eth_newPendingTransactionFilter

eth_newPendingTransactionFilter creates a server-side filter that watches for incoming pending transactions on Base — Coinbase's OP Stack rollup where gas is paid in ETH — and returns a hex filter ID. Polling that ID with eth_getFilterChanges returns the hashes of transactions that entered the node's mempool since your last poll. On Base, transactions flow to the sequencer for ordering, and the ~2s block time means pending hashes move into blocks quickly. Create the filter against https://base.therpc.io/YOUR_API_KEY (Base mainnet, chain ID 8453 / 0x2105); it takes no parameters.

Use cases

• Watch the Base mempool for pending transactions and, after fetching each one with eth_getTransactionByHash, react to those from a specific sender address.
• Build a live gas-price tracker by sampling the maxPriorityFeePerGas and maxFeePerGas of pending transactions to gauge current tip pressure on Base before you submit your own.

Parameters

هذا الأسلوب لا يأخذ أي معاملات. مرر مصفوفة فارغة [].

Response

Example request

1curl https://base.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 Base playground.

Errors & troubleshooting

Common pitfalls

• Each poll returns only transaction hashes; call eth_getTransactionByHash to retrieve the full transaction details for any hash you care about.
• A pending transaction on Base may never be included — it can be dropped or replaced by a same-nonce transaction with a higher fee — so never treat a pending hash as confirmed; wait for a receipt.
• During heavy consumer-app and DEX activity the Base mempool can flood a single poll with thousands of hashes; for sustained real-time use prefer a WebSocket eth_subscribe("newPendingTransactions") stream over repeated filter polling.

Supported networks

• Mainnet — Chain ID: 8453
• Sepolia — Chain ID: 84532

See also

• eth_getFilterChanges
• eth_uninstallFilter
• eth_newFilter
• eth_subscribe

1curl https://base.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":[]}'