Become a Reef chain validator and help secure the future of Reef network.

Who is this for?

Becoming a Validator is a serious responsibility that requires strong technical skills and quick problem solving ability as the baseline. Validators are elected by Nominators, so strong communication skills and ecosystem contributions are a good traits as well.

Validators’s core responsibility is reliable block production. However in practice becoming a validator is a highly competitive game, and as a result Validators may also provide additional services to the community, such as:

  • host Reef chain boot nodes
  • host fast sync block export/import infrastructure
  • develop and maintain DevOps tooling
  • develop and maintain security tooling
  • develop and maintain block explorers, RPC nodes, SQL indexers and other public good infrastructure

Become a validator

This guide only covers setting up the validator node, however there is a lot more to being a validator than running a node.


The first step is bonding (staking) Reef tokens. This step is the same as bonding for Nominators.

Start the validator node

Here is the sample command for spinning up a --validator node on testnet.

./reef-node \
  --base-path /tmp/reefnode \
  --chain testnet \
  --validator \
  --port 30333 \
  --ws-port 9944 \
  --rpc-port 9933 \
  --rpc-methods Unsafe \
  --no-mdns \
  --no-telemetry \
  --name MyValidatorNode

Note the --rpc-methods Unsafe flag. This flag is necessary to enable key management endpoints. Do not expose these endpoints to the public internet. You are solely responsible for adequate operational security.

Setup the session keys

There are 2 options for setting the session keys:

1.) Generate them offline and submit via author_setKeys

2.) Let the node generate the keys via author_rotateKeys

Generating the keys by hand

To generate the keys by hand we can use our keypair tool. Note that the GRANDPA keys are ED25519, while the rest are SR25519.

We can then submit the seed+key derivation paths (suri) and the corresponding AccountId’s for BABE and GRANDPA keys via RPC:

curl http://localhost:9934 -H "Content-Type:application/json;charset=utf-8" -d \
  '{ "jsonrpc":"2.0", "id":1, "method":"author_insertKey", "params": [ "babe", "seed//babe", "0x..." ] }'

curl http://localhost:9934 -H "Content-Type:application/json;charset=utf-8" -d \
  '{ "jsonrpc":"2.0", "id":1, "method":"author_insertKey", "params": [ "babe", "seed//grandpa", "0x..." ] }'

Generating the keys within node

Generating the session keys (or rotating the keys) can be done by calling the author_rotateKeys RPC method.

The result will be hex encoded:

{'jsonrpc': '2.0',
 'result': '0x4e0f43d7196b342b86c634ce6b1797e49e4ba5f01763324f2c9960ea33899561de3a616370becc71cb01775dc938f69d17b1ee0a4fd1689ede79c107f24b224c',
 'id': 7}

The result needs to be submitted as session.setKeys(keys, proof) extrinsic call.



The last step is to signal that we want to become a validator. This is done by calling session.validate(ValidatorPreferences).


Congratulations, you are now a candidate validator. To become elected as a Validator you will need to get Nominator’s support and win the elections. Good luck!