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Object Storage Service:ListVectorIndexes

Last Updated:Sep 25, 2025

You can call the ListVectorIndexes operation to list all vector indexes in a vector bucket.

Notes

  • The ListVectorIndexes operation returns a maximum of 500 indexes per call. Use paging to retrieve subsequent batches.

  • The maximum number of concurrent ListVectorIndexes calls is 16.

Permissions

An Alibaba Cloud account has all permissions by default. By default, Resource Access Management (RAM) users or RAM roles under an Alibaba Cloud account have no permissions. The Alibaba Cloud account owner or an administrator must grant permissions using a RAM policy or a bucket policy.

API

Action

Description

ListVectorIndexes

oss:ListVectorIndexes

Lists vector indexes.

Request syntax

POST /?listVectorIndexes HTTP/1.1
Host: examplebucket-123***456.cn-hangzhou.oss-vectors.aliyuncs.com
Date: GMT Date
Authorization: SignatureValue
Content-type: application/json

{
   "maxResults": int,
   "nextToken": "string",
   "prefix": "string"
}

Request headers

This operation uses only common request headers. For more information, see Common HTTP headers.

Request parameters

Name

Data type

Required

Example

Description

maxResults

Number

No

100

The maximum number of indexes to return. Valid values: 0 to 500. If you do not set this parameter or set it to 0, the default value is 100.

nextToken

String

No

myindex1

The results start from the first entry that comes after nextToken in alphabetical order.

prefix

String

No

my

Prefix matching for vector indexes.

Response headers

This operation uses only common response headers. For more information, see Common HTTP headers.

Response elements

Name

Data type

Example

Description

indexes

Array of objects

-

An array that contains information about the vector indexes.

indexName

String

vectorindex1

The name of the index.

Parent node: index

createTime

String

2025-04-17T10:56:21.000Z

The time when the index was created. The time is in GMT.

Parent node: index

dataType

String

float32

The data type of the vector.

Parent node: index

dimension

Integer

1024

The vector dimensions.

Parent node: index

distanceMetric

String

euclidean

The distance measure function.

Parent node: index

metadata

Container

-

The metadata configuration.

Parent node: index

nonFilterableMetadataKeys

Array of strings

["category", "timestamp"]

A list of non-filterable metadata fields.

Parent node: metadata

status

String

enable

The current status of the index. Valid values:

  • Creating

  • Enabled (active)

  • deleting: The index is being deleted.

nextToken

String

myindex1

The token to use for the next query. If not all results are returned in the current call, this token is included for subsequent queries.

Examples

Example request

POST /?listVectorIndexes HTTP/1.1
Host: examplebucket-123***456.cn-hangzhou.oss-vectors.aliyuncs.com
Date: Thu, 17 Apr 2025 01:33:47 GMT
Authorization: OSS4-HMAC-SHA256 Credential=LTAI********************/20250417/cn-hangzhou/oss/aliyun_v4_request,Signature=a7c3554c729d71929e0b84489addee6b2e8d5cb48595adfc51868c299c0c218
Content-type: application/json

{
   "maxResults": 10,
   "prefix": "my"
}

Example response

HTTP/1.1 200 OK
x-oss-request-id: 534B371674E88A4D8906****
Date: Thu, 17 Apr 2025 01:33:47 GMT
Connection: keep-alive
Server: AliyunOSS
Content-type: application/json

{
   "indexes": [ 
      { 
         "createTime": "2025-04-17T10:56:21.000Z",
         "indexName": "vectorindex1",
         "dataType": "float32",
         "dimension": 1024,
         "distanceMetric": "euclidean",
         "metadata": { 
             "nonFilterableMetadataKeys": ["category", "timestamp"]
          },
         "status": "enable"
      },
      { 
         "createTime": "2025-04-17T11:20:15.000Z",
         "indexName": "vectorindex2",
         "dataType": "float32",
         "dimension": 512,
         "distanceMetric": "cosine",
         "metadata": { 
             "nonFilterableMetadataKeys": ["type", "source"]
          },
         "status": "enable"
      }
   ],
   "nextToken": "myindex1"
}

Error codes

Error code

HTTP status code

Description

VectorIndexParameterInvalid

400

The vector index parameter in the request is invalid.

MalformedJson

400

The JSON format in the request body is invalid.

AccessDenied

403

Possible causes for this error:

  • The user authentication information is not included in the request.

  • You do not have the required permissions.