A presentation at FOSDEM in in Brussels, Belgium by Lorna Jane Mitchell
Working with Webhooks Lorna Mitchell, Nexmo
What is a Webhook? An HTTP POST request. @lornajane
Why Webhooks? Event-driven HTTP = Webhooks @lornajane
Webhooks in the Wild @lornajane
Slack Integrations @lornajane
GitHub Builds @lornajane
Webhook Use Cases • Notify of events • Deliver data when available • Broadcast to multiple receivers as-it-happens @lornajane
How APIs Work @lornajane
How APIs Work @lornajane
How APIs Work @lornajane
How APIs Work @lornajane
How Webhooks Work @lornajane
How Webhooks Work @lornajane
How Webhooks Work @lornajane
What About Time? @lornajane
APIs Over Time @lornajane
Webhooks Over Time @lornajane
Where To Webhook To? @lornajane
Webhooks Need Pre-arrangement With APIs, the client calls the server. With Webhooks, the client has to register with the server, to get data later. @lornajane
Receiving Webhooks Warning: minor tangent ahead @lornajane
Ngrok for Testing Webhooks https://ngrok.com/ - secure tunnel to your dev platform Use this tool to: • webhook into code running locally • inspect the request and response of the webhook • replay requests and see the responses @lornajane
Ngrok for Testing Webhooks Start the tunnel on your laptop: receive a public URL @lornajane
Example: Nexmo SMS When you register a phone number and receive an SMS, your application receives a webhook. @lornajane
I’m running open endpoints on the internet and accepting data, now what? @lornajane
Webhook Security When working with webhooks: • be aware of attack vectors • always use SSL • consider shared secrets and hashing • all good HTTP security practices apply @lornajane
Nexmo SMS Security Nexmo can sign messages using a shared secret. The PHP library https://github.com/nexmo/nexmo-php can do this for you. $signature = new \Nexmo\Client\Signature($_GET, SIGNATURE_SECRET, ‘sha256’); $isValid = $signature->check($_GET[‘sig’]); @lornajane
Webhooks … are awesome :) @lornajane
Webhooks in Your Applications • Use them WHEN you want to notify other systems • Examples of HOW to use webhooks hopefully gave you some ideas • Webhooks are HTTP: we already understand this @lornajane
Thanks! • Nexmo: https://nexmo.com (DM me for credit) • Me: https://lornajane.net and @lornajane • Ngrok: https://ngrok.com/ • PHP Web Services from O’Reilly @lornajane
In an increasingly connected world, APIs are key to great tools and effective workflows. What is better than an API? A webhook of course! Webhooks are the modern way for integrating systems and allowing them to react to one another. This session will cover what a webhook is, when you might want to use one, and some examples for handling webhooks in your own PHP projects. You’ll see some examples of tools to help during the development process, and some real examples of webhooks in action.
