Automatic Unavoidable Verification

I've been working on this programming language and long term we plan to make a like sort of centralized package index. One thing that's always bothered me about those systems in most languages is that they're all based on URLs. So I came up with a system which we haven't rolled out yet, but it's pretty simple. Just the URL has to end in the hash of what you're downloading. The downside is that the URLs when you want to share things this way look really ugly because they end in this gigantic hash.