TypeError when Downloading to PDF in Azure App Service: undici failure

Download to PDF Not Working in Azure App Service

I'm running an express app using Node v18.19.1. My endpoint does the following:

Saves a document to a sharepoint folder
Performs the download/convert to pdf
Saves the downloaded pdf to a Mongo db.
Deletes the original file

Steps 1, 2, and 4 use the @microsoft/microsoft-graph-client@3.0.7 package. This all works locally. However, when I deploy it to my Azure App Services (running Windows and Node v18.19.1), it breaks at step 2 with the following error:

TypeError: fetch failed at node:internal/deps/undici/undici:12625:11
at process.processTicksAndRejections (node:internal/process/task_queues:95:5)

The conversion download method:

const conversionDownloadToPdf = async (fileItemId) => {
    try {
        console.log(chalk.blue(`Attempting to downloaded file (${fileItemId})...`));

        const response = await client.api(`drives/${process.env.DRIVE_ID}/items/${fileItemId}/content?format=pdf`)
            .responseType(ResponseType.RAW) // ensure raw stream
            .get();

        const stream = await apiRequest.responseType(ResponseType.RAW).get(); // BREAKS HERE

        console.log(chalk.blue(`Stream downloaded. Streaming to buffer...`));
      
        return await toBuffer(stream);
    } catch (error) {
        console.error(chalk.red(`Full error details:`));
        console.error(chalk.red(`Message: ${error.message}`));
        console.error(chalk.red(`Status Code: ${error.statusCode}`));
        console.error(chalk.red(`Code: ${error.code}`));
        console.error(chalk.red(`Stack: ${error.stack}`));
        
        // Log the cause if available (undici errors have this)
        if (error.cause)
            console.error(chalk.red(`Cause: ${JSON.stringify(error.cause, null, 2)}`));

        throw error;
    }
}

Do I need to use that ProxyAgent? Do you have official docs on a workaround?

I also tried using a raw fetch like this:

const conversionDownloadToPdf_usingFetch = async (fileItemId) => {
  try {
    // Get access token
    const authProvider = new DocMgmtAuthentication();
    const accessToken = await authProvider.getAccessToken();

    // Use native fetch() to call Microsoft Graph directly
    const response = await fetch(
      `https://graph.microsoft.com/v1.0/drives/${process.env.DRIVE_ID}/items/${fileItemId}/content?format=pdf`,
      {
        headers: {
          'Authorization': `Bearer ${accessToken}`
        }
      }
    );

    if (!response.ok) {
      throw new Error(`Graph API error: ${response.status} ${response.statusText}`);
    }

    const arrayBuffer = await response.arrayBuffer();
    const buffer = Buffer.from(arrayBuffer);

    return buffer;
  } catch (error) {
    throw error;
  }
}

I got this error:

TypeError: fetch failed
    at node:internal/deps/undici/undici:12625:11 
    at process.processTicksAndRejections (node:internal/process/task_queues:95:5)
    at async conversionDownloadToPdf (C:\home\site\wwwroot\util\msGraph.js:34:22)
    at async C:\home\site\wwwroot\controllers\my.controller.js:92:27
    at async Promise.all (index 0)
    at async Object.uploadDocs (C:\home\site\wwwroot\controllers\doc.controller.js:65:3)
    at async C:\home\site\wwwroot\routes.js:71:18 {cause: Error: getaddrinfo ENOTFOUND usgovtexas1-mediap.svc.ms
    at GetAddrInfoReqWrap.onlookup [as oncomplete] (node:dns:107:26)
    at GetAddrInfoReqWrap.callbackTrampoline (node:internal/async_hooks:128:17)
    {
        errno: -3008,
        code: 'ENOTFOUND',
        syscall: 'getaddrinfo',
        hostname: 'usgovtexas1-mediap.svc.ms'
    }

After clicking the upload button on my frontend code (which triggers this function) several times, the conversion ends up working after the 3-4 attempt. Still not sure what the cause of the initial 1-3 failures is.

I added retry logic to this method so that the initial click runs the function up to 3 times if it fails.

I recommend moving away from this library as it's not maintained anymore.
Not throwing snowballs at it, jus stating the obvious facts.

Lorand Sandor (@lorand93)

Lorand Sandor (@lorand93) Oh wow. I just looked at the commit history. You think MS Graph is going away? Is there a better library to use?

There is a preview SDK under relatively active development over at https://github.com/microsoftgraph/msgraph-sdk-typescript

However, be aware it is pre-release software

Erik Rasmussen (@UnstoppableMango)

Erik Rasmussen (@UnstoppableMango) Thank you for the reference. I guess I'll pass on that one until they can release something official. I guess I just need to reach MS Graph team directly about this issue.

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TypeError when Downloading to PDF in Azure App Service: undici failure #1990

Download to PDF Not Working in Azure App Service

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TypeError when Downloading to PDF in Azure App Service: undici failure #1990

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Download to PDF Not Working in Azure App Service

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am35-00 commented on Nov 19, 2025

am35-00 commented on Nov 21, 2025

lorand93 commented on Nov 27, 2025

am35-00 commented on Dec 1, 2025

UnstoppableMango commented on Dec 18, 2025

am35-00 commented on Dec 18, 2025

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