How It Works
The minimum setup to get running trains: sign up and drive from Throttle, and the Server bridges everything to your EX-CommandStation and out to the track.
DEJA Throttle
Sign up, set up & drive
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 computer to run the server — Raspberry Pi, Mac, Linux, or Windows
- A phone, tablet, or laptop to control your trains
- A USB cable connecting the EX-CommandStation to your computer
Step 1: Create Your Account
Head to throttle.dejadcc.com and sign up with Google, GitHub, or email.
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.
Step 2: 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.
DEJA is free — every feature, no limits. Stuck? Book a session with Track & Trestle.
Step 3: Your Free Account
DEJA is free — every feature, no limits, no card. Optional donations during setup support development; you can skip them and nothing is locked.
Need hands-on help? See Support.
Step 4: Install the Server
Open a terminal on the machine connected to your EX-CommandStation and run one command:
curl -fsSL https://install.dejadcc.com | bashThe script downloads the server and CLI to ~/.deja. While it installs, you can set up 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.
On Windows, open PowerShell and run:
irm https://install.dejadcc.com/install.ps1 | iexThe Windows installer sets up Node.js automatically (via winget) and installs everything under %USERPROFILE%\.deja.
Step 5: Start the Server
Link your account, then start the server:
deja loginOpens a browser tab to connect this install to your DEJA account and layout.
deja startConnects 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
Step 6: Your First Locomotive
Your roster already has one locomotive, DEFAULT DCC #3, on address 3 — the address most new decoders ship with — so a fresh decoder is ready to drive as soon as the server connects. Rename it in the roster if you like.
Loco on a different address? Add it from the roster's Quick Add row — just the DCC address (usually printed on the decoder) and a name — or snap a photo and let DejaBot Identify suggest the address, name, roadname, color, and a full function mapping for you.
Step 7: Open the Throttle & Drive
Once the server connects, open throttle.dejadcc.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
Manage Devices & Access →
Connect hardware, invite operators, and tune your layout
Connect IO Devices →
Expand with Arduino, ESP32, Pico W, and WLED for lights, sounds, and servos