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.

Start the validator node

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

./reef-node \
  --chain testnet \
  --validator \
  --base-path /reef/validator \
  --port 30333 \
  --ws-port 9944 \
  --rpc-port 9933 \
  --rpc-methods Unsafe \
  --no-mdns \
  --no-private-ipv4 \
  --no-telemetry \
  --name MyValidatorNode

If you have compiled your own binary, you need to pass the appropriate chain spec file, ie: --chain chain_spec_testnet.json/--chain chain_spec_mainnet.json instead of --chain testnet/--chain mainnet.

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.) Let the node generate the keys via author_rotateKeys (recommended)

2.) Generate them offline and submit via author_setKeys

Option 1: Generating the keys within node

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

curl http://localhost:9933 -H "Content-Type: application/json" -d \
  '{"id":1, "jsonrpc":"2.0", "method": "author_rotateKeys", "params":[]}'

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 from the controller account. See bonding section below.


Option 2: Inserting existing authoring keys

This is useful if our authoring keys have been generated via 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 all session keys via RPC:

curl http://localhost:9933 -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:9933 -H "Content-Type:application/json;charset=utf-8" -d \
  '{ "jsonrpc":"2.0", "id":1, "method":"author_insertKey", "params": [ "babe", "seed//grandpa", "0x..." ] }'

curl http://localhost:9933 -H "Content-Type:application/json;charset=utf-8" -d \
  '{ "jsonrpc":"2.0", "id":1, "method":"author_insertKey", "params": [ "imon", "seed//im-online", "0x..." ] }'

curl http://localhost:9933 -H "Content-Type:application/json;charset=utf-8" -d \
  '{ "jsonrpc":"2.0", "id":1, "method":"author_insertKey", "params": [ "audi", "seed//authority-discovery", "0x..." ] }'


This step is the same as when bonding as Nominators.

Note: The controller account set via should be used to make the session.setKeys and session.validate calls as well.


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!


To make yourself identifiable to the Reef community you can set on-chain identity for your address. The identity consists of display name, as well as socials (website, twitter, etc).

The easiest way to set the idenitity is via the console.