Linq Tournament Manager

Demo Video: https://drive.google.com/file/d/1QkB8Z0JpacVcc4Xwcv1yWIa2-mzF__-w

Running a local gaming tournament is a logistical headache. Players miss their matches, don't know their bracket position, and organizers spend the whole event chasing people down. Phones are already in everyone's pocket — why not just text them?

Linq Tournament Manager lets players register, check their bracket, and report results entirely over iMessage. No app to download, no website to navigate — just a conversation. An AI agent handles everything: answering questions about who you play next, what station to go to, and recording your result when the match is done. When a tournament fills up, the bracket generates automatically and every player gets an iMessage with their first matchup.

Built on the Linq API for the Linq technical challenge.

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Architecture

Player (iMessage) → Linq webhook → Express backend → LLM agent (OpenRouter)
                                                              ↕ MCP tools
                                                        SQLite database
                       React frontend ↗

The backend receives iMessage events from Linq, runs them through a tool-calling LLM agent, and sends replies back via the Linq API. The agent's tools are exposed through an MCP server (stdio transport), keeping the tool logic isolated and reusable. A React frontend gives organizers a live bracket view and provides a web registration form as an alternative to texting in.

Layer	Tech
Messaging	Linq API (iMessage)
Backend	Node.js + Express + TypeScript
Agent	OpenRouter LLM (tool-calling)
Tools	MCP server (stdio transport)
Database	SQLite (better-sqlite3)
Frontend	React + Vite

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Getting started

Prerequisites

• Node.js 20+
• A Linq partner account with an API key and phone number
• An OpenRouter API key
• ngrok (or equivalent) to expose the local webhook to Linq

Setup

npm install
cp .env.example .env
# fill in .env with your credentials

# Start everything (backend + MCP server + frontend)
npm run dev

The database is created and seeded automatically on first run.

Expose the webhook

To receive live iMessages from Linq, expose port 3001 with ngrok:

ngrok http 3001

Register the ngrok HTTPS URL + /webhook as your Linq webhook endpoint. scripts/setup-webhook.sh automates this once your tunnel is running.

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Configuration

Copy .env.example to .env:

Variable	Description
LINQ_API_KEY	Linq partner API key
LINQ_FROM_NUMBER	Your Linq phone number (E.164)
LINQ_WEBHOOK_SECRET	Webhook signing secret from Linq dashboard
OPENROUTER_API_KEY	OpenRouter API key
LLM_MODEL	OpenRouter model ID (default: nvidia/nemotron-3-super-120b-a12b:free)
DB_PATH	SQLite file path (default: ./db/tournament.db)
PORT	Backend port (default: 3001)
NGROK_AUTHTOKEN	ngrok auth token for the setup script

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Project structure

packages/
  backend/      Express server — webhook handler, REST API, LLM agent
  mcp-server/   MCP tool server — tournament CRUD exposed as LLM tools
  frontend/     React bracket viewer and web registration form
db/
  schema.sql    Database schema
  seed.sql      Demo tournaments and CPU players
scripts/
  setup-webhook.sh  Register ngrok URL with Linq

Demo / simulator

The backend exposes simulator endpoints for demoing without real players:

• POST /api/simulate/advance-cpu — auto-advance a CPU-vs-CPU match
• POST /api/simulate/reset — reset the database to seed state

The frontend includes a simulator panel for clicking through these flows.