@diagonal-finance/sdk-be

Diagonal Backend SDK

SDK for easier interaction with the Diagonal backend (webhooks).

👥 Contributing   |   🤝 Code of conduct   |   🔎 Issues

Diagonal SDK backend is a collection of classes which enables developers easier interaction with the Diagonal backend.

♜ Jest tests & common test coverage for all packages (npm test)
♞ ESLint & Prettier to keep the code neat and well organized (npm run format & npm run lint)
♝ Automatic deployment of documentation generated with typedocs

📦 Package

Package	Version	Downloads	Size
@diagonal-finance/sdk-be (docs)

🛠 Installation

ESMModule:

yarn add @diagonal-finance/sdk-be

📜 Usage

ESModule:

Webhook:

import {
  IWebhookEvent,
  WebhookEvent,
  DiagonalError,
} from '@diagonal-finance/sdk-be'

import express from 'express'

const app = express()
const endpointSecret = '78...b1'

// Parse body into JSON
app.post('/webhook', express.raw({ type: 'application/json' }), (req, res) => {
  let payload = req.body
  let signatureHeader = req.headers['diagonal-signature'] as string

  let event: IWebhookEvent

  try {
    event = WebhookEvent.construct(payload, signatureHeader, endpointSecret)
  } catch (e) {
    if (e instanceof DiagonalError.InvalidPayloadError) {
      // handle invalid payload error
    } else if (e instanceof DiagonalError.InvalidEndpointSecretError) {
      // handle invalid endpoint secret error
    } else if (e instanceof DiagonalError.InvalidSignatureHeaderError) {
      // handle invalid signature header
    } else if (e instanceof DiagonalError.InvalidSignatureError) {
      // handle invalid signature error
    } else {
      // handle another type of error
    }
    return res.sendStatus(400)
  }

  // Handle the event
  switch (event.type) {
    case WebhookEvent.Type.SubscriptionAcknowledged:
      console.log(
        `Account ${event.customerAddress} subscription was acknowledged!`,
      )
      // Then define and call a method to handle the acknowledged event
      // handleAcknowledged(data);
      break
    case WebhookEvent.Type.SubscriptionFinalized:
      console.log(
        `Account ${event.customerAddress} subscription was finalized!`,
      )
      // Then define and call a method to handle the successful attachment of a PaymentMethod.
      // handleFinalized(event);
      break
    case WebhookEvent.Type.SubscriptionReorged:
      console.log(`Account ${event.customerAddress} subscription was re-orged!`)
      // Then define and call a method to handle the successful attachment of a PaymentMethod.
      // handleReorg(event);
      break
    case WebhookEvent.Type.SubscriptionCanceled:
      console.log(`Account ${event.customerAddress} has canceled the subscription!`)
      // Then define and call a method to handle the successful attachment of a PaymentMethod.
      // handleUnsubscribe(event);
      break
    default:
      // Unexpected event type
      console.log(`Unhandled event type ${event.type}.`)
  }

  // Return a 200 response to acknowledge receipt of the event
  res.sendStatus(200)
})


...

app.listen(3000, () => console.log('Running on port 3000'));

Checkout session

import {
    Diagonal,
    Config,
    ICreateCheckoutSessionInput,
} from "@diagonal-finance/sdk-be";

const express = require("express");
const app = express();

const apiKey = "abc...";
const diagonal = new Diagonal(apiKey);
const YOUR_DOMAIN = "http://example.com";

app.post("/create-checkout-session", async (req, res) => {
    const checkoutSessionInput: ICreateCheckoutSessionInput = {
        customerId: "de49e7f2-bc33-4f4f-a3ae-c1207b02819c", // Immutable ID of your customer.
        packageId: "ff4e1d23-54ab-4385-9ea9-02c58ec5e32a",
        allowedChains: [Config.ChainId.Mumbai], // Optional. Can be used to limit to specific chains on runtime.
        cancelUrl: new URL(`${YOUR_DOMAIN}/cancel`),
        successUrl: new URL(`${YOUR_DOMAIN}/success`),
        optimisticRedirect: true, // Optional. Used to redirect to the success url if TX has been confirmed (no waiting for long confirmation).
    };

    const checkoutSession = await diagonal.checkout.sessions.create(
        checkoutSessionInput
    );

    console.info(`Checkout session created, UUID: ${checkoutSession.id}`);

    res.redirect(303, checkoutSession.url);
});

Portal Session

import {
    Diagonal,
    Config,
    ICreatePortalSessionInput,
} from "@diagonal-finance/sdk-be";

const express = require("express");
const app = express();

const apiKey = "abc...";
const diagonal = new Diagonal(apiKey);
const YOUR_DOMAIN = "http://example.com";

app.post("/create-portal-session", async (req, res) => {
    const portalSessionInput: ICreatePortalSessionInput = {
        customerId: "de49e7f2-bc33-4f4f-a3ae-c1207b02819c", // Immutable ID of your customer. Should not be email nor phone number.
        configuration: {
            availableChains: [Config.ChainId.Polygon],
            availablePackages: ["de49e7f2-bc33-4f4f-a3ae-c1207b02819c"],
        },
        returnUrl: new URL(`${YOUR_DOMAIN}/return`),
    };

    const portalSession = await diagonal.portal.sessions.create(
        portalSessionInput
    );

    console.info(`Portal session created, UUID: ${portalSession.id}`);

    res.redirect(303, portalSession.url);
});

🛠 Development

Clone this repository and install the dependencies:

git clone https://github.com/diagonal-finance/sdk-be.git
cd sdk-be && npm i

📜 Usage

npm run lint # Syntax check with ESLint (yarn lint:fix to fix errors).
npm run prettier # Syntax check with Prettier (yarn prettier:fix to fix errors).
npm test # Run tests (with common coverage).
npm run build # Create a JS build.
npm run publish # Publish a package on npm.