---
title: "Put Object Metadata"
url: https://docs.catalyst.zoho.com/en/api/code-reference/cloud-scale/stratus/put-object-meta/
description: "This API enables you to create a signature for the bucket."
last_updated: 2026-08-28T06:26:16Z
service: Cloud Scale
type: api
---

# Put Object Metadata

### Description

This API allows you to add metadata for the required [object](https://docs.catalyst.zoho.com/en/cloud-scale/help/stratus/objects/introduction/) stored in a bucket. The Bucket is referred by its [unique bucket name](https://docs.catalyst.zoho.com/en/cloud-scale/help/stratus/buckets/name-bucket/#ideal-practices-to-name-a-bucket), and the required object is referred using its name.

> **Note:**

* You can use alphanumeric, underscores, or whitespace characters, as well as hyphens, to write your metadata. No other special character is allowed other than the once mentioned.

* You can fetch the metadata of an object using the `HEAD` request method. In the response, the metadata will be listed in the key '`x-user-meta`'.

* The maximum size limit of characters allowed for the overall metadata is **2047** characters. The character count used to determine the size limit also includes the colon ":" special character used to define the key value pair.

### Request Details

#### Request URL

`POST` {api-domain}/baas/v1/project/{project_id}/bucket/object/metadata

- **project_id** (Numerical): The [unique ID](https://docs.catalyst.zoho.com/en/getting-started/set-up-a-catalyst-project/general-settings/) of the project

#### Request JSON

You must send a JSON with its corresponding values as shown below.

**Sample Payload**

```json

    {
    "meta_data": {
        "key1": "value1",
        "key2": "value2"
    }
    }

```

You will feed this **Request JSON** to your **Request Body**, and you need to provide the value of:

- **meta_data** ( , mandatory):  This JSON will contain the required [meta data](https://docs.catalyst.zoho.com/en/cloud-scale/help/stratus/objects/introduction/#metadata) in the form of JSON key value pairs.

#### Query Parameters

- **bucket_name** (Alphanumeric, mandatory): The [name of the bucket](https://docs.catalyst.zoho.com/en/cloud-scale/help/stratus/buckets/name-bucket/#ideal-practices-to-name-a-bucket)

- **object_key** (String, mandatory): Will contain the complete name of the object.

#### Request Headers
 **Authorization:** Zoho-oauthtoken {oauth_token} 

**Optional Headers** 

 **CATALYST-ORG:** {org_id}

 **Environment:** Development

#### Scope

ZohoCatalyst.buckets.objects.CREATE

### Response Details

On successful execution, the response will contain the success message indicating that the metadata has been added to the required object.

**Sample Request**

```bash

curl -X PUT https://api.catalyst.zoho.com/baas/v1/project/10108000003823392/bucket/object/metadata?bucket_name=myBucketName&object_key=image2.png/
-H "Authorization: Zoho-oauthtoken 1000.910*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*16.2f*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*57"
-H “Content-Type:application/json”
-\-data-raw $’{"{"meta_data" : {"key1" : "value1","key2" : "value2"}}"}'

```

**Sample Response**

```json

    {
    "status": "success",
    "data": {
        "message": "Metadata added successfully"
    }
    }

```

### SDK Documentation

* [Put Object Meta Data - Java SDK](https://docs.catalyst.zoho.com/en/sdk/java/v1/cloud-scale/stratus/put-object-meta/)
* [Put Object Meta Data - Node.js SDK](https://docs.catalyst.zoho.com/en/sdk/nodejs/v2/cloud-scale/stratus/put-object-meta/)
* [Put Object Meta Data - Python SDK](https://docs.catalyst.zoho.com/en/sdk/python/v1/cloud-scale/stratus/put-object-meta/)
* [Stratus - Web SDK](https://docs.catalyst.zoho.com/en/sdk/web/v4/cloud-scale/stratus/overview/)
* [Stratus - iOS SDK](https://docs.catalyst.zoho.com/en/sdk/ios/v2/cloud-scale/stratus/overview/)
* [Stratus - Android SDK](https://docs.catalyst.zoho.com/en/sdk/android/v2/cloud-scale/stratus/overview/)
* [Stratus - Flutter SDK](https://docs.catalyst.zoho.com/en/sdk/flutter/v2/cloud-scale/stratus/overview/)