algorembrant/agent-bridge

Agent Bridge

A TypeScript framework for bridging a web application to the Google Antigravity CLI. Single-page interface with MCP-like tool system and real-time agent communication.

Architecture

Browser (Single Page)  <--WebSocket-->  Node/Express Server  <--child_process-->  Antigravity CLI
                                               |
                                          Tool Registry
                                         (MCP-like system)

Quick Start

cd c:\Users\User\Desktop\debugrem\agent-bridge
npm install
npm start
# Open http://localhost:3777

Project Structure

agent-bridge/
  server/
    index.ts            Entry point (Express + Socket.IO)
    bridge.ts           Unified WebSocket event hub
    toolRegistry.ts     Typed MCP-like tool system
    cliDetector.ts      Real multi-strategy CLI auto-detection
    tools/
      transcript.ts     YouTube URL to transcript (yt-dlp + API fallback)
  client/
    index.html          Single-page app
    src/
      style.css         Light theme, dot-grid canvas, Google aesthetic
      main.js           WebSocket, chat UI, tool rail, suggestion chips
  output/               Generated files
  tsconfig.json
  package.json

CLI Auto-Detection

The server automatically searches for the Antigravity CLI using 5 strategies:

Priority	Method	Location
1	Environment variable	ANTIGRAVITY_CLI_PATH
2	System PATH	where antigravity / which antigravity
3	Common install paths	AppData, Program Files, ~/.local/bin
4	npm globals	npm root -g parent directory
5	Bare execution	Direct antigravity --version probe

No mock status. The detection result is real -- if it says "not detected", the CLI is genuinely not found.

Configuration

Variable	Default	Description
PORT	3777	Server port
ANTIGRAVITY_CLI_PATH	antigravity	Override CLI binary path

Tool System

Drop a .ts file in server/tools/ with a register(registry) export. The server auto-loads it on startup.

import type { ToolRegistry } from '../toolRegistry';

export function register(registry: ToolRegistry): void {
  registry.register({
    name: 'my_tool',
    description: 'Does something useful',
    syntax: 'use <my_tool> <param>',
    pattern: /use\s+<my_tool>\s+(?<param>.+)/i,
    mock: false,
    async execute(params, emitProgress) {
      emitProgress('Working...');
      return { message: 'Done' };
    },
  });
}

WebSocket Events

Event	Direction	Description
bridge:init	Server -> Client	Initial state (tools, CLI status)
prompt:send	Client -> Server	User sends a message
tool:started/progress/completed/error	Server -> All	Tool lifecycle
tool:list	Client -> Server	Query tools (callback)
tool:invoke	Client -> Server	Invoke a tool (callback)
agent:message	Bidirectional	Agent communication
cli:stdout/stderr/done	Server -> All	CLI output streaming

Usage Example

Type in the chatbox:

use <transcript_tool> https://www.youtube.com/watch?v=y8KofLWrkeU

The tool extracts subtitles and provides a downloadable transcript.

License

MIT -- Rembrant Oyangoren Albeos, 2026