An Electrum Server written in Java

This is designed as replacement for the python electrum server:

Reasons to exist

1) The inital blockchain sync is multithreaded and a good bit faster than the python implementation (2 - 3 days with a fast system and SSD)

2) It is good to have multiple implementations of things in general

DB Options

Not sure what to use? Use slopbucket or rocksdb.

More details DATABASE

How to run

Make your SSL cert: ./

Build: ant jar

Config: cp jelly.default.conf jelly.conf edit jelly.conf as makes sense

Run: while true do java -Xmx3g -jar jar/Jelectrum.jar jelly.conf done

My Instance

Feel free to connect to my instance which should be running the latest version. 50001 (tcp) 50002 (ssl) 50001 (tcp) 50002 (ssl)

What Doesn't Work

1) HTTP/HTTPS. I see no strong reason to support those over TCP and SSL+TCP. I imagine it wouldn't be too hard but I don't see the need. If someone feels otherwise, let me know.

2) The following commands that clients don't seem to issue (yet):


(To check this list compare src/ from electrum-server to


If you are going to run it, monitor it!

I've made a monitoring tool that anyone to can use to monitor their electrum server (jelectrum or otherwise):

UTXO Troublehsooting


Getting a heap dump

Example command: jmap -dump:live,format=b,file=jelectrum-20151124.bin 19958

Mini Server Instructions

Mini Server Instructions