---
title: "MarkThreadReadBody"
description: "Request body for a Thread operation."
section: "Reference"
group: "Types"
order: 233
---

## Definition

```ts
interface MarkThreadReadBody {
  messageId?: string | undefined;
}
```

## Fields

| Field       | Type                  | Notes                                                                                |
| ----------- | --------------------- | ------------------------------------------------------------------------------------ |
| `messageId` | `string \| undefined` | `optional` — Message to mark as read up to. Defaults to the thread's latest message. |