eth_newBlockFilter

A fresh block lands on BNB Smart Chain about every three seconds under PoSA, and eth_newBlockFilter lets you catch each one without holding a socket open. Chain ID 56 pays fees in BNB. Call the method against https://bsc.therpc.io/YOUR_API_KEY and it spins up a server-side filter that tracks new block arrivals, returning a hex filter ID. Poll that ID with eth_getFilterChanges to collect the block hashes seen since your previous poll. Think of it as the request-response counterpart to a streaming newHeads subscription, a good fit for clients that cannot hold a persistent WebSocket to BNB Smart Chain.

Use cases

Kick off block-level work each time a hash appears — for instance re-checking whether your pending BNB transfers have now been included.
Keep a cache fresh by invalidating account balances or PancakeSwap pool reserves whenever a new BNB Smart Chain block hash shows up in the poll.

Parameters

This method takes no parameters. Pass an empty array [].

Response

Type	Description
string	Hex filter ID. When polled with eth_getFilterChanges, yields an array of new block hashes since the last poll.

Example request

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

Try it live in the BNB Smart Chain playground.

Errors & troubleshooting

Code	Message	Cause
`-32000`	`filter not found`	Provider rejected filter creation or the filter limit was reached.

Common pitfalls

The poll yields bare block hashes only; pull the header and transactions yourself with eth_getBlockByHash when you need the contents.
A filter the node hasn't seen polled for about five minutes is dropped, so recreate it the moment a filter not found error surfaces.
Even with PoSA's fast finality a freshly seen block can still be reorganized at the tip, so confirm finality before treating its data as settled.

Supported networks

Mainnet — Chain ID: 56
Testnet — Chain ID: 97