> ## Documentation Index
> Fetch the complete documentation index at: https://developer.z-api.io/llms.txt
> Use this file to discover all available pages before exploring further.

# Read messages

> Mark a message in a chat as read

## Overview

Method used to mark a message in a chat as read.

***

## Attributes

### Header

<ParamField path="instanceId" type="string" required>
  Your instance ID. Available in the Z-API panel under **Instances**.
</ParamField>

<ParamField path="token" type="string" required>
  Your Z-API instance token.
</ParamField>

### Required

<ParamField body="phone" type="string" required>
  Recipient/sender phone number (or group ID for group messages) in DDI DDD NUMBER format. E.g.: 551199999999. **IMPORTANT** Send only numbers, without formatting or masks
</ParamField>

<ParamField body="messageId" type="string" required>
  Original message ID. For messages sent by you, it's the code from your response. For messages sent by a contact, you'll receive this messageId through your receive webhook
</ParamField>

***

## Request Body

```json theme={"theme":{"light":"github-light","dark":"poimandres"}}
{
  "phone": "5511999998888",
  "messageId": "3999984263738042930CD6ECDE9VDWSA"
}
```

***

## Response

### 204

No content

```json theme={"theme":{"light":"github-light","dark":"poimandres"}}
{}
```

### 405

Make sure you are correctly sending the method specification, that is, verify that you sent POST or GET as specified at the beginning of this topic.

### 415

If you receive a 415 error, make sure to add the "Content-Type" header to your request, which in most cases is "application/json".