Uploading Image

Update Time：2025.01.07

Merchants or institutions call this API to upload the certificate images in jpeg, jpg, bmp, png format. The API should be called through POST form, with enctype set as multipart/form-data.

1. API Instructions

Applicable to：Common mode Institutional mode

Request URL：https://apihk.mch.weixin.qq.com/v3/merchant/media/upload

Request body type：multipart/form-data

Request method：POST

Path parameter is a path parameter.

Query parameter needs to be passed in the request URL.

Body parameter needs to be passed in the request JSON.

2. Request Parameters

Name

Variable Name

Type

Required

Description

File information

file

object

Yes

Body Binary conversion of the media image to obtain the binary content of the media image, upload the binary content in the request body. Media images only support JPG, BMP, and PNG formats, and the file size cannot exceed 2M
Example：pic1

Media file meta information

3. Request examples with different development languages

JAVA

1String filePath = "/your/home/hellokitty.png";
2URI uri = new URI("https://apihk.mch.weixin.qq.com/v3/merchant/media/upload");
3File file = new File(filePath);
4
5try (FileInputStream ins1 = new FileInputStream(file)) { 
6  String sha256 = DigestUtils.sha256Hex(ins1);
7  try (InputStream ins2 = new FileInputStream(file)) {
8    HttpPost request = new WechatPayUploadHttpPost.Builder(uri)
9        .withImage(file.getName(), sha256, ins2)
10        .build();
11    CloseableHttpResponse response1 = httpClient.execute(request);
12  }
13}

PHP

1// 参考上述指引说明，并引入 `MediaUtil` 正常初始化，无额外条件
2use WechatPay\GuzzleMiddleware\Util\MediaUtil;
3// 实例化一个媒体文件流，注意文件后缀名需符合接口要求
4$media = new MediaUtil('/your/file/path/with.extension');
5
6// 正常使用Guzzle发起API请求
7try {
8    $resp = $client->request('POST', 'https://apihk.mch.weixin.qq.com/v3/[merchant/media/video_upload|marketing/favor/media/image-upload]', [
9        'body'    => $media->getStream(),
10        'headers' => [
11            'Accept'       => 'application/json',
12            'content-type' => $media->getContentType(),
13        ]
14    ]);
15    // POST 语法糖
16    $resp = $client->post('merchant/media/upload', [
17        'body'    => $media->getStream(),
18        'headers' => [
19            'Accept'       => 'application/json',
20            'content-type' => $media->getContentType(),
21        ]
22    ]);
23    echo $resp->getStatusCode().' '.$resp->getReasonPhrase()."\n";
24    echo $resp->getBody()."\n";
25} catch (Exception $e) {
26    echo $e->getMessage()."\n";
27    if ($e->hasResponse()) {
28        echo $e->getResponse()->getStatusCode().' '.$e->getResponse()->getReasonPhrase()."\n";
29        echo $e->getResponse()->getBody();
30    }
31    return;
32}

Request examples with Java, please refer to：wechatpay-apache-httpclient

Request examples with PHP, please refer to：wechatpay-guzzle-middleware

4. Return Parameters

Name	Variable Name	Type	Required	Description
Media file ID	media_id	string[1, 512]	Yes	Id of the media file returned by WeChat. Example：b6a17e2a-1dc4-4376-8630-e73d06490c0d

Return Example

Normal example

1{
2  "media_id": "6uqyGjvHzOhsLleGFQVRF"
3}

5. Request Procedure

5.1. Create a POST method request/upload URI

For example：

HTTP

1POST https://apihk.mch.weixin.qq.com/v3/merchant/media/upload HTTP/1.1

5.2.Add the file data to the request body

5.2.1 How to obtain the file parameter of an image:
The binary content of an image is included in the body of the request HTTP.

5.2.2 How to obtain the meta parameter of a media file:
Media file meta information, expressed in JSON, contains two objects: filename and sha256.
● How to obtain the filename parameter:
The custom name of an image uploaded by the merchant and must be suffixed with ".JPG", ".BMP", or ".PNG".
● How to obtain the sha256 parameter:
The image digest, obtained by calculating the binary content of an image with sha256.

