The newPendingTransactions subscription type subscribes to all pending transactions via WebSockets (regardless if you sent them or not), and returns their transaction hashes.

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NOTE

When listening to pending transactions with this endpoint, you will only get pending transactions in Alchemy mempool.

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alchemy_pendingTransactions vs. newPendingTransactions

We highly recommend using alchemy_pendingTransactions instead of newPendingTransactions to receive more detailed information like full transaction objects as well as filtering on from and to addresses for pending transactions.

Supported Networks

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Which chains are supported?

Check the Services page for details about product and chain support!

Returns the hash for all transactions that are added to the pending state (regardless if you sent them or not).

Parameters

None

Returns

• result: string - transaction hash for pending transaction
• subscription: string - subscription ID

Request

// initiate websocket stream first
wscat -c wss://eth-mainnet.g.alchemy.com/v2/demo

// then call subscription 
{"jsonrpc":"2.0","id": 2, "method": "eth_subscribe", "params": ["newPendingTransactions"]}

// Installation: https://github.com/alchemyplatform/alchemy-web3
const { createAlchemyWeb3 } = require("@alch/alchemy-web3");

// Initialize alchemy-web3 object.
const web3 = createAlchemyWeb3(`wss://eth-mainnet.g.alchemy.com/v2/demo`);

// Subcribes to the event and prints results 
web3.eth.subscribe("newPendingTransactions").on("data", (data) => console.log(data));

Result

{"id":1,"result":"0xc3b33aa549fb9a60e95d21862596617c","jsonrpc":"2.0"}

{
    "jsonrpc":"2.0",
    "method":"eth_subscription",
    "params":{
        "subscription":"0xc3b33aa549fb9a60e95d21862596617c",
        "result":"0xd6fdc5cc41a9959e922f30cb772a9aef46f4daea279307bc5f7024edc4ccd7fa"
    }
}