eth_newPendingTransactionFilter

eth_newPendingTransactionFilter watches the mempool rather than the chain. It registers a server-side filter that records the hash of each pending transaction the node sees before that transaction is mined, and returns a hex filter ID. You poll eth_getFilterChanges with the ID to get the batch of new pending hashes since your last call. This is your window into transactions that are queued but not yet in a block, the same in-flight ETH transfers and contract calls that a validator will choose from for the next slot. Set up the filter at https://ethereum.therpc.io/YOUR_API_KEY on chain ID 1. Of the three new-filter methods, this one is the noisiest, since mempool churn far outpaces block production.

Use cases

• Watch for a specific sender's transactions hitting the mempool: pull each new hash, resolve it with eth_getTransactionByHash, and match on the from address to catch their activity before inclusion.
• Sample pending transactions' maxFeePerGas and maxPriorityFeePerGas to build a live gas tracker that reflects what senders are actually bidding for the next Ethereum block.

Parameters

Este método no acepta parámetros. Pasa un array vacío [].

Response

Example request

1curl https://ethereum.therpc.io/YOUR_API_KEY \
2  -X POST \
3  -H "Content-Type: application/json" \
4  -d '{
5    "jsonrpc": "2.0",
6    "method": "eth_newPendingTransactionFilter",
7    "params": [],
8    "id": 1
9  }'

Try it live in the Ethereum playground.

Errors & troubleshooting

Common pitfalls

• You only receive hashes. To see the value, fee, or calldata of a pending transaction, resolve each hash through eth_getTransactionByHash.
• A pending transaction is not a promise. It may be dropped, replaced by a same-nonce bump, or simply never mined, so never treat a hash from this filter as a confirmation.
• During congestion the Ethereum mempool can churn through thousands of pending transactions, and a single poll may return a flood of hashes. For sustained real-time use, eth_subscribe with newPendingTransactions over WebSocket scales better than this poll loop.

Supported networks

• Mainnet — Chain ID: 1
• Sepolia — Chain ID: 11155111

See also

• eth_getFilterChanges
• eth_uninstallFilter
• eth_newFilter
• eth_subscribe

1curl https://ethereum.therpc.io/YOUR_API_KEY \
2  -X POST \
3  -H 'Content-Type: application/json' \
4  -d '{"jsonrpc":"2.0","id":1,"method":"eth_newPendingTransactionFilter","params":[]}'