ZenMux Provider Extension for pi

Adds a zenmux provider to pi as a pi package, as requested in badlogic/pi-mono#1811.

ZenMux speaks both the OpenAI Chat Completions and the Anthropic Messages protocol for the same catalog, so this extension only supplies endpoints, model metadata, and catalog discovery: requests are converted and streamed by pi's built-in API implementations.

Features

• Registers provider zenmux, API key env var ZENMUX_API_KEY
• Discovers the live catalog from https://zenmux.ai/api/v1/models at startup and through pi's refreshModels
• Keeps the last good catalog as a snapshot, so offline startups still list models
• Routes anthropic/* models to https://zenmux.ai/api/anthropic (anthropic-messages) and every other model to https://zenmux.ai/api/v1 (openai-completions)
• Registers chat models only: image, video, speech, transcription, embedding, and rerank models from the same catalog are skipped
• Maps tiered ZenMux pricing to pi's request-wide cost tiers, cache prices (5 minute, generic, 1 hour) to cost.cacheWrite, and prompt-cache TTLs to promptCache so pi can warm caches
• Fills in output limits and prices from the zenmux provider in models.dev for the catalog entries where ZenMux publishes none
• Takes the output cap from ZenMux's own per-endpoint catalog (/api/frontend/model/available/list), because models.dev reports the upstream vendor's limit, which differs on most models; the fetch is best-effort and falls back to models.dev, then to a built-in default

Install

pi install npm:pi-zenmux
pi install /absolute/path/to/pi-zenmux

Requires pi 0.87.1 or newer (@earendil-works/pi-coding-agent); the former @mariozechner/pi-coding-agent scope is deprecated.

Configure

export ZENMUX_API_KEY="sk-ai-v1-..."

Or store the key in ~/.pi/agent/auth.json:

{
  "zenmux": {
    "type": "api_key",
    "key": "sk-ai-v1-..."
  }
}

Use

pi --provider zenmux --model anthropic/claude-opus-5
pi --list-models zenmux

You can also start pi normally and switch with /model.

Optional endpoint override

export ZENMUX_BASE_URL="https://zenmux.ai"

The extension derives ${ZENMUX_BASE_URL}/api/v1, ${ZENMUX_BASE_URL}/api/anthropic, and the catalog URL ${ZENMUX_BASE_URL}/api/v1/models.

Related

ZenMux also publishes an OAuth PKCE plugin, @zenmux/pi-zenmux-oauth, which signs in through /login instead of an API key. Install only one of the two: both register the provider id zenmux.

Breaking changes in 0.3.0

• Requires pi 0.87.1+ and imports @earendil-works/pi-*
• The retired custom zenmux-router API and its streamSimple router are gone; models now carry their own api and baseUrl
• routeModel, asZenmuxRouterModels, streamSimpleZenmux, and ZENMUX_ROUTER_API are no longer exported; use routingFor for the routing rule
• Non-chat models are no longer registered

Publish

npm run check
npm login
npm publish --access public

Dev / Test

npm install
npm run typecheck
npm test