> For the complete documentation index, see [llms.txt](https://docs.chainrpc.io/chainrpc/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.chainrpc.io/chainrpc/networks/ethereum/json-rpc-methods/filter-methods/eth_newblockfilter.md).

# eth\_newBlockFilter

Creates a filter in the node, to notify when a new block arrives. To check if the state has changed, call [eth\_getFilterChanges](/chainrpc/networks/ethereum/json-rpc-methods/filter-methods/eth_getfilterchanges.md).

Filter IDs will be valid for up to fifteen minutes, and can polled by any connection using the same v3 project ID.

#### EXAMPLE

```bash
## JSON-RPC over HTTPS POST
## Replace YOUR-API-KEY with an API key from your chainRPC Dashboard
## You can also replace mainnet with a different supported network
curl https://eth.chainrpc.io/v3/YOUR-API-KEY \
    -X POST \
    -H "Content-Type: application/json" \
    -d '{"jsonrpc":"2.0","method":"eth_newBlockFilter","params":[],"id":1}'

## JSON-RPC over WSS
## Replace YOUR-API-KEY with an API key from your chainRPC Dashboard
## You can also replace mainnet with a different supported network
wscat -c wss://eth.chainrpc.io/v3/YOUR-API-KEY
>{"jsonrpc":"2.0","method":"eth_newBlockFilter","params":[],"id":1}
```

### RESPONSE

#### RESULT FIELDS

* `FILTER ID` - hexadecimal denoting the newly created filter ID

#### BODY

```json
{
    "jsonrpc":"2.0",
    "id":1,
    "result":"0x81440bfbd6138ec9fe6d6ec4398b0b4879fb182f3cd8"
}
```