klay_getFilterChanges

Polling method for a filter, which returns an array of logs which occurred since last poll.

It is disabled by default and can be enabled by --sendertxhashindexing.

📘
Supported on Klaytn (mainnet) only.

Parameters

Request

Name	Type	Description
QUANTITY	string	The filter id (e.g., "0x16" // 22).

Result

Array - Array of log objects, or an empty array if nothing has changed since last poll.

For filters created with klay_newBlockFilter, the return are block hashes (32-byte DATA),
e.g., ["0x3454645634534..."].
For filters created with klay_newPendingTransactionFilter, the return are transaction
hashes (32-byte DATA), e.g., ["0x6345343454645..."].
For filters created with klay_newFilter, logs are objects with following parameters:

Name	Type	Description
removed	TAG	`true` when the log was removed, due to a chain reorganization. `false` if it is a valid log.
logIndex	QUANTITY	Integer of the log index position in the block. `null` when it is a pending log.
transactionIndex	QUANTITY	Integer of the transactions index position log was created from. `null` when pending.
transactionHash	32-byte DATA	Hash of the transactions this log was created from. `null` when pending.
blockHash	32-byte DATA	Hash of the block where this log was in. `null` when pending.
blockNumber	QUANTITY	The block number where this log was in. `null` when pending.
address	20-byte DATA	Address from which this log originated.
data	DATA	Contains the non-indexed arguments of the log.
topics	Array of DATA	Array of 0 to 4 32-byte DATA of indexed log arguments. (In Solidity: The first topic is the hash of the signature of the event (e.g., `Deposit(address,bytes32,uint256)`), except you declared the event with the `anonymous` specifier.).

API Endpoint

The format of a Klaytn API endpoint is
https://open-platform.nodereal.io/{{apiKey}}/klaytn/

Here is an example:
https://open-platform.nodereal.io/4c0a1c23661a4e26bcbcwed461e34ea9/klaytn/

Example

// Request
curl https://open-platform.nodereal.io/{{apiKey}}/klaytn/ \
  -X POST \
  -H "Content-Type: application/json" \
  --data '{"jsonrpc":"2.0","method":"klay_getFilterChanges","params":["0x16"],"id":73}' https://api.baobab.klaytn.net:8651

// Result
{
    "id":1,
    "jsonrpc":"2.0",
    "result": [{
    "logIndex": "0x1", // 1
    "blockNumber":"0x1b4", // 436
    "blockHash": "0x8216c5785ac562ff41e2dcfdf5785ac562ff41e2dcfdf829c5a142f1fccd7d",
    "transactionHash":  "0xdf829c5a142f1fccd7d8216c5785ac562ff41e2dcfdf5785ac562ff41e2dcf",
    "transactionIndex": "0x0", // 0
    "address": "0x16c5785ac562ff41e2dcfdf829c5a142f1fccd7d",
    "data":"0x0000000000000000000000000000000000000000000000000000000000000000",
    "topics": ["0x59ebeb90bc63057b6515673c3ecf9438e5058bca0f92585014eced636878c9a5"]
    },{
        ...
    }]
}