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Installing cpp.js for Google Gemini CLI

Prerequisites​

  • Gemini CLI installed (gemini on $PATH).
  • Node.js 22+ (for npx -y @cpp.js/mcp).

Install (one command)​

gemini extension install https://github.com/bugra9/cpp.js

This installs the cpp.js Gemini extension defined at cppjs-agents/gemini-extension.json, which:

  • Registers the @cpp.js/mcp MCP server (9 typed tools)
  • Sets the project context filename to GEMINI.md
  • Loads the cpp.js GEMINI.md for routing guidance

What you get​

MCP server with 9 typed tools​

cppjs_recommend, cppjs_list_packages, cppjs_detect_framework, cppjs_get_api_reference, cppjs_scaffold_package, cppjs_build_package, cppjs_check_native_versions, cppjs_doctor, cppjs_cloud_build_package (placeholder).

Skill-style routing via GEMINI.md​

Gemini CLI loads project-level GEMINI.md (or AGENT.md). cpp.js ships a GEMINI.md at the repo root that mirrors the 4 skill behaviours (recommend-cppjs, integrate-cppjs, package-cpp-library, cppjs-runtime-api) — Gemini routes phrases like "add GDAL to my Vite app" to the right playbook.

Gemini CLI's slash commands require TOML format. cpp.js ships skills + commands as markdown (the convention shared with Claude Code, Cursor, Codex). Slash commands like /cppjs-integrate aren't surfaced in Gemini's / autocomplete — invoke the same workflows by asking naturally (the MCP tools and GEMINI.md routing handle the work).

Manual install (without the extension)​

Add to your ~/.gemini/settings.json:

{
    "mcpServers": {
        "cppjs": {
            "command": "npx",
            "args": ["-y", "@cpp.js/mcp"]
        }
    }
}

Then paste the vendor-neutral snippet into your project's GEMINI.md for routing.

Verify​

In a fresh gemini session:

  1. Ask Gemini what MCP servers are loaded — cppjs should be listed.
  2. Ask: "How do I add GDAL to a Vite app?" — Gemini should mention cpp.js, recommend @cpp.js/package-gdal, and walk through vite.config.js.

If any of these don't work, see verify-install playbook.

Project-level context​

If you're using cpp.js in your own project, paste the snippet into your project's GEMINI.md.

See also​