Repay (Aave V3) event signature and topic0

import { createPublicClient, http, parseAbiItem } from "viem"
import { mainnet } from "viem/chains"

const client = createPublicClient({ chain: mainnet, transport: http() })

const logs = await client.getLogs({
  address: "0x87870bca3f3fd6335c3f4ce8392d69350b4fa4e2",
  event: parseAbiItem("event Repay(address indexed reserve, address indexed user, address indexed repayer, uint256 amount, bool useATokens)"),
  fromBlock: "latest",
})

for (const log of logs) console.log(log.args) // { reserve, user, repayer, amount, useATokens }

import { Interface, JsonRpcProvider } from "ethers"

const provider = new JsonRpcProvider(process.env.RPC_URL)
const iface = new Interface(["event Repay(address indexed reserve, address indexed user, address indexed repayer, uint256 amount, bool useATokens)"])

const logs = await provider.getLogs({
  address: "0x87870bca3f3fd6335c3f4ce8392d69350b4fa4e2",
  topics: [iface.getEvent("Repay")!.topicHash],
})

for (const log of logs) console.log(iface.parseLog(log)?.args)

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "eth_getLogs",
  "params": [
    {
      "address": "0x87870bca3f3fd6335c3f4ce8392d69350b4fa4e2",
      "topics": [
        "0xa534c8dbe71f871f9f3530e97a74601fea17b426cae02e1c5aee42c96c784051"
      ],
      "fromBlock": "latest"
    }
  ]
}

event Repay(address indexed reserve, address indexed user, address indexed repayer, uint256 amount, bool useATokens);

// inside a function:
emit Repay(reserve, user, repayer, amount, useATokens);