Teku

Overview

PegaSys Teku (formerly known as Artemis) is a Java-based Ethereum client designed & built to meet institutional needs and security requirements. PegaSys is an arm of ConsenSys dedicated to building enterprise-ready clients and tools for interacting with the core Ethereum platform. Teku is Apache 2 licensed and written in Java, a language notable for its materity & ubiquity.

Note: Teku is configured to run both validator client and beacon chain client in one process.

Official Links

Subject	Links
Releases
Documentation
Website

1. Initial configuration

Create a service user for the consensus service, create data directory and assign ownership.

sudo adduser --system --no-create-home --group consensus
sudo mkdir -p /var/lib/teku
sudo chown -R consensus:consensus /var/lib/teku

Install dependencies.

sudo apt install curl ccze openjdk-21-jdk libsnappy-dev libc6-dev jq git libc6 unzip -y

2. Install Binaries

• Downloading binaries is often faster and more convenient.

• Building from source code can offer better compatibility and is more aligned with the spirit of FOSS (free open source software).

Option 1 - Download binaries

Run the following to automatically download the latest linux release, un-tar and cleanup.

RELEASE_URL="https://api.github.com/repos/ConsenSys/teku/releases/latest"
LATEST_TAG="$(curl -s $RELEASE_URL | jq -r ".tag_name")"
BINARIES_URL="https://artifacts.consensys.net/public/teku/raw/names/teku.tar.gz/versions/${LATEST_TAG}/teku-${LATEST_TAG}.tar.gz"
echo Downloading URL: $BINARIES_URL

cd $HOME
# Download
wget -O teku.tar.gz $BINARIES_URL
# Untar
tar -xzvf teku.tar.gz -C $HOME
# Rename folder
mv teku-${LATEST_TAG} teku
# Cleanup
rm teku.tar.gz

Install the binaries.

sudo mv $HOME/teku /usr/local/bin/teku

Option 2 - Build from source code

Build the binaries.

mkdir -p ~/git
cd ~/git
git clone https://github.com/ConsenSys/teku.git
cd teku
# Get new tags
git fetch --tags
RELEASETAG=$(curl -s https://api.github.com/repos/ConsenSys/teku/releases/latest | jq -r .tag_name)
git checkout tags/$RELEASETAG
./gradlew distTar installDist

Verify Teku was built properly by displaying the version.

cd $HOME/git/teku/build/install/teku/bin
./teku --version

Install the binaries.

sudo cp -a $HOME/git/teku/build/install/teku /usr/local/bin/teku

3. Setup and configure systemd

Create a systemd unit file to define your consensus.service configuration.

sudo nano /etc/systemd/system/consensus.service

Paste the following configuration into the file.

Standalone Beacon Node (Recommended)

[Unit]
Description=Teku Beacon Node Consensus Client service for Holesky
Wants=network-online.target
After=network-online.target
Documentation=https://www.coincashew.com

[Service]
Type=simple
User=consensus
Group=consensus
Restart=on-failure
RestartSec=3
KillSignal=SIGINT
TimeoutStopSec=900
Environment=JAVA_OPTS=-Xmx6g
Environment=TEKU_OPTS=-XX:-HeapDumpOnOutOfMemoryError
ExecStart=/usr/local/bin/teku/bin/teku \
  --network=holesky \
  --data-path=/var/lib/teku/ \
  --data-storage-mode="minimal" \
  --initial-state="https://holesky.beaconstate.ethstaker.cc" \
  --ee-endpoint=http://127.0.0.1:8551 \
  --ee-jwt-secret-file=/secrets/jwtsecret \
  --rest-api-enabled=true \
  --rest-api-port=5052 \
  --p2p-port=9000 \
  --p2p-peer-upper-bound=100 \
  --p2p-peer-lower-bound=60 \
  --metrics-enabled=true \
  --metrics-port=8008 \
  --validators-proposer-default-fee-recipient=<0x_CHANGE_THIS_TO_MY_ETH_FEE_RECIPIENT_ADDRESS>

[Install]
WantedBy=multi-user.target

• Replace<0x_CHANGE_THIS_TO_MY_ETH_FEE_RECIPIENT_ADDRESS> with your own Ethereum address that you control. Tips are sent to this address and are immediately spendable.

• Not staking? If you only want a full node, delete the line beginning with

--validators-proposer-default-fee-recipient

To exit and save, press Ctrl + X, then Y, then Enter.

