Run Your Own Play-Money Server

Docker

The instructions below are for running native binaries. If you instead prefer running things through Docker, take a look at docker-compose.yml. In there you'll find configuration for L1 Bitcoin Core, the BIP300/301 enforcer, several sidechains, Electrum, a L2 fast withdrawal server and L1 faucet.

A couple of important notes, if you want to run this in Docker:

1. The signet setup described in section 2 and 3 still needs to be performed, in such a way that the signet mining key exists within the Bitcoin Core L1 wallet
2. In order to receive the freshly mined signet coins you need to update the --signet-miner-coinbase-recipient parameter to the BIP300/301 enforcer to an address belonging to your Bitcoin Core L1 wallet.

Note that some of the values in the configuration file might need slight changes,

Native binaries

1. Basics

• Spin up a new server (such as Linode), with Ubuntu 24 (or whatever you prefer).

• To it, add:

• • Bitcoin Core (patched)
• • The BIP 300/301 Enforcer

Create bitcoin.conf (at $HOME/.bitcoin/bitcoin.conf) , and make sure it contains:

rpcuser=user
rpcpassword=password
txindex=1
server=1
zmqpubsequence=tcp://0.0.0.0:29000
  # required to interact with the enforcer   
signet=1
signetblocktime=60
  # 1 minute block times. Note that /everyone/ who connects to this signet
  # must have this exact configuration value.

Step 2 (below) will add the signetchallenge=... line.

2. Create a Mining Key

This key will sign a new block into existence, every 60 seconds.

Note: This is using Fish shell, if you are using Bash or Zsh then ask an AI for help.

$ mkdir custom-signet
$ ./build/src/bitcoind -daemon -regtest -datadir=$PWD/custom-signet

$ ./build/src/bitcoin-cli -regtest -datadir=$PWD/custom-signet \
     createwallet custom-signet

$ set signet_challenge (./build/src/bitcoin-cli -regtest -datadir=$PWD/custom-signet \
                     getaddressinfo $address | jq -r .scriptPubKey)

# Add the output of this command to your bitcoin.conf file!
$ echo signetchallenge=$signet_challenge 

# Need the wallet descriptors to be able to import the wallet into
$ set descriptors (./build/src/bitcoin-cli -regtest -datadir=$PWD/custom-signet \
                     listdescriptors true | jq -r .descriptors)

# We're finished with the regtest wallet!
$ ./build/src/bitcoin-cli -regtest -datadir=$PWD/custom-signet stop

3. Create the signet wallet

$ ./build/src/bitcoind -daemon -signet -datadir=$PWD/custom-signet

$ ./build/src/bitcoin-cli -signet -datadir=$PWD/custom-signet \
     createwallet custom-signet

$ ./build/src/bitcoin-cli -signet -datadir=$PWD/custom-signet \
    importdescriptors "$descriptors"

# Save an address from the wallet. This will be used for mining
# purposes, later. 
$ set address (./build/src/bitcoin-cli -signet -datadir=$PWD/custom-signet getnewaddress)

4. Start the enforcer

$ set mining_address (./build/src/bitcoin-cli -signet getnewaddress)
$ ./bip300301_enforcer \
    --node-rpc-addr=localhost:38332 \
    --node-rpc-user=user \
    --node-rpc-pass=password \
    --node-zmq-addr-sequence=tcp://0.0.0.0:29000 \
    --enable-wallet \
    --wallet-auto-create \
    --signet-miner-coinbase-recipient=$address

5. Start mining

Mining blocks happen through a gRPC endpoint on the BIP300/301 enforcer wallet. This is so we're able to construct the necessary BIP300 coinbase messages.

Calling the endpoint can be done with the Buf CLI.

$ buf curl --protocol grpc \
    --http2-prior-knowledge \
    http://localhost:50051/cusf.mainchain.v1.WalletService/GenerateBlocks

If you want to continuously generate blocks you could run this command in a loop with 1 minute wait times in between, or configure a Cron job.

Congrats, you now have your own play money server!

6. Give This Info To Your Friends

Those joining the network (ie, non-mining nodes) must have the same bitcoin.conf , plus an "addnode" line.

The addnode line is your server's IP address + port 8332. The L2L hosted signet server runs on 172.105.148.135:8332.

rpcuser=user
rpcpassword=password
server=1
txindex=1
signet=1
signetblocktime=60
signetchallenge=00141f61d57873d70d28bd28b3c9f9d6bf818b5a0d6a
zmqpubsequence=tcp://0.0.0.0:29000
addnode=172.105.148.135:8332

But yours will have different values for addnode and signetchallenge.