Run Kiln

Kiln is the latest long-running merge testnet. It provides the perfect opportunity to verify your setup works as expected through the proof-of-stake transition and in a post-merge context. If you come across any issues, please report them here.

N.B. Post merge, Node runners will need to run both a consensus and execution layer client.

1. Preparation

1.1 Download configs

To download the merge testnet configurations, run:

git clone
cd merge-testnets/kiln 

1.2 Generate secret

To generate and write the JWT secret to a file, run:

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

You will need to pass this file to both the Execution Client and the Consensus Client (the JWT secret is an authentication mechanism between CL/EL).

2. Execution client

We recommend running either Nethermind or Geth with Nimbus


2.1N Clone and build

Clone and build the kiln branch of Nethermind:

git clone --recursive -b kiln
cd nethermind/src/Nethermind
dotnet build Nethermind.sln -c Release

2.2N Start the client

Start Nethermind:

cd kiln/nethermind/src/Nethermind/Nethermind.Runner
dotnet run -c Release -- --config kiln --JsonRpc.Host= --JsonRpc.JwtSecretFile=/tmp/jwtsecret


2.1G Clone and build

Clone and build the merge-kiln-v2 branch from Marius' fork of Geth:

git clone -b merge-kiln-v2
cd go-ethereum 
make geth
cd ..

2.2G Start the client

Start Geth:

cd kiln
./go-ethereum/build/bin/geth init genesis.json  --datadir "geth-datadir"
./go-ethereum/build/bin/geth --datadir "geth-datadir" --http --http.api="engine,eth,web3,net,debug" --ws --ws.api="engine,eth,web3,net,debug" --http.corsdomain "*" --networkid=1337802 --syncmode=full --authrpc.jwtsecret=/tmp/jwtsecret --bootnodes "enode://c354db99124f0faf677ff0e75c3cbbd568b2febc186af664e0c51ac435609bade[email protected]" console

3. Nimbus

3.1 Clone and build Nimbus from source

Clone and build Nimbus from source from the kiln-dev-auth branch:

git clone --branch=kiln-dev-auth
cd nimbus-eth2
make update OVERRIDE=1
make nimbus_beacon_node
cd ..

3.2 Start the client

Start Nimbus:

nimbus-eth2/build/nimbus_beacon_node \
    --network=merge-testnets/kiln \
    --web3-url=ws:// \
    --rest \
    --metrics \
    --log-level=DEBUG \
    --terminal-total-difficulty-override=20000000000000 \

Useful resources