Gemini Digest, Vol 23, Issue 40

[Rohan Kumar]

On Thu, Jun 24, 2021 at 12:02:32PM +0200, Omar Polo wrote:
> What could be done is use a HTTP header to inform the web browser that
> that site is available also over Gemini.  This way, the effort wouldn't
> be on a bunch of people running a directory, but rather on the server
> administrator.  Something like a `Gemini-location: <url>'.  From my
> understanding it's something that the tor project is doing:
>
> 	% curl --head https://www.torproject.org | grep -i location
> 	Onion-Location: http://2gzyxa5ihm7nsggfxnu52rck2vv4rvmdlkiu3zzui5du4xyclen53wid.onion/index.html

Something that could work is an Alt-Svc header:

https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Alt-Svc

These were sometimes used to advertise Onion sites before the Onion-Location header spec was released and supported by the Tor Browser.

This is unlikely to give any major benefit for Gemini though, esp. if gemini:// isn't IANA-registered; browsers don't know what Gemini is and will ignore it. Perhaps a browser addon could sniff out an Alt-Svc header advertising a Gemini capsule?

I'm generally against adding HTTP headers if they don't make a significant difference, especially if they're ignored by all the existing user agents. If information needs to reach a user and is ignored by the user agent, it should be included in the response body rather than the header.

-- 
/Seirdy (seirdy.one)