Watch AMM Rebalance Swaps

amm.watchRebalanceSwap

Watches RebalanceSwap events on the fee AMM.

Usage

import {  } from './viem.config'
 
const  = ..()
 
.(() => {
  for (const  of ) .(.)
{ userToken: '0x20c0000000000000000000000000000000000001', validatorToken: '0x20c0000000000000000000000000000000000002', swapper: '0x742d35Cc6634C0532925a3b844Bc9e7595f0bEbb' }
})
 
// Later, tear down the watcher.
.()

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

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

Recipes

Monitor Arbitrage Flow Through a Pool

Filter args.userToken and args.validatorToken to a pool you provide liquidity for, so you can track each rebalance and who performed it.

import {  } from './viem.config'
 
const  = ..({
  : {
    : '0x20c0000000000000000000000000000000000001',
    : '0x20c0000000000000000000000000000000000002',
  },
})
 
.(() => {
  for (const  of )
    .('Rebalance:', .., ..)
Rebalance: 0xf39Fd6e51aad88F6F4ce6aB8827279cffFb92266 1001000n
})

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

Refresh Reserve Metrics on Each Rebalance

Combine the watcher with amm.getPool to re-read reserves whenever a swap lands, keeping reserve metrics current without polling.

import {  } from './viem.config'
 
const  = '0x20c0000000000000000000000000000000000001'
const  = '0x20c0000000000000000000000000000000000002'
 
const  = ..({
  : { ,  },
})
 
.(async () => {
  const  = await ..({ ,  })
  .('Reserves:', ., .)
})

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 `RebalanceSwap` event arguments. */
  args: {
    /** User token address. */
    userToken: Address
    /** Validator token address. */
    validatorToken: Address
    /** Address that performed the swap. */
    swapper: Address
    /** Amount of validator token spent. */
    amountIn: bigint
    /** Amount of user token received. */
    amountOut: bigint
  }
  /** Name of the emitted event. */
  eventName: 'RebalanceSwap'
  // ...standard log fields (address, blockHash, blockNumber, logIndex, transactionHash, ...)
}

Parameters

args

Type: object

type Args = {
  /** Filter by user token address. */
  userToken?: Address | Address[] | null
  /** Filter by validator token address. */
  validatorToken?: Address | Address[] | null
  /** Filter by address that performed the swap. */
  swapper?: 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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