DEJA.js

Simple to start. Built to grow.
The cloud platform for DCC-EX.

DEJA.js connects your DCC-EX EX-CommandStation to every phone, tablet, and laptop in the room. Throttle, manage, and automate your layout from any browser — no app store required.

Get Started See the Docs

Web app · iOS & Android coming soon · No app store required

You tap

Server routes

deja — tamarack

✓ Ready

← throttle {addr:3, speed:50}

→ <t 3 50 1>

DCC-EX Translates

DCC-EX EX-CommandStation — Arduino Mega with Motor Shield

DCC-EX Translates

Train moves

Scroll

Quick Start

Running trains in three steps.

Sign Up

Create your free DEJA Cloud account. Choose a plan that fits your layout. Your roster, settings, and layout data sync instantly across every device.

Install the Server

Plug in your DCC-EX EX-CommandStation via USB and install the CLI. Then run deja login to connect your account, and deja start to launch the server.

bash

$curl -fsSL https://install.dejajs.com | bash

Need help? Read the Getting Started guide →

Run

Open the Throttle app on any device — phone, tablet, or desktop. Scan the QR code to launch it instantly on your phone.

Launch Throttle App

Scan to open on phone

See It In Action

Watch the 2-minute quickstart

DEJA.js — Getting Started

$ curl -fsSL https://install.dejajs.com | bash

Downloading DEJA Server v1.2.0...

Installing dependencies...

✓ DEJA Server v1.2.0 installed

→ Starting server...

✓ Server running on ws://localhost:8082

✓ EX-CommandStation connected on /dev/ttyUSB0

ℹ Signed in · Layout: Pittsburg & Shasta 1:87

Video coming soon

Check back shortly

~2 min

Throttle App

DEJA Throttle

Precision locomotive control.

Precise speed control, function mapping, EZ Consist, and CV programming — from any browser. No app store, no install. Add it to your homescreen and open it with a tap.

🎚️Speed & Direction Smooth 0–126 step control with momentary and toggle functions
🚂EZ Consist Build multi-loco consists with independent function control per unit
⚙️CV Programming Read and write decoder CVs directly from the Throttle app
🗂️Roster Snap a photo and AI fills in the roster entry — addresses, names, road numbers, and function mapping
🚦Track Diagrams Turnouts, routes, and signals — all automated from a clickable track map
🎆Effects, WLED & Sounds Toggle lights and relays, activate WLED scenes, and play your sound library from any device
♿Accessible by Design Large, chonky touch targets and four throttle styles to match how you operate.Buttons · Slider · Dashboard · Proto

📱

Web App — works on any device

Open throttle.dejajs.com in Safari or Chrome and tap "Add to Homescreen". Full-screen, no browser chrome.

Try Now in Demo Mode Learn Moredocs

📱

More screens
coming soon

Server + CLI

One command. Everything connects.

The DEJA Server is a lightweight Node.js process that bridges your DCC-EX EX-CommandStation to the cloud. Install it once, start it with a single command, and your entire layout — throttles, turnouts, signals, effects — is live.

🔌USB serial bridge to DCC-EX EX-CommandStation at 115,200 baud
📡MQTT broker for IO devices, WebSocket server for real-time browser sync
☁️DEJA Cloud sync — layout commands flow from cloud to track instantly
🕹️WiThrottle server — ProtoThrottle, Engine Driver, ThrottleCard, and JMRI-style throttles connect directly
🔄Self-updating via deja update — always on the latest version

macOSLinuxRaspberry Pi

install

bash

$ curl -fsSL https://install.dejajs.com | bash

Downloading DEJA Server v1.2.0...

Installing dependencies...

✓ DEJA Server v1.2.0 installed

→ Starting server...

✓ Server running on ws://localhost:8082

✓ EX-CommandStation connected on /dev/ttyUSB0

→ Signed in · Layout: Pittsburg & Shasta 1:87

deja cli

deja

$ deja start # Start the server

$ deja stop # Stop the server

$ deja restart # Restart the server

$ deja update # Update to latest version

$ deja status # Check server health

$ deja logs # Stream server logs

$ deja init # Re-initialize layout

Cloud App

DEJA Cloud

Command central for your layout.

Configure your roster, wire up turnouts and signals, manage devices and connections, and control your layout from anywhere. Connects via USB, WebSocket, or MQTT — including DEJA IO devices.

🗂️Roster Management Add locos with addresses, names, road numbers, and photos — or snap a photo and let AI fill in the details and function mapping
🔌Device & Connection Management Connect via USB, WebSocket, or MQTT — configure DEJA IO devices or use custom integrations
🔀Turnouts & Routes Map physical turnouts and build automated route sequences
🚦Signals Configure signal heads and assign them to track blocks
🎆Effects, WLED & Sounds Toggle lights and relays, activate WLED scenes, and play your sound library from any device
🖥️DCC Console Send raw DCC-EX commands and view live serial output

☁️

Instant sync across all devices

Change a setting on your desktop — it instantly updates on your phone, tablet, and every connected device.

