How to add inline image by Microsoft Graph API? - json

Question

Background
When I use Outlook client to send a mail with inline image.
The image in html email looks like this, which has cid:
<img size="100" src="cid:3bb599fc-f3eb-465b-af83-aa6a495f563a" style="max-width:100%">
When I use
GET /me/messages/{messageId}/attachments
The contentId in the result returned matched the cid in html.
{
"value": [
{
"#odata.type": "#microsoft.graph.fileAttachment",
"id": "aaa",
"lastModifiedDateTime": "2017-11-30T09:32:09Z",
"name": "image.png",
"contentType": "image/png",
"size": 100,
"isInline": true,
"contentId": "3bb599fc-f3eb-465b-af83-aa6a495f563a",
"contentLocation": null,
"contentBytes": "validBase64Bytes"
}
]
}
Using Microsoft Graph API
Now I am trying to use Microsoft Graph API to add inline image.
POST /me/messages/{messageId}/attachments
{
"#odata.type": "#microsoft.graph.fileAttachment",
"name": "1.jpg",
"isInline": true,
"contentBytes": "validBase64Bytes"
}
However, the contentId is null in the result returned.
{
"#odata.type": "#microsoft.graph.fileAttachment",
"id": "aaa",
"lastModifiedDateTime": "2017-11-30T09:35:50Z",
"name": "1.jpg",
"contentType": "image/jpeg",
"size": 100,
"isInline": true,
"contentId": null,
"contentLocation": null,
"contentBytes": "validBase64Bytes"
}
And if I set contentId manually in POST
POST /me/messages/{messageId}/attachments
{
"#odata.type": "#microsoft.graph.fileAttachment",
"name": "1.jpg",
"isInline": true,
"contentId": "myContentId",
"contentBytes": "validBase64Bytes"
}
It will return the error
{
"error": {
"code": "BadRequest",
"message": "Unable to read JSON request payload. Please ensure Content-Type header is set and payload is of valid JSON format.",
"innerError": {
"request-id": "36e95f0a-ad75-46c6-b86c-d585a150b96d",
"date": "2017-11-30T09:37:41"
}
}
}
So how to add inline image correctly?

Answer 1

Weird, I tried to run the exact same code again, it won't give me any error now.
POST /me/messages/{messageId}/attachments
{
"#odata.type": "#microsoft.graph.fileAttachment",
"name": "1.jpg",
"isInline": true,
"contentId": "myContentId",
"contentBytes": "validBase64Bytes"
}
Not sure whether it is a temporary issue. I will inform Microsoft team to check the log.
If I am wrong for how to use the API, please definitely point out. Thanks.
I will leave it here for future people to save some time to implement adding inline image.