lighthouse/book/src/graffiti.md

Validator Graffiti

Lighthouse provides four options for setting validator graffiti.

1. Using the "--graffiti-file" flag on the validator client

Users can specify a file with the --graffiti-file flag. This option is useful for dynamically changing graffitis for various use cases (e.g. drawing on the beaconcha.in graffiti wall). This file is loaded once on startup and reloaded everytime a validator is chosen to propose a block.

Usage: lighthouse vc --graffiti-file graffiti_file.txt

The file should contain key value pairs corresponding to validator public keys and their associated graffiti. The file can also contain a default key for the default case.

default: default_graffiti
public_key1: graffiti1
public_key2: graffiti2
...

Below is an example of a graffiti file:

default: Lighthouse
0x87a580d31d7bc69069b55f5a01995a610dd391a26dc9e36e81057a17211983a79266800ab8531f21f1083d7d84085007: mr f was here
0xa5566f9ec3c6e1fdf362634ebec9ef7aceb0e460e5079714808388e5d48f4ae1e12897fed1bea951c17fa389d511e477: mr v was here

Lighthouse will first search for the graffiti corresponding to the public key of the proposing validator, if there are no matches for the public key, then it uses the graffiti corresponding to the default key if present.

2. Setting the graffiti in the validator_definitions.yml

Users can set validator specific graffitis in validator_definitions.yml with the graffiti key. This option is recommended for static setups where the graffitis won't change on every new block proposal.

You can also update the graffitis in the validator_definitions.yml file using the Lighthouse API. See example in Set Graffiti via HTTP.

Below is an example of the validator_definitions.yml with validator specific graffitis:

---
- enabled: true
  voting_public_key: "0x87a580d31d7bc69069b55f5a01995a610dd391a26dc9e36e81057a17211983a79266800ab8531f21f1083d7d84085007"
  type: local_keystore
  voting_keystore_path: /home/paul/.lighthouse/validators/0x87a580d31d7bc69069b55f5a01995a610dd391a26dc9e36e81057a17211983a79266800ab8531f21f1083d7d84085007/voting-keystore.json
  voting_keystore_password_path: /home/paul/.lighthouse/secrets/0x87a580d31d7bc69069b55f5a01995a610dd391a26dc9e36e81057a17211983a79266800ab8531f21f1083d7d84085007
  graffiti: "mr f was here"
- enabled: false
  voting_public_key: "0xa5566f9ec3c6e1fdf362634ebec9ef7aceb0e460e5079714808388e5d48f4ae1e12897fed1bea951c17fa389d511e477"
  type: local_keystore
  voting_keystore_path: /home/paul/.lighthouse/validators/0xa5566f9ec3c6e1fdf362634ebec9ef7aceb0e460e5079714808388e5d48f4ae1e12897fed1bea951c17fa389d511e477/voting-keystore.json
  voting_keystore_password: myStrongpa55word123&$
  graffiti: "somethingprofound"

3. Using the "--graffiti" flag on the validator client

Users can specify a common graffiti for all their validators using the --graffiti flag on the validator client.

Usage: lighthouse vc --graffiti example

4. Using the "--graffiti" flag on the beacon node

Users can also specify a common graffiti using the --graffiti flag on the beacon node as a common graffiti for all validators.

Usage: lighthouse bn --graffiti fortytwo

Note: The order of preference for loading the graffiti is as follows:

1. Read from --graffiti-file if provided.
2. If --graffiti-file is not provided or errors, read graffiti from validator_definitions.yml.
3. If graffiti is not specified in validator_definitions.yml, load the graffiti passed in the --graffiti flag on the validator client.
4. If the --graffiti flag on the validator client is not passed, load the graffiti passed in the --graffiti flag on the beacon node.
5. If the --graffiti flag is not passed, load the default Lighthouse graffiti.

Set Graffiti via HTTP

Use the Lighthouse API to set graffiti on a per-validator basis. This method updates the graffiti both in memory and in the validator_definitions.yml file. The new graffiti will be used in the next block proposal without requiring a validator client restart.

Refer to Lighthouse API for API specification.

Example Command

DATADIR=/var/lib/lighthouse
curl -X PATCH "http://localhost:5062/lighthouse/validators/0xb0148e6348264131bf47bcd1829590e870c836dc893050fd0dadc7a28949f9d0a72f2805d027521b45441101f0cc1cde" \
-H "Authorization: Bearer $(cat ${DATADIR}/validators/api-token.txt)" \
-H "Content-Type: application/json" \
-d '{
    "graffiti": "Mr F was here"
}' | jq

A null response indicates that the request is successful.