How to use new feature Image Injectionin in MCP?

How To
1

I have already read the documentation carefully: Cursor – Model Context Protocol

I believe my personal MCP server is returning the data in the correct format:

{
  "content": [
    {
      "type": "text",
      "data": "纯文字图片\n=====\n\n"
    },
    {
      "type": "image",
      "data": "77+9UoT77+977+9Yy.....Pvv73vv716FRv70=",
      "mimeType": "image/jpeg"
    },
    {
      "type": "text",
      "data": "  \n\n"
    }
  ]
}

However, the image still isn’t showing up in the chat context.

image
image743×684 71.1 KB

image
image730×605 85.3 KB

Version: 0.49.4
VSCode Version: 1.96.2
Commit: ec408037b24566b11e6132c58bbe6ad27046eb90
Date: 2025-04-22T00:13:20.211Z
Electron: 34.3.4
Chromium: 132.0.6834.210
Node.js: 20.18.3
V8: 13.2.152.41-electron.0
OS: Darwin arm64 23.5.0

2

Could someone please help me figure this out? I’d really appreciate it!

3

Your format looks spot on. I have the same format.

image
image1184×688 140 KB

Cursor shows image fine my MCP return has:
content:

             {
                type: 'image',
                mimeType: firstItem.mimeType,
                data: firstItem.blob,
             }

where data is base64 image.

However.. even though cursor renders the image fine. If you’re using google gemini then It’s totally blind to it, claude can see it. So I think Cursor isn’t fully functional and this new feature is buggy.

In your case, triple check mime type, perhaps it’s a PNG not a JPEG?

4

(post deleted by author)

5

Thank you for reply, I’m sure the image mime type is correct, I tried official JS example, replace the image with my own base64url—it worked fine in my Cursor too!

I’m thinking the issue might be related to my SSE server. I’m using Spring.AI to implement my MCP server, so maybe the data eventually sent to Cursor is different from a standard STDIO MCP.

6

Could be, if you have copy of base64 in full, you could try to reassemble it back into a .jpg and see if it’s a valid image to rule that out.