Use the SendFileToPrinter API for Your Cloud-Based Printing Needs

1. Ensure that the multipart form body complies with the format below, so that it can be parsed correct by the backend. Any other headers in each part are not allowed and will result in a bad request error.

--203fab52-5a95-4e51-9e5c-53248aae2256
Content-Disposition: form-data; name="sn"

XXZJJ174600934
--203fab52-5a95-4e51-9e5c-53248aae2256
Content-Disposition: form-data; name="zpl_file"; filename="HelloWorld.txt"
Content-Type: text/plain

^XA^FO50,50^ADN,36,20^FDHello World!^FS^XZ
--203fab52-5a95-4e51-9e5c-53248aae2256--

2. Here are a few examples available on GitHub of how to use this API

• JavaScript:

PrintFromCloud - A JavaScript example demonstrates how to use the SendFileToPrinter API to print labels and receipts from anywhere to any Link-OS printers connected to the Zebra Data Services cloud platform.

• Java

Use the Zebra SendFileToPrinter Multipart BodyPublisher (ZebraSftpMpBodyPublisher.java), which is based on the java.net.http.HttpRequest package,  for your convenience. The following code snippet shows how to use ZebraSftpMpBodyPublisher.java.

// Create URI from the URL of SendFileToPrinter API
URI uri = URI.create("https://api.zebra.com/v2/devices/printers/send");

String apikey = "z2GI9d7UAlMLMDMEE7qA6RVK1GAigRJJ"; // Replace it with your apikey
String tenant = "695315b271dd374c76fad074e6b1f8cf"; // Replace it with your tenant ID
String sn = "XXZJJ174600912";                       // Replace it with your printer serial number

// Example ZPL file containing - "^XA ^FO50,50^ADN,36,20^FDHello World^FS ^XZ"
Path zplFilePath = Paths.get("C:\\Users\\john\\HelloWorld.txt"); // Replace it with your ZPL file path

// Use ZebraSftpMpBodyPublisher.java
ZebraSftpMpBodyPublisher publisher 
                    = new ZebraSftpMpBodyPublisher().addSn(sn).addSn(sn).addSn(sn).setZplFilePath(zplFilePath);

HttpRequest request = HttpRequest.newBuilder().uri(uri).header("apikey", apikey).header("tenant", tenant)
                      .header("Content-Type", "multipart/form-data; boundary=" + publisher.getBoundary())
                      .POST(publisher.build()).build();

HttpClient httpclient = HttpClient.newBuilder().build();
HttpResponse response = httpclient.send(request, BodyHandlers.ofString());

System.out.println(response.body());

• C#

Use the Zebra SendFileToPrinter Multipart BodyPublisher (ZebraSftpMpBodyPublisher.cs), which is based on the System.Net.Http,  for your convenience. The following code snippet shows how to use ZebraSftpMpBodyPublisher.cs.

string sftpPostUrl = "https://api.zebra.com/v2/devices/printers/send"; // The endpoint of the SendFileToPrinter API
string apikey = "z2GI9d7UAlMLMDMEE7qA6RVK1GAigRJJ";         // Replace it with your apikey
string tenant = "695315b271dd374c76fad074e6b1f8cf";         // Replace it with your tenant ID
string sn1 = "XXZJJ174600912";                              // Replace it with your printer serial number
string sn2 = "XXZJJ174600913";                              // Replace it with your printer serial number
string zplFilePath = @"/Users/john/Desktop/HelloWorld.txt"; // Replace it with your ZPL file path

HttpClient httpClient = new HttpClient();
httpClient.DefaultRequestHeaders.Add("apikey", apikey); // Add the apikey to the header
httpClient.DefaultRequestHeaders.Add("tenant", tenant); // Add the tenant ID to the header

// Use ZebraSftpMpBodyPublisher to compose the form data
MultipartFormDataContent formData = 
                  new ZebraSftpMpBodyPublisher().AddSn(sn1).AddSn(sn2).SetZplFilePath(zplFilePath).Build();

// Post the form data
HttpResponseMessage response = await httpClient.PostAsync(sftpPostUrl, formData);

response.EnsureSuccessStatusCode();
httpClient.Dispose();
string description = response.Content.ReadAsStringAsync().Result;

• OkHttp

You can use OkHttp open source from Square. By default, however, the Content-Length header is added to each part in the multipart form data, which will result in an error thrown back from the server of SendFileToFile API. We need to remove this unwanted header from the request body before posting the request to the server. Here is the code to remove the Content-Length headers from the multipart form body.

private static RequestBody remvoeContentLengthHeaders(final RequestBody original) {
    return new RequestBody() {

        @Override
        public @Nullable
        MediaType contentType() {
            return original.contentType();
        }

        @Override
        public void writeTo(final BufferedSink sink) throws IOException {
            final Buffer buffer = new Buffer();
            original.writeTo(buffer);
            String reqBodyStr = buffer.readUtf8();

            // Remove the Content-Length headers for all parts in the multipart form body
            String reqBodyNoContentLengthStr = reqBodyStr.replaceAll("(?i)\r?\ncontent-length:\\s*[0-9]+", "");
            sink.writeUtf8(reqBodyNoContentLengthStr);
        }
    };
}

Here is the example code of posting the request without the Content-Length headers.

