Watch Transfer Policy Whitelist

policy.watchWhitelistUpdated

Watches WhitelistUpdated events on the TIP-403 registry.

Usage

import {  } from './viem.config'
 
const  = ..()
 
.(() => {
  for (const  of ) .(.)
{ policyId: 1n, updater: '0xf39Fd6e51aad88F6F4ce6aB8827279cffFb92266', account: '0x742d35Cc6634C0532925a3b844Bc9e7595f0bEbb', allowed: true }
})
 
// Later, tear down the watcher.
.()

import { ,  } from 'viem/tempo'
 
export const  = .({
  : .('0x...'),
})

Also callable standalone: Actions.policy.watchWhitelistUpdated(client, options), with Actions imported from 'viem/tempo'.

Recipes

Rebuild Whitelist Membership from Event History

Pass fromBlock and replay the allowed flag to derive current membership, since the registry only answers point queries via policy.isAuthorized.

import {  } from './viem.config'
 
const  = new <string>()
 
const  = ..({
  : { : 1n },
  : 1n,
})
 
.(() => {
  for (const  of ) {
    if (..) .(..)
    else .(..)
  }
})

import { ,  } from 'viem/tempo'
 
export const  = .({
  : .('0x...'),
})

Pause Payouts When a Recipient Loses Access

Pass args.account to track a payee's status under your token's policy, and pause scheduled payouts when they are removed.

import {  } from './viem.config'
 
const  = ..({
  : {
    : '0x742d35Cc6634C0532925a3b844Bc9e7595f0bEbb',
    : 1n,
  },
})
 
for await (const {  } of ) {
  for (const  of )
    if (!..) .('Pause payouts to:', ..)
Pause payouts to: 0x742d35Cc6634C0532925a3b844Bc9e7595f0bEbb
}

import { ,  } from 'viem/tempo'
 
export const  = .({
  : .('0x...'),
})

Return Value

Returns a watcher handle. Watching starts when the first listener (or async iterator) attaches, and stops when off is called.

type ReturnType = {
  /** Registers a log listener. Starts the watcher on first registration. Returns an unregister function. */
  onLogs: (fn: (logs: readonly Log[]) => void) => () => void
  /** Registers an error listener. Returns an unregister function. */
  onError: (fn: (error: Error) => void) => () => void
  /** Tears down the watcher: removes listeners, ends iterators, stops the poll or subscription. */
  off: () => void
  /** Async-iterates emitted log batches (latest-only stream). */
  [Symbol.asyncIterator]: () => AsyncIterableIterator<{ logs: readonly Log[] }>
}

Each log is decoded, with the event arguments on args:

type Log = {
  /** Decoded `WhitelistUpdated` event arguments. */
  args: {
    policyId: bigint
    updater: Address
    account: Address
    allowed: boolean
  }
  /** Name of the emitted event. */
  eventName: 'WhitelistUpdated'
  // ...standard log fields (address, blockHash, blockNumber, logIndex, transactionHash, ...)
}

Parameters

args

Type: object

type Args = {
  policyId?: bigint | bigint[] | null
  updater?: Address | Address[] | null
  account?: Address | Address[] | null
}

Indexed argument values to filter logs by.

batch

Type: boolean
Default: true

Whether to batch the logs found within a poll interval into a single emission. When false, each log is emitted on its own.

fromBlock

Type: bigint

Block number from which to start watching for logs.

poll

Type: boolean

Whether to poll for new logs instead of using a subscription. Defaults to true when the transport cannot subscribe or fromBlock is provided.

pollingInterval

Type: number
Default: client.pollingInterval

Polling frequency (in ms).

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