APIs That Make Things Happen

APIs That Make Things Happen
WebHooks and the Evented Web

came from my previous talk? expecting talk about npr api?
how many are developers? there will be code...

@progrium
#webhooks

this is my twitter username and a handy hashtag if you want to reference this talk

What are webhooks?

can’t get very far without addressing this, since i’m sure most of you have no idea
what webhooks are. they’re the basis of this talk.

When something happens, perform
HTTP POST with relevant data to a URL
that the user gives you.

webhooks are event callbacks over http. the server/app calls your URL. that’s it.
it’s not a protocol, there is no standard. it’s more like ajax: just a useful design pattern.

command line: pipes. we used talk about the equivalent of pipes on the web and people say RSS! and I
say nooo.... it’s something else. (webhooks)

Input Output
Program

pipes are amazing in their simplicity. it’s all from a bit of infrastructure involving input and output

STDIN STDOUT
Program

STDERR

stdin, stdout were available to reroute wherever the user wanted
most common use was chaining commands together: piping
feedback loop, which is the key to emergent systems

xargs
wget
echo
mail

grep
wc

cat

so you had all these simple little programs, that might not even be useful alone

cat

xargs
wget
echo
mail

grep
wc

string them together...

cat grep

xargs
wget
echo
mail

wc

cat grep mail

xargs
wget
echo

wc

and you have something more useful than just the sum of the parts.
remember this because we’ll come back to it.

STDIN
Program

but it doesn’t work without the output. it just breaks.

API
Web App

unfortunately that’s how the web is today.
we can talk to web apps, but they really can’t talk to us.
its as if you had a telephone system where you could only make calls, but never receive them.
unacceptable.

API Events
Web App

it’s not that they can’t, they just don’t. we need to start placing event hooks in them.
if this were as ubiquitous as apis are today, we would have something amazing:

Event-driven programming
at the web ecosystem level

event-driven programming...
hence:

Evented Web

a web where when something happens in one system, something can happen in another:
trivially. you’ve all seen twitter to facebook (or vice versa). that would almost not be worth
making a service for, it would just be a line of code. let me show you with another example:

function clickHandler() {
alert("Click!");
}

element.addEventListener('click', clickHandler);

element.addEventListener('click', function() {
alert("Click!");
});

element.addEventListener('click', function() {
var name = $("input#name").val();
if (name != "") {
alert("Hello, " + name);
}
});

element.addEventListener('click', function(event) {
var name = $("input#name").val();
if (name != "") {
alert("Hello, " + name + ". " +
"I'm " + event.target.id);
}
});

twitter.addEventListener('newfollower', function(event) {
var twitterUser = event.follower;
var friends = facebook.getFriendsNames();

if (twitterUser['name'] in friends) {
twitter.follow(twitterUser);
}
})



} else if (twitterUser['following'] > 1000 &&
twitterUser['followers'] < twitterUser['following'] / 2) {

twitter.block(twitterUser);
}
})

twitter.addEventListener('newfollower',
v eventHandler);

twitter.addWebHook('newfollower',
'http://example.com/eventhandler');

twitter.addWebHook('friendupdate',

some other events you could imagine writing handlers for

twitter.addWebHook('directmessage',

twitter.addWebHook('myupdate',

makes twitter an even more powerful platform than it is

MAILHOOKS
DEMO

let’s see this in action. mailhooks was one of the ﬁrst “adapters” i built for the evented web.
in the evented web ecosystem, you can have very simple web services like this because
integrating them together with webhooks is very easy... just like pipes led to simple
programs.

facebook should be added. pop quiz! what do you get when you combine facebook and
webhooks?

MORE DEMOS
(and then code)

create postbin, setup/show tender, pivotal tracker, twilio.
demo clickhooks with postbin and and then show the code.
http://2.latest.scriptletsapp.appspot.com/1w47Cs/run

webhooks are simple as you saw. their simplicity affords them to be used as a simple building
block in slightly more complex systems like pubsubhubbub.

basically real-time feeds using webhooks as the core delivery mechanic.
a speciﬁc use case of webhooks for new content updates.
brad is here, he can tell you more...

all these sites publish content with pubsubhubbub, meaning they all effectively have
webhooks for new content events... as a result, you can consume their content in realtime.

simple mechanics, if done right, yield rich, emergent dynamics.
the emergent system with webhooks is the evented web.

