Help with knowledge base retrieval, how to obtain image access addresses

[ju123123]

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1. Is this request related to a challenge you're experiencing? Tell me about your story.

How to obtain access links to the images returned by knowledge base retrieval, as shown in! image
How to Calculate Signature

2. Additional context or comments

Retrieve only results from the knowledge base! [image] (/files/04e66676-fee-4925-b761-506a6680a0a87/file preview, signature not obtained, how to calculate on your own?

[dosubot[bot]]

The image URLs from knowledge base retrieval use HMAC-SHA256 signatures. Here's how to calculate them:

Signature Format:
The message to sign is: "image-preview|{upload_file_id}|{timestamp}|{nonce}"

Python Example:

import os, time, hmac, hashlib, base64, urllib.parse

def get_signed_image_url(upload_file_id, secret_key, files_url):
    timestamp = str(int(time.time()))
    nonce = os.urandom(16).hex()
    msg = f"image-preview|{upload_file_id}|{timestamp}|{nonce}"
    sign = hmac.new(secret_key.encode(), msg.encode(), hashlib.sha256).digest()
    encoded_sign = base64.urlsafe_b64encode(sign).decode()
    
    query = {"timestamp": timestamp, "nonce": nonce, "sign": encoded_sign}
    return f"{files_url}/files/{upload_file_id}/image-preview?{urllib.parse.urlencode(query)}"

Important Notes:

• Use your Dify SECRET_KEY as the signing key
• Signed URLs expire after 5 minutes by default (configurable via FILES_ACCESS_TIMEOUT environment variable)
• Ensure FILES_URL is set to a client-accessible address (not localhost if using Docker)
• When using workflow Knowledge Retrieval nodes, URLs should automatically include signatures in the source_url field

If you're seeing unsigned URLs returned from the Knowledge Base Retrieval API, this may be a known issue in some versions where you'll need to generate signatures manually using the code above.

To reply, just mention @dosu.

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[ju123123]

How to obtain secret_key?

[ju123123]

ok thanks, I find the retrieve have sign_content field