chat/docs/subject.mdx

Unified chat abstraction for Slack, Teams, Google Chat, and Discord

---
title: Message Subject
description: Fetch the parent resource that a message is about.
type: guide
prerequisites:
  - /docs/handling-events
related:
  - /docs/conversation-history
---

When your bot receives a comment on a Linear issue or GitHub PR, `message.subject` resolves the parent resource so your handler knows what the conversation is about.

## Usage

```typescript title="lib/bot.ts" lineNumbers
bot.onNewMention(async (thread, message) => {
  const subject = await message.subject;

  if (subject) {
    await thread.post(
      `This is about: ${subject.title} (${subject.status})\n${subject.url}`
    );
  }
});
```

On Linear and GitHub, comment webhooks deliver the comment text but not the parent issue or pull request — `message.subject` fetches it from the platform API on first access. The result is cached on the message instance. On chat platforms (which have no parent-resource concept), or if the API call fails, it returns `null`.

See [`MessageSubject`](/docs/api/message#messagesubject) for the full type shape.

### Platform support

| Platform | `message.subject` returns |
|----------|--------------------------|
| Linear | Parent issue (from comment webhooks) |
| GitHub | Parent issue or PR (from comment webhooks) |

All other platforms return `null`.

## User info

For user profile details, use [`bot.getUser`](/docs/api/chat#getuser):

```typescript title="lib/bot.ts" lineNumbers
bot.onNewMention(async (thread, message) => {
  const user = await bot.getUser(message.author);
  if (user) {
    await thread.post(`Hi ${user.fullName} (${user.email})`);
  }
});
```

For anything beyond `message.subject`, access the platform's typed API client via [`bot.getAdapter("github").octokit`](/docs/api/chat#getadapter) or [`bot.getAdapter("linear").linearClient`](/docs/api/chat#getadapter).