dify api response JSONDecodeError: Expecting value: line 1 column 1 (char 0)

[kfchandsome]

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Dify version

1.6.0

Cloud or Self Hosted

Self Hosted (Docker)

Steps to reproduce

def run_workflow(file_id, user, response_mode="streaming"):
workflow_url = WORKFLOW_URL
headers = {
"Authorization": f"Bearer {API_KEY}",
"Content-Type": "application/json"
}

data = {
    "inputs": {
        "video": {
            "transfer_method": "local_file",
            "upload_file_id": file_id,
            "type": "video"
        }
    },
    "response_mode": response_mode,
    "user": user
}

try:
    print("运行工作流...")
    response = requests.post(workflow_url, headers=headers, json=data)
    response.encoding = 'utf-8'
    # print("响应内容:", response.text)
    if response.status_code == 200:
        print("完成运行工作流")
        try:
            return response.json()
        except Exception as e:
            return {"status": "error", "message": f"返回内容不是合法JSON: {str(e)}"}
            return response
            print("返回内容不是合法JSON，原始内容：", response.text)
            
    else:
        return {"status": "error", "message": f"{response.text}, status code: {response.status_code}"}
except Exception as e:
    print(f"发生错误: {str(e)}")
    return {"status": "error", "message": str(e)}

return response.json() error:
JSONDecodeError: Expecting value: line 1 column 1 (char 0)

✔️ Expected Behavior

I checked that the formatting in the text of the response is a bit problematic, and I want to parse the response normally.

❌ Actual Behavior

I called the API of the workflow and everything was fine, but an error was reported in parsing the response, I checked the text format in the response and found that there was a formatting problem in it, and it couldn't be j'son properly.

[dosubot]

This error usually means the API response is either empty, not valid JSON, or possibly an HTML error page. In Dify, if you use response_mode="streaming", the API may return a text/event-stream or even an empty body if the generator yields nothing, which will cause JSONDecodeError when you try to parse it as JSON. Also, if there's an unhandled backend exception, Flask might return HTML instead of JSON, which will also trigger this error.

To debug, print out both response.text and response.headers.get("Content-Type") before calling response.json(). If the Content-Type is not application/json, don't try to parse it as JSON. For streaming responses, you should handle the event stream accordingly instead of calling .json() directly.

If you see an empty response or HTML, check your Dify backend logs (in your Docker containers) for errors at the time of the request. This can help identify if there was an internal server error or misconfiguration. Also, make sure your workflow is properly initialized and published, as missing or invalid workflows can cause backend errors that may not return JSON responses see code details.

For a more robust client, always check the Content-Type header before parsing, and handle non-JSON responses gracefully. If you keep running into this, sharing the actual response content and relevant backend logs will help pinpoint the root cause.

To reply, just mention @dosu.

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[kfchandsome]

Thank you very much, I've solved the problem