Suggested replies

Add a suggested reply to a thread for a user to review, edit, and send.

Suggested replies (also called generated replies) allow you to programmatically add AI-generated or pre-composed reply suggestions to a thread. These suggestions are shown to the user in Plain so they can review and send them to the customer.

For TypeScript, the GraphQL SDK gives you a fully typed client for these operations.

This is useful if you are building your own AI integration or want to suggest replies based on your own logic, external knowledge bases, or automation workflows.

Adding a suggested reply

To add a suggested reply you need to provide the threadId, the timelineEntryId of the message you are responding to, and the markdown content of the reply.

The timeline entry must be a message, from either the customer or a machine user. Use the most recent inbound message on the thread. Notes, user replies and timeline events such as label or status changes are not valid targets.

A timelineEntryId identifies a single entry on a customer’s timeline (e.g. an email or chat message). You can get one by querying a thread’s timelineEntries connection, where each entry has an id you can use here.

The markdown field supports a maximum of 5,000 characters.

Your replies show even when suggested responses are turned off, and take precedence over Ari’s for the same message.

To add a suggested reply, you need an API key with the following permissions:

• generatedReply:create

Mutation

mutation addGeneratedReply($input: AddGeneratedReplyInput!) {
  addGeneratedReply(input: $input) {
    generatedReply {
      id
      markdown
      timelineEntryId
      createdAt {
        iso8601
      }
      updatedAt {
        iso8601
      }
    }
    error {
      message
      type
      code
      fields {
        field
        message
        type
      }
    }
  }
}

Variables

{
  "input": {
    "threadId": "th_01H8H46YPB2S4MAJM382FG9423",
    "timelineEntryId": "t_01H8H46YPB2S4MAJM382FG9423",
    "markdown": "Hi there! Based on our documentation, you can reset your password by going to **Settings > Security > Reset password**. Let me know if you need any further help!"
  }
}

Threads created through the API

A thread that your integration opens with createThread has its first message authored by your machine user, not by the customer. That message is a valid target, so an agent can suggest a reply on a thread it opened itself. Do not filter the timeline down to customer entries before you choose a timelineEntryId, or you will find no target on these threads.