Pi Chutes Extension

A pi coding agent extension that provides access to models from Chutes.ai, a platform offering various open and proprietary LLM models via an OpenAI-compatible API.

Features

• Automatic Model Discovery: Fetches the latest models from Chutes.ai on every startup
• Offline Fallback: Uses cached models from previous fetch if API is unreachable
• Multiple Input Types: Supports both text-only and vision (text + image) models
• Reasoning Detection: Automatically identifies models with reasoning capabilities
• Cost Tracking: Preserves pricing information from the API
• Secure API Key Storage: Stores keys as api_key type with atomic writes and rollback

Installation

Option 1: npm (recommended)

pi install npm:pi-chutes

Then restart pi.

Option 2: Git

pi install git:github.com/mark182es/pi-chutes

Then restart pi.

Option 3: Manual

1. Create the directory:

   mkdir -p ~/.pi/agent/extensions/pi-chutes
   

2. Copy or create the index.ts file in that directory

Quick Start

After the extension is loaded:

# 1. Login with your API key (select Chutes.ai from the list)
/login

# 2. Select a model
/model chutes

That's it. Models are fetched automatically on every pi startup.

Usage

Login

Use the standard /login command to authenticate:

/login

Select Chutes.ai from the provider list and enter your API key when prompted (format: cpk_...). The key will be:

1. Validated for correct format
2. Verified against the Chutes API
3. Saved securely to ~/.pi/agent/auth.json

To logout and clear credentials:

/logout chutes

Model Selection

Use the /model command to select a chutes model:

/model chutes

This will show all available chutes models in the model selector.

Automatic Model Updates

Models are fetched automatically from the Chutes API every time pi starts. No manual update command is needed. If the API is unreachable, cached models from the previous fetch are used instead.

The model cache is stored at ~/.pi/agent/extensions/pi-chutes/models.json.

Configuration

Option 1: Using /login (Recommended)

/login

Select Chutes.ai from the provider list and enter your API key. This integrates with pi's built-in authentication system.

Option 2: Environment Variable

Variable	Description
CHUTES_API_KEY	Your API key for chutes.ai

export CHUTES_API_KEY=cpk_...

Option 3: Auth File

Manually add your API key to ~/.pi/agent/auth.json:

{
  "chutes": { "type": "api_key", "key": "cpk_..." }
}

Model Properties

The extension automatically converts these properties from the Chutes API:

API Field	Model Property	Description
id	id	Model identifier
id	name	Display name
supported_features includes "reasoning"	reasoning	Supports extended thinking
input_modalities	input	["text"] or ["text", "image"]
pricing.prompt	cost.input	Input cost per 1M tokens
pricing.completion	cost.output	Output cost per 1M tokens
pricing.input_cache_read	cost.cacheRead	Cache read cost per 1M tokens
context_length / max_model_len	contextWindow	Context window size
max_output_length	maxTokens	Maximum output tokens

Files

• index.ts — Main extension code
• ~/.pi/agent/extensions/pi-chutes/models.json — Cached models (auto-created)

Troubleshooting

"API key contains invalid characters" error

Make sure you're entering your full API key including dots (e.g., cpk_xxx.yyy.zzz). The key format uses dot-separated segments.

"API key is invalid or unauthorized" error

• Verify your API key is correct and active at chutes.ai
• Make sure the key hasn't been revoked
• Try logging in again with /login

Models not appearing

• Models are fetched automatically on startup — just restart pi
• If offline, cached models from the last successful fetch are used
• Check your internet connection if models seem outdated

Startup is slow

The extension fetches models from the Chutes API on startup. If the API is slow to respond, pi will take a moment longer to start. The fetched models are cached, so offline startups use the cache instantly.

Migrating from a previous version

If you previously used an older version of this extension that stored credentials in OAuth format, they will be automatically migrated to the proper api_key format on startup. No action needed.

Security

API Key Validation

• API keys are validated for length (16-512 characters)
• Only alphanumeric characters, dots, hyphens, and underscores are allowed (matching Chutes.ai key format: cpk_<hex>.<hex>.<base64>)
• Invalid keys are rejected before saving

API Key Verification

• The /login flow verifies your API key against the Chutes API before accepting it
• This prevents storing invalid keys that would fail at runtime

Secure Credential Storage

• API keys are stored as type: "api_key" in auth.json (not as OAuth credentials)
• Credentials are written to a temporary file first, then atomically renamed
• File permissions are set to 0600 (owner read/write only)
• Write failures include automatic rollback to prevent corrupted auth files

Automatic Migration

• Legacy OAuth-type credentials are automatically converted to api_key format on startup

Model Data Validation

• All model data from the API is validated before registration
• Invalid or malformed models are filtered out

License

This extension is provided as-is for use with pi coding agent.