VoteCast 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: "0x408ed6354d4973f66138c91495f2f2fcbd8724c3",
  event: parseAbiItem("event VoteCast(address indexed voter, uint256 proposalId, uint8 support, uint256 weight, string reason)"),
  fromBlock: "latest",
})

for (const log of logs) console.log(log.args) // { voter, proposalId, support, weight, reason }

import { Interface, JsonRpcProvider } from "ethers"

const provider = new JsonRpcProvider(process.env.RPC_URL)
const iface = new Interface(["event VoteCast(address indexed voter, uint256 proposalId, uint8 support, uint256 weight, string reason)"])

const logs = await provider.getLogs({
  address: "0x408ed6354d4973f66138c91495f2f2fcbd8724c3",
  topics: [iface.getEvent("VoteCast")!.topicHash],
})

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

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "eth_getLogs",
  "params": [
    {
      "address": "0x408ed6354d4973f66138c91495f2f2fcbd8724c3",
      "topics": [
        "0xb8e138887d0aa13bab447e82de9d5c1777041ecd21ca36ba824ff1e6c07ddda4"
      ],
      "fromBlock": "latest"
    }
  ]
}

event VoteCast(address indexed voter, uint256 proposalId, uint8 support, uint256 weight, string reason);

// inside a function:
emit VoteCast(voter, proposalId, support, weight, reason);