pi-fast-mode

简体中文

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 each model's current switch in memory only. It is never written to the session jsonl.
• Set the next-process default for the current model with /fast default on|off. That command also turns the current session switch to match.
• Unconfigured models start off. There is no all-models default.
• Show a footer status on supported models. Hide it on unsupported models and leave the request unchanged.

Install

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:

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

Commands

/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.

/fast default on
/fast default off

Write this model's startup default and turn the current session switch to match. Unsupported models reject the command.

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

Settings

Defaults are a list of provider/id in Pi settings.json. Only listed models start Fast:

{
  "fast-mode": {
    "models": ["openai/gpt-5.6"]
  }
}

/fast default is the supported way to change that list. Manual edits are read on /reload or process restart. An old fast-mode.enabled boolean or { "provider/id": true } map is rewritten on startup or /reload. A former global ON does not enable every model; Fast Mode posts a warning in the chat when that happens.

Footer

• Supported model, on: ⚡ FAST
• Supported model, off: dim fast
• Unsupported model: hide the status and do not mutate the request
• /fast and Ctrl+F update the footer only. They do not add a chat notification.

Supported providers

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

• OpenAI and Codex request priority when Fast Mode is on.
• Pi's built-in xAI models all use Responses and request priority when Fast Mode is on.
• Custom xAI Completions models in models.json remain supported.

Unsupported models hide the footer and leave the request unchanged.

Pricing and billing

Do not assume every model is granted priority.

• OpenAI Fast / priority is officially priced for the GPT-5.6 family. Older models may reject or ignore the request.
• On Responses models, Pi uses the returned service_tier for local usage.cost: priority is typically about 2×, while default stays at 1×.
• Custom xAI Completions models can request priority, but their local cost does not receive the Responses-specific adjustment.

Session lifetime

• /fast and Ctrl+F change the current model's in-memory switch only.
• Switching models follows that model's switch. First use reads its startup default, or off if it has none.
• /new, /resume, and /fork in the same Pi process keep each model's current switch.
• /reload or a process restart rereads per-model defaults from settings.json.
• /fast default on|off writes the current model's settings default and turns this session's switch to match.