Pi Laya Model Router

A Pi extension that asks a local Laya server to classify each user task as low, medium, or high strength, then selects the model mapped to that level by the user.

The extension only chooses among your mappings. It does not proxy model traffic or handle provider credentials.

Install

Start the companion server from the repository root:

cd laya-server
uv venv .venv
uv pip install --python .venv/bin/python "laya==0.3.3"
.venv/bin/python server.py

Install the extension locally:

pi install ./laya-model-router

For a one-off run:

pi --no-extensions -e ./laya-model-router/extensions/laya-model-router.ts

Configure model mappings

Create ~/.pi/agent/laya-model-router.json:

{
  "mode": "initial",
  "levels": {
    "low": {
      "provider": "openai-codex",
      "model": "gpt-5.6-luna",
      "thinkingLevel": "off"
    },
    "medium": {
      "provider": "openai-codex",
      "model": "gpt-5.6-luna",
      "thinkingLevel": "xhigh"
    },
    "high": {
      "provider": "openai-codex",
      "model": "gpt-5.6-sol",
      "thinkingLevel": "medium"
    }
  }
}

A trusted project can override individual levels in .pi/laya-model-router.json. Targets must already be available to Pi and authenticated. thinkingLevel is optional.

Routing modes:

• initial (default) — classify the first prompt in a session, then keep that model for the rest of the session.
• every — classify every new prompt and switch models as needed.

You can also select the mode for a run with PI_LAYA_ROUTER_MODE=initial or PI_LAYA_ROUTER_MODE=every. The environment variable takes precedence over the config file. On resumed sessions, initial mode does not route again if the session already contains a user message.

The levels mean:

• low — simple, well-specified, low-risk tasks
• medium — multi-step tasks requiring normal reasoning
• high — ambiguous, architectural, security-sensitive, or otherwise demanding tasks

Run /laya-router to inspect the active mappings. The footer shows the most recently selected level and model.

Routing fails open: if Laya is unavailable, a level is unmapped, or its target cannot be used, Pi keeps the current model and displays a warning.

Environment

| Variable | Default | Purpose | |---|---|---| | PI_LAYA_SOCKET | /tmp/pi-laya-guardrails.sock | Shared Laya server Unix socket | | PI_LAYA_TIMEOUT_MS | 2000 | Routing request timeout | | PI_LAYA_ROUTER_MODE | config or initial | initial or every |

Tests

npm test