Derive Macro TapMessage 

#[derive(TapMessage)]
{
    // Attributes available to this derive:
    #[tap]
}

Procedural derive macro for implementing TapMessage, MessageContext, and optionally TapMessageBody traits.

Usage

Basic Usage (TapMessage + MessageContext only)

use tap_msg::TapMessage;
use tap_msg::message::{Party, Agent};
use tap_caip::AssetId;

#[derive(TapMessage)]
pub struct Transfer {
    #[tap(participant)]
    pub originator: Party,
     
    #[tap(participant)]
    pub beneficiary: Option<Party>,
     
    #[tap(participant_list)]
    pub agents: Vec<Agent>,
     
    #[tap(transaction_id)]
    pub transaction_id: String,
     
    // regular fields don't need attributes
    pub amount: String,
    pub asset: AssetId,
}

Full Usage (includes TapMessageBody with auto-generated to_didcomm)

use tap_msg::TapMessage;
use tap_msg::message::{Party, Agent};
use serde::{Serialize, Deserialize};

#[derive(Debug, Clone, Serialize, Deserialize, TapMessage)]
#[tap(message_type = "https://tap.rsvp/schema/1.0#Transfer", initiator, authorizable, transactable)]
pub struct Transfer {
    #[tap(participant)]
    pub originator: Party,
     
    #[tap(participant)]
    pub beneficiary: Option<Party>,
     
    #[tap(participant_list)]
    pub agents: Vec<Agent>,
     
    #[tap(transaction_id)]
    pub transaction_id: String,
     
    pub amount: String,
}

// TapMessageBody is automatically implemented with:
// - message_type() returning the specified string
// - validate() with basic validation (can be overridden)
// - to_didcomm() with automatic participant extraction and message construction
// - Authorizable trait (if authorizable attribute is present)
// - Transaction trait (if transactable attribute is present)

Supported Attributes

Struct-level Attributes

• #[tap(message_type = "url")] - TAP message type URL (enables TapMessageBody generation)
• #[tap(initiator)] - Marks this as a conversation-initiating message
• #[tap(authorizable)] - Auto-generates Authorizable trait implementation
• #[tap(transactable)] - Auto-generates Transaction trait implementation
• #[tap(builder)] - Auto-generates builder pattern

Field-level Attributes

• #[tap(participant)] - Single participant field (Party or Agent, required or optional)
• #[tap(participant_list)] - Vec field for lists of agents
• #[tap(transaction_id)] - Transaction ID field (creates new transaction for initiators)
• #[tap(thread_id)] - Thread ID field (references existing transaction for replies)
• #[tap(connection_id)] - Connection ID field (for linking to Connect messages)