# Teku

## Overview

{% hint style="info" %}
[PegaSys Teku](https://consensys.net/knowledge-base/ethereum-2/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](https://consensys.net) 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.
{% endhint %}

{% hint style="info" %}
**Note**: Teku is configured to run both **validator client** and **beacon chain client** in one process.
{% endhint %}

#### Official Links

| Subject       | Links                                                                                                         |
| ------------- | ------------------------------------------------------------------------------------------------------------- |
| Releases      | <https://github.com/ConsenSys/teku/releases>                                                                  |
| Documentation | <https://docs.teku.consensys.net/introduction>                                                                |
| Website       | [https://consensys.net/knowledge-base/ethereum-2/teku](https://consensys.net/knowledge-base/ethereum-2/teku/) |

### 1. Initial configuration

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

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

Install dependencies.

```bash
sudo apt install curl ccze openjdk-17-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).

<details>

<summary>Option 1 - Download binaries</summary>

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

```bash
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-* teku
# Cleanup
rm teku.tar.gz
```

Install the binaries.

<pre class="language-bash"><code class="lang-bash"><strong>sudo mv $HOME/teku /usr/local/bin/teku
</strong></code></pre>

</details>

<details>

<summary>Option 2 - Build from source code</summary>

Build the binaries.

```bash
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.

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

Install the binaries.

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

</details>

### **3. Setup and configure systemd**

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

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

Paste the following configuration into the file.

{% tabs %}
{% tab title="Standalone Beacon Node (Recommended)" %}

```shell
[Unit]
Description=Teku Beacon Node Consensus Client service for Holesky
Wants=network-online.target
After=network-online.target
Documentation=https://www.nodebridgeafrica.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`.
{% endtab %}

{% tab title="Combined BN+VC" %}
{% hint style="info" %}
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](https://rescuenode.com/docs/how-to-connect/solo).
{% endhint %}

```shell
[Unit]
Description=Teku Beacon Node + Validator Consensus Layer Client service for Holesky
Wants=network-online.target
After=network-online.target
Documentation=https://www.nodebridgeafrica.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`.
{% endtab %}
{% endtabs %}

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

```bash
sudo systemctl daemon-reload
sudo systemctl enable consensus
```

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

```bash
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.

```bash
sudo journalctl -fu consensus | ccze
```

**Example of Synced Consensus Client Logs**

```bash
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

{% tabs %}
{% tab title="View Logs" %}

```bash
sudo journalctl -fu consensus | ccze
```

**Example of Synced Teku Consensus Client Logs**

```bash
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
```

{% endtab %}

{% tab title="Stop" %}

```bash
sudo systemctl stop consensus
```

{% endtab %}

{% tab title="Start" %}

```bash
sudo systemctl start consensus
```

{% endtab %}

{% tab title="View Status" %}

```bash
sudo systemctl status consensus
```

{% endtab %}

{% tab title="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

```bash
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.
{% endtab %}
{% endtabs %}

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.

{% hint style="info" %}
If you wanted to setup a full node, not a staking node, stop here! Congrats on running your own full node! :tada:
{% endhint %}
