@metaharness/host-copilot

GitHub Copilot (VSCode) host adapter for agent-harness-generator. The 7th host adapter, per ADR-032.

What it does

Generates the config files a harness needs to run inside GitHub Copilot Chat on VSCode 1.99+. The adapter emits:

• .vscode/mcp.json — the MCP server registration table Copilot reads to discover the harness's tools
• install.md — the runbook that walks the user through the one-time workspace-trust gate VSCode requires before .vscode/mcp.json loads

Schema

VSCode 1.99 reads two keys: the newer servers (top-level) and the Claude-Code-compatible mcpServers. This adapter emits both for forward + backward compatibility.

{
  "servers": {
    "codeindex": {
      "command": "node",
      "args": ["./dist/mcp-server.js"],
      "env": { "LOG_LEVEL": "info" }
    },
    "remote": {
      "url": "https://example.com/mcp"
    }
  },
  "mcpServers": { "...": "(same map, for older runtimes)" }
}

Each server entry must have either command (stdio) OR url (HTTP streamable). The package's test contract enforces this.

Constraints

• VSCode 1.99+ — earlier versions don't have first-class MCP support
• Active Copilot subscription required
• Workspace trust gate — VSCode refuses to load .vscode/mcp.json until the user trusts the workspace once. The adapter ships install.md walking through this.

Install + run

This adapter is normally consumed via npx metaharness <name> --host copilot, which picks it up from the canonical HOSTS catalog. Direct programmatic use:

import { adapter } from '@metaharness/host-copilot';
const files = adapter.generateConfig!(harnessSpec);
// files === { '.vscode/mcp.json': '...', 'install.md': '...' }

License

MIT — see LICENSE.