VS Code + Copilot

• VS Code with GitHub Copilot Chat (agent / MCP capable).
• Node.js 20+ on PATH (node -v).
• Fat Heron key from app.fatheron.dev/keys — start with fh_test_.
• Built MCP binary: clone this monorepo, then npm install && npm run build -w @fat-heron/mcp.

Copy the example from the repo (packages/mcp/examples/vscode-mcp.json or .vscode/mcp.json.example) to .vscode/mcp.json:

{
  "inputs": [
    {
      "type": "promptString",
      "id": "fh-api-key",
      "description": "Fat Heron API key (fh_test_… or fh_live_…)",
      "password": true
    }
  ],
  "servers": {
    "fat-heron": {
      "type": "stdio",
      "command": "node",
      "args": ["${workspaceFolder}/packages/mcp/dist/stdio.js"],
      "env": {
        "FH_API_KEY": "${input:fh-api-key}",
        "FH_API_URL": "https://api.fatheron.dev"
      }
    }
  }
}

Outside the monorepo, point args at an absolute path to stdio.js (or VM path /opt/fatheron/packages/mcp/dist/stdio.js).

1. Command Palette → MCP: List Servers (or open the MCP view).
2. Start fat-heron. When prompted, paste your fh_test_ / fh_live_ key.
3. Status should show running / connected — not errored.

Copilot instructions for this workspace live in .github/copilot-instructions.md (committed in the monorepo).

In Copilot Chat (Agent mode), ask:

Using Fat Heron MCP:
1) Call sandbox_status
2) Create a project named "VS Code Verify" (expect sb- slug on fh_test_)
3) Summarize dry_run / sandbox fields

Pass criteria:

• sandbox_mode: true when using fh_test_
• Project id/slug namespaced (bprj-sb- / sb-) under test keys
• No secret echoed back into the chat transcript

Domainers path: use check_alias then skip live claim under test, or claim only with a live key after review. Recipe index: /docs/agents.

• FH_API_KEY is required

  Restart the MCP server and complete the input prompt.

• Cannot find module …/stdio.js

  Run npm run build -w @fat-heron/mcp or fix the absolute path.

• mcpServers ignored

  VS Code needs root key servers (Cursor/Claude use mcpServers).

• Tools missing in chat

  Enable Agent mode / MCP tools in Copilot Chat; reload window.