Developing with the BTC testnet can be quite slow:

• difficulty can be very unpredictable.
• sending/receiving transactions can take 10mins at least.
• to make transactions, you need money from faucets.

This repo sets up:

• a Bitcoin testnet using btcd and btcwallet.
• a local ElectrumX server, forked to work with btcd.
• pre-funded Bitcoin account for funding tBTC deposits.

Install.

git clone https://github.com/liamzebedee/tbtc-testnet-starter
cd tbtc-testnet-starter/
git submodule update --init --recursive

Usage.

btcd and ElectrumX are both built using Docker images. No additional software is needed.

# Start btcd, btcwallet.
$ ./scripts/run-btcd.sh

# Start ElectrumX.
$ ./scripts/run-electrumx.sh

The ElectrumX server will be running on ports 50001-50004.

Configuring tBTC

You must configure tbtc.js with the correct bitcoinNetwork and ElectrumX server.

const tbtc = await TBTC.withConfig({
    web3: web3,
    bitcoinNetwork: "simnet",    // (1)
    electrum: {
        testnetWS: {             // (2)
            server: "127.0.0.1",
            port: 50003,
            protocol: "ws"
        },
    }
})

You must also configure the tbtc-maintainer to connect to your local ElectrumX server. Edit your config.toml:

# Connection details of a Electrum Server.
[electrum]
    ServerHost  = "127.0.0.1"
    ServerPort  = "50002"
    Protocol    = "SSL" # TCP or SSL

Interacting with your bitcoin simnet.

$ docker exec -it btcd sh

# Send bitcoin from the "default" miner account.
/app $ btcctl -C ./btcctl.conf --wallet sendfrom default sb1qe2s2ag7n63jcrktewzfvfuawmgqscd5rdvet6y 0.001

# Mine a block.
/app $ btcctl -C ./btcctl.conf --wallet generate 1
[
  "7e4764ea96630a88c8cf2868393e72222b9f8f1a152f11c798ab717142ffbb98"
]

A brief explainer.

btcd is an alternative to the bitcoind software. It features a separate server, btcwallet, that hosts a wallet RPC interface. It comes with a tool called btcctl to send RPC calls to the btcd and btcwallet daemons.

We run a testnet instance of the bitcoin network called simnet. Simnet has its own address prefix, different from Bitcoin Testnet and Bitcoin Mainnet. simnet is a btcd-only feature (it's not part of bitcoind/bitcoin core).

ElectrumX doesn't support btcd out-of-the-box, and doesn't have a configuration for the simnet genesis. Hence, we use a forked version which is patched to support this.