5.2.3 Signature calculation:：
Signature generation
The request body involved in signature calculation is a JSON string of meta：
{"filename": "filea.jpg", "sha256": "hjkahkjsjkfsjk78687dhjahdajhk"}

Example of a string to be signed：

1POST
2/v3/merchant/media/upload
31566987169           // Timestamp
412ced2db6f0193dda91ba86224ea1cd8   // Random number
5{"filename": "file1.jpg", "sha256": "hjkahkjsjkfsjk78687dhjahdajhk"}

5.3.Add the HTTP header：

1Content-Type：multipart/form-data.Set to the MIME media type of the object to be uploaded.
2Authorization: WECHATPAY2-SHA256-RSA2048 mchid="1900231671",
3nonce_str="PCHK6HSOEDTACETP6P3AL7DWPHTBKIAT",timestamp="1567067659",
4serial_no="1FB89742D19F2BD30B69948D16DECA0FCB4481EB",
5signature="PB6M7+3JL7TSCl5zqD1sdWVypOIEQsD4dgOU+vPiVM6GMRo2qYSWKf8u46i9ZJFhyZTBdZ7SFR+BjDZh6
689hFgN8LZL+QWTvq3cse/FEUFYyOLN7L/2IZX4GA4cWInuJ2MpOhZRMpm+emrcn42gTMKAPNQ7dBLO7ux6MoSuQp69
7PW+p1ogmkER68exTVUXYqA5P3vITlWNr++RDy2+ExvB7qVISOKW0vBkxUxN9e7hwUbDwGln170ZXomoO1KpQSbw3f1u
8WUCx/IlWJhJIun7rUMtVT+kfijNUqcILtSfE4hWKKVaZn9j5CX8M7aKbbDOFy3SvbSJ3WQgRnRbgog5w=="
9
10Content-Type: multipart/form-data;boundary=boundary

5.4.Add a body：

1// The content of the body is as follows
2--boundary  // boundary is a string customized by the merchant
3Content-Disposition: form-data; name="meta";
4Content-Type: application/json
5//There must be a blank line here
6{ "filename": "filea.jpg", "sha256": " hjkahkjsjkfsjk78687dhjahdajhk " }
7--boundary
8Content-Disposition: form-data; name="file"; filename="filea.jpg";
9Content-Type: image/jpg
10//There must be a blank line here
11pic1    //pic1 is the binary content of an image.
12--boundary--

Note：The end of each line of the request packet body needs to contain \r\n (including the blank lines).

5.5.Send request

1POST /v3/merchant/media/upload HTTP/1.1
2Host: api.mch.weixin.qq.com
3Authorization: WECHATPAY2-SHA256-RSA2048 
4mchid="1900231671",nonce_str="PCHK6HSOEDTACETP6P3AL7DWPHTBKIAT",
5timestamp="1567067659",
6serial_no="1FB89742D19F2BD30B69948D16DECA0FCB4481EB",
7signature="PB6M7+3JL7TSCl5zqD1sdWVypOIEQsD4dgOU+vPiVM6GMRo2qYSWKf8u46i9ZJFhyZTBdZ7
8SFR+BjDZh689hFgN8LZL+QWTvq3cse/FEUFYyOLN7L/2IZX4GA4cWInuJ2MpOhZRMpm+emrcn42gTMKAPN
9Q7dBLO7ux6MoSuQp69PW+p1ogmkER68exTVUXYqA5P3vITlWNr++RDy2+ExvB7qVISOKW0vBkxUxN9e
107hwUbDwGln170ZXomoO1KpQSbw3f1uWUCx/IlWJhJIun7rUMtVT+kfijNUqcILtSfE4hWKKVaZn9j5CX8M
117aKbbDOFy3SvbSJ3WQgRnRbgog5w=="
12Content-Type: multipart/form-data;boundary=boundary
13
14--boundary  
15Content-Disposition: form-data; name="meta";
16Content-Type: application/json
17
18{ "filename": "filea.jpg", "sha256": " hjkahkjsjkfsjk78687dhjahdajhk " }
19--boundary
20Content-Disposition: form-data; name="file"; filename="filea.jpg";
21Content-Type: image/jpg
22
23pic1
24--boundary--

6. Error Code

Error Codes	Error Message	Description	Solution
500	SYSTEMERROR	System error	System error occurred when viewing a sub-vendor. Try again later.
400	PARAM_ERROR	Regular Validation	XXX has invalid format. Check and try again.
	PARAM_ERROR	Image format error	The image format is wrong, please check and retry. The image size should be less than 2M. Image Hash value error, please check and retry.
	PARAM_ERROR	FIle exceed the size limit	FIle is bigger than 2M
429	FREQUENCY_LIMIT_EXCEED	Frequency limit	Operation is too fast, please retry later
403	NO_AUTH	No permissions to call this endpoint	No permissions. Check and try again.