Updated on 2023-11-10 GMT+08:00

Making an API Request

This section describes the structure of a REST API request, and uses Short Sentence Recognition as an example.

Request URI

A request URI is in the following format:

{URI-scheme} :// {Endpoint} / {resource-path} ? {query-string}

Table 1 Request URI

Parameter

Description

URI-scheme

Protocol used to transmit requests. All APIs use HTTPS.

Endpoint

Domain name or IP address of the server bearing the REST service. The endpoint varies between services in different regions. It can be obtained from Endpoints. For example, the endpoint of Sentence Transcription in the AP-Singapore region is sis-ext.ap-southeast-3.myhuaweicloud.com.

resource-path

Access path of an API for performing a specified operation. Obtain the path from the URI of an API. For example, the resource-path of the Sentence Transcription API is /v1/{project_id}/asr/short-audio. Replace project_id with the user's actual project ID. For details about how to obtain the project ID, see Obtaining a Project ID.

query-string

Query parameter, which is optional. Ensure that a question mark (?) is included before each query parameter that is in the format of "Parameter name=Parameter value".

For example, to call the Short Sentence Recognition API in the AP-Singapore region, use the endpoint (sis-ext.ap-southeast-3.myhuaweicloud.com). The combination is as follows:

https://sis-ext.ap-southeast-3.myhuaweicloud.com/v1/{project_id}/asr/short-audio
Figure 1 Example URI

To simplify the URI display in this document, each API is provided only with a resource-path and a request method. The URI-scheme of all APIs is HTTPS, and the endpoints of all APIs in the same region are identical.

Request Methods

The HTTP protocol defines the following request methods that can be used to send a request to the server:

  • GET: requests the server to return specified resources.
  • PUT: requests the server to update specified resources.
  • POST: requests the server to add resources or perform special operations.
  • DELETE: requests the server to delete specified resources, for example, an object.
  • HEAD: same as GET except that the server must return only the response header.
  • PATCH: requests the server to update partial content of a specified resource. If the resource does not exist, a new resource will be created.

For example, in the case of the Short Sentence Recognition API, the request method is POST. The request is as follows:

POST https://sis-ext.ap-southeast-3.myhuaweicloud.com/v1/{project_id}/asr/short-audio

Request Header

You can also add additional header fields to a request, such as the fields required by a specified URI or HTTP method. For example, to request for the authentication information, add Content-Type, which specifies the request body type.

Common request headers are as follows:

  • Content-Type: specifies the request body type or format. This field is mandatory and its default value is application/json.
  • X-Auth-Token: specifies a user token only for token-based API authentication. For details about user tokens, see Token-based Authentication in Authentication.

The following provides an example request with a header included.

POST https://sis-ext.ap-southeast-3.myhuaweicloud.com/v1/{project_id}/asr/short-audio
Content-Type: application/json
X-Auth-Token: MIINRwYJKoZIhvcNAQcCoIINOD... 

Request Body

The body of a request is often sent in a structured format as specified in the Content-Type header field. The request body transfers content except the request header. If the request body contains Chinese characters, these characters must be coded in UTF-8.

The request body varies between APIs. Some APIs do not require the request body, such as the APIs requested using the GET and DELETE methods.

In the case of the Short Sentence Recognition API, the request parameters and parameter descriptions can be obtained from the API request. The following is an example request with the body added. The data parameter indicates the Base64-encoded character string converted from the audio.
POST https://sis-ext.ap-southeast-3.myhuaweicloud.com/v1/{project_id}/asr/short-audio
Content-Type: application/json
X-Auth-Token: MIINRwYJKoZIhvcNAQcCoIINOD... 

{
    "data": "encode audio by Base64",
    "config": {
        "audio_format": "wav",
        
        "property": "english_8k_common"
    }
}

If all data required for the API request is available, you can send the request to call the API through curl, Postman, or coding. For the Short Sentence Recognition API, you can obtain the request parameters and parameter descriptions from the response message.