How to use Claude, Codex, and BYOK in GitHub Copilot for VS Code | GitHub Copilot Day

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Original language: English

Original video: How to use Claude, Codex, and BYOK in GitHub Copilot for VS Code | GitHub Copilot Day · Channel: GitHub · 08:17 · Watch on YouTube

Topics: AI agents, AI developer tools

Summary

Tyler Leanhart demonstrates how VS Code supports multiple agent harnesses and bring-your-own-key (BYOK) model access in one interface. He configures the Copilot harness with an OpenRouter API key, the Claude agent with an Anthropic API key, and the Codex agent with a ChatGPT subscription. He also shows that a Copilot subscription can provide access to these harnesses from within VS Code. The talk closes by noting that Claude and Codex are supported third-party harnesses and that other options may be considered.

Key points

BYOK lets users connect models through their own provider keys, use existing compute, or bring in locally run models.
VS Code offers a choice of agent harnesses, including Copilot, Claude, and Codex.
The Agents window provides a top-level view of agent and chat sessions.
The Copilot harness can use models added through OpenRouter.
The Claude agent can be configured with an Anthropic API key.
The Codex agent can be accessed by signing in with a ChatGPT subscription.
Each harness brings its own prompts and tools, so agents may function differently.
A Copilot subscription can provide access to the supported harnesses within VS Code.
Claude and Codex are described as supported third-party harnesses, with potential expansion under consideration.

Chapters

Start	Chapter	Summary
00:05	BYOK and agent choice in VS Code	Leanhart introduces BYOK and explains that VS Code lets users choose among Copilot, Claude, and Codex harnesses.
01:50	Setting up models and the Copilot harness	He opens the Agents window and adds models using an OpenRouter API key for the Copilot harness.
04:03	Trying Claude and Codex	He switches to Claude using an Anthropic API key, then signs in to Codex with a ChatGPT subscription.
05:39	Copilot subscription and recap	He demonstrates using a Copilot subscription across the harnesses, recaps the setup options, and mentions the Agent Host Protocol and possible future harnesses.

Quotes

We also support BY and that means bring your own key. — 00:38

you have one UI, one place uh, to interact with those agents, and that’s VS Code. — 01:13

they all bring their own prompts and they bring their own tools as well. — 03:29

you could keep it simple and just use a copilot subscription which would give you access to all of those all from within VS Code. — 07:17

Concepts and entities

BYOK, agent harness, VS Code, GitHub Copilot, Claude, Codex, OpenRouter, Anthropic, ChatGPT, Agent Host Protocol, Tyler Leanhart, Patrick

Full transcript (original language)

00:05 Hi, I’m Tyler Leanhart. You may remember me from uh my oneliner in the VS Code documentary and also my college submission to a film festival. I’m going to be talking to you about BY and multi-agent harness in VS Code. So, what does that even mean? Uh well, it’s basically two kinds of freedom, right? Copilot as you know already provides multi- uh models models from uh various different vendors openai anthropic etc. Uh but uh you don’t have to get your

00:38 models directly from a co-pilot subscription. We also support BY and that means bring your own key. So that means using the compute that you already have or if you’re working inside of a private or air gap network uh that also works or if you run uh models locally on your machine you can al also bring those in to the co-pilot uh agent harness uh but that’s not the only bit of flexibility that we have in VS Code and the copilot agent uh in VS Code itself you have uh you have an agent choice as well. So, we have Co-Pilot as our as our

01:13 default agent. Uh, we think it’s pretty great. Uh, but if you also want to try out some other harnesses, we’ve got Claude and Codeex available for you to try out. Uh, so you can keep using the tools that feel natural to you. Uh, and you have one UI, one place uh, to interact with those agents, and that’s VS Code. So, what does any of that mean? I feel like I just need to show you a demo. And so, let me tell you what I’m going to show you. So, we’ve got three different harnesses. We got C-Pilot, Claude and Codeex. And I want to show you uh BY stuff uh and also like how these things uh can be integrated with

01:50 with not only Copilot as the model provider but other providers as well. So C-pilot uh copilot harness is going to use BY uh via open router. So I’m going to provide an open router API key and we’ll get models from that and use that in the co-pilot harness. Our claude agent is going to use anthropic uh an anthropic API key. Um, and then the codeex uh agent harness is going to actually have a chachi PT sign in. In other words, a chachi PT subscription to use uh in the C codeex in the codeex agent inside of VS Code. Uh, so that’s a

