Support replies with your agent built with XMTP

Use the reply content type to support quote replies with your agent. A reply is a method to directly respond to a specific message in a conversation. Users can select and reply to a particular message instead of sending a new one.

Use a local database for performance

Use a local database to store replies. This will enable your app to performantly display a reply with its referenced message when rendering message lists.

Install the package

In some SDKs, the ReplyCodec is already included in the SDK. If not, you can install the package using the following command:

npm

npm i @xmtp/content-type-reply

Configure the content type

After importing the package, you can register the codec.

Node

import { ReplyCodec } from "@xmtp/content-type-reply";
// Create the XMTP client
const xmtp = await Client.create(signer, {
  env: "dev",
  codecs: [new ReplyCodec()],
});

Send a reply

Once you've created a reply, you can send it. Replies are represented as objects with two keys:

reference: ID of the message being replied to
content: String representation of the reply

Node

import { ContentTypeText } from "@xmtp/content-type-text";
import { ContentTypeReply } from "@xmtp/content-type-reply";
import type { Reply } from "@xmtp/content-type-reply";
 
const reply: Reply = {
  reference: someMessageID,
  contentType: ContentTypeText,
  content: "I concur",
};
 
await conversation.send(reply, {
  contentType: ContentTypeReply,
});

Receive the content type

Node

if (message.contentType.sameAs(ContentTypeReply)) {
  // We've got a reply.
  const reply: Reply = message.content;
}