1. Ubuntu
2. Bitcoin Core
3. Fulcrum 2.0 (Fast and stable electrum server)

Why Run Your Own Mempool?

Prerequisites: Your Foundation

1. A Synced Bitcoin Core Node:
   • Your bitcoin.conf file must have txindex=1 and ZMQ enabled.
   • Your bitcoin.conf must be configured to bind to both localhost (for Fulcrum) and the Docker host network, and it must allow RPC connections from two different Docker networks.

   Example: /home/satoshis/.bitcoin/bitcoin.conf

   
   # [For a node serving Fulcrum, Ashigaru and Mempool via Docker]
   
   # Network
   server=1
   txindex=1
   
   # RPC
   rpcbind=127.0.0.1
   rpcbind=172.17.0.1
   rpcport=8332
   rpcuser=YOUR_USER_NAME #CHANGE THIS!!!!!!
   rpcpassword=YOUR_VERY_STRONG_PASSWORD #CHANGE THIS!!!!!!
   
   # Allow connections from the Docker network
   rpcallowip=172.17.0.0/16
   # Allow connections from the Mempool container network
   rpcallowip=172.18.0.0/16
   
   # ZMQ (ZeroMQ)
   zmqpubrawblock=tcp://127.0.0.1:28332
   zmqpubrawtx=tcp://127.0.0.1:28333
   
   # Disable the wallet
   disablewallet=1
   
   # Use a large cache (in MB) to speed up IBD
   dbcache=4096
   
   

2. A Synced Fulcrum Electrum Server:
   • Your Fulcrum node must be configured to listen for wallet connections. This guide uses the unencrypted tcp port, which is perfectly secure on an internal network (like Docker's or your LAN).

   Example: /home/satoshis/fulcrum/fulcrum.conf

   # --- Fulcrum Config ---
   # This is the main database directory.
   # It MUST be on your NVMe.
   datadir = /home/satoshis/fulcrum_db
   
   # --- Bitcoin Core Connection ---
   # Point to your bitcoind service
   bitcoind = 127.0.0.1:8332
   
   # These MUST match your bitcoin.conf
   rpcuser = YOUR_USER_NAME # CHANGE THIS!!!
   rpcpassword = YOUR_VERY_STRONG_PASSWORD # CHANGE THIS!!!!
   
   # --- Server Ports ---
   # Allow other computers on your network (like your desktop)
   # to connect over an encrypted channel.
   ssl = 0.0.0.0:50002
   tcp = 0.0.0.0:50001
   # Point to the SSL certs we just made
   cert = /home/satoshis/fulcrum/cert.pem
   key = /home/satoshis/fulcrum/key.pem
   
   # Optional: Uncomment and set a banner file
   banner = /home/satoshis/fulcrum/banner.txt
   
   # --- Performance & Privacy ---
   # We have 24GB RAM. bitcoind is using 4GB.
   # Let's give Fulcrum 5GB (5120MB).
   db_mem = 5120
   
   # We are a private node, no need to peer.
   peering = false 
   
   

Phase 1: Install the Docker Engine

1. Add Docker's Security Key

# Update your package list and install prerequisites
sudo apt-get update
sudo apt-get install ca-certificates curl

# Add Docker's official GPG key
sudo install -m 0755 -d /etc/apt/keyrings
sudo curl -fsSL https://download.docker.com/linux/ubuntu/gpg -o /etc/apt/keyrings/docker.asc
sudo chmod a+r /etc/apt/keyrings/docker.asc

2. Add the Docker Repository

# This is one single command, broken up with \ for readability
echo \
  "deb [arch=$(dpkg --print-architecture) signed-by=/etc/apt/keyrings/docker.asc] https://download.docker.com/linux/ubuntu \
  $(. /etc/os-release && echo "${UBUNTU_CODENAME:-$VERSION_CODENAME}") stable" | \
  sudo tee /etc/apt/sources.list.d/docker.list > /dev/null

3. Install Docker

sudo apt-get update

sudo apt-get install docker-ce docker-ce-cli containerd.io docker-buildx-plugin docker-compose-plugin

4. (CRITICAL) Add Your User to the docker Group

# Replace 'satoshis' with your own username
sudo usermod -aG docker satoshis

IMPORTANT: This permission change only applies to new terminal sessions. For the change to take effect, you MUST log out of your SSH session and log back in before proceeding.

