Let's make a discovery-enabled web service!
There are a couple of possible starting points:
Leon's contributed a skeleton REST server, rest-server.js.
a. Try adding a discovery rest endpoint to it - you can start with the restAPI.json and rest-client.js I started.
b. Make the server do something!
Pick your favorite underserved API (which would be pretty much any of them).
a. Write a discovery rest document for it.
b. Try it out!
If you're feeling really ambitious, try to build something like the Google API Explorer.
a. You'll either need to add (at least) description and parameter info to our REST.json files, or use one of Google's.
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