Getting Started
You'll be running trains in minutes
DEJA.js is the new DCC platform — built for today's devices, designed to replace outdated interfaces with something you'll actually enjoy using. Browser-based, multi-device, cloud-synced. Here's how to get started.
Video walkthrough coming soon
How It Works
The minimum setup to get running trains: sign up in Cloud, drive from Throttle, and the Server bridges everything to your EX-CommandStation and out to the track.
DEJA Cloud
Sign up & set up
DEJA Throttle
Drive your trains
DEJA Server
Your Pi or computer
EX-CommandStation
DCC-EX via USB
Track
Your trains run
EX-CommandStation
The DCC-EX hardware you already have — Arduino Mega + Motor Shield
DEJA Server
Runs on the machine connected to your EX-CommandStation via USB
DEJA Apps
Open in any browser — phone, tablet, laptop. All stay in sync.
What You'll Need
- A DCC-EX EX-CommandStation (Arduino Mega + Motor Shield)
- A computer to run the server — Raspberry Pi, Mac, or Linux
- A phone, tablet, or laptop to control your trains
- A USB cable connecting the EX-CommandStation to your computer
Create Your Account
Head to cloud.dejajs.com and sign up with Google, GitHub, or email. It takes about 10 seconds.
The onboarding wizard walks you through everything from here — you won't need to leave the browser until it's time to install the server.
Name Your Layout
Give your railroad a name and we'll generate a unique Layout ID. Your layout is officially created when you install the server — no commitment until then.
The free Hobbyist plan includes 1 layout. Engineer adds 3 and Conductor is unlimited — see the pricing page.
Your Free Account
The free Hobbyist plan includes everything you need — up to 10 locomotives, plus 10 each of turnouts, signals, effects, sounds, routes, and sensors, with 4 IO devices and 1 layout. No credit card, no commitment.
See the pricing page for details.
Install the Server
Open a terminal on the machine connected to your EX-CommandStation and run one command:
The script downloads the server and CLI to ~/.deja. While it installs, you can start adding locomotives to your roster right in the browser — you'll link your account and start the server in the next step.
Raspberry Pi? DEJA Server runs great on a Pi 4 or 5. Just plug your EX-CommandStation in via USB and run the command above.
Windows users: install via WSL, then run the command from a WSL terminal.
Start the Server
Link your account, then start the server:
Opens a browser tab to connect this install to your DEJA Cloud account and layout.
Connects to your EX-CommandStation over USB and opens a live status view with logs. Leave it running — this is what bridges your apps to the track.
deja stop
Stop the server
deja restart
Restart the server
deja status
Check server status
deja logs
View server logs
deja update
Update to latest version
Add Your First Locomotive
While the server installs, add a locomotive to your roster. You just need the DCC address (usually printed on the decoder) and a name — or snap a photo and let ✨ AI Enrich fill in the address, name, roadname, color, and a full function mapping for you.
Not sure of the address? Most new decoders default to address 3. You can always change it later.
Open the Throttle & Drive
Once the server connects, open throttle.dejajs.com on any device — your phone, a tablet, your laptop. Or scan the QR code:
Scan to open DEJA Throttle
Select your locomotive, turn on track power, and drive. 🚂 Everything syncs in real time — open the throttle on multiple devices and they all stay in perfect sync.
What's Next?
You're driving trains — nice. Here's where it gets even better.
Add More Locos →
Build out your roster with photos, AI-suggested details, and function mappings
Add Turnouts & Effects →
Turnouts, effects, signals, sounds, and sensors are all included
Explore the Cloud Dashboard →
Manage your layout, devices, and settings
Connect IO Devices →
Expand with Arduino, ESP32, Pico W, and WLED for lights, sounds, and servos