The Evented Web
Programmable Web 2.0

Web APIs

Event Triggers Handler Scripts
WebHooks

how i think of the evented web: at the top, you have key to pw 1.0.
then webhooks, consist of two parts: triggers of events in apps... and handler scripts.
the webhooks are usually the scripts, but i use it to talk about that hole side: trigger and
handler.

“In computer programming, hooking is
a technique used to alter or augment the
behavior of [a program], often without
having access to its source code.”

there’s a reason why it’s hooks, not callbacks or just “events”.
i wanted to frame it with this idea. you can feed the result of a hook back into the system.
this lets you build plugin systems etc that change behavior of web apps.

here’s a video explaining hookpress, a plugin for wordpress that exposes their internal
hooks as webhooks and what that can do.
matt mullenweg realized this is how wordpress.com can have user plugins like
the open source version... this is now deployed on wordpress.com

The Evented Web
Programmable Web 2.0

Web APIs

Event Triggers Handler Scripts
WebHooks

i focus on the trigger side at talks since that’s the hard part:
getting people to put in event triggers.
as an ecosystem you need infrastructure for this other side of handler scripts.


to the app that triggers it though, it doesn’t matter.
the idea is the handler is a URL...




}
})

but this code has to live somewhere. i’ll come back to this, but i wanted to touch on
a point about this indirection via url


because it’s a URL you can just assume its a web app/script on the other end, which is *key* to why
the evented web is about http webhooks instead of something like xmpp. it turns out...

HTTP is the easiest
way to trigger code

since cgi in 1993, http is essentially rpc. in fact, its the most widely understood/used rpc in
the world. now with everything in the cloud, web development being so popular, it’s the
easiest way to get code to run. write a php script or ruby script. put it in the cloud for free,
instantly. where? there’s free php hosting, app engine, heroku ... but we can make it better.

if writing webhooks is to be ubiquitous, we need to make it EASY to write them. you don’t
need all of app engine to write a simple little hook script. so i imagined something like a
pastebin site... only it runs code.

so i built scriptlets, which is basically that. use php, python, javascript to write simple little
scripts hosted in the cloud. write it, save it, get a url to run it. perfect for webhook handler
scripts.

here’s a wrapper that makes postbin work for pubsubhubbub

here’s a script used with hookpress to add comment notiﬁcations via notify.io to wordpress

this is the code i used for the clickhooks demo. you can see how simple it is, notify.io does
most of the work.

notify.io is a useful part of the ecosystem. it solves the notiﬁcation part.
“how do you get events to the desktop?” pubsubhubbub for example
also a gateway drug for webhooks...

NOTIFY.IO
DEMO

intro. twitter DM example. outlets. curl. NioCallback. DrEval...

What are webhooks?
Event callbacks over HTTP
enabling the Evented Web

The Evented Web blends our existing ecosystem of web APIs with event-driven programming,
creating a web that is both more programmable and real-time.

Infrastructure as
Education

i’m heavily interested in education -- hacker dojo, experiment in education.
but also i think there are some huge lessons to be learned from hacker culture.
one idea is this idea of infrastructure as education. OLPC -- not enough? no, it is.

hole in the wall experiment. put a computer in a small city in india and see what happens.
turns out they learn and teach themselves how to use the computer. no guidance at all.
"We need a faster processor and a better mouse."

“Creating content is not what's
important. What is important is
infrastructure and access.”
—Sugata Mitra

Montesorri
Natural language
Google.
taking this idea, and returning to programming...

maybe wrong generation here, but many of the great programmers i know started
on something like these

programming was almost unavoidable on them.
i love this screen.

Programming is discovered.

today, the closest thing is myspace: css hacks to pimp your proﬁle.
but while this IS programming, it’s doesn’t convey the POWER of programming.
its not enough for people to “get” programming and want to become a programmer, BUT
myspace style programming has relevance, expression, and... view source

view page source is a huge reason why there are so many web people (esp frontend)
browser as a sandbox to explore and learn.
unfortunately its not the cool stuff. it’s not the stuff that changes the world.




}
})

evented web gives us a sandbox to play with code that actually DOES cool and important things that
are relevant to us. making the apps we use *do more* in a very personal and expressive way.
i think this will help make programming discoverable again, which i think is sorely needed.

The world is trending towards
being programmable

USA Today on CES: “You’re going to be hard-pressed to ﬁnd a new gadget or gizmo in 2010
that doesn’t also connect you to web services.” That’s just a step away from having apis and
hooks. Imagine a world where everything has an API and webhooks. Programmers can use it
all as building blocks, literally programming the world around them.

@progrium
#webhooks

questions...

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