exit

Phase 2: Prepare the Mempool Environment

# Go to your home directory
cd ~

# Clone the project from GitHub
git clone https://github.com/mempool/mempool.git

# Move into the new docker directory
cd mempool/docker

Phase 3: Find Your Host's "Secret Passageway" IP

ip addr show docker0 | grep "inet\b" | awk '{print $2}' | cut -d/ -f1

Phase 4: Configure the docker-compose.yml Blueprint

cp docker-compose.yml docker-compose.original.yml

nano docker-compose.yml

1. ctrl + 6 marks the beginning of text to be cut
2. ctrl + / + 999 jumps to the end whilst marking
3. ctrl + k cuts the selected text

# This is the blueprint for our Mempool stack
# We removed 'version: "3.7"' as it's obsolete and causes a warning.

services:
  # 1. The Web Frontend (what you see)
  web:
    image: mempool/frontend:latest # Use the latest official image
    container_name: mempool-web
    restart: unless-stopped
    ports:
      # This connects your server's port 8080 to the container's port 8080
      # You will access your instance at http://YOUR_NODE_IP:8080
      - "8080:8080"
    environment:
      FRONTEND_HTTP_PORT: "8080"
      BACKEND_MAINNET_HTTP_HOST: "api" # Tells the frontend to get data from the 'api' container
    depends_on:
      - api # Won't start until the 'api' is running

  # 2. The Backend API (the brain)
  api:
    image: mempool/backend:latest
    container_name: mempool-api
    restart: unless-stopped
    depends_on:
      - db # Won't start until the 'db' is running
    volumes:
      - ./data:/data # Saves mempool's cache to your server's disk
    environment:
      # --- Connection to Fulcrum (Electrum) ---
      MEMPOOL_BACKEND: "electrum"
      ELECTRUM_HOST: "172.17.0.1"     # [REPLACE IF YOURS WAS DIFFERENT] The 'docker0' IP from Phase 3
      ELECTRUM_PORT: "50001"          # Your Fulcrum's unencrypted TCP port
      ELECTRUM_TLS_ENABLED: "false"

      # --- Connection to Bitcoin Core ---
      CORE_RPC_HOST: "172.17.0.1"     # [REPLACE IF YOURS WAS DIFFERENT] The 'docker0' IP from Phase 3
      CORE_RPC_PORT: "8332"
      
      # [REPLACE THESE VALUES]
      # These MUST match your bitcoin.conf
      CORE_RPC_USERNAME: "YOUR_USER_NAME"
      CORE_RPC_PASSWORD: "YOUR_VERY_STRONG_PASSWORD"

      # --- Connection to the Database ---
      DATABASE_HOST: "db"             # Tells the API to find the 'db' container
      DATABASE_DATABASE: "mempool"
      DATABASE_USERNAME: "mempool"
      DATABASE_PASSWORD: "mempool"

  # 3. The Database (the memory)
  db:
    image: mariadb:10.5               # A MariaDB (MySQL) database
    container_name: mempool-db
    restart: unless-stopped
    environment:
      MYSQL_DATABASE: "mempool"
      MYSQL_USER: "mempool"
      MYSQL_PASSWORD: "mempool"
      MYSQL_ROOT_PASSWORD: "admin"    # Internal password, you don't need to change this
    volumes:
      - ./mysql/data:/var/lib/mysql  # Saves the database to your server's disk

Phase 5: Launch and Secure

docker compose up -d

Common Sticking Point: "Permission Denied"

If you immediately get a permission denied while trying to connect to the Docker daemon socket error, it means you did not log out and log back in after Phase 1, Step 4.

The Fix:

1. Log out: exit
2. Log back in: ssh satoshis@node
3. Go back to the directory: cd ~/mempool/docker
4. Run the command again: docker compose up -d

Docker will now download the images. This may take a few minutes.

Let's fix the server's firewall settings.

# Open your server's firewall to allow access to the web frontend from your LAN.
sudo ufw allow 8080/tcp

# Allow the Docker host network
sudo ufw allow from 172.17.0.0/16 to any port 8332

# Allow the Docker Compose network
sudo ufw allow from 172.18.0.0/16 to any port 8332

sudo ufw reload

Phase 6: Access Your Private Mempool

docker compose ps

• If you are on your local network: http://192.168.8.50:8080 (Replace with your node's LAN IP)
• If you are connecting via Tailscale (from anywhere): http://100.111.61.50:8080 (Replace with your node's Tailscale IP)

Maintenance: How to Stop and Update

• To stop your Mempool instance:

  # Navigate to the blueprint directory
  cd ~/mempool/docker
  # Tell Docker to take the stack "down"
  docker compose down
  

• To update to the latest version:

  cd ~/mempool/docker
  docker compose pull  # Downloads the latest images
  docker compose up -d # Restarts the stack with the new images