PairCreated (Uniswap V2) 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: "0x5c69bee701ef814a2b6a3edd4b1652cb9cc5aa6f",
  event: parseAbiItem("event PairCreated(address indexed token0, address indexed token1, address pair, uint256)"),
  fromBlock: "latest",
})

for (const log of logs) console.log(log.args) // { token0, token1, pair,  }

import { Interface, JsonRpcProvider } from "ethers"

const provider = new JsonRpcProvider(process.env.RPC_URL)
const iface = new Interface(["event PairCreated(address indexed token0, address indexed token1, address pair, uint256)"])

const logs = await provider.getLogs({
  address: "0x5c69bee701ef814a2b6a3edd4b1652cb9cc5aa6f",
  topics: [iface.getEvent("PairCreated")!.topicHash],
})

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

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "eth_getLogs",
  "params": [
    {
      "address": "0x5c69bee701ef814a2b6a3edd4b1652cb9cc5aa6f",
      "topics": [
        "0x0d3648bd0f6ba80134a33ba9275ac585d9d315f0ad8355cddefde31afa28d0e9"
      ],
      "fromBlock": "latest"
    }
  ]
}

event PairCreated(address indexed token0, address indexed token1, address pair, uint256);

// inside a function:
emit PairCreated(token0, token1, pair, );