@transferwise/approve-api-action-helpers NPM

Approve api action helpers

A tiny library that lets you handle Strong Customer Authentication (SCA) required calls easily.

Example

sca-iframe-1

Sequence diagram of the flow

SCA flow diagram

Usage

Installation

Using npm:

npm install @transferwise/approve-api-action-helpers

Using CDN and script tags:

<script src="https://unpkg.com/@transferwise/approve-api-action-helpers@latest/dist/main.js"></script>

Note that to use this library with Internet Explorer (11) fetch and Promise must be polyfilled. For example: https://polyfill-fastly.io/v3/polyfill.min.js?features=fetch%2CPromise. Comment out the script in the demo (demo/src/inex.html) to see it in action.

Consuming

This library exports a create function for SCA protected requests. It returns a request wrapper that can be used like a regular fetch request. Use it as follows:

import { create, Mode } from '@transferwise/approve-api-action-helpers';

const request = create({ mode: Mode.PRODUCTION });

const res = await request('https://my-backend-api.com/sca-protected-call', { method: 'GET', ... });

When the backend returns that SCA is required, it will run the user through an SCA flow and retry that request. Also, it will throw an error if you get a 4xx or 5xx response.

NB! make sure that your backend proxies 'x-2fa-approval' response header to the frontend and forwards it back to Wise when this library passes it back. Also please reflect the response status (403) back to the frontend.