That guess was actually quite close. The target system does support the GET way out of the box as a way to pre-fill data into a form; but only over GET.
I implemented an enterprise data migration in javascript, running in end-user's browsers. (So no server-side node.js or such.)
It was a project scheduled for 2-3 months, for a large corporation. The customer wanted a button that a user would click in the old system, requesting a record to be copied over to the new system (Dynamics CRM).
Since the systems would be used in parallel for a time, it could be done repeatedly, with later clicks of the button sending updates to the new system.
I designed it to run on an integration server in a dedicated WS, nothing extraordinary. But 3 days before the scheduled end of the project, it became clear that the customer simply will not have the server to run the WS on. They were incapable of provisioning it and configuring the network.
So I came up with a silly solution: hey, the user will already be logged in to both systems, so let's do it in their browser.
The user clicked the button in the old system, which invoked a javascript that prepared the data to migrate into a payload (data -> JSON -> Base64 -> URL escape) and GET-ed it in a URL parameter onto a 'New Record' creation form into the new system. That entire record type was just my shim; when its form loaded, it woke another javascript up, which triggered a Save, which triggered a server-side plugin that decoded and parsed the data, which then processed them, triggering like 30 other plugins that were already there - some of them sending data on into a different system.
I coded this over the weekend and handed it in, with the caveat that since it has to be a GET request, it simply will not work if the data payload exceeds the maximum URL length allowed by the server, ha ha.
You will not be surprised to learn the payload contained large HTMLs from rich text editors, so it did happen a few times.
But it ran successfully for over a year until the old system eventually was fully deprecated.
(Shout out to my boss, who was grateful for the solution and automatically offered to pay for the overtime.)
(Today, the landing page loaded in Dutch for me for some reason. No idea why, probably some 'very smart' lang detection gone wrong? Either way, it _is_ available in english, so don't be deterred if that happens to you as well. After logging in, I saw eng again.)
I use it for some data gathering and most importantly, notifications and a 'personal newsletter'.
There are quite a few people in this thread that wrote things that send notifications to them; my setup kinda goes the other direction, because I don't want to be constantly spammed and nagged by my own bots.
So for instance, there are some software projects I want to keep up with, but I neither want to be interrupted by notifications, nor do I want to have a bunch of spam in my RSS reader.
So I set Huginn up to watch some RSSs, some webs and instagrams and things like that, collects them, and then sends me one summary mail every two days.
Similarly, I also get one Pushbullet notification with all the headlines from a news portal every day.
Oh, I love some good world-building, and especially when there is a set of rules that's followed to their consequences. [Ayuc sums it up nicely in this comment. https://news.ycombinator.com/item?id=9056594 ]
If you look at it this way, it CAN be done in fantasy. Check out Brandon Sanderson's Warbreaker (a great one-off), or the Mistborn series. (There are quite a few similarities between them.)
Or Max Brooks' World War Z was great in this way, I think. Although it's been quite a while since I read that.
(I know this is an older thread, so I hope you'll find this comment. Made a HN account for this. :D )