Download file attachments from an Azure bot

Article
11/23/2023

Omnichannel for Customer Service offers a suite of capabilities that extend the power of Dynamics 365 Customer Service Enterprise to enable organizations to instantly connect and engage with their customers across digital messaging channels. An additional license is required to access Omnichannel for Customer Service. For more information, see the Dynamics 365 Customer Service pricing overview and Dynamics 365 Customer Service pricing plan pages.

Follow these steps to download attachments from an Azure bot in the Microsoft Teams channel.

Get the token for your bot using your bot's Microsoft App ID and client secret.
Get the attachmentId from the attachment URL.

For example, if the URL is https://us-api.asm.skype.com/v1/objects/0-eus-d1-5360689c55c308cb4e3b51722e46b801/, then the attachmentId is 0-eus-d1-5360689c55c308cb4e3b51722e46b801.

Insert the attachmentId in a RequestUri variable and then use RequestUri in a GET request, like this:

string requestUri = $"https://botapi.skype.com/amer/v3/attachments/{attachmentId}/views/original";
var httpRequest = new HttpRequestMessage(HttpMethod.Get, requestUri);

var authorization = new AuthenticationHeaderValue("bearer", <add the botToken here>);
var requestHeaders = new Dictionary<string, string>()
  {
     { "Authorization", authorization.ToString() }
  };

foreach (var header in requestHeaders)
  {
      httpRequest.Headers.Add(header.Key, header.Value);
  }

HttpResponseMessage response = await client.SendAsync(httpRequest);

Manage file attachments during migration

Note

The information in this section is applicable to Government Community Cloud (GCC) only.

This section describes how to manage file attachments when you migrate an omnichannel implementation from the Microsoft Teams channel to the Omnichannel bot service messaging platform.

First, let's quickly review file attachment formats in the Teams bot service channel and the Omnichannel bot service channel.

File attachment formats

When file attachments are sent from Omnichannel for Customer Service to an Azure bot on the Teams bot service channel, the attachment format is passed in the Activity.Attachments property. The attachment's content type is "application/vnd.microsoft.teams.file.download.info".

Teams bot service channel

{
   "attachments":[
      {
         "contentType":" text/html",
         "contentUrl":null,
         "content ":{
            "name":null,
            "thumbnailUrl":null
         }
      },
      {
         "contentType":"application/vnd.microsoft.teams.file.download.info",
         "contentUrl":"https://us-api.asm.skype.com/v1/objects/0-wus-d8-111 a550dfI 6e947f250519ffc242763d/",
         "content":{
            "downloadUrl":"https://us-api.asm.skype.com/v1/objects/0-wus-d8-111 a550dfI 6e947f250519ffc242763d/",
            "uniqueld":"0-wus-d8-111 a550dfI 6e947f250519ffc242763d",
            "fileType":"png "
         },
         "name":"bot.png",
         "thumbnailUrl":null
      }
   ]
}

However, when file attachments are sent from Omnichannel for Customer Service to the Azure bot on the Omnichannel bot service channel, the information required to download the files is passed in the amsReferences and amsMetadata fields of the Activity.ChannelData property.

Omnichannel bot service channel

{
   "recipient":{
      "id":"8:acs:5ecf37b1-11 Oc-414g-ab33-804ffd6b4a33_eooe0010-7c57-1ceb-nec-113aOdOOb272",
      "name":"Omnichannel-test-bot",
      "aadObjectId":null,
      "role":null
   },
   "attachments ":null,
   "channelData":{
      "tags":"Channelld-lcw,FromCustomer",
      "deliveryMode":"bridged",
      "fromUserId":"8:acs:5ecf37b1-110c-4149-ab33-804ffd6b4a33_00000010-61 b9-ab1 d-3dfe-9c3aOd009ea4",
      "amsReferences":[
         "0-wus-d6-20e7797d208fab388cc11b09674d166"
      ],
      "amsMetadata":[
         {
            "contentType":"image/png",
            "fileName":"SurnmerTime.png"
         }
      ],
      "sourceChannelId":"omnichannel"
   }
}

How to manage file attachments in your Azure bot code

Attachment information is passed differently in the Omnichannel bot service channel and the Teams bot service channel. To ensure smooth migration between the two chat channels, keep both the Teams channel-specific logic and the Omnichannel bot service channel-specific logic in the bot code, as shown in the following example.

// 1. Retrieve Attachment ID from ChannelData["amsReferences"]
if (turnContext.Activity.ChannelData != null &&
    turnContext.Activity.ChannelData is JObject incomingRequestChannelData &&
    incomingRequestChannelData.TryGetValue("amsReferences", out JToken amsReferencesArray))
{
    string attachmentId = JsonConvert.DeserializeObject<string[]>(amsReferencesArray.ToString()).FirstOrDefault();

    // 2. Build HTTP request for specified attachment ID.
    string requestUri = $"https://botapi.skype.com/amer/v3/attachments/{attachmentId}/views/original";
    var httpRequest = new HttpRequestMessage(HttpMethod.Get, requestUri);

    // 3. Acquire authentication token and add it to request headers
    var token = await new MicrosoftAppCredentials("botAppId", "botAppSecret").GetTokenAsync();
    var authorization = new AuthenticationHeaderValue("bearer", token);
    httpRequest.Headers.Add("Authorization", authorization.ToString());

    // 4. Add Azure Communication Services Bot ID to request header. This is required to achieve good download performance.
    httpRequest.Headers.Add("BotAcsId", turnContext.Activity.Recipient.Id);

    // 5. Use HttpClient to execute the request and download attachment
    var response = await client.SendAsync(httpRequest);
    
    // 6. Save HTTP response stream to the file
    var responseContentStream = await response.Content.ReadAsStreamAsync();
    using (FileStream fileCreateStream = new FileStream("file path", FileMode.Create))
    {
        fileCreateStream.CopyTo(responseContentStream);
    }
}
else if (turnContext.Activity.Attachments != null)
{
    // 1. Retrieve Teams attachment
    var teamsAttachment = turnContext.Activity.Attachments.FirstOrDefault(attachment => attachment.ContentType.Equals("application/vnd.microsoft.teams.file.download.info", StringComparison.OrdinalIgnoreCase));

    if (teamsAttachment != null)
    {
        // 1. Retrieve Teams Attachment ID from Content["uniqueId"] field
        string attachmentId = (teamsAttachment.Content as JObject).GetValue("uniqueId").ToString();

        // 2. Build HTTP request for specified attachment ID.
        string requestUri = $"https://botapi.skype.com/amer/v3/attachments/{attachmentId}/views/original";
        var httpRequest = new HttpRequestMessage(HttpMethod.Get, requestUri);

        // 3. Acquire authentication token and add it to request headers
        var token = await new MicrosoftAppCredentials("botAppId", "botAppSecret").GetTokenAsync();
        var authorization = new AuthenticationHeaderValue("bearer", token);

        httpRequest.Headers.Add("Authorization", authorization.ToString());

        HttpClient client = new HttpClient();
        HttpResponseMessage response = await client.SendAsync(httpRequest);
    }
}

Download file attachments from an Azure bot

Manage file attachments during migration

File attachment formats

How to manage file attachments in your Azure bot code

See also

Feedback

Feedback

Additional resources