model** for higher scheduling priority. It is not a faster model variant and it is not a thinking-level control.

## Features

- Toggle Fast / Priority with `/fast` or `Ctrl+F`.
- Keep the current switch in memory only. It is never written to the session jsonl.
- Set the next-process default with `/fast default on|off`. That command writes `settings.json` only and does not change the current switch.
- Show a footer status on supported models. Hide it on unsupported models and leave the request unchanged.

## Install

```bash
pi install npm:@zhcsyncer/pi-fast-mode
# or via the root bundle
pi install npm:@zhcsyncer/pi-extensions
# local
pi -e ./packages/pi-fast-mode
```

The root Git bundle also includes this extension:

```bash
pi install git:github.com/zhcsyncer/pi-extensions
```

## Commands

```text
/fast
/fast on
/fast off
```

Toggle or set the **current** in-memory switch. `Ctrl+F` is the same toggle, with a short repeat guard so a held key does not flip the switch repeatedly. Releasing the key does not toggle again.

```text
/fast default on
/fast default off
```

Write only `settings.json` `fast-mode.enabled`. The current switch stays as it is.

There is no `/fast status` command and no `gpt-fast-mode` compatibility alias.

## Settings

The supported settings key is `fast-mode.enabled` in Pi `settings.json`:

```json
{
  "fast-mode": {
    "enabled": false
  }
}
```

`/fast default` is the supported way to change that field. Manual edits are read on `/reload` or process restart.

## Footer

![Fast Mode footer status](./assets/demo-fast-mode-status.png)

- Supported model, on: `⚡ FAST` plus `priority if granted`
- Supported model, off: dim `fast: off · Ctrl+F`
- Unsupported model: hide the status and do not mutate the request

## Supported providers

The provider list is fixed. There is no user allowlist.

- OpenAI and Codex request `priority` when Fast Mode is on.
- xAI requests `priority` when Fast Mode is on.

Unsupported models hide the footer and leave the request unchanged.

## Pricing and billing

Do not assume every model is granted priority, and do not assume local cost is always about 2×.

- OpenAI Fast / priority is officially priced for the GPT-5.6 family. Older models may reject or ignore the request.
- xAI may return `service_tier: "default"`.
- Completions (current grok-4.6) does not apply priority to local `usage.cost`. Glance and session cost can under-report.

## Session lifetime

- `/fast` and `Ctrl+F` change the in-memory switch only.
- `/new`, `/resume`, and `/fork` in the same Pi process keep the current switch.
- `/reload` or a process restart reloads `fast-mode.enabled` from `settings.json`.
- `/fast default on|off` writes only the settings default.