Up again

I did something wrong previously :) Called destroyamount.

2025-05-21T10:39:09Z
ERROR: ReadBlockFromDisk: Deserialize or I/O error -
Superfluous issuance record: iostream error at FlatFilePos(nFile=0, nPos=762487)

Now everything works but is at an older state restored from backup. Feel free to send blocks you already have (or generate) to try to reorg :)

What is Liquid Testnet4?

It's a testnet for the Liquid sidechain, using Testnet4 for pegins and enabling discount CT fees.

No block signers here (in contrast to the real Liquid network). Generate your blocks. Play. Learn. Zero-fees? Easy. Generate the zero-fee-paying transactions into your blocks and learn about the other fee-related configuration settings (the same as in Bitcoin Core).

Why unofficial?

There can be many networks like this.

Confidential pegins?

Read more in Elements issue #1325 and other inter-linked related issues.

See example and find its testnet4 inputs.

See lt4-pegins.txt.

How to join?

First make sure to have a recent Bitcoin Core daemon (v29.0 works) with testnet4 running locally..

Following is the related part of bitcoin.conf:

[testnet4]
rpcuser=t4user
rpcpassword=t4password

# Can be pruned since Elements
# daemon needs just headers
#prune=550

Add following lines to your elements.conf file:

[liquidtestnet4]
blockmintxfee=0.0000001
acceptdiscountct=1
creatediscountct=1
parentgenesisblockhash=00000000da84f2bafbbc53dee25a72ae507ff4914b867c565be350b0da8bf043
fedpegscript=5321039ef28cb2d4ba1a2652ee6268c5e3252beeb4b6154659edab632991222b71d8102103e0bdc9a133e3a7b3eded49cda15c17c5f27ec997eae7b5aafc63fce9e7e1740b21033d83a7f7424b380fe85f01355e7ec2f381703ae4c73838d82fce2b57c3bd8d0d53ae736402c00fb2695221021947dc0383665f8587b5db47d2f69e8e784977c22eefca6b5e19671c81ab6de921026ab4753ec9f194078d86acb095176dc7aedf43d6df818837974af89d769f85e921023cdcc46d5fc8b06e180cf59d3878e4499b24d214a5165085be5ed07052fbb40d53ae68
server=1
listen=1
txindex=1
validatepegin=1
initialfreecoins=2100000000000000
fallbackfee=0.000002
rpcport=17774
port=18444
mainchainrpcport=48332

mainchainrpcuser=t4user
mainchainrpcpassword=t4password
# above two should match their counterparts in bitcon.conf for testnet4
# i.e. rpcuser=t4user and rpcpassword=t4password in [testnet4] section

addnode=mgqys7ja25qhuysnj73bznbhbmzzneamxvvfkmuz67uua22c7kfvtoid.onion:18444

Now make a directory and run elementsd:

cd ~/.elements
mkdir liquidtestnet4
elementsd -datadir=$PWD \
  -chain=liquidtestnet4

Stats

See /liquid/gi-lt4.txt and /liquid/lt4-gbci.json (getblockchaininfo)

Updates

The port number is now 18444 on Tor and there is no public IPv4 address now.

Setting blockmintxfee low is needed to put discounted CTs into blocks. Feel free to generate blocks with no tx fees.

Leaving

Please send leftover sats to el1qqdqjfahlc4flc6y0w8d0ld4rvmkqsltvuvjxh78rdd4j5tz5qx6pdm87zv8ryr0uplevrz3wcw42q2afsfh5q2m5hxlh93szn or send (and do not "mine") a transaction paying everything in fees (example). Peg-outs back to Testnet4 are not automated yet.

Terminal demo

See this screen cast.

It all works still on 2025-05-20. Tested like in the screencast, just with the current Tor node name.

2025-05-22T16:08:48Z UpdateTip: new
best=72a583aa00256d95c8e250dad195dc5048c609a05b545fd1b81c600ba72de23b
height=12433 version=0x20000000 log2_work=13.602003 tx=12573
date='2025-05-22T16:08:48Z'
progress=1.000000 cache=0.0MiB(0txo)