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GitHub Copilot App Integration

Use any tool-calling model in GitHub's Copilot desktop app through LLM Gateway. One BYOK provider, full cost tracking.

The GitHub Copilot app is GitHub's desktop app for agent-driven development — start agent sessions from issues, pull requests, or prompts, run parallel workflows in isolated workspaces, and merge PRs without leaving the app. It supports bring your own key (BYOK), so you can run agent sessions against your own model provider.

Add LLM Gateway as that provider and every session can use Claude, Gemini, GPT, or any model in the catalog that supports tool calling — with full cost visibility in your dashboard.

One provider entry. No config files. Works on any Copilot plan, or with no Copilot plan at all.

Using DevPass? This integration also works with a DevPass plan key. Use root model IDs without a provider prefix (claude-sonnet-4-5, not anthropic/claude-sonnet-4-5) — provider-pinned routing is not available on coding plans; the gateway picks the provider for you.

Quick Start

1. Install the GitHub Copilot app from github.com/features/ai/github-app (macOS, Windows, or Linux) and sign in with your GitHub account.

2. Get your LLM Gateway API key — sign up free and copy your key (starts with llmgtwy_) from the dashboard.

3. Add LLM Gateway as a model provider in the app:

  1. Open Settings → Model Providers
  2. Select Add provider and choose the OpenAI-compatible provider type
  3. Set the Base URL to:
1https://api.llmgateway.io/v1
  1. Paste your LLM Gateway API key and save

4. Pick a model. LLM Gateway's models now appear in the model picker alongside Copilot-hosted models. Choose one when you start a session — each session can use a different model.

Why This Works

LLM Gateway's /v1 endpoint is fully OpenAI-compatible. The Copilot app fetches the model list from the gateway and routes each agent session through it, and we route requests to the right provider behind the scenes. This means:

  • Use any tool-calling model — Claude, Gemini, GPT, and the rest of the catalog in Copilot agent sessions
  • Keep your workflow — sessions, workspaces, and PR merging work exactly the same
  • Track costs — every request appears in your LLM Gateway dashboard
  • Automatic caching — repeated requests hit cache, saving money

Choosing Models

All models available to your account show up in the app's model picker; agent sessions work with models that support tool calling and streaming. Browse the models page to compare capabilities and pricing, or check discounted models for savings up to 90%.

Good to Know

  • Keys stay local — the app stores your API key in the OS keychain and never reads it back into the UI.
  • Any plan works — BYOK providers work on every Copilot plan, including Free. You don't need a paid Copilot subscription to run agent sessions through LLM Gateway.
  • Business and Enterprise — adding model providers is gated by the Enable custom models (BYOK) policy, which your admin must turn on. Accessing the Copilot app itself also requires the Copilot CLI enabled in policy settings.
  • Agent sessions only — BYOK covers the app's model-powered agent sessions. Inline code completions in your editor still use Copilot's own service.

GitHub Copilot in VS Code

Copilot Chat in VS Code supports custom endpoints too. Run Chat: Manage Language Models from the Command Palette, choose Add Models → Custom Endpoint, enter your LLM Gateway API key, and select Chat Completions as the API type (LLM Gateway is OpenAI-compatible). Then point the model url at https://api.llmgateway.io/v1/chat/completions in the generated chatLanguageModels.json. Your gateway models then appear in the VS Code chat model picker.

Troubleshooting

Models don't appear in the picker

  1. Verify the Base URL is exactly https://api.llmgateway.io/v1 (note the /v1 at the end)
  2. Check your API key starts with llmgtwy_ and is active in your dashboard

401 Unauthorized

Your API key is invalid or was revoked. Generate a new key in the dashboard and update the provider entry in Settings → Model Providers.

402 or credit errors

Your LLM Gateway organization is out of credits. Top up in the dashboard — BYOK sessions bill through LLM Gateway, not Copilot premium requests.

Provider option is missing

BYOK in the Copilot app shipped in June 2026 — update to the latest app version. On Business or Enterprise plans, ask your admin to enable the Enable custom models (BYOK) policy — and the Copilot CLI policy if you can't access the app at all.

Get Started

  1. Sign up free — no credit card required
  2. Copy your API key from the dashboard
  3. Install the GitHub Copilot app and sign in
  4. Add LLM Gateway under Settings → Model Providers with the base URL above
  5. Start an agent session with any model

Questions? Check our docs or join Discord.