Link Unroller Service

September 23, 2015

As a small side project, I recently launched a “link unroller” service. This is a very simple service. You give it a URI, and it follows any redirect chain for you. Then it spits out the final URI via a friendly JSON API.

Give it a spin:

https://unroll.kbys.me/unroll?uri=http://bit.ly/1QZ6acT

Basically, all you do is send a GET request to:

https://unroll.kbys.me/unroll?uri=<URI to unroll>

Done. If there are no problems, you will get a JSON response:

{
  "uri":"http://bit.ly/1QZ6acT",
  "unrolled_uri":"/",
  "redirect_path":[
    "http://bit.ly/1QZ6acT",
    "/"
  ],
  "error":false
}

The unrolled_uri parameter is the final link in the chain, and the redirect_path is an array of the links that were traversed.

If you’d like to take a look at the code, make some contributions, or submit some bugs, please head over to the GitHub page.

Technical details:

• The server is in Tokyo.
• Written in Elixir.
• Backend responses are ~ 600 microseconds on a cache hit.

Policy details:

• Up to 7 redirects will be followed.
• The request will time out after 20 seconds and return an error.
• 301 redirects are cached forever, regardless of Cache-Control or Expires headers present in the response.
• 302 redirects will honor caching headers, with a minimum TTL of 1 minute (this is for DoS protection on my side)
• 200 responses are cached for 1 hour.