Mpesa Callback Listener

A listener for MPesa post requests from Safaricom's gateway API.

The app uses CloudFunctions for Firebase to expose a publicly accessible endpoint, stores the transaction details in Firebase Realtime Database and sends a noticiation to a user's device using Firebase Cloud Messaging.

Related Android app: LNMOnlineAndroidSample.

Installation

git clone https://github.com/MarkNjunge/MPesaCallbackListener.git

cd MPesaCallbackListener

yarn install

Testing locally

To test Messaging locally, you will need to Set up admin credentials

Serve using
firebase serve --only functions

Firebase will give you an address for the endpoints. For example,
http://localhost:5000/mpesahandler/us-central1/callback_url

To make the endpoints reachable outside your network, you wil need to use a http tunneling client such as Ngrok.

Using Ngrok

Expose port 5000 (Firebase's default port) using
Ngrok http 5000

Ngrok will give you an address such as
http://f2ca75f0.ngrok.io

The resulting url for the endpoint will therefore be
http://f2ca75f0.ngrok.io/mpesahandler/us-central1/callback_url

Deploy to Firebase

Run firebase init functions, choosing not to overwrite existing files.

Deploy using
firebase deploy --only functions

Endpoints

/callback_url/:tokenId

Receives a callback for Lipa na MPesa transactions.
It stores the transaction details in the Realtime Database under LNM/success for successful transactions and LNM/failed for failed transactions.

Url Parameters

Name	Required	Description
tokenId	Yes	A Firebase Cloud messaging token from a device. It is used to send a notification with the transaction result to the user.