Claiming Rewards

PoVW was added to RISC Zero’s zkVM (R0VM) in version 3.0.1. To enable PoVW within Bento, requires release v0.14.0 and above.

To install the latest release, and use the helpful setup script, provers can follow the instructions on the Quick Start before continuing with the next step.

Provers use the Boundless CLI to stake $ZKC, prepare work log updates, and submit them onchain. To install the Boundless CLI (and build with CUDA support), run:

cargo install --locked --git https://github.com/boundless-xyz/boundless boundless-cli --branch release-1.0 --bin boundless -F cuda

Some commands in this tutorial use cast from the Foundry toolkit. This is not necessary, but it will make some CLI commands more straightforward.

Follow the instructions here.

Follow the instructions here.

Run the following:

rzup install risc0-groth16

To enable PoVW in Bento, first make sure to stop Bento safely. This ensures that any in-progress proving jobs are completed before terminating the proving process. If Bento is backing the Broker, please carry out Step 1 from Safe Upgrade Steps and then return to this page.

If Bento is running without the Broker, Bento can be safely stopped with:

just bento down

Before starting Bento again, provers need to enable the PoVW feature. This requires a valid Ethereum address set to the POVW_LOG_ID environment variable. It is recommended to set this directly with your compose.yml file:

x-base-environment: &base-environment
    DATABASE_URL: postgresql://${POSTGRES_USER:-worker}:${POSTGRES_PASSWORD:-password}@${POSTGRES_HOST:-postgres}:${POSTGRES_PORT:-5432}/${POSTGRES_DB:-taskdb}
  REDIS_URL: redis://${REDIS_HOST:-redis}:6379
  S3_URL: http://${MINIO_HOST:-minio}:9000
  S3_BUCKET: ${MINIO_BUCKET:-workflow}
  S3_ACCESS_KEY: ${MINIO_ROOT_USER:-admin}
  S3_SECRET_KEY: ${MINIO_ROOT_PASS:-password}
  RUST_LOG: ${RUST_LOG:-info}
  RISC0_HOME: /usr/local/risc0
  RUST_BACKTRACE: 1
  POVW_LOG_ID: "0x1234...5678"

Provers will need the private key for this address when using the PoVW CLI to prepare and submit valid work to the PoVW contracts. Please see Provers submit a Work Log Update for more information.

Export the private key for the POVW_LOG_ID, and a valid RPC endpoint URL for Ethereum mainnet:

export PRIVATE_KEY=[PRIVATE_KEY]
export RPC_URL=[RPC_URL]

Once enabled, Bento can be run as normal with:

just bento

Or if running the broker as well:

just broker

will start both the broker and Bento.

Before provers can begin contributing work to claim PoVW rewards, they must stake $ZKC. The amount of PoVW rewards that provers claim every epoch is determined by the amount of $ZKC they have staked. This is currently set to staked amount / 15. Therefore if a prover has staked 150 $ZKC, they are eligible to receive a maximum of 10 $ZKC every epoch. For further details, please see Staking $ZKC.

Once staked, provers are eligible for $ZKC rewards effective immediately i.e. starting from the reward epoch they staked in; reward epochs are approximately 2 days long.

First, make sure to set a valid RPC URL environment variable for Ethereum mainnet:

export RPC_URL=https://...

To check the current $ZKC balance of POVW_LOG_ID:

boundless zkc balance ${POVW_LOG_ID:?} --rpc-url ${RPC_URL}

To stake 100 $ZKC, run the following command:

boundless zkc stake --amount $(cast parse-units 100 18)

Provers are now ready to run proving workloads with PoVW enabled; this can be done by running a prover on the Boundless marketplace or elsewhere.

For each proving job, R0VM will automatically generate work receipts. These work receipts track the amount of proving work done. Each epoch, provers will need to submit their accumulated work to the PoVW accounting smart contract. To do this, provers must use the PoVW CLI and run the following three commands, prepare, submit and claim.

Once provers have run some jobs, they can create a new work log (i.e. state file) from receipts stored in Bento using prepare:

boundless povw prepare --new ${POVW_LOG_ID} --state ${STATE_FILE_LOCATION} --from-bento

where ${STATE_FILE_LOCATION} is something like: ~/folder/state.bin. Please note that this state file is very important and it should be kept in a durable location. Please see Keeping the State File Safe.

prepare compresses all work receipts and stores the work log update to the state file. This process is entirely local (i.e. it does not send any transaction). For this work to be eligible for $ZKC rewards from the PoVW contract, this work log update must now be sent onchain.

Provers only specify the --new ${POVW_LOG_ID} flag once, this is necessary to create the state file for that specific Log ID. Once the state file is created, for any further updates to the work log, run the following:

boundless povw prepare --state ${STATE_FILE_LOCATION} --from-bento

After running prepare, provers are ready to post the work log update onchain:

boundless povw submit --state ${STATE_FILE_LOCATION} --rpc-url ${RPC_URL}

After the reward epoch has finalized, rewards can be claimed with:

boundless povw claim --log-id ${POVW_LOG_ID} --beacon-api-url${BEACON_CHAIN_RPC_ENDPOINT} --rpc-url ${RPC_URL}

If the reward epoch has not been finalized yet, provers can check details of the the current epoch:

boundless zkc get-current-epoch

This will return the epoch number; this epoch number can be passed into the following command to get the end time for the current epoch:

boundless zkc get-epoch-end-time <EPOCH_NUMBER>

Generating any ZK proofs, with the POVW feature enabled in Bento, will generate work receipts.

The prepare command compresses all local work receipts to reflect work done during any given epoch - this update is stored in a local “state” file.

Towards the end of an epoch, the prover must verify their work done to the PoVW contracts using the submit command. This will sign the work log update using the Log ID’s private key and post the update to the PoVW contracts.

The prover waits for the current reward epoch to finalize. This allows all work log updates to be tallied, and all the respective rewards for each log ID to be calculated.

To check details of the current epoch, please see Checking Details of Current Reward Epoch,

Once the epoch has been finalized, the claim command can be used to claim any unclaimed rewards; claim uses Steel to query all work log updates and verify reward calculations.

claim requires both a valid archive node RPC endpoint and a Beacon Chain RPC endpoint (Quicknode offers both types of nodes with their paid plan).

Claiming rewards does not have to be done every epoch; all unclaimed rewards from past epochs will be claimed automatically on the next valid claim call.