ACH Authentication via Plaid using Asp.Net in Six Steps

October 13, 2020

This blog explains why and the way to use Plaid for bank payment over the manual bank payment process.

Introduction to Plaid

Plaid is a technology platform which enables applications to attach with a user’s checking account, eliminating the necessity for users to enter the account and routing numbers or cope with micro-deposits which is an error-prone process, that is hard for users and forces businesses to withstand through sensitive information on their own systems.

Key Advantages of using Plaid

Instant ACH authentication: Automated Clearing House (ACH), is a secure bank payment transfer system that coordinates inland Electronic Fund Transfer (EFT) transactions and connects all U.S. Banking channels.
Account Information: Get the bank account information that is connected to Plaid
Transaction Data: Audit account and transaction data
Balance Check: Real-time balance checks

How to start?

Step 1: Register on the Plaid website

First, Register on the Plaid website with this link (https://dashboard.plaid.com/signup), it is free for a sandbox mode.
Login to dashboard > Account > Keys
Collect sandbox API key, client