Asset delivery API does not respect client compression preferences

Bug Reports Cloud Services Bugs
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The asset delivery API randomly delivers gzipped data and non-gzipped data, regardless of your headers regarding compression.

Side note: The Content-Type header indicates that Roblox is sending application/octet-stream, when it is actually sending XML.

Expected behavior

The asset delivery API should respect the Accept-Encoding header.

Forgive me if this is under the wrong category, but I figured it should get to the right team anyway.

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Hi Jack, Please could you share the url you are trying to call on assetdelivery API and how you’re calling it?

What you are expecting as a response and what you are getting back ?

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https;//assetdelivery.roblox.com/v1/asset and the CDN link returned by https;//assetdelivery.roblox.com/v2/asset both seem to randomly return gzipped and non-gzipped content based on asset ID.

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I can confirm this happens on https://assetdelivery.roblox.com/v1/asset even when setting the Accept-Encoding request header to identity, which according to spec should disable any kind of compression from the server.

At random, sometimes the server returns an uncompressed body, and sometimes it sends a gzip compressed body, and when this happens a response header Content-Encoding: gzip is correctly set.

Important: I’ve noticed that whenever the response is gzip compressed, it is accompanied by another header, X-Cache: Miss from cloudfront or X-Cache: Hit from cloudfront. I’ve also noticed that when the response is not compressed, the rbx-cdn-provider header is set to ak instead of aws.

I’ve only used this endpoint for decals, which is where I’ve encountered this issue. For example, GET https://assetdelivery.roblox.com/v1/asset/?id=118316249145279.

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The Accept-Encoding header is supposed to be a negotiation mechanism between the client and server, not a guarantee. A server can respond in one of three ways:

  1. Send the representation in one of the encodings the client requested.
    Example: client says Accept-Encoding: gzip, server has a gzip version, so it returns gzip + Content-Encoding: gzip.
  2. Send the representation in identity (no compression).
    If the client’s header includes identity (or omits Accept-Encoding entirely, since identity is the default), the server can choose to return plain bytes.

Why it looks “random”

Roblox leverages multiple CDN vendors that have sligh variations on how they respond to these headers. This switching between CDNs is why it feels random — it depends which edge or cache tier handled your request.

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