[DOCS]: Does the MCP client support the picture type in the message? #233

New Issue

2026-02-16T05:19:31-05:00

yindo commented

2026-02-16 05:19:31 -05:00

Originally created by @zjrjb on GitHub (Aug 28, 2025).

Type of Documentation Change

Error/Typo fix

Documentation Page URL or Path

https://modelcontextprotocol.io/specification/2025-06-18/server/tools#image-content

Current Content

No response

Suggested Changes

I find that when MCP Tools return image, such as:
{
"type": "image",
"data": "base64-encoded-data",
"mimeType": "image/png"
"annotations": {
"audience": ["user"],
"priority": 0.9
}
}

then the MCP Client will ignore it. Does the MCP client support the picture type in the message?

Reason for Change

No response

Code of Conduct

I agree to follow Dify's documentation contribution guidelines
I have searched for existing issues search for existing issues, including closed ones.
I confirm that I am using English to submit this report, otherwise it will be closed.
【中文用户 & Non English User】请使用英语提交，否则会被关闭：）
Please do not modify this template :) and fill in all the required fields.

Originally created by @zjrjb on GitHub (Aug 28, 2025). ### Type of Documentation Change Error/Typo fix ### Documentation Page URL or Path https://modelcontextprotocol.io/specification/2025-06-18/server/tools#image-content ### Current Content _No response_ ### Suggested Changes I find that when MCP Tools return image, such as: { "type": "image", "data": "base64-encoded-data", "mimeType": "image/png" "annotations": { "audience": ["user"], "priority": 0.9 } } then the MCP Client will ignore it. Does the MCP client support the picture type in the message? ### Reason for Change _No response_ ### Code of Conduct - [x] I agree to follow Dify's documentation [contribution guidelines](https://github.com/langgenius/dify/blob/0277a37fcad5ad86aeb239485c27fffd5cd90043/CONTRIBUTING.md) - [x] I have searched for existing issues [search for existing issues](https://github.com/langgenius/dify/issues), including closed ones. - [x] I confirm that I am using English to submit this report, otherwise it will be closed. - [x] 【中文用户 & Non English User】请使用英语提交，否则会被关闭：） - [x] Please do not modify this template :) and fill in all the required fields.

yindo added the documentation question labels 2026-02-16 05:19:31 -05:00

yindo closed this issue

2026-02-16 05:19:31 -05:00

yindo commented

2026-02-16 05:19:31 -05:00

@dosubot[bot] commented on GitHub (Aug 28, 2025):

Hi @zjrjb! I'm Dosu and I’m helping the dify-docs team.

The MCP protocol and client code do support messages of type "image"—the schema and message handling logic are designed to accept image content with base64 data and MIME type. However, in practice, the Dify MCP server's tool invocation is currently hardcoded to return only text results and includes a comment stating that image support is "not supported yet" for tool payloads. This means that even though the client can technically process image messages, the server does not send them, so the client ends up ignoring image-type messages from tools. You can see this in the server code and comments here.

If you need to document this, it's accurate to say:
The MCP client and protocol support image-type messages, but the current server implementation does not deliver image payloads to the client, so image messages from tools are ignored.

To reply, just mention @dosu.

^{How did I do? Good | Irrelevant | Incorrect | Verbose | Hallucination | Report 🐛 | Other}

@dosubot[bot] commented on GitHub (Aug 28, 2025):  Hi @zjrjb! I'm [Dosu](https://go.dosu.dev/dosubot) and I’m helping the dify-docs team.  The MCP protocol and client code do support messages of type `"image"`—the schema and message handling logic are designed to accept image content with base64 data and MIME type. However, in practice, the Dify MCP server's tool invocation is currently hardcoded to return only text results and includes a comment stating that image support is "not supported yet" for tool payloads. This means that even though the client can technically process image messages, the server does not send them, so the client ends up ignoring image-type messages from tools. You can see this in the server code and comments [here](https://github.com/langgenius/dify/blob/7c340695d60c4d7fa829fde65162e371b8bf45e8/api/core/mcp/server/streamable_http.py). If you need to document this, it's accurate to say: **The MCP client and protocol support image-type messages, but the current server implementation does not deliver image payloads to the client, so image messages from tools are ignored.**  *To reply, just mention [@dosu](https://go.dosu.dev/dosubot).* --- <sup>How did I do? [Good](https://app.dosu.dev/response-feedback/8135a771-c8ae-464d-8338-fa417b00eb41?feedback_type=great_response) | [Irrelevant](https://app.dosu.dev/response-feedback/8135a771-c8ae-464d-8338-fa417b00eb41?feedback_type=irrelevant_answer) | [Incorrect](https://app.dosu.dev/response-feedback/8135a771-c8ae-464d-8338-fa417b00eb41?feedback_type=incorrect_sources) | [Verbose](https://app.dosu.dev/response-feedback/8135a771-c8ae-464d-8338-fa417b00eb41?feedback_type=too_verbose) | [Hallucination](https://app.dosu.dev/response-feedback/8135a771-c8ae-464d-8338-fa417b00eb41?feedback_type=hallucination) | [Report 🐛](https://app.dosu.dev/response-feedback/8135a771-c8ae-464d-8338-fa417b00eb41?feedback_type=bug_report) | [Other](https://app.dosu.dev/response-feedback/8135a771-c8ae-464d-8338-fa417b00eb41?feedback_type=other)</sup>  [![Join Discord](https://img.shields.io/badge/join-5865F2?logo=discord&logoColor=white&label=)](https://go.dosu.dev/discord-bot) [![Share on X](https://img.shields.io/badge/X-share-black)](https://twitter.com/intent/tweet?text=%40dosu_ai%20helped%20me%20solve%20this%20issue!&url=https%3A//github.com/langgenius/dify-docs/issues/439)

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Reference: langgenius/dify-docs#233