Last update: April 20, 2022

Run Besu and Teku on the Merge testnet

You can test Besu as an execution client and Teku as a consensus client on the Kiln Merge testnet.

1. Install Besu and Teku

Install Besu and Teku.

Ensure you meet the prerequisites for the installation option you use. For example, you must have Java version 11–16 if using the Besu and Teku binary distributions.

Ensure you meet the system requirements for Besu on Mainnet.

2. Generate the shared secret

Run the following command:

openssl rand -hex 32 | tr -d "\n" > jwtsecret.hex

You will specify jwtsecret.hex when starting both Besu and Teku. This is a shared JWT secret the clients use to authenticate each other when using the Engine API.

3. Generate validator keys and stake ETH

If you’re running a validator client, create a test Ethereum address (you can do this in MetaMask). Fund this address with testnet ETH using the Kiln Faucet.

Note

If you’re unable to get ETH using the faucet, you can ask for help on the EthStaker Discord.

Generate validator keys and stake your testnet ETH for one or more validators using the Kiln Staking Launchpad.

Important

Save the password you use to generate each key pair in a .txt file. You should also have a .json file for each validator key pair.

4. Start Besu

Run the following command:

besu \
  --network=kiln              \
  --rpc-http-enabled=true     \
  --rpc-http-host="0.0.0.0"   \
  --rpc-http-cors-origins="*" \
  --rpc-ws-enabled=true       \
  --rpc-ws-host="0.0.0.0"     \
  --host-allowlist="*"        \
  --engine-host-allowlist="*" \
  --engine-jwt-enabled=true   \
  --engine-rpc-http-port=8550 \
  --engine-rpc-ws-port=8551   \
  --Xmerge-support=true       \
  --engine-jwt-secret=<path to jwtsecret.hex>

Specify the path to the jwtsecret.hex file generated in step 2 using the --engine-jwt-secret option.

See the --engine-* options for more information on running Besu as an execution client.

5. Start Teku

Open a new terminal window.

Beacon node only

To run Teku as a beacon node (without validator duties), run the following command:

teku \
  --data-path "datadir-teku"                   \
  --network kiln                               \
  --ee-endpoint http://localhost:8550          \
  --Xee-version kilnv2                         \
  --ee-jwt-secret-file <path to jwtsecret.hex> \
  --log-destination console                    \
  --rest-api-enabled=true                      \
  --p2p-discovery-bootnodes "enr:-Iq4QMCTfIMXnow27baRUb35Q8iiFHSIDBJh6hQM5Axohhf4b6Kr_cOCu0htQ5WvVqKvFgY28893DHAg8gnBAXsAVqmGAX53x8JggmlkgnY0gmlwhLKAlv6Jc2VjcDI1NmsxoQK6S-Cii_KmfFdUJL2TANL3ksaKUnNXvTCv1tLwXs0QgIN1ZHCCIyk"

Specify the path to the jwtsecret.hex file generated in step 2 using the --ee-jwt-secret-file option.

Beacon node and validator client

To run Teku as a beacon node and validator in a single process, run the following command:

teku \
  --data-path "datadir-teku"                                \
  --network kiln                                            \
  --ee-endpoint http://localhost:8550                       \
  --Xee-version kilnv2                                      \
  --ee-jwt-secret-file <path to jwtsecret.hex>              \
  --log-destination console                                 \
  --rest-api-enabled=true                                   \
  --validators-proposer-default-fee-recipient=<ETH address> \
  --validator-keys=<path to key file>:<path to mnemonic file>[,<path to key file>:<path to mnemonic file>,...] \
  --p2p-discovery-bootnodes "enr:-Iq4QMCTfIMXnow27baRUb35Q8iiFHSIDBJh6hQM5Axohhf4b6Kr_cOCu0htQ5WvVqKvFgY28893DHAg8gnBAXsAVqmGAX53x8JggmlkgnY0gmlwhLKAlv6Jc2VjcDI1NmsxoQK6S-Cii_KmfFdUJL2TANL3ksaKUnNXvTCv1tLwXs0QgIN1ZHCCIyk"

Specify:

The path to the jwtsecret.hex file generated in step 2 using the --ee-jwt-secret-file option.
The test Ethereum address created in step 3 as the default fee recipient using the --validators-proposer-default-fee-recipient option.
The paths to the keystore .json file and password .txt file created in step 3 for each validator using the --validator-keys option. Separate the .json and .txt files with a colon, and separate entries for multiple validators with commas.

See the Teku --validators-* options for more information on running Teku as a validator.

6. Check validator status

After starting Besu and Teku, your node should start syncing and connecting to peers.

Example

Besu logs

2022-03-21 20:42:09.295-07:00 | EthScheduler-Timer-0 | INFO  | FullSyncTargetManager | No sync target, waiting for peers. Current peers: 0
2022-03-21 20:42:14.298-07:00 | EthScheduler-Timer-0 | INFO  | FullSyncTargetManager | No sync target, waiting for peers. Current peers: 0
2022-03-21 20:42:14.848-07:00 | nioEventLoopGroup-3-8 | INFO  | FullSyncTargetManager | No sync target, waiting for peers. Current peers: 4
2022-03-21 20:42:18.452-07:00 | nioEventLoopGroup-3-8 | INFO  | SyncTargetManager | Found common ancestor with peer Peer 0xab3a286b181721c794... at block 55127
2022-03-21 20:42:18.454-07:00 | nioEventLoopGroup-3-8 | INFO  | PipelineChainDownloader | PipelineChain download complete

Teku logs

2022-03-21 20:43:24.355 INFO  - Syncing     *** Target slot: 76092, Head slot: 2680, Remaining slots: 73412, Connected peers: 8
2022-03-21 20:43:36.363 INFO  - Syncing     *** Target slot: 76093, Head slot: 2879, Remaining slots: 73214, Connected peers: 10
2022-03-21 20:43:48.327 INFO  - Syncing     *** Target slot: 76094, Head slot: 3080, Remaining slots: 73014, Connected peers: 8
2022-03-21 20:44:00.339 INFO  - Syncing     *** Target slot: 76095, Head slot: 3317, Remaining slots: 72778, Connected peers: 6
2022-03-21 20:44:12.353 INFO  - Syncing     *** Target slot: 76096, Head slot: 3519, Remaining slots: 72577, Connected peers: 9

You can check your validator status by searching your Ethereum address on the Kiln Beacon Chain explorer. It may take up to multiple days for your validator to reach active status.