DarkFi x Monero Merge Mining using p2pool and xmrig

DISCLAIMER: This is a work in progress and not available on the current deployed testnet as of 22-May-2025.

This document provides a way to set up a Monero testnet that is able to merge-mine DarkFi using p2pool.

Build binaries from source

We can build Monero, p2pool, and xmrig from their respective source code repositories.

For Monero, we'll take the latest release tag:

$ git clone --recursive https://github.com/monero-project/monero
$ git checkout v0.18.4.0
$ make -j$(nproc)

Same for p2pool:

$ git clone --recursive https://github.com/SChernykh/p2pool
$ git checkout v4.6
$ mkdir build && cd build && cmake .. && make -j$(nproc)

And xmrig:

$ git clone --recursive https://github.com/xmrig/xmrig
$ git checkout v6.22.2
$ mkdir build && cd build && cmake .. && make -j$(nproc)

Copy the resulting binaries into a working directory where we'll be doing the network setup. We'll need monerod, monero-wallet-cli, p2pool, and xmrig.

Monero setup

We should first sync the Monero Testnet locally. We can simply do this by starting up monerod and waiting for the sync to finish:

$ ./monerod --testnet --no-igd --data-dir bitmonero --log-level 0 --hide-my-port --add-peer 125.229.105.12:28081 --add-peer 37.187.74.171:28089 --fast-block-sync=1

2025-05-22 13:04:16.492 I Synced 3601/2754128 (0%, 2750527 left)
2025-05-22 13:04:27.315 I Synced 5801/2754128 (0%, 2748327 left)
...
2025-05-22 13:04:38.705 I Synced 8101/2754128 (0%, 2746027 left)
2025-05-22 13:04:44.676 I Synced 9301/2754128 (0%, 2744827 left)
2025-05-22 13:04:47.174 I Synced 9801/2754128 (0%, 2744327 left)

After the sync is finished, we will take the node offline and continue our work locally. So quit the monerod node, and restart it offline with fixed difficulty that will make our mining process faster:

$ ./monerod --testnet --no-igd --data-dir bitmonero --log-level 0 --hide-my-port --fixed-difficulty 5000 --disable-rpc-ban --offline --zmq-pub tcp://127.0.0.1:28083

Now we should also create a Monero wallet. Run monero-wallet-cli and follow the wizard to create a wallet:

$ ./monero-wallet-cli --testnet --trusted-daemon

Generated new wallet: 9zMUzh73iWm5pXha95quaQjW1BnL5w2kBA8np1RqNsaSKoK7nA3ZPg1VPmtpHjhDV1WHd6sVyuePPGdaWiQqyQTcN6RuQA4
View key: xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
**********************************************************************
Your wallet has been generated!

Now we have our Monero address 9zMUzh73iWm5pXha95quaQjW1BnL5w2kBA8np1RqNsaSKoK7nA3ZPg1VPmtpHjhDV1WHd6sVyuePPGdaWiQqyQTcN6RuQA4 that we can use with p2pool to receive mining rewards.

p2pool setup (without merge-mining)

First we'll start p2pool without merge-mining to make sure everything works in order. After we get xmrig set up, we'll restart p2pool with merge-mining enabled.

p2pool connects to monerod's JSONRPC and ZMQ Pub ports in order to retrieve necessary mining data. It also provides a Stratum mining endpoint that xmrig is able to connect to in order to receive mining jobs and actually mine the proposed blocks.

We can start p2pool with the following command:

$ ./p2pool --host 127.0.0.1 --rpc-port 28081 --zmq-port 28083 --wallet 9zMUzh73iWm5pXha95quaQjW1BnL5w2kBA8np1RqNsaSKoK7nA3ZPg1VPmtpHjhDV1WHd6sVyuePPGdaWiQqyQTcN6RuQA4 --stratum 127.0.0.1:3333 --data-dir ./p2pool-data --no-igd

Once started, it should connect to monerod and retrieve the latest blockchain info. Now we can proceed with xmrig to try and mine some blocks.

xmrig setup

xmrig is pretty simple. Just start it with a chosen number of threads and point it to p2pool's Stratum port. -u x+1 5000 is defined by the --fixed-difficulty setting we started monerod with. -t 1 is the number of CPU threads to use for mining. With a low difficulty, one thread should be enough.

$ ./xmrig -u x+1 5000 -o 127.0.0.1:3333 -t 1

Now we should see blocks being mined in p2pool and submitted to our Monero testnet. To stop mining you can ^C xmrig anytime to quit it or press p to pause mining.

p2pool setup (with merge-mining)

Now that everything is in order, we can use p2pool with merge-mining enabled in order to merge mine DarkFi. For receiving mining rewards on DarkFi, we'll need a DarkFi wallet address. In this example we'll use the following:

GCP5e1aGWPTy347WzAbn4uA5yT8mzQ25GV3gpp3MBihS

We will also need darkfid running. Make sure you enable the RPC endpoint that will be used by p2pool in darkfid's config:

[network_config."testnet".mm_rpc]
rpc_listen = "http+tcp://127.0.0.1:8341"

Then start darkfid as usual.

Stop p2pool if it's running, and re-run it with the merge-mining parameters appended:

$ ./p2pool --host 127.0.0.1 --rpc-port 28081 --zmq-port 28083 --wallet 9zMUzh73iWm5pXha95quaQjW1BnL5w2kBA8np1RqNsaSKoK7nA3ZPg1VPmtpHjhDV1WHd6sVyuePPGdaWiQqyQTcN6RuQA4 --stratum 127.0.0.1:3333 --data-dir ./p2pool-data --no-igd --merge-mine 127.0.0.1:8341 GCP5e1aGWPTy347WzAbn4uA5yT8mzQ25GV3gpp3MBihS

Now p2pool should communicate with both monerod and darkfid in order to pick up Monero blocktemplates and inject them with DarkFi data necessary for merge-mining verification on the DarkFi side. Re-run xmrig and now we should be mining blocks again. Once blocks are found, they will be submitted to both monerod and darkfid and darkfid should verify them and release block rewards to the address provided to p2pool's merge-mine parameters.

Happy mining!

The DarkFi Book