Chat Model Provider Sample

This VS Code extension demonstrates how to implement a custom chat model provider using the Language Model (LM) API. It serves as a sample implementation for developers who want to integrate their own AI models with VS Code's chat functionality.

Features

This extension provides:

• Custom Chat Model Provider: Implements the LanguageModelChatProvider2 interface to register custom AI models
• Multiple Model Support: Demonstrates how to provide multiple models from a single provider
• Sample Models: Includes two example models:
  • Dog Model: Responds with dog-themed messages ("Woof!")
  • Cat Model: Responds with cat-themed messages ("Meow!")

Architecture

The extension consists of two main components:

Extension Activation (src/extension.ts)

• Registers the sample chat model provider with VS Code's LM API
• Uses the vendor ID "sample" to identify the provider

Chat Model Provider (src/provider.ts)

• Implements LanguageModelChatProvider2 interface
• Provides model information including capabilities (tool calling, vision support)
• Handles chat requests and returns appropriate responses
• Includes token counting functionality

Model Capabilities

Each sample model declares the following capabilities:

• Tool Calling: ✅ Enabled
• Vision: ✅ Enabled
• Max Input Tokens: 120,000
• Max Output Tokens: 8,192

Getting Started

Prerequisites

• VS Code version 1.103.0 or higher
• Node.js and npm installed

Installation and Development

1. Clone this repository
2. Navigate to the extension directory:

   cd chat-model-provider-sample
   

3. Install dependencies:

   npm install
   

4. Compile the extension:

   npm run compile
   

5. Press F5 to launch a new Extension Development Host window
6. The extension will be active and ready to provide chat models

Building and Watching

• Build once: npm run compile
• Watch mode: npm run watch (automatically recompiles on file changes)
• Lint code: npm run lint

Usage

Once the extension is active:

1. Open VS Code's chat interface
2. Click the model picker and click manage models
3. Select the sample provider
4. Check the models based on what you want in the model picker
5. Send a request to the model

API Usage

This extension uses the proposed chatProvider API. The key components include:

• vscode.lm.registerChatModelProvider() - Registers the provider
• LanguageModelChatProvider2 interface - Defines the provider contract
• LanguageModelChatInformation - Describes model capabilities
• ChatResponseFragment2 - Handles streaming responses

Customization

To create your own chat model provider:

1. Modify the SampleChatModelProvider class in src/provider.ts
2. Update the model information in getChatModelInfo()
3. Implement your custom logic in provideLanguageModelChatResponse()
4. Adjust the vendor ID and model IDs as needed
5. Update the package.json with your extension details

Related

• VS Code Extension API
• Language Model API Documentation
• VS Code Extension Samples