ebb ebb 
 
  
  
Build apps that are fast, work offline, and just sync.
 
The real-time backend for your vibe coded frontend.
 
 
 
   
  
  
 
Read the devlog →
   
Star on GitHub
 
 
  
  
    
 
 
 
  
 
 
 
 
Project goals
 
 
  
Incredible DX
 
A declarative API that helps humans and agents get things right the first time.
 
 
  
Fully open source
 
No vendor lock-in. Designed to self-host. Deploy to a VPS or on bare metal at home.
 
 
  
Fast, reactive, and multiplayer
 
Data lives on the device, can be edited offline, and stays in sync with others.
 
 
 
 
 
 
  
 
 
 
 
  
  
Build apps, not infrastructure
 

Define your data. Query with a type-safe ORM. React when data changes — online or off.

 
     
  •  -- Full type-safety with client-side validation 
    •  
  •  -- Declare relationships and permissions 
    •  
  •  -- Compose and reuse mutations easily 
    •  
 
  
 
  
    model.ts 
  
  
  
  
 
 
import {
  e,
  defineEntity,
  defineSchema,
} from "@ebbjs/client";

const todo = defineEntity("todo", {
  title: e.string(),
  completed: e.boolean(),
});

export const schema = defineSchema({
  entities: { todo },
  version: 1,
});
 
 
import { createClient } from "@ebbjs/client";
import { schema } from "./model";

export const client = createClient({
  serverUrl: "http://localhost:4000",
  actorId: "user_123",
  schema,
});
 
 
import { client } from "./client";

// Create
const todo = await client.todo.create({
  title: "Ship it",
  completed: false,
});

// Update
await client.todo.update(todo.id, {
  completed: true,
});

// Query — works offline
const openTodos = await client.todo
  .query()
  .where("completed", false)
  .orderBy("createdAt", "desc");
 
 
 
 
 
 
 
 
   
 
  
 
 
 
 
  
 
  
     terminal 
  
 
$ ebb deploy

  Bundling functions...
  ✓ sendEmail      12.3 KB
  ✓ processOrder    8.1 KB
  ✓ generateReport  5.7 KB

  Uploading to sidecar...
  ✓ 3 functions deployed

  Activating v14 → v15...
  ✓ Live — zero downtime

  Deploy complete in 1.2s
 
 
 
  
  
Deploy in seconds. Rollback instantly.
 

Your server runs two processes: a persistent sync engine and a stateless sidecar. ebb deploy ships new code to the sidecar — the sync engine never restarts. Versions activate atomically, so there's zero downtime. Rolling back is just as fast.

 
     
  •  -- ebb deploy — one command to ship 
    •  
  •  -- Atomic version swap — zero downtime 
    •  
  •  -- Instant rollback to any previous version 
    •  
 
 
 
 
 
 
  
 
 
 
 
  
  
Real-time in no-time.
 

Every client gets a local replica that reads and writes instantly. Changes sync to all connected users in real-time — with presence, awareness, and conflict resolution. No polling, no spinners, no plumbing.

 
     
  •  -- Local reads and optimistic writes — zero latency 
    •  
  •  -- Live presence and real-time updates across clients 
    •  
  •  -- Custom conflict resolution and no data loss 
    •  
 
  
 
  
    
  
  
   
  
  
  
  
  
  
  
    You 
  
    Alice 
  
    Bob 
 
 
 
 
 
 
   
 
  
 
 
 
 
 
Roadmap
 
Where we are and where we're headed.
 
 
 
 
 
Core storage engine
  Shipped  
 
RocksDB-backed Action log with a single Writer in production (pipelined writes enabled) and on-demand entity materialization via SQLite.
 
 
 
Sync protocol
  Shipped  
 
Three-phase sync: handshake, per-group catch-up with CDN-friendly pagination, and live SSE streaming.
 
 
 
Auth & permissions
  Shipped  
 
BYO auth integration with group-based access control. Permission checks run against an in-memory cache — never block on disk.
 
 
 
Real-time presence
  Shipped  
 
Ephemeral cursor and selection broadcasting for live multiplayer — fire-and-forget, not persisted.
 
 
 
Self-hosting
  Shipped  
 
Run the full sync server on your own infrastructure with a single Docker image.
 
 
 
Client SDK
  In Progress  
 
Local-first reactive client with a typed query engine for reads, entity verbs and atomic actions for writes, and optimistic local writes. The durable offline outbox is in progress.
 
 
 
Observability hooks
  Planned  
 
Server-side telemetry events and a developer-facing onAction hook for piping the Action stream to analytics, audit logs, webhooks, or data warehouses.
 
 
 
Causal-tree collaborative text
  Shipped  
 
Character-level concurrent editing built on existing Action/Update primitives with HLC-based causal ordering — not Yjs. Conflict surfacing for human resolution.
 
 
 
React bindings
  In Progress  
 
EbbProvider, useClient, useConnection, useQuery, and useEntityMutations ship today; SSR and Suspense are out of scope.
 
 
 
Server functions
  Planned  
 
defineFunction handlers that run server-side with direct data access. Deploy, version, and roll back with a single CLI command.
 
 
 
Server-side SDK
  Planned  
 
HTTP client for reading and writing ebb data from SSR frameworks, server actions, and external processes.
 
 
 
CLI tooling
  Planned  
 
ebb deploy, function management, schema migrations, and project scaffolding from the command line.
 
 
 
Horizontal scaling
  Planned  
 
Multi-master replication across nodes for elastic throughput — no single writer bottleneck, automatic conflict resolution at the cluster level.
 
 
 
 
 
 
  
 
 
 
 
 
  
 
 
Stay in sync
 
ebb is in early development. Sign up to receive updates.
 
 
 
   
  
  
 
Read the devlog →
   
Star on GitHub