Firebase Emulator Server

GitHub

A Model Context Protocol server that exposes Firebase emulator data — Firestore, Auth, Logs, and Realtime Database — to AI agents over stdio.

Designed for local development workflows where AI coding assistants (Claude Code, GitHub Copilot, etc.) need to inspect emulator state without leaving the editor.

Created by Laish Glenberg, please drop a star on the repo if this package helped you!

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Features

Tool	Description
emulator_status	Ping all emulators and report reachability
firestore_list_collections	List root-level collection IDs
firestore_query	Query documents with optional field filters (==, >=, <=, in, etc.)
firestore_get	Fetch a single document by path (e.g. Member/abc123)
rtdb_get	Read any path from the Realtime Database emulator
auth_list_users	List Firebase Auth users
auth_get_user	Look up a user by email or localId
emulator_logs	Stream recent log entries from the emulator hub WebSocket

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Prerequisites

• Node.js 18+ (native fetch and WebSocket — v21+ recommended)

• Firebase emulators running locally — start from your project root:

  firebase emulators:start
  

  The server connects to the default emulator ports:

  • Firestore: 8080
  • Auth: 9099
  • Realtime Database: 9000
  • Hub (logs): 4500

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Install & Run

Via npm (recommended)

npm install -g firebase-emulator-mcp
firebase-emulator-mcp

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VS Code / MCP Client Setup

Add to your project's .vscode/mcp.json or VS Code user settings:

{
  "servers": {
    "firebase-emulator": {
      "type": "stdio",
      "command": "node",
      "args": ["./mcp-server/lib/index.js"],
      "env": {
        "FIREBASE_PROJECT_ID": "<proj_id>",
        "FIREBASE_RTDB_NAMESPACE": "<proj_id>-default-rtdb"
      }
    }
  }
}

Or if installed globally:

{
  "servers": {
    "firebase-emulator": {
      "type": "stdio",
      "command": "firebase-emulator-mcp",
      "env": {
        "FIREBASE_PROJECT_ID": "<proj_id>",
        "FIREBASE_RTDB_NAMESPACE": "<proj_id>-default-rtdb"
      }
    }
  }
}

Optionally can skip install and run directly through npx

{
  "servers": {
    "firebase-emulator": {
      "type": "stdio",
      "command": "npx",
      "args": ["@lglen/firebase-emulator-mcp"],
      "env": {
        "FIREBASE_PROJECT_ID": "<proj_id>",
        "FIREBASE_RTDB_NAMESPACE": "<proj_id>-default-rtdb"
      }
    }
  }
}

For Claude Code or other MCP clients, use the same stdio configuration.

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Project structure

mcp-server/
├── src/
│   └── index.ts          # TypeScript source (all tools)
├── lib/                   # Compiled output (git-ignored)
├── test.mjs              # Smoke test runner
├── tsconfig.json
├── package.json
├── .gitignore
├── LICENSE               # MIT
└── README.md

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Configuration

Default emulator ports are defined in src/index.ts under the EMULATORS constant. Edit them to match your firebase.json if you use non-standard ports:

Service	Default Port
Firestore	8080
Auth	9099
Realtime DB	9000
Storage	9199
Emulator UI	4000
Hub (logs)	4500

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License

MIT

Author

Check me out on GitHub