TopGun

Alpha — API may change

Hybrid offline-first in-memory data grid. Zero-latency reads and writes via local CRDTs, real-time sync via WebSockets, durable storage on your own infrastructure.

TopGun v2 is a complete rewrite. It's not a port — it's a new architecture designed for production workloads.

Key features

• Local-first: Data lives in memory. Reads and writes never wait for network.
• Offline support: Changes persist to IndexedDB/SQLite and sync when reconnected.
• CRDT conflict resolution: LWW-Map and OR-Map with Hybrid Logical Clocks.
• Merkle tree sync: Efficient delta synchronization — only changed data moves over the wire.
• Pluggable storage: PostgreSQL, SQLite, S3, or bring your own adapter.
• Cluster-ready: Server-side partitioning, distributed locks, pub/sub.
• TypeScript-first: Full type safety from client to server.

Quick start

npm install @topgunbuild/client @topgunbuild/adapters @topgunbuild/react

import { TopGunClient } from '@topgunbuild/client';
import { IDBAdapter } from '@topgunbuild/adapters';

const adapter = new IDBAdapter();
const client = new TopGunClient({
  serverUrl: 'ws://localhost:8080',
  storage: adapter,
});

client.start();

// Write data (instant, works offline)
const todos = client.getMap('todos');
todos.set('todo-1', {
  id: 'todo-1',
  text: 'Buy milk',
  done: false,
});

// Read data
const todo = todos.get('todo-1');

// Subscribe to changes via live queries
// See useQuery hook for React integration

With React:

import { TopGunProvider, useQuery, useClient } from '@topgunbuild/react';

function App() {
  return (
    <TopGunProvider client={client}>
      <TodoList />
    </TopGunProvider>
  );
}

function TodoList() {
  const client = useClient();
  const { data, loading } = useQuery('todos');

  if (loading) return <div>Loading...</div>;

  const toggleTodo = (todo) => {
    const todosMap = client.getMap('todos');
    todosMap.set(todo.id, { ...todo, done: !todo.done });
  };

  return (
    <ul>
      {data.map((todo) => (
        <li key={todo.id} onClick={() => toggleTodo(todo)}>
          {todo.text}
        </li>
      ))}
    </ul>
  );
}

Documentation

Full docs: topgun.build/docs

Specifications in this repo:

• System Architecture
• CRDT & Data Structures
• Synchronization Protocol

Packages

Package	Description
@topgunbuild/core	CRDTs, Hybrid Logical Clock, Merkle trees, message schemas
@topgunbuild/client	Browser/Node.js SDK with IndexedDB persistence
@topgunbuild/server	WebSocket server, clustering, storage adapters
@topgunbuild/react	React hooks: useQuery, useMap, useMutation, useTopic
@topgunbuild/adapters	Storage adapters: IndexedDB, SQLite, LevelDB
@topgunbuild/adapter-better-auth	Better Auth integration

Running locally

# Start server with Postgres
docker compose up --build

# Or run the example app
cd examples/notes-app
pnpm install
pnpm dev

License

Business Source License 1.1 (BSL)

You can use TopGun freely for:

• Internal applications
• Your product's backend (when TopGun is not the product you're selling)
• Consulting and professional services

You cannot:

• Offer TopGun as a managed database service or DBaaS

After 4 years from each release, the code converts to Apache 2.0.

See LICENSE for full terms.

TopGun v1

Looking for the original gun.js TypeScript port? See the legacy-v1 branch (unmaintained).

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Built by Ivan Kalashnik