Subscribe to events, such as logs, using either or filters over HTTP.
Access logs using the following KalyChain API methods:
.
Use to create the filter before using and ).
The following examples use the sample contract included in [events and logs](../../concepts/events-and-logs.md).
Create a filter
Create a filter using .
!!! example
If the [example contract](../../concepts/events-and-logs.md) was deployed to
0x42699a7612a82f1d9c36148af9c77354759b210b, the following request for `eth_newFilter` creates a
filter to log when `valueIndexed` is set to 5:
```json
{
"jsonrpc":"2.0",
"method":"eth_newFilter",
"params":[
{
"fromBlock":"earliest",
"toBlock":"latest",
"address":"0x42699a7612a82f1d9c36148af9c77354759b210b",
"topics":[
["0xd3610b1c54575b7f4f0dc03d210b8ac55624ae007679b7a928a4f25a709331a8"],
["0x0000000000000000000000000000000000000000000000000000000000000005"]
]
}
],
"id":1
}
```
Poll a filter for changes
!!! example
If the contract had been executed twice since the last poll, with `valueIndexed` set to 1 and
5, [`eth_getFilterChanges`](../../reference/api/index.md#eth_getfilterchanges) returns
only the log where the [topic](../../concepts/events-and-logs.md#event-parameters) for
`valueIndexed` is 5:
```json
{
"jsonrpc": "2.0",
"id": 1,
"result": [
{
"logIndex": "0x0",
"removed": false,
"blockNumber": "0x21c",
"blockHash": "0xc7e6c9d5b9f522b2c9d2991546be0a8737e587beb6628c056f3c327a44b45132",
"transactionHash": "0xfd1a40f9fbf89c97b4545ec9db774c85e51dd8a3545f969418a22f9cb79417c5",
"transactionIndex": "0x0",
"address": "0x42699a7612a82f1d9c36148af9c77354759b210b",
"data": "0x0000000000000000000000000000000000000000000000000000000000000005",
"topics": [
"0xd3610b1c54575b7f4f0dc03d210b8ac55624ae007679b7a928a4f25a709331a8",
"0x0000000000000000000000000000000000000000000000000000000000000005"
]
}
]
}
```
Get all logs for a filter
!!! example
If the contract had been executed twice with `valueIndexed` set to 5 since the filter was
created using `eth_newFilter`, `eth_getFilterLogs` returns:
```json
{
"jsonrpc": "2.0",
"id": 1,
"result": [
{
"logIndex": "0x0",
"removed": false,
"blockNumber": "0x1a7",
"blockHash": "0x4edda22a242ddc7bc51e2b6b11e63cd67be1af7389470cdea9c869768ff75d42",
"transactionHash": "0x9535bf8830a72ca7d0020df0b547adc4d0ecc4321b7d5b5d6beb1eccee5c0afa",
"transactionIndex": "0x0",
"address": "0x42699a7612a82f1d9c36148af9c77354759b210b",
"data": "0x0000000000000000000000000000000000000000000000000000000000000005",
"topics": [
"0xd3610b1c54575b7f4f0dc03d210b8ac55624ae007679b7a928a4f25a709331a8",
"0x0000000000000000000000000000000000000000000000000000000000000005"
]
},
{
"logIndex": "0x0",
"removed": false,
"blockNumber": "0x21c",
"blockHash": "0xc7e6c9d5b9f522b2c9d2991546be0a8737e587beb6628c056f3c327a44b45132",
"transactionHash": "0xfd1a40f9fbf89c97b4545ec9db774c85e51dd8a3545f969418a22f9cb79417c5",
"transactionIndex": "0x0",
"address": "0x42699a7612a82f1d9c36148af9c77354759b210b",
"data": "0x0000000000000000000000000000000000000000000000000000000000000005",
"topics": [
"0xd3610b1c54575b7f4f0dc03d210b8ac55624ae007679b7a928a4f25a709331a8",
"0x0000000000000000000000000000000000000000000000000000000000000005"
]
}
]
}
```
You can use [`eth_getLogs`](#get-logs-using-a-filter-options-object) with a filter options
object to get all logs matching the filter options instead of using
[`eth_newFilter`](../../reference/api/index.md#eth_newfilter) followed by
[`eth_getFilterLogs`](../../reference/api/index.md#eth_getfilterlogs).
Uninstall a filter
Filters for private contracts
Filters for private contracts are created, accessed, and uninstalled using:
Get logs using a filter options object
!!! example
The following request for `eth_getLogs` returns all the logs where the example contract has
been deployed to `0x42699a7612a82f1d9c36148af9c77354759b210b` and executed with `valueIndexed`
set to 5.
```json
{
"jsonrpc":"2.0",
"method":"eth_getLogs",
"params":[
{
"fromBlock":"earliest",
"toBlock":"latest",
"address":"0x42699a7612a82f1d9c36148af9c77354759b210b",
"topics":[
["0xd3610b1c54575b7f4f0dc03d210b8ac55624ae007679b7a928a4f25a709331a8"],
["0x0000000000000000000000000000000000000000000000000000000000000005"]
]
}
],
"id":1
}
```
The above example returns the same result as calling [eth_newFilter](#creating-a-filter)
followed by [eth_getFilterLogs](#getting-all-logs-for-a-filter).
returns a filter ID hash (for example, 0x1ddf0c00989044e9b41cc0ae40272df3).
To poll the filter for changes since the last poll, use with the filter ID hash returned by .
To get all logs for a filter, use .
When a filter is no longer required, use to remove the filter.
.
To get all logs for a filter options object, use or for a private contract.