02:24 lot, but I’ve got six minutes to do it. And so, let’s just go ahead and get started. I’m going to hit hit uh click to get that going. All right. So, VS Code, you know it, I know it, I love it. Uh I’m going to do this demo from inside of the agents window which you can get at the very top of the editor window. We can open agents window. This is our like kind of uh top level view of all of your agent sessions, your chat sessions. Uh when you get here, you can see that I’m not actually signed in with GitHub or a C-pilot subscription today. Um and I

02:59 need to add models. Now I could sign in and get my co-pilot subscription, but that’s not what this talk is about yet. I want to actually add models through a different mechanism. So I’m going to add models and I’m going to go to open router and I’m going to tab over copy my open router API key JK and put that here. And you can see that brings in just a ton of models here. Right, great. So uh we’re going to hide all of those because I really don’t want to be overwhelmed with how many models they have. And then we’re going

03:29 to add uh we’ll just have highQ there. Okay, sound good. Uh so from there I can go to the model picker in the agent harness uh in the agents window here and I can say uh what kind of uh who are you and what tools do you have? Now what’s important to note is that like the copilot agent, the claude agent and the codeex agent, they all bring their own prompts and they bring their own tools as well. So uh they’re going to function differently. Uh, but that is

04:03 the beauty of being able to try all of them right within VS Code. So, this one says, “Hey, I’m the co-pilot SDK uh in VS Code.” Great. So, I’m going to make a new chat. Hit the agent harness drop down here and pick Claude. Uh, now I’ve already hooked up a Claude API key uh this way. And you can see uh in my claude settings file here, I’m using uh this API key helper here so I don’t uh leak my anthropic API key. Uh and so then I’m going to ask Claude the same

04:35 question as before again using Haiku because I only got six minutes to go through this demo. And you can see that Claude says that it’s Claude obviously and uh and tools that it has. Uh and then finally, I wanted to show you codeex as well. Uh so when you pick codeex you’ve got the option of course to sign into GitHub. We’ll cover that in a second. Uh but you can sign in with your chatpt subscription as well. So I will uh go ahead and pick uh my chatpt subscription here. It’s a it’s a free subscription, right? The the one that like so many people have uh and I’m going to go to my phone in order to get

05:06 a code uh because that’s the only way to log into things these days. Uh great. Cool. So now we’re signed into codeex and uh I can say the same prompt to uh to Luna here and we see that we have the the codeex uh harness as well. And so I’m signed in with my chatbt uh free skew. So last thing I wanted to show here is that I can also sign into my co-pilot

05:39 subscription. So I’ll go ahead and do that hopefully without having to uh put in a bunch of random stuff. Um, great. So fast. We love to see it. And uh, with this, I’m now signing with my co-pilot subscription. And one of the benefits of the co-pilot subscription is that I can actually like I can interact with all of these harnesses through my co-pilot subscription. So, I get access to everything. Uh I can say hi here now using uh

06:12 using Luna from my co-pilot subscription and also you can see there’s a section for uh co-pilot here uh in claude and also in of course uh copilot right so I can use all of these harnesses with a co-pilot subscription and that’s uh one thing that I think is really powerful about a copilot subscription is that you can you can actually play with all of these harnesses uh without having to uh have multiple subscriptions across different um different places. So, uh

06:44 all right. Well, okay. Hey, that that was actually uh not so bad all things considered with the with text messages and whatnot. So, just to recap what you what you just saw in that demo, the co-pilot harness, I first added an open router API key uh showing that we have by uh support in the co-pilot harness. Then in the cloud agent we added uh an anthropic API key and used uh anthropic uh API key compute through the cloud agent. And in the codeex agent we added

07:17 uh chatpt subscription to sign in and use the codeex agent. Now of course you can configure all three of those agents with their own subscriptions and their own ways of getting models or you could keep it simple and just use a copilot subscription which would give you access to all of those all from within VS Code. So, uh, that is my biggest takeaway in all of this. Uh, go forth and go play, uh, and have fun with, uh, with these different, uh, agents. Uh, they’re all powered by something called, uh, agent host protocol, which my friend Patrick

07:47 is going to tell you about in a little bit. Uh, but, uh, yeah, Claude and Codeex are a couple of harnesses we support today. Uh, we’re thinking about expanding those to to harnesses beyond those uh, those two uh, third party harnesses. But uh but yeah, take a look at this space. It’s it’s really fun, really cool. Uh and yeah, that’s uh that’s actually uh all I have to to say. Um my demo actually was a lot faster than before. So um sweet.

08:17 I guess I will just pass it on over to the next segment, which is a very cool video. Just you wait.