#23342The `_invoke` method in `ApiTool` always returns `TEXT` message type, even when the response is valid JSON. This should be fixed to return `JSON` message type when appropriate.

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Dify version

1.3.0

Cloud or Self Hosted

Self Hosted (Source)

Steps to reproduce

1. Configure an Custom API tool that returns JSON responses
2. Ensure the server returns Content-Type: application/json; charset=utf-8
3. The tool will always treat it as plain text. JSON field is empty. Here is the stream message outputs fields example:

{
  "text": "{\"status_code\": 200, \"stat\": 1, \"errcode\": \"success\", \"msg\": \"success\", \"data\": null}"
  "files": [],
  "json": []
}

✔️ Expected Behavior

I expect it should be like this:

{
  "text": ""
  "files": [],
  "json": [{"status_code": 200, "stat": 1, "errcode": "success", "msg": "success", "data": null}]
}

I have fixed it simply like this,but it is ugly. in api/core/tools/custom_tool/tool.py

❌ Actual Behavior

No response