VS Code

VS Code uses MCP servers in GitHub Copilot’s agent mode. Add OnlyX with the install link or one command, then sign in.

One click

Add to VS Code

Opens VS Code’s install prompt for the OnlyX server.

Add to VS Code Insiders

The same, for the Insiders build.

The button uses VS Code’s MCP install link, whose query is the URL-encoded server configuration {"name":"onlyx","type":"http","url":"https://mcp.onlyx.ai/mcp"}:

vscode:mcp/install?%7B%22name%22%3A%22onlyx%22%2C%22type%22%3A%22http%22%2C%22url%22%3A%22https%3A%2F%2Fmcp.onlyx.ai%2Fmcp%22%7D

If your browser does not open VS Code, this web link redirects to the same install prompt:

https://vscode.dev/redirect/mcp/install?name=onlyx&config=%7B%22type%22%3A%22http%22%2C%22url%22%3A%22https%3A%2F%2Fmcp.onlyx.ai%2Fmcp%22%7D

One command

With the code command on your path:

code --add-mcp '{"name":"onlyx","type":"http","url":"https://mcp.onlyx.ai/mcp"}'

This adds OnlyX to your user profile, so it is available in every workspace.

Start the server

Open the Copilot Chat view, switch to Agent mode, and open the tools picker. OnlyX appears in the list. The first time it starts, VS Code asks whether to allow OnlyX to sign in.

Click Allow. Your browser opens OnlyX: sign in, choose the workspace, and click Approve. VS Code registers itself automatically; you do not need a client ID.

Ask

“Using OnlyX, which workspace am I connected to?” Copilot asks before running tools that change something.

Configure by hand

Run MCP: Open User Configuration from the command palette (or create .vscode/mcp.json in a workspace) and add:

OAuth
API key

mcp.json

{
  "servers": {
    "onlyx": {
      "type": "http",
      "url": "https://mcp.onlyx.ai/mcp"
    }
  }
}

VS Code prompts for the key once and stores it securely, so it never sits in the file:

mcp.json

{
  "inputs": [
    {
      "type": "promptString",
      "id": "onlyx-key",
      "description": "OnlyX API key (onx_sk_...)",
      "password": true
    }
  ],
  "servers": {
    "onlyx": {
      "type": "http",
      "url": "https://mcp.onlyx.ai/mcp",
      "headers": {
        "Authorization": "Bearer ${input:onlyx-key}"
      }
    }
  }
}

Use a Read only key if Copilot should only read.

Troubleshooting

Problem	Fix
The button does nothing	VS Code is not installed or the browser blocked `vscode:` links. Use the `vscode.dev/redirect` link or the `code --add-mcp` command.
OnlyX does not appear in the tools picker	Make sure Copilot Chat is in Agent mode, and check MCP: List Servers for errors.
Signed in to the wrong workspace	Run Authentication: Remove Dynamic Authentication Providers, remove OnlyX, then start the server again and sign in. Or revoke the connection in OnlyX under Settings → API & MCP → Connected apps.
”Unauthorized” with an API key	The key is wrong, revoked or expired. Remove the stored input value and enter a new key.

Using OnlyX with Claude and other assistants: recipes.
Tools: the full tool list.

MCP server

Connect your assistant

Reference

One click

Add to VS Code

Add to VS Code Insiders

One command

Configure by hand

Troubleshooting

Next

​One click

Add to VS Code

Add to VS Code Insiders

​One command

​Sign in and use it

​Configure by hand

​Troubleshooting

​Next

One click

One command

Sign in and use it

Configure by hand

Troubleshooting

Next