Support onchain transaction references with your agent built with XMTP

This package provides an XMTP content type to support onchain transaction references. It is a reference to an onchain transaction sent as a message. This content type facilitates sharing transaction hashes or IDs, thereby providing a direct link to onchain activities. Transaction references serve to display transaction details, facilitating the sharing of onchain activities, such as token transfers, between users.

Install the package

npm

npm i @xmtp/content-type-transaction-reference

Configure the content type

After importing the package, you can register the codec.

Node

import {
  ContentTypeTransactionReference,
  TransactionReferenceCodec,
} from '@xmtp/content-type-transaction-reference';
// Create the XMTP agent
const agent = await Agent.create(signer, {
  env: 'dev',
  codecs: [new TransactionReferenceCodec()],
});

Send a transaction reference

With XMTP, a transaction reference is represented as an object with the following keys:

Node

const transactionReference: TransactionReference = {
  /**
   * Optional namespace for the networkId
   */
  namespace: 'eip155',
  /**
   * The networkId for the transaction, in decimal or hexadecimal format
   */
  networkId: 1,
  /**
   * The transaction hash
   */
  reference: '0x123...abc',
  /**
   * Optional metadata object
   */
  metadata: {
    transactionType: 'transfer',
    currency: 'USDC',
    amount: 100000, // In integer format, this represents 1 USDC (100000/10^6)
    decimals: 6, // Specifies that the currency uses 6 decimal places
    fromAddress: '0x456...def',
    toAddress: '0x789...ghi',
  },
};

Once you have a transaction reference, you can send it as part of your conversation:

Node

await ctx.conversation.send(transactionReference, {
  contentType: ContentTypeTransactionReference,
});

Receive a transaction reference

To receive and process a transaction reference, you can use the following code samples.

Node

// Assume `loadLastMessage` is a thing you have
const message: DecodedMessage = await loadLastMessage();
 
if (!message.contentType.sameAs(ContentTypeTransactionReference)) {
  // Handle non-transaction reference message
  return;
}
 
const transactionRef: TransactionReference = message.content;
// Process the transaction reference here

You are welcome to provide feedback on this implementation by commenting on XIP-59: Trigger on-chain calls via wallet_sendCalls.