Webhooks

Automate your life and work (and possibly even build a business from them?)

a.k.a.
What are they are how are they useful?

What are they?

Notification that something has happened
From a system that you use
To your own code*
To do custom processing

* or service that you configure to process webhooks

System A

System B

System C

Why use them?

Extend functionality
- Connect 2 separate systems that don't natively / normally talk to each other
- Be a "translator" / "transporter"
Possible to do it without any code!

Why use them?

Make life easier/lazier with automation!
Not needing to build an entire system
- Build prototypes in Zapier

What kind of notifications?

It depends
Based on what the system has provided
RTFM:
- Search the docs
- Configure from web

Utilise 3rd party webhook processing systems to explore

How to use it?

Code-free

General

Specialised

Event/Topic:

Specifies which kind of notification this is
(e.g. incoming message or deleted comment)

{
    "action": "created",
    "issue": {
        "url": "https://api.github.com/repos/CornerGeeks/test-git/issues/16",
        "title": "Test issue",
        "user": {
            "login": "thewheat", ... 
        },
        "state": "open", ...
    },
    "comment": {
        "url": "https://api.github.com/repos/CornerGeeks/test-git/issues/comments/423866229",
        "user": {
            "login": "thewheat", ...
        },
        "created_at": "2018-09-24T02:21:50Z",
        "updated_at": "2018-09-24T02:21:50Z",
        "author_association": "MEMBER",
        "body": "Hello world!", ...
    },
    "repository": { "name": "test-git", ... },
    "organization": { "login": "CornerGeeks", ... },
    "sender": { "login": "thewheat", ... }
}

Payload

Specific details of event/topic
(e.g. contents of incoming message or person who performed the deletion)
E.g. Github

How to use it? Not so code-free

No Set Payload Standard

{
  "type" : "notification_event",
  "app_id" : "YOUR_APP_ID",
  "data" : {
    "type" : "notification_event_data",
    "item" : {
      "type" : "user",
      "id" : "57179d0fcda796048c00046d",
      "user_id" : null,
      "anonymous" : false,
      "email" : "user@example.com",
      "name" : "John Smith",
      ...
    }
  },
  "id" : "notif_b665efa0-070a-11e6-a52e-73634a395e93",
  "topic" : "user.created",
  "delivery_status" : null,
  "first_sent_at" : 1461165327,
  "created_at" : 1461165327,
   ...
}

Intercom

Facebook

{
  "object":"page",
  "entry":[
    {
      "id":"<PAGE_ID>",
      "time":1458692752478,
      "messaging":[
        {
          "sender":{
            "id":"<PSID>"
          },
          "recipient":{
            "id":"<PAGE_ID>"
          },

          ...
        }
      ]
    }
  ]
}

How to use it? Not so code-free

Configuration

Server URL running processing code

Security

Secret & Signature

Sample Code

Intercom webhooks https://github.com/thewheat/intercom-webhooks/
Github PHP handler https://gist.github.com/milo/daed6e958ea534e4eba3

Webhook POST may not provide data similar to web POST requests using parameters
- E.g. PHP may need to use php://input not $_POST["payload"]
- Github allows x-www-form-urlencoded which will provide a "payload" POST parameter
- Check sample code if any

We wary of possible duplicate webhooks
- Webhooks retry if couldn't successfully send
- Or subscribing to multiple topics can create "duplicate" notifications