Combined BN+VC

This configuration combines the beacon chain and validator into one running service. While it is simpler to manage and run, this configuration is less flexible when it comes to running EL+CL failover nodes or in times you wish to resync your execution client and temporarily use Rocket Pool's Rescue Node.

[Unit]
Description=Teku Beacon Node + Validator Consensus Layer Client service for Holesky
Wants=network-online.target
After=network-online.target
Documentation=https://www.coincashew.com

[Service]
Type=simple
User=consensus
Group=consensus
Restart=on-failure
RestartSec=3
KillSignal=SIGINT
TimeoutStopSec=900
Environment=JAVA_OPTS=-Xmx6g
Environment=TEKU_OPTS=-XX:-HeapDumpOnOutOfMemoryError
ExecStart=/usr/local/bin/teku/bin/teku \
  --network=holesky \
  --data-path=/var/lib/teku/ \
  --data-storage-mode="minimal" \
  --initial-state="https://holesky.beaconstate.ethstaker.cc" \
  --ee-endpoint=http://127.0.0.1:8551 \
  --ee-jwt-secret-file=/secrets/jwtsecret \
  --rest-api-enabled=true \
  --rest-api-port=5052 \
  --p2p-port=9000 \
  --p2p-peer-upper-bound=100 \
  --p2p-peer-lower-bound=60 \
  --metrics-enabled=true \
  --metrics-port=8008 \
  --validator-keys=/var/lib/teku/validator_keys:/var/lib/teku/validator_keys \
  --validators-graffiti="🏠🥩🪙🛡️" \
  --validators-proposer-default-fee-recipient=<0x_CHANGE_THIS_TO_MY_ETH_FEE_RECIPIENT_ADDRESS>

[Install]
WantedBy=multi-user.target

• Replace<0x_CHANGE_THIS_TO_MY_ETH_FEE_RECIPIENT_ADDRESS> with your own Ethereum address that you control. Tips are sent to this address and are immediately spendable.

• Not staking? If you only want a full node, delete the whole three lines beginning with

--validator-keys
--validators-graffiti
--validators-proposer-default-fee-recipient

To exit and save, press Ctrl + X, then Y, then Enter.

Run the following to enable auto-start at boot time.

sudo systemctl daemon-reload
sudo systemctl enable consensus

Finally, start your consensus layer client and check it's status.

sudo systemctl start consensus
sudo systemctl status consensus

Press Ctrl + C to exit the status.

Check your logs to confirm that the consensus clients are up and syncing.

sudo journalctl -fu consensus | ccze

Example of Synced Consensus Client Logs

teku[64122]: 02:24:28.010 INFO  - Slot Event  *** Slot: 19200, Block: 1468A43F874EDE790DB6B499A51003500B5BA85226E9500A7A187DB9A169DE20, Justified: 1132, Finalized: 1133, Peers: 70
teku[64122]: 02:24:40.010 INFO  - Slot Event  *** Slot: 19200, Block: 72B092AADFE146F5D3F395A720C0AA3B2354B2095E3F10DC18F0E9716D286DCB, Justified: 1132, Finalized: 1133, Peers: 70

4. Helpful consensus client commands

View Logs

sudo journalctl -fu consensus | ccze

Example of Synced Teku Consensus Client Logs

teku[64122]: 02:24:28.010 INFO  - Slot Event  *** Slot: 19200, Block: 1468A43F874EDE790DB6B499A51003500B5BA85226E9500A7A187DB9A169DE20, Justified: 1132, Finalized: 1133, Peers: 70
teku[64122]: 02:24:40.010 INFO  - Slot Event  *** Slot: 19200, Block: 72B092AADFE146F5D3F395A720C0AA3B2354B2095E3F10DC18F0E9716D286DCB, Justified: 1132, Finalized: 1133, Peers: 70

Stop

sudo systemctl stop consensus

Start

sudo systemctl start consensus

View Status

sudo systemctl status consensus

Reset Database

Common reasons to reset the database can include:

• To reduce disk space usage

• To recover from a corrupted database due to power outage or hardware failure

• To upgrade to a new storage format

sudo systemctl stop consensus
sudo rm -rf /var/lib/teku/beacon
sudo systemctl restart consensus

With checkpoint sync enabled, time to re-sync the consensus client should take only a minute or two.

Now that your consensus client is configured and started, you have a full node.

Proceed to the next step on setting up your validator client, which turns a full node into a staking node.