createContractEventFilter

Creates a filter to retrieve contract event logs with ABI decoding

Creates a filter to retrieve contract event logs that can be used with GetFilterChanges or GetFilterLogs.

Import

Import the public actions package so you can call this action.

import "github.com/ChefBingbong/viem-go/actions/public"

Usage

An example showing how to create an ABI-aware contract event filter and use it to fetch logs.

import (
  "context"
  "log"

  "github.com/ethereum/go-ethereum/common"
  "github.com/ChefBingbong/viem-go/actions/public"
  "github.com/ChefBingbong/viem-go/abi"
  "github.com/ChefBingbong/viem-go/client"
  "github.com/ChefBingbong/viem-go/client/transport"
  "github.com/ChefBingbong/viem-go/chain/definitions"
)

ctx := context.Background()

publicClient, err := client.CreatePublicClient(client.PublicClientConfig{
  Chain:     definitions.Mainnet,
  Transport: transport.HTTP("https://eth.llamarpc.com"),
})
if err != nil {
  log.Fatal(err)
}
defer func() { _ = publicClient.Close() }()

contractAddr := common.HexToAddress("0xa0b86991c6218b36c1d19d4a2e9eb0ce3606eb48")
erc20ABI, _ := abi.ParseABI(`[{"anonymous":false,"inputs":[{"indexed":true,"name":"from","type":"address"},{"indexed":true,"name":"to","type":"address"},{"indexed":false,"name":"value","type":"uint256"}],"name":"Transfer","type":"event"}]`)

filter, err := public.CreateContractEventFilter(ctx, publicClient, public.CreateContractEventFilterParameters{
  Address:   contractAddr,
  ABI:       erc20ABI,
  EventName: "Transfer",
})
if err != nil {
  log.Fatal(err)
}

// Use filter.ID with GetFilterChanges or GetFilterLogs
logs, err := public.GetFilterLogs(ctx, publicClient, public.GetFilterLogsParameters{
  Filter: filter,
})

Returns

*CreateContractEventFilterReturnType

A filter object containing:

ID FilterID - The filter identifier
Type string - Always "event" for event filters
ABI *abi.ABI - The parsed ABI for decoding logs later
EventName string - The filtered event name (empty if filtering all events)
Args []any - The indexed args used for filtering
Strict bool - Whether strict mode is enabled

Parameters

Configuration options accepted by this action.

Address

Type: any (accepts common.Address, *common.Address, []common.Address, string, or []string)
Required

The contract address(es) to filter logs from.

import (
  "github.com/ethereum/go-ethereum/common"
  "github.com/ChefBingbong/viem-go/actions/public"
)

contractAddr := common.HexToAddress("0xa0b86991c6218b36c1d19d4a2e9eb0ce3606eb48")
filter, err := public.CreateContractEventFilter(ctx, publicClient, public.CreateContractEventFilterParameters{
  Address:   contractAddr,
  ABI:       erc20ABI,
  EventName: "Transfer",
})

ABI

Type: any (accepts *abi.ABI, JSON bytes, or string)
Required

The contract ABI for decoding event logs.

import "github.com/ChefBingbong/viem-go/abi"

erc20ABI, _ := abi.ParseABI(`[{"anonymous":false,"inputs":[...],"name":"Transfer",...}]`)
filter, err := public.CreateContractEventFilter(ctx, publicClient, public.CreateContractEventFilterParameters{
  Address:   contractAddr,
  ABI:       erc20ABI,
  EventName: "Transfer",
})

EventName

Type: string
Optional

Filters logs to a specific event. If omitted, all events from the ABI are matched.

filter, err := public.CreateContractEventFilter(ctx, publicClient, public.CreateContractEventFilterParameters{
  Address:   contractAddr,
  ABI:       erc20ABI,
  EventName: "Transfer",
})

Args

Type: []any
Optional

Filters logs by indexed event parameters. Provide indexed args in order (use nil for "any" match).

senderAddr := common.HexToAddress("0xd8da6bf26964af9d7eed9e03e53415d37aa96045")
filter, err := public.CreateContractEventFilter(ctx, publicClient, public.CreateContractEventFilterParameters{
  Address:   contractAddr,
  ABI:       erc20ABI,
  EventName: "Transfer",
  Args:      []any{senderAddr, nil}, // from=specific, to=any
})

FromBlock

Type: *uint64
Optional

The block number to start filtering from. Mutually exclusive with FromBlockTag.

fromBlock := uint64(16330000)
filter, err := public.CreateContractEventFilter(ctx, publicClient, public.CreateContractEventFilterParameters{
  Address:   contractAddr,
  ABI:       erc20ABI,
  EventName: "Transfer",
  FromBlock: &fromBlock,
})

FromBlockTag

Type: BlockTag
Optional

The block tag to start filtering from. Mutually exclusive with FromBlock.

filter, err := public.CreateContractEventFilter(ctx, publicClient, public.CreateContractEventFilterParameters{
  Address:      contractAddr,
  ABI:          erc20ABI,
  EventName:    "Transfer",
  FromBlockTag: public.BlockTagSafe,
})

ToBlock

Type: *uint64
Optional

The block number to stop filtering at. Mutually exclusive with ToBlockTag.

toBlock := uint64(16330050)
filter, err := public.CreateContractEventFilter(ctx, publicClient, public.CreateContractEventFilterParameters{
  Address:   contractAddr,
  ABI:       erc20ABI,
  EventName: "Transfer",
  ToBlock:   &toBlock,
})

ToBlockTag

Type: BlockTag
Optional

The block tag to stop filtering at. Mutually exclusive with ToBlock.

filter, err := public.CreateContractEventFilter(ctx, publicClient, public.CreateContractEventFilterParameters{
  Address:   contractAddr,
  ABI:       erc20ABI,
  EventName: "Transfer",
  ToBlockTag: public.BlockTagLatest,
})

Strict

Type: bool
Default: false
Optional

Filters out logs that don't match the indexed/non-indexed arguments in the event ABI.

filter, err := public.CreateContractEventFilter(ctx, publicClient, public.CreateContractEventFilterParameters{
  Address:   contractAddr,
  ABI:       erc20ABI,
  EventName: "Transfer",
  Strict:    true,
})

JSON-RPC Method

Underlying JSON-RPC method used by this action.

eth_newFilter