In this example, you’ve created an NFT on Zora, and want to incentivize users to mint it by offering additional rewards.
Make sure you’ve completed the quick start guide before proceeding with this example.

See the code

See the full example code

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Set up a Managed Budget

First you’ll need to either initialize a new budget, or use an existing one, and allow the budget to spend a certain amount of your selected ERC20. 
import { BoostCore } from '@boostxyz/sdk/BoostCore'
import { BoostRegistry } from '@boostxyz/sdk/BoostRegistry'
import { ManagedBudget, Roles } from '@boostxyz/sdk'
import { parseUnits, erc20Abi } from 'viem'
import { wagmiConfig } from '../config'

// Initialize the BoostCore and BoostRegistry modules
const registry = new BoostRegistry({ config: wagmiConfig })
const core = new BoostCore({ config: wagmiConfig })

// Get the address of the BoostCore module
const coreAddress = core.assertValidAddress()

// Create a new budget and grant the correct permissions to the protocol
const budget = await registry.initialize('MyBudget', core.ManagedBudget({
  owner: "0xME",
  authorized: ["0xME", coreAddress], // authorized addresses
  roles: [Roles.ADMIN, Roles.MANAGER] // roles that the budget can assign to the protocol
}))

// scaffold your desired incentive to help calculate the total amount required to fund your budget
const erc20Incentive = core.ERC20Incentive({
  asset: '0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2',
  reward: parseEther('1'),
  limit: 10n,
  strategy: StrategyType.POOL,
})

const budgetedAmount = await erc20Incentive.getTotalBudget() // 10 WETH
const amountIncludingFees = await core.calculateProtocolFee(budgetedAmount)

// Allow the budget to spend your ERC20 token.
await writeContract(wagmiConfig, {
  abi: erc20Abi,
  address: '0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2', // The address of the ERC20 token you want to approve
  functionName: 'approve',
  args: [
    budget.assertValidAddress(), // The address of the budget account
    budgetedAmount // The amount of ERC20 token you want to approve, including protocol fee
  ],
})

// Allocate assets to the budget
await budget.allocate({
  amount: budgetedAmount
  asset: '0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2',
  target: "0xME",
})

​
Define The Action

Next you’ll need to define the action that qualifies a user to claim the reward. For Zora, we want to reward users that mint a specific NFT on Zora. To do this, we’ll key off of the Purchased event, which has the event signature Purchased(address indexed,address indexed,uint256 indexed,uint256,uint256).
Purchased Event

'Purchased' Event Structure. We reference the event arguments using zero-based indexing. The third argument represents the tokenId, which corresponds to index 2.

Here is how you can structure the EventActionPayload to target the Purchased event. The important parameters to target in the event data are the tokenId and the NFT contract address.
If you’re using a known event, you can use the selectors package to get the signature.
import { selectors } from '@boostxyz/signatures/events'
const selector = selectors[
  'Purchased(address indexed,address indexed,uint256 indexed,uint256,uint256)'
] as Hex;
Here is an example of the Purchased event 
import {
  EventActionPayload,
  ActionStep,
  ActionClaimant,
  SignatureType,
  FilterType,
  PrimitiveType
} from '@boostxyz/sdk/Actions/EventAction'
import { selectors } from '@boostxyz/signatures/events'

// Use the Purchased signature from the selectors package
const selectedSignature = selectors[
  'Purchased(address indexed,address indexed,uint256 indexed,uint256,uint256)'
] as Hex;

// The EventAction step outlines the criteria that the validator uses to determine eligibility for reward redemption.
const eventActionStep: ActionStep = {
  signature: selectedSignature,
  signatureType: SignatureType.EVENT,
  targetContract: '0x9D2FC5fFE5939Efd1d573f975BC5EEFd364779ae', // The address of the Zora NFT contract
  // We want to target the `tokenId` property on the Purchase event
  actionParameter: {
    filterType: FilterType.EQUAL, // Filter to check for equality
    fieldType: PrimitiveType.UINT, // The field we're filtering is the tokenId
    fieldIndex: 2, // The index of the tokenId in the event data
    filterData: toHex(3n, { size: 1 }), // Targetting tokenId 3 on the collection (filter data must be in hex)
  },
};
Next, we need to define the action claimant and create the payload for the new event action. The eventAction payload consists of the actionClaimant and the actionSteps we defined previously. The purpose of the eventAction is to track and reward users based on their interactions with the specified event.
  1. actionClaimant: This object defines the conditions under which a user is eligible to claim rewards. It includes:
    • signatureType: Specifies that the signature type is an event.
    • signature: The event signature we are targeting, in this case, the Purchased event.
    • fieldIndex: Indicates which field in the event data we are interested in; We can target any field that contains the claimants address.
    • targetContract: The address of the contract we are monitoring for the event.
  2. actionSteps: This array can contain up to four action steps that outline the specific actions or conditions that must be met for the event action to be valid. In this example, we include the previously defined eventActionStep.
Next, we create an EventAction, passing in the constructed eventActionPayload. 
const eventActionPayload = {
  actionClaimant: {
    signatureType: SignatureType.EVENT,
    signature: selectedSignature, // Purchased event signature
    fieldIndex: 0, // Targeting the 'sender' argument which is the address that initiated the purchase
    targetContract: '0x9D2FC5fFE5939Efd1d573f975BC5EEFd364779ae', // The address of the Zora NFT contract
  },
  actionSteps: [eventActionStep] // use can place up to 4 action steps
};

// create the EventAction with the custom payload
const eventAction = core.EventAction(eventActionPayload);

​
Deploy the Boost

Once the event action is created, we can set up the incentives and deploy our boost. 
import { StrategyType } from '@boostxyz/sdk/Incentive'

// This allows for 10 participants to be rewarded with 1 token each
const incentives = [
    core.ERC20Incentive({
      asset: '0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2',
      reward: parseEther('1'),
      limit: 10n,
      strategy: StrategyType.POOL,
    }),
  ],

// Deploy the boost
const boost = await core.createBoost({
  maxParticipants: 10n, // Set a max number of participants
  budget: budget, // Use the ManagedBudget we set up earlier
  action: eventAction, // Pass the manually created EventAction
  incentives: incentives,
  allowList: core.OpenAllowList(),
});

​
Claiming Incentives

Once a claimant has successfully completed the action, you can claim the incentive for that claimant.
ERC20Incentive is a fixed reward incentive. If you would like to have a variable reward based on on-chain logic, you can use the ERC20VariableCriteriaIncentive type.
In order to successfully claim the reward for a claimant, you will need to generate the signature payload. To generate the signature payload you will need to call the Boost /signatures api endpoint with the following params:
  • boostId: The id of the boost where the action was completed. The format is chainId:boostId (e.g. 8453:0x378632819f39c74c4f56b1429e760739c5fb51b7:12)
  • txHash: The hash of the transaction that completed the action.
The signatures api will return an array of signatures, one for each available incentive on the boost.

Claim Signature API

See additional documentation on how to build a claim signature
 
  import axios from 'axios';

  const { data } = await axios.get(`${BOOST_API_URL}/signatures`, {
    params: {
      boostId: `${chainId}:${boostCoreAddress}:${boost.id}`,
      txHash,
    }
  });

  for (const item of data) {
    const { signature, incentiveId, claimant } = item;

    // Claim the incentive for the claimant
    await core.claimIncentiveFor(
      boost.id,
      incentiveId,
      referrer,
      signature,
      claimant,
    );
  }
There can be multiple incentives to claim in a single boost. The example shown only has one incentive.
The boost will stay active until the maxParticipants set for the boost is reached.