⚠️ Advanced Software — requires Radarr & Sonarr setup first
Radarr and Sonarr are brains; they organize and monitor. Transmission is the muscle; it actually does the downloading. We need to link them together so the brains can control the muscle.
Overview
Transmission is a lightweight, highly reliable BitTorrent client. When Radarr finds a movie you want, it sends the magnet link directly to Transmission's API. Transmission downloads the file into a temporary "Downloads" folder. Once finished, it alerts Radarr, which then grabs the file, renames it, and moves it into Jellyfin.
Step 1: Verifying Transmission
First, we just need to ensure Transmission is running and accessible.
Go to your LocalNode dashboard.
Click the Transmission app icon.
A simple web interface should load. It will be empty.
Note the URL in your browser. It should be http://localnode.local:9091.
Step 2: Adding the Download Client in Radarr
Now we tell Radarr where Transmission lives.
Open Radarr from the LocalNode dashboard.
Go to Settings > Download Clients.
Click the large + button.
A list of supported clients will appear. Scroll down and select Transmission.
A configuration window will pop up. Fill it out exactly as follows:
Name: Transmission
Enable: Checked
Host:transmission (Do not use an IP address. Because these apps run in Docker on the LocalNode, they can talk to each other using their container names!)
Port: 9091
Category:movies (This tells Transmission to tag movie downloads, separating them from TV shows).
At the bottom of the window, click Test.
You should see a green checkmark appear, meaning Radarr successfully pinged Transmission.
Click Save.
Servarr wiki screenshot (wiki.servarr.com), bundled with Servarr/Wiki alongside GPLv3 Radarr/Sonarr/Prowlarr releases.
💡 Tip: Using transmission as the Host address instead of 192.168.1.50 ensures that even if your router assigns your server a new IP address, the apps will never lose connection to each other.
Step 3: Repeating for Sonarr
You must repeat this exact process in Sonarr, with one tiny difference.
Open Sonarr.
Go to Settings > Download Clients > +.
Select Transmission.
Host: transmission, Port: 9091.
Category: Type tv (This is the only difference!).
Test and Save.
Now both apps are connected to your download client. The final piece of the puzzle is giving them a search engine to find the files in the first place, which we do using Prowlarr.
