ERC-8004 Registrar Transaction Builder

This tool constructs a raw Ethereum transaction object for interacting with the ERC-8004 Agent Identity canonical registry on Base at 0x8004A169FB4a3325136EB29fA0ceB6D2e539a432. It accepts an operation value of register or update, the agent metadata string containing profile details as JSON or a URI, and an optional paymentValue string in Wei. Based on operation, it ABI-encodes either register(string metadata) or update(string metadata) into the data field, sets the to field to the registry address, and sets value from paymentValue. Any additional transaction fields required by the system-provided structured output schema must be populated only when derivable from these inputs or schema defaults. The final output must strictly validate against the system-provided structured output schema that is auto-produced and not supplied here.