This example demonstrates how to use the eventfilter package to detect and display ERC20, ERC721, and ERC1155 transfer events for a specific account within a block range.

What it demonstrates

Command-line interface with flexible options
Multi-token support for ERC20, ERC721, and ERC1155 transfers
Direction filtering (send, receive, or both)
Comprehensive transfer details extracted from the Unpacked field
Enhanced formatting with shortened addresses and scientific notation for large numbers
Raw event metadata including event signatures, data length, and log properties
Debug information showing contract keys, event keys, and unpacked types
Error handling and validation

Run

Basic Usage

go run main.go -account 0x1234567890123456789012345678901234567890 -start 18000000 -end 18001000

With Custom RPC

go run main.go -rpc https://mainnet.infura.io/v3/YOUR_KEY -account 0x1234567890123456789012345678901234567890 -start 18000000 -end 18001000

Filter by Direction

# Only outgoing transfers
go run main.go -account 0x1234567890123456789012345678901234567890 -start 18000000 -end 18001000 -direction send

# Only incoming transfers
go run main.go -account 0x1234567890123456789012345678901234567890 -start 18000000 -end 18001000 -direction receive

Command Line Options

Option	Description	Required	Default
`-account`	Account address to filter transfers for	Yes	-
`-start`	Start block number	Yes	-
`-end`	End block number	Yes	-
`-rpc`	Ethereum RPC URL	No	`https://mainnet.infura.io/v3/YOUR_KEY`
`-direction`	Transfer direction (send/receive/both)	No	`both`
`-help`	Show help message	No	-

Output Format

The example displays transfers grouped by token type with comprehensive details extracted from the Unpacked field:

ERC20 Transfers

=== ERC20 Transfers (5) ===
1. ERC20 Transfer
   Block: 18000001
   Transaction: 0x1234567890abcdef...
   From: 0x1234567890123456789012345678901234567890 (0x1234...7890)
   To: 0x5678901234567890123456789012345678901234 (0x5678...1234)
   Amount: 1000000000000000000
   Token Contract: 0xA0b86a33E6441c8C06Cdd238c2df0F7A8a8c8c8c (0xA0b8...c8c8)
   Log Index: 0
   Topics: 3
   Event Signature: 0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef
   Data Length: 32 bytes
   Removed: false

ERC721 Transfers

=== ERC721 Transfers (2) ===
1. ERC721 Transfer (NFT)
   Block: 18000002
   Transaction: 0x1234567890abcdef...
   From: 0x1234567890123456789012345678901234567890 (0x1234...7890)
   To: 0x5678901234567890123456789012345678901234 (0x5678...1234)
   Token ID: 123
   NFT Contract: 0xB0b86a33E6441c8C06Cdd238c2df0F7A8a8c8c8c (0xB0b8...c8c8)
   Log Index: 1
   Topics: 4
   Event Signature: 0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef
   Data Length: 0 bytes
   Removed: false

ERC1155 Transfers

=== ERC1155 Transfers (3) ===
1. ERC1155 Transfer Single
   Block: 18000003
   Transaction: 0x1234567890abcdef...
   Operator: 0x1234567890123456789012345678901234567890 (0x1234...7890)
   From: 0x1234567890123456789012345678901234567890 (0x1234...7890)
   To: 0x5678901234567890123456789012345678901234 (0x5678...1234)
   Token ID: 456
   Amount: 5
   Contract: 0xC0b86a33E6441c8C06Cdd238c2df0F7A8a8c8c8c (0xC0b8...c8c8)
   Log Index: 2
   Topics: 4
   Event Signature: 0xc3d58168c5ae7397731d063d5bbf3d657854427343f4c083240f7aacaa2d0f62
   Data Length: 64 bytes
   Removed: false

2. ERC1155 Transfer Batch
   Block: 18000004
   Transaction: 0x1234567890abcdef...
   Operator: 0x1234567890123456789012345678901234567890 (0x1234...7890)
   From: 0x1234567890123456789012345678901234567890 (0x1234...7890)
   To: 0x5678901234567890123456789012345678901234 (0x5678...1234)
   Contract: 0xD0b86a33E6441c8C06Cdd238c2df0F7A8a8c8c8c (0xD0b8...c8c8)
   Log Index: 3
   Topics: 4
   Batch Items (2):
     - Token ID: 789, Amount: 10
     - Token ID: 101, Amount: 2
   Event Signature: 0x4a39dc06d4c0dbc64b70af90fd698a233a518aa5d07e595d983b8c0526c8f7fb
   Data Length: 128 bytes
   Removed: false

Raw Event Data (Debugging)

=== Raw Event Data (First 3 events) ===
Event 1:
  Contract Key: erc20
  Event Key: erc20transfer
  ABI Event Name: Transfer
  Unpacked Type: erc20.Erc20Transfer

Event 2:
  Contract Key: erc721
  Event Key: erc721transfer
  ABI Event Name: Transfer
  Unpacked Type: erc721.Erc721Transfer

Setup

Install dependencies:
```
go mod tidy
```
Configure RPC endpoint:
- Replace YOUR_KEY in the default RPC URL with your Infura/Alchemy API key
- Or use the -rpc flag to specify a custom endpoint

Run the example:

go run main.go -account <ADDRESS> -start <START_BLOCK> -end <END_BLOCK>

Example Output

Connecting to Ethereum RPC: https://mainnet.infura.io/v3/YOUR_KEY
Latest block: 18500000
Scanning blocks 18000000 to 18001000 for account 0x1234567890123456789012345678901234567890
Direction: both

Filtering transfer events...

Found 15 transfer events:

=== ERC20 Transfers (8) ===
1. Block 18000001 | 0x1234... -> 0x5678... | Amount: 1000000000000000000 | Token: 0xA0b86a33E6441c8C06Cdd238c2df0F7A8a8c8c8c
...

=== ERC721 Transfers (3) ===
1. Block 18000005 | 0x1234... -> 0x5678... | Token ID: 123 | Contract: 0xB0b86a33E6441c8C06Cdd238c2df0F7A8a8c8c8c
...

=== ERC1155 Transfers (4) ===
1. Block 18000008 | 0x1234... -> 0x5678... | Token ID: 456 | Amount: 5 | Contract: 0xC0b86a33E6441c8C06Cdd238c2df0F7A8a8c8c8c
...

Summary:
- ERC20 transfers: 8
- ERC721 transfers: 3
- ERC1155 transfers: 4
- Total transfers: 15

Error Handling

The example includes comprehensive error handling for:

Invalid account addresses
Invalid block ranges
RPC connection failures
Network timeouts
Invalid command line arguments

Performance Notes

The example uses the optimized eventfilter.FilterTransfers function
Query optimization minimizes API calls to the Ethereum node
Large block ranges may take time to process depending on network activity