# pi-vertex-ai-provider

Pi package/extension that makes Pi's built-in `google-vertex` provider use **Vertex AI Application Default Credentials (ADC)** instead of an API key, plus registers `gemini-3.5-flash` until Pi ships it built-in.

## Why extension, not a new provider?

Pi already ships an official `google-vertex` provider and model serializer for Gemini on Vertex AI, including streaming, tools/function calling, multimodal input, usage accounting, and thinking controls. This package keeps those built-in models, overrides provider auth/config so the official provider runs with Google Cloud ADC, and appends `gemini-3.5-flash`.

## Setup

```bash
# 1) Install/login Google Cloud CLI
 gcloud auth login
 gcloud auth application-default login

# 2) Select project and optional location
 gcloud config set project YOUR_PROJECT_ID
 # Optional; defaults to global
 set GOOGLE_CLOUD_LOCATION=global
```

You can also configure without changing gcloud defaults:

```bash
set PI_VERTEX_AI_PROJECT=YOUR_PROJECT_ID
set PI_VERTEX_AI_LOCATION=global
```

## Use with Pi

Install from npm:

```bash
pi install npm:pi-vertex-ai-provider
```

Or from GitHub:

```bash
pi install git:github.com/AlyusLabs/pi-vertex-ai-provider
```

For local development from this repo:

```bash
pi -e .
```

Then select a Vertex model such as:

```text
google-vertex/gemini-3.5-flash
google-vertex/gemini-3-pro-preview
google-vertex/gemini-2.5-pro
google-vertex/gemini-2.5-flash
```

`gemini-3.5-flash` is registered with a 1,048,576-token context window, 65,536 max output tokens, thinking enabled, and base-tier Vertex pricing in Pi's usage display.

## Check status

Inside Pi:

```text
/vertex-ai-status
```

## Environment variables

- `PI_VERTEX_AI_PROJECT` - preferred project override.
- `PI_VERTEX_AI_LOCATION` - preferred location override; defaults to `global`.
- `PI_VERTEX_AI_FORCE_ADC=0` - do **not** force-disable `GOOGLE_CLOUD_API_KEY`.

By default, the extension sets Pi's Vertex API-key marker (`gcp-vertex-credentials`) so Pi uses ADC/gcloud credentials, not API keys.