Become an Amplifier Verifier

By running a verifier for a chain integration with Axelar’s Amplifier, you will be responsible for voting on the validity of transactions on the Axelar network and signing command batches for a given chain.

tofnd and ampd

A verifier uses ampd, an off-chain daemon responsible for voting and signing with the Amplifier protocol, and tofnd, a threshold cryptography library that ampd depends on.

There are three ways to set up and run a verifier:

• Option 1: Source — Clone and build directly from the GitHub source code.
• Option 2: Binaries — This method requires you to install and run the tofnd and ampd binaries on your local machine.
• Option 3: Docker — Use Docker to set up tofnd and ampd.

Set up tofnd

ampd needs access to a locally running tofnd instance in order to onboard as a verifier or run the daemon. See the tofnd repository for more information.

git clone git@github.com:axelarnetwork/tofnd.git --recursive
cd tofnd
cargo build --release --locked

tofnd -m create
mv ~/.tofnd/export ~/.tofnd/export-new-location

~/Downloads/tofnd*-v1.0.1 -m create
mv ~/.tofnd/export ~/.tofnd/export-new-location

docker pull axelarnet/tofnd:v1.0.1
docker run -p 50051:50051 --env MNEMONIC_CMD=auto --env NOPASSWORD=true --env ADDRESS=0.0.0.0 -v tofnd:/.tofnd axelarnet/tofnd:v1.0.1

Set up ampd

docker pull axelarnet/axelar-ampd:v0.6.0
docker run axelarnet/axelar-ampd:v0.6.0 verifier-address

Add ampd to your PATH

This will allow you to begin commands with ampd. If you set up ampd through source or Docker, you can skip this step.

Configure the verifier

Create an ampd configuration file at ~/.ampd/config.toml.

This configuration file tells ampd how to connect to your local tofnd, how to talk to the devnet and the Amplifier smart contracts, and includes a default configuration for verifying transactions on the Avalanche testnet.

The following is an example config.toml file for the verifier devnet:

tm_jsonrpc="http://devnet-verifiers.axelar.dev:26657"
tm_grpc="tcp://devnet-verifiers.axelar.dev:9090"
event_buffer_cap=10000

[service_registry]
cosmwasm_contract="axelar1qk00h5atutpsv900x202pxx42npjr9thg58dnqpa72f2p7m2luas9x8txw"

[broadcast]
batch_gas_limit="20000000"
broadcast_interval="1s"
chain_id="devnet-verifiers"
gas_adjustment="2"
gas_price="0.00005uverifiers"
queue_cap="1000"
tx_fetch_interval="1000ms"
tx_fetch_max_retries="15"

[tofnd_config]
batch_gas_limit="10000000"
key_uid="axelar"
party_uid="ampd"
url="http://127.0.0.1:50051"

[[handlers]]
cosmwasm_contract="axelar15nczwuqh0zcu6syeqsc4td6dphql7n2p7cgkl9raz97z5s3zdjrsc8we9y"
type="MultisigSigner"

[[handlers]]
chain_name="avalanche"
chain_rpc_url="https://avalanche-fuji-c-chain-rpc.publicnode.com"
cosmwasm_contract="axelar1elaymnd2epmfr498h2x9p2nezc4eklv95uv92u9csfs8wl75w7yqdc0h67"
type="EvmMsgVerifier"

[[handlers]]
chain_name="ethereum-sepolia"
chain_rpc_url="https://rpc.ankr.com/eth_sepolia"
cosmwasm_contract="axelar1sxujcvele5eqtx0xc4wuy6jr0m28y0yt8spn7efc3527vc2j2xrqk6wkay"
type="EvmMsgVerifier"

See the ampd README on GitHub for instructions on formatting a config file for your own projects.

Fund your wallet

Prior to running the ampd daemon, you will need to set up your wallet with devnet funds.

1. Determine your verifier address:

   ampd verifier-address
   

   💡

   If you get a security warning while trying to run ampd on an Apple Silicon Mac, you can disable the gatekeeper for a single binary with sudo xattr -d com.apple.quarantine ~/Downloads/ampd-darwin-arm64-v0.6.0 or disable gatekeeper globally with sudo spctl --master-disable.

2. Fund your verifier address.

   1. Join the Axelar Discord.

   2. Get the Developer Role.

   3. Go to the #faucet channel and submit a request with your account to get 100 test tokens:

      !faucet devnet-verifiers [my verifier address]
      

Activate and run the verifier

1. Bond your verifier:

   ampd bond-verifier validators 100 uverifiers
   

   Bonded verifiers will stay bonded until they unbond or are removed by governance.

2. Register your public key with ecdsa or ed25519:

   ampd register-public-key ecdsa
   

3. Register support for desired chains, enabling ampd to participate in voting and signing for your supported chains.

   ampd register-chain-support validators avalanche ethereum-sepolia
   

   Multiple chain names can be passed, separated by a space (ampd register-chain-support [service name] [chains]...). Note that any chain you want to support here must be configured in your ampd config.toml file.

4. Authorize your verifier.

   This is dependent on the environment, and can be done via governance, or by the network operators.

   For devnet, fill out the Amplifier Verifier Onboarding Form for your address to be whitelisted.

5. Run the ampd daemon.

   Running ampd without any command will run the daemon. A state file will be created if it doesn’t yet exist. Its default location is ~/.ampd/state.json, which can be overridden by passing --state [path].

Productionizing

As you move towards testnet and mainnet, you should switch to running your own full Axelar node and your own full node or light client for any chains you are voting on.

Help

For more info about the available commands and options, run:

ampd --help

Feedback

If you have any feedback or would like to report a bug, please file an issue in the Axelar Developer Support repository.