String sn = "XXZJJ174600912";
String url = "https://api.zebra.com/v2/devices/printers/send";
String apikey = "z2GI9d7UAlMLMDMEE7qA6RVK1GAigRJJ";
String tenant = "695315b271dd374c76fad074e6b1f8cf";

File file = new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS) + "/HelloWorld.txt");

// OKHttp client
OkHttpClient client = new OkHttpClient.Builder()
        .build();

RequestBody fileReqBody = RequestBody.create(file, MediaType.parse("text/plain"));

RequestBody requestBody = new MultipartBody.Builder()
        .setType(MultipartBody.FORM)
        .addFormDataPart("sn", sn)
        .addFormDataPart("zpl_file", "HelloWorld.txt", fileReqBody)
        .build();

Request request = new Request.Builder()
        .url(url)
        .post(remvoeContentLengthHeaders(requestBody)) // Remove the Content-Length headers
        .addHeader("apikey", apikey)
        .addHeader("tenant", tenant)
        .build();

try {
    Response response = client.newCall(request).execute();
    System.out.println(response.body().string());
} catch (Exception e) {
    // Do something
    System.out.println(e.toString());
}

Hello,
It appears that this currently only works using ZPL code. I would like to leverage PDF Direct with your API. Is there any way to send a PDF to the printer through the API?
Thank you.

Thanks Steven,
This blog is very helpful.
And we would love to use the sendFileToPrinter API.
One issue we encounter is the CORS error if we try to call the API from a web app (i.e. React).
Any suggested solution ?
By any chance we can set Access-Control-Allow-Origin: * on the API server side ?
Best regards,
Sing

I am getting
{"error":"invalid_token","error_description":"Cannot convert access token to JSON"}
any help?

Can I use this API with the ZD421 printer? Is there a list of printers that can be connected this way through the cloud?

I was chatting with Zebra support and the rep said that the ZD421 is not possible to allow cloud printing. Is this true? Reading the spec sheet it says that the ZD421 is Print DNA compatible and runs the Link-OS Operating System which this API seems to require.

Can someone please confirm if I can use the SendFileToPrinter API to print to the ZD421?

That put me on the right track, I succeeded, thank you so much!

For anyone else who works with Power Automate: This did the trick. https://durasyst-my.sharepoint.com/:i:/g/personal/j_jansma_durasyst_nl/…

And have a look at this thread: https://powerusers.microsoft.com/t5/Using-Connectors/Using-HTTP-POST-wi…

I am unfamiliar with the tool you are using and don't see the form-data for the body on your screenshot. If you just want to test the SendFileToPrinter API, please try to use the Postman. Under the Body tab, choose the form-data. Select the file as the type for the key zpl_file and the text as the type for the key sn.

Wow what a quick reply, thank you!

Hmm.. Problem here is that I'm kind of limited to the functions that are offered by the platform I'm using (Power Automate).

Is there a possibility to just post this miltipart form-data as raw text? Had a similar situation before and it worked.
https://durasyst-my.sharepoint.com/:i:/g/personal/j_jansma_durasyst_nl/…

This attempt didn't succeed.

Hi Jelle,

The endpoint of the SendFileToPrinter doesn't accept JSON as the payload. It only accepts the multipart/form-data as the payload. For the part of the zpl_file, however, you can have the SGD commands in JSON format as the file content to send to the printer. This is the only legitimate JSON the printer accepts. For the details of the JSON equivalent of the SGD commands, please refer to the JSON section of the ZPL manual.

Hi Steven,
I'm looking for an example of a JSON payload for a HTTP request to this endpoint. I'm not much of a programmer so I have some trouble to translate these examples above, especially regarding the zpl file.
I've searched the internet for examples but couldn't find any. Would really appreciate if you could help me out!
Kind regards,
Jelle

I receive the following response, but the label is not coming out. I have been using this API for months now and it stopped printing today. Any ideas on what the issue could be?

{"responses":[{"guid":"01GWxxxxxxxxxxxxxxxxx","sn":"D7xxxxxxxxxxx","status":"SUCCESS"}],"status":"SUCCESS"}

Thank you in advance!

Hey Steven I was wondering, in JavaScript, instead of attaching a ZPL file, is it possible to send a string of raw ZPL. I'm looking to have my own HTML form data populate a label. Thanks again for all your help setting up!

Hi there.  Why do you think I get an Internal Server Error with this request:
 

"uri": "https://api.zebra.com/v2/devices/printers/send",
"method": "POST",
"headers": 
        "tenant": "<Removed>",
        "apikey": "<Removed>",
        "content-type": "multipart/form-data; boundary=----WebKitFormBoundary7MA4YWxkTrZu0gW"

------WebKitFormBoundary7MA4YWxkTrZu0gW
Content-Disposition: form-data; name="sn"

D8N221111111
------WebKitFormBoundary7MA4YWxkTrZu0gW
Content-Disposition: form-data; name="zpl_file"; filename="CheckInLabel.txt"
Content-Type: text/plain

^XA^FO50,50^ADN,36,20^FDHello World!^FS^XZ
------WebKitFormBoundary7MA4YWxkTrZu0gW--

Is a PDF file sent as zpl_file ?