# monadLogs
> Returns logs (that match a given filter) as soon as the block is Proposed.
> For the complete documentation index, see [llms.txt](/docs/llms.txt).
The `monadLogs` subscription type emits logs that match a specified topic filter as soon as the block is Proposed and the node has speculatively executed the transactions. This provides earlier access to log data compared to regular [`logs`](/docs/reference/logs) subscriptions which wait for block finalization.
# Supported Networks
Check the [Chains](https://dashboard.alchemy.com/chains) page for details about product and chain support!
# Parameters
An object with the following fields:
* `address` (optional): `string` or `array of strings` Singular address or array of addresses. Only logs created from one of these addresses will be emitted.
* `topics`: an array of topic specifiers (**up to 4 topics allowed per address**).
* Each topic specifier is either `null`, a single string, or an array of strings.
* For every non `null` topic, a log will be emitted when activity associated with that topic occurs.
# Request
```shell javascript
// initiate websocket stream first
wscat -c wss://eth-mainnet.g.alchemy.com/v2/demo
// then call subscription
{"jsonrpc":"2.0","id": 1, "method": "eth_subscribe", "params": ["logs", {"address": "0xa0b86991c6218b36c1d19d4a2e9eb0ce3606eb48", "topics": ["0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef"]}]}
```
```javascript Viem
import { createPublicClient, webSocket, parseAbiItem } from 'viem'
import { mainnet } from 'viem/chains'
const client = createPublicClient({
chain: mainnet,
transport: webSocket('wss://eth-mainnet.g.alchemy.com/v2/<-- ALCHEMY APP API KEY -->')
})
// Watch for Transfer events (monadLogs provides earlier access)
const unsubscribe = client.watchEvent({
address: '0xa0b86991c6218b36c1d19d4a2e9eb0ce3606eb48', // USDC contract
event: parseAbiItem('event Transfer(address indexed from, address indexed to, uint256 value)'),
onLogs: (logs) => {
logs.forEach((log) => {
console.log('Early Transfer event detected:', {
from: log.args.from,
to: log.args.to,
value: log.args.value,
blockNumber: log.blockNumber,
transactionHash: log.transactionHash
})
})
}
})
// Watch for multiple event types
const unsubscribeMultiple = client.watchEvent({
address: '0xa0b86991c6218b36c1d19d4a2e9eb0ce3606eb48',
events: [
parseAbiItem('event Transfer(address indexed from, address indexed to, uint256 value)'),
parseAbiItem('event Approval(address indexed owner, address indexed spender, uint256 value)')
],
onLogs: (logs) => {
console.log('Early token events detected:', logs)
}
})
```
```javascript Ethers.js
import { WebSocketProvider, Contract, id } from 'ethers'
const provider = new WebSocketProvider('wss://eth-mainnet.g.alchemy.com/v2/<-- ALCHEMY APP API KEY -->')
// Create a contract instance for event filtering
const contractAddress = '0xa0b86991c6218b36c1d19d4a2e9eb0ce3606eb48' // USDC
const abi = [
'event Transfer(address indexed from, address indexed to, uint256 value)',
'event Approval(address indexed owner, address indexed spender, uint256 value)'
]
const contract = new Contract(contractAddress, abi, provider)
// Listen for Transfer events (monadLogs provides earlier access)
contract.on('Transfer', (from, to, value, event) => {
console.log('Early Transfer event detected:', {
from: from,
to: to,
value: value.toString(),
blockNumber: event.blockNumber,
transactionHash: event.transactionHash
})
})
// Listen for raw logs with topic filtering
const transferTopic = id("Transfer(address,address,uint256)")
const filter = {
address: contractAddress,
topics: [transferTopic]
}
provider.on(filter, (log) => {
console.log('Early raw log detected:', log)
})
```
# Result
```json result
{
"jsonrpc":"2.0",
"method":"eth_subscription",
"params": {
"subscription":"0x4a8a4c0517381924f9838102c5a4dcb7",
"result":{
"blockId": "0x71ce47f39a1eb490354166f762d78bf6e2acaf80b24b4bcd756118d93ef81be0",
"commitState": "Proposed",
"address":"0x8320fe7702b96808f7bbc0d4a888ed1468216cfd",
"blockHash":"0x61cdb2a09ab99abf791d474f20c2ea89bf8de2923a2d42bb49944c8c993cbf04",
"blockNumber":"0x29e87",
"data":"0x00000000000000000000000000000000000000000000000000000000000000010000000000000000000000000000000000000000000000000000000000000003",
"logIndex":"0x0",
"topics":["0xd78a0cb8bb633d06981248b816e7bd33c2a35a6089241d099fa519e361cab902"],
"transactionHash":"0xe044554a0a55067caafd07f8020ab9f2af60bdfe337e395ecd84b4877a3d1ab4",
"transactionIndex":"0x0"
}
}
}
```
Below you can find the explanation for individual properties of the response:
* **`jsonrpc`**: The `jsonrpc` property specifies the version of the JSON-RPC protocol that is being used, which in this case is "2.0".
* **`method`**: The `method` property specifies the method that was called, which in this case is `eth_subscription`.
* **`params`**: The `params` property contains the parameters of the method call. In this case, it contains a `subscription` property, which specifies the subscription identifier, and a `result` property, which contains the result of the subscription.
* **`result`**: The `result` property contains information about a specific transaction on the Ethereum blockchain.
* **`address`**: The `address` property specifies the address from which this log originated.
* **`blockhash`**: The `blockHash` property specifies the hash of the block in which the transaction was included.
* **`blockNumber`**: The `blockNumber` property specifies the number of the block in which the transaction was included. It is encoded as a hexadecimal string.
* **`data`**: Contains one or more 32 Bytes non-indexed arguments of the log.
* **`logIndex`**: The `logIndex` property specifies the index or position of the log entry within the block. It is encoded as a hexadecimal string.
* **`topics`**: An array of 0 to 4 32 bytes topic hashes of indexed log arguments (up to 4 topics allowed per address).
* **`transactionHash`**: The `transactionHash` property specifies the hash of the transaction.
* **`transactionIndex`**: The `transactionIndex` property specifies the index or position of the transaction within the block. It is encoded as a hexadecimal string.