Learn More DEJA Clouddocs

DEJA IO

Expand your layout. On your terms.

DEJA IO lets you connect common devices — Arduino, Raspberry Pi Pico W, ESP32, or your own custom build — communicating over any supported protocol to expand what your layout can do.

Protocols

MQTTUSB SerialWebSocketWiThrottle

DCC-EX Track Modes

🚂DCC Main⚙️Programming⚡DC / PWM📡Booster

Hardware Devices

🚂

EX-CommandStation

USB Serial

The DCC-EX hardware that drives your track. Connects to the DEJA Server over USB at 115,200 baud.

🔌

Arduino Mega

USB Serial

Connect via USB to DEJA Server for pin-level control of outputs, sensors, and signal heads. WiFi support coming soon.

📡

ESP32

USB SerialMQTT

Connect via USB, or go WiFi-native over MQTT for pin-level control without a cable. WebSocket support coming soon.

📶

Raspberry Pi Pico W

MQTT

WiFi-native CircuitPython device. Connects over your network via MQTT — no USB cable required. WebSocket support coming soon.

💡

WLED

WiFi

Expansion Capabilities

Lights

Sounds

Servos

Sensors

Relays

Signals

Turnouts

Outputs

Guides

Learn DEJA.js

Step-by-step guides to help you get the most out of the platform — whether you're just getting started or expanding a club layout.

🚀

Getting Started

From zero to driving trains in minutes. Sign up, install the server, and take control.

🏗️

Architecture

How DEJA.js works — from a tap on your phone to a train on the track. The full platform explained.

🚂

Throttle

Train control, function buttons, consists, and everything you can do from the Throttle app.

💻

Server

Installation, CLI reference, configuration, and running the DEJA Server on any platform.

☁️

Cloud

Roster management, turnout configuration, route automation, and effects setup.

🔌

Hardware expansion with Arduino and Pico W — LEDs, servos, signals, sensors, and MQTT.

📊

Monitor

Soon

Diagnostics, DCC command logging, device status, and system health monitoring.

🎟️

Tour

Soon

Guest-facing layout tours — interactive effects, media, and area exploration.

Platform

Built for the way you operate.

🤖

AI Roster Enrichment

Snap a photo — AI fills in your roster entry, function mapping and all. Review and accept field-by-field.

☁️

Cloud Sync

Roster, turnouts, and settings sync instantly across all devices through DEJA Cloud.

📱

Any Device

Web app works on phone, tablet, and desktop. PWA install — no app store.

🔒

Private Platform

Subscription-gated access. Your layout data is yours — secured end-to-end by DEJA.js.

⚡

Real-Time

Commands reach your track in under 100ms via WebSocket + serial bridge.

🔧

DCC-EX Native

Built specifically for DCC-EX. Full protocol support — not a general-purpose tool.

🎮

WiThrottle Compatible

Built-in WiThrottle server replaces JMRI for that role. Engine Driver, ThrottleCard, ProtoThrottle, and other WiThrottle clients connect directly — including ThrottleCard’s Apple Watch and game-controller support.

🎆

Effects, WLED & Sounds

Toggle lights and relays, activate WLED scenes, and play your sound library from any device on your network.

📡

MQTT Ready

Optional MQTT broker integration for advanced automation and sensor inputs.

🗺️

Track Diagrams

Drag-and-drop schematic editor — turnouts, routes, and signals, all automated from a clickable track map.

🔀

Multi-Track

Support for Main, Programming, DC/PWM, and Booster modes on separate EX-CommandStations.

🚦

Signal Control

Configure signal heads with full aspect control tied to block occupancy.

Coming Soon

📱 iOS Native App🤖 Android Native App🗺️ Layout Map Editor🎬 Automated Sequences📊 Operations Mode🔔 Push Notifications🔗 Multi-layout Support📱 iOS Native App🤖 Android Native App🗺️ Layout Map Editor🎬 Automated Sequences📊 Operations Mode🔔 Push Notifications🔗 Multi-layout Support

FAQ

Common questions.

Support

Help when you need it.

From community forums to hands-on consulting — we've got you covered.

Community (Discord)

Ask questions, share layouts, and connect with other DEJA.js users. Free for all.

Join Discord →

AI Chat Support

Coming Soon

Get instant answers about setup, configuration, and troubleshooting from our AI assistant.

Support Tickets

Paid plans include support tickets with a guaranteed response time. Priority handling for Engineer and Conductor.

View Plans →

Consulting Services

Per-incident help, prepaid hours, or direct consultation with Track and Trestle Technology for complex layouts and custom integrations.

Get in Touch →