How to use Claude, Codex, and BYOK in GitHub Copilot for VS Code | GitHub Copilot Day
Tyler Leonhardt explains how to use different model “harnesses” in VS Code with GitHub Copilot, including Claude and Codex, and how bring-your-own-key (BYOK) changes the ways you can access models from your editor.
Overview
The session walks through how VS Code supports multiple agent harnesses and different model access methods, and how a single GitHub Copilot subscription can be used across these options.
BYOK (bring your own key)
- Introduces BYOK as an option for accessing models using your own provider credentials.
Agent choice in VS Code
- Covers the idea of choosing between different agent harnesses inside VS Code.
- Demonstrates the agents window in VS Code.
Demo: three harnesses, three providers
- Shows a plan to compare three harnesses and how each connects to different model providers.
- Highlights that each harness can bring its own prompts and tools into the workspace.
Adding models via OpenRouter
- Demonstrates adding models through OpenRouter.
Running Claude and Codex
- Shows running Claude using an Anthropic key.
- Shows signing into Codex using ChatGPT.
Subscription model
- Explains how one GitHub Copilot subscription can be used with all three harnesses.
What’s next
- Points to Agent Host Protocol as the next step in this area.