Upgraded (proxy) 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 Upgraded(address indexed implementation)"),
  fromBlock: "latest",
})

for (const log of logs) console.log(log.args) // { implementation }

import { Interface, JsonRpcProvider } from "ethers"

const provider = new JsonRpcProvider(process.env.RPC_URL)
const iface = new Interface(["event Upgraded(address indexed implementation)"])

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

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

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "eth_getLogs",
  "params": [
    {
      "address": "0x87870bca3f3fd6335c3f4ce8392d69350b4fa4e2",
      "topics": [
        "0xbc7cd75a20ee27fd9adebab32041f755214dbc6bffa90cc0225b39da2e5c2d3b"
      ],
      "fromBlock": "latest"
    }
  ]
}

event Upgraded(address indexed implementation);

// inside a function:
emit Upgraded(implementation);