Neutron Interchain Queries (ICQ) Relayer Setup

Repository: ICQ Relayer (v0.3.0 is the latest tag)

First we need to set up a configuration that will be used by the ICQ relayer. Create a file (e.g. “.env_icq_relayer” in current directory) with the following content (provided values are just an example on pion-1 Neutron testnet; comments explaining specific parameters can be removed):

RELAYER_NEUTRON_CHAIN_RPC_ADDR=https://rpc-falcron.pion-1.ntrn.tech:443
RELAYER_NEUTRON_CHAIN_REST_ADDR=https://rest-falcron.pion-1.ntrn.tech
# Path to a directory that contains a key that ICQ relayer will use for signing transactions.
# Usually a node home directory (e.g. $HOME/.neutrond)
RELAYER_NEUTRON_CHAIN_HOME_DIR=$HOME/.neutrond
# The name of the key in directory above that ICQ relayer will use for signing transactions
RELAYER_NEUTRON_CHAIN_SIGN_KEY_NAME=wallet1
# Keyring backend used to lookup the key above
RELAYER_NEUTRON_CHAIN_KEYRING_BACKEND=test
RELAYER_NEUTRON_CHAIN_DENOM=untrn
RELAYER_NEUTRON_CHAIN_GAS_PRICES=0.0055untrn
# Since Neutron is using dynamic gas prices with feemarket, the queried gas price will be multiplied by this multiplier
RELAYER_NEUTRON_CHAIN_GAS_PRICE_MULTIPLIER=2
# If the multiplied value goes above the maximum gas price, then the maximum gas price is used
RELAYER_NEUTRON_CHAIN_MAX_GAS_PRICE=0.011
# Gas adjustment used after transaction gas estimation
RELAYER_NEUTRON_CHAIN_GAS_ADJUSTMENT=1.5
# Connection ID (Neutron end) of IBC connection between Neutron and target chain (Gaia)
RELAYER_NEUTRON_CHAIN_CONNECTION_ID=connection-42
RELAYER_NEUTRON_CHAIN_OUTPUT_FORMAT=json or yaml
# RPC address of target chain (in our case Gaia)
RELAYER_TARGET_CHAIN_RPC_ADDR=https://rpc-rs.cosmos.nodestake.top:443
# Hydro contract address only, to relay only ICQ results for our needs
RELAYER_REGISTRY_ADDRESSES=[HYDRO_CONTRACT_ADDRESS]
# We are only using key-value ICQs
RELAYER_ALLOW_TX_QUERIES=false
# Essential for Hydro to work is to set this param to true
RELAYER_ALLOW_KV_CALLBACKS=true
RELAYER_STORAGE_PATH=$HOME/.neutron_queries_relayer/leveldb
LOGGER_LEVEL=debug
# For other (optional) parameters description see the github repository at the top

Then, execute the following command to load the previously defined environment:

sh export $(grep -v '^#' .env_icq_relayer | xargs)

Finally, start the Relayer:

neutron_query_relayer start

Notes

• After executing start command, any misconfiguration will be seen in the logs and the relayer will fail to start. This only applies to misconfigurations such as providing invalid RPC/REST addreses, an absence of the signer key, etc. If, for example, a wrong smart contract address (or no address at all) is provided for RELAYER_REGISTRY_ADDRESSES, or a wrong connection ID is provided for RELAYER_NEUTRON_CHAIN_CONNECTION_ID parameter, then the relayer will start with whatever values it was provided with.

• To verify if the relayer started relaying ICQ results for the Hydro smart contract, make the smart contract create at least one ICQ and run the following query against the Neutron:

  neutrond q interchainqueries registered-queries --owners $HYDRO_CONTRACT_ADDR

  The given ICQ should have non-zero and non-null values for last_submitted_result_local_height and last_submitted_result_remote_height.