GitHub Copilot

Use FastMetal models inside GitHub Copilot Chat in VS Code. Copilot's Custom Endpoint provider speaks the same OpenAI-compatible API as the FastMetal gateway, so no extra extension is needed.

Requirements

A GitHub Copilot subscription in VS Code and a FastMetal API key. On Copilot Business and Enterprise, your administrator must have the "Bring Your Own Language Model Key in VS Code" policy enabled.

1. Create an API key

Create or reveal a key on the API keys page. It is shown once, so paste it somewhere safe.

Open API keys

2. Add a Custom Endpoint provider

Run the command below from the Command Palette (Ctrl+Shift+P / Cmd+Shift+P), choose Add Models, then Custom Endpoint. Enter a group name such as FastMetal, paste your API key, and select Chat Completions as the API type.

Chat: Manage Language Models

3. List the models in chatLanguageModels.json

VS Code opens chatLanguageModels.json for the new provider. Add one entry per model you want in the picker. The URL is the same for every model; only the id changes.

[
  {
    "name": "FastMetal",
    "vendor": "customendpoint",
    "apiKey": "${input:fastmetalApiKey}",
    "apiType": "chat-completions",
    "models": [
      {
        "id": "deepseek-v4.1-flash",
        "name": "DeepSeek V4.1 Flash (FastMetal)",
        "url": "https://api.fastmetal.ai/v1/chat/completions",
        "toolCalling": true,
        "vision": true,
        "maxInputTokens": 1048576,
        "maxOutputTokens": 32768
      },
      {
        "id": "kimi-k3",
        "name": "Kimi K3 (FastMetal)",
        "url": "https://api.fastmetal.ai/v1/chat/completions",
        "toolCalling": true,
        "vision": true,
        "maxInputTokens": 1048576,
        "maxOutputTokens": 32768
      }
    ]
  }
]

idThe FastMetal model id, exactly as the gateway names it

urlThe gateway's chat endpoint, shared by every model

toolCallingWhether Copilot may use tools (agent mode) with this model

Model ids must match the gateway exactly

Take the id from the code sample on a model's page, or from the list below. A page URL is not the id: it swaps dots for dashes, so deepseek-v4-1-flash is rejected while deepseek-v4.1-flash works. Do not prefix it with a provider name.

List every id your key can use:

curl https://api.fastmetal.ai/v1/models \
  -H "Authorization: Bearer your-api-key"

4. Pick the model

Open the model picker in the Chat view and select a FastMetal model. Each request is billed to your key at the per-token price on the model's page and appears on your usage page.