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Chain metadata helps the parser understand smart contract interactions. Without metadata, contract calls may appear as raw hex data. With metadata, they’re parsed into meaningful field names and values.

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When to provide metadata

ScenarioMetadata needed?
Native transfers (ETH, SOL, SUI)No
Known protocols (Uniswap, Jupiter, Aave)No (built-in support)
Standard token transfers (ERC-20, SPL)No (built-in support)
Custom smart contractsYes
Anchor programs without public IDLYes

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Ethereum: Contract ABI

For Ethereum and EVM chains, provide the contract ABI to decode function calls:

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gRPC example

request := &pb.ParseRequest{
    UnsignedPayload: txBytes,
    Chain: pb.Chain_CHAIN_ETHEREUM,
    ChainMetadata: &pb.ChainMetadata{
        Metadata: &pb.ChainMetadata_Ethereum{
            Ethereum: &pb.EthereumMetadata{
                Abi: &pb.Abi{
                    Value: contractABI, // JSON ABI string
                },
            },
        },
    },
}

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ABI format

The ABI is standard Solidity ABI JSON: 
[
  {
    "name": "transfer",
    "type": "function",
    "inputs": [
      { "name": "recipient", "type": "address" },
      { "name": "amount", "type": "uint256" }
    ]
  },
  {
    "name": "approve",
    "type": "function",
    "inputs": [
      { "name": "spender", "type": "address" },
      { "name": "amount", "type": "uint256" }
    ]
  }
]

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Specifying network

For EVM chains other than mainnet, specify the network: 
ChainMetadata: &pb.ChainMetadata{
    Metadata: &pb.ChainMetadata_Ethereum{
        Ethereum: &pb.EthereumMetadata{
            NetworkId: "POLYGON_MAINNET",  // or ARBITRUM_MAINNET, etc.
            Abi: &pb.Abi{
                Value: contractABI,
            },
        },
    },
}

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Solana: Program IDL

For Solana programs, provide the Anchor IDL to decode instructions:

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gRPC example

request := &pb.ParseRequest{
    UnsignedPayload: txBytes,
    Chain: pb.Chain_CHAIN_SOLANA,
    ChainMetadata: &pb.ChainMetadata{
        Metadata: &pb.ChainMetadata_Solana{
            Solana: &pb.SolanaMetadata{
                Idl: &pb.Idl{
                    Value: anchorIDL, // JSON IDL string
                    IdlType: pb.SolanaIdlType_SOLANA_IDL_TYPE_ANCHOR,
                },
            },
        },
    },
}

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Multiple programs

If your transaction interacts with multiple programs, use the IDL mappings: 
ChainMetadata: &pb.ChainMetadata{
    Metadata: &pb.ChainMetadata_Solana{
        Solana: &pb.SolanaMetadata{
            IdlMappings: map[string]*pb.Idl{
                "Program1111111111111111111111111111111111111": {
                    Value: program1IDL,
                    IdlType: pb.SolanaIdlType_SOLANA_IDL_TYPE_ANCHOR,
                },
                "Program2222222222222222222222222222222222222": {
                    Value: program2IDL,
                    IdlType: pb.SolanaIdlType_SOLANA_IDL_TYPE_ANCHOR,
                },
            },
        },
    },
}

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Supported IDL types

TypeDescription
SOLANA_IDL_TYPE_ANCHORAnchor framework IDL
SOLANA_IDL_TYPE_SHANKShank IDL format

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Library integration

When using the library directly (not gRPC), pass metadata as a function parameter: 
use visualsign_parser::{parse_transaction, Chain, ChainMetadata, EthereumMetadata};

let metadata = ChainMetadata::Ethereum(EthereumMetadata {
    abi: Some(contract_abi.to_string()),
    network_id: None,
});

let result = parse_transaction(raw_tx, Chain::Ethereum, Some(metadata));

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Obtaining metadata

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Ethereum ABIs

SourceHow to get
EtherscanView verified contract → Contract tab → ABI
Compilationsolc --abi Contract.sol
Hardhatartifacts/contracts/Contract.sol/Contract.json
Foundryout/Contract.sol/Contract.json

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Solana IDLs

SourceHow to get
Anchor buildtarget/idl/program_name.json
On-chainSome programs publish IDL on-chain
Program repoCheck the program’s source repository

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Without metadata

If you don’t provide metadata for a contract interaction, the parser will:
  1. Decode what it can (addresses, amounts in native token)
  2. Show the function selector (first 4 bytes) as hex
  3. Display raw calldata for unknown parameters
This is safe but less informative. Users see something like: 
Contract Interaction
Method: 0xa9059cbb (unknown)
To: 0x1234...
Data: 0x...

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Next steps