MetaHarness × VSCode/Copilot mcp.json

A minimal scaffold that wires up GitHub Copilot in VSCode with MCP (Model Context Protocol) servers via mcp.json. This is for developers who already use Copilot Chat in VSCode and want to extend it with custom tools, file-system context, and MCP-backed integrations without hand-rolling configuration files. It does NOT ship a custom Copilot model, agent runtime, or replacement for Copilot Chat — it just generates the config layer that VSCode's Copilot reads on startup.

Quickstart

npx @metaharness/copilot@latest my-bot
cd my-bot && npm install && harness doctor

Then open my-bot/ in VSCode. Copilot Chat will detect mcp.json and offer to enable the configured servers on first launch.

What you get

• .vscode/mcp.json — Copilot-compatible MCP server registry with sensible defaults (filesystem, fetch, memory)
• .github/copilot-instructions.md — repo-scoped instructions Copilot Chat reads automatically
• harness.config.json — MetaHarness manifest declaring the host, template, and validation rules
• package.json with harness CLI wired up for doctor/validate/sync workflows
• agents/ directory with one starter agent definition and a README on how to add more
• .gitignore and .vscodeignore tuned for MCP server logs and local secrets

Advanced

Run the built-in health check after scaffolding to confirm Copilot can see the config:

$ harness doctor
[ok] VSCode detected (1.95.0+)
[ok] .vscode/mcp.json valid (3 servers declared)
[ok] copilot-instructions.md present
[ok] node >= 20

Validate your mcp.json against the Copilot schema before committing:

$ harness validate --strict
validating .vscode/mcp.json...
  servers.filesystem    ok
  servers.fetch         ok
  servers.memory        ok
all checks passed

Inspect the resolved config that Copilot will actually load (useful when diagnosing why a server is silently disabled):

$ harness sync --dry-run
would write: .vscode/mcp.json
would write: .github/copilot-instructions.md
no changes (config in sync)

FAQ

Q: Do I need a Copilot subscription for this? A: Yes — this scaffolds config for the Copilot Chat extension in VSCode, which requires an active GitHub Copilot subscription. The scaffold itself is free.

Q: Will this work with Copilot in JetBrains or Neovim? A: Not directly. The .vscode/mcp.json format is VSCode-specific. JetBrains uses a different MCP integration path; pick a different host template for that.

Q: Can I commit .vscode/mcp.json to a shared repo? A: Yes, and it's recommended for team consistency. Keep secrets out of it — use ${env:VAR} substitution and document the required env vars in copilot-instructions.md.

License

MIT. Built on metaharness (https://www.npmjs.com/package/metaharness).

Deep-dive

Full explainer gist: https://gist.github.com/ruvnet/532201b1e66c528df87857002a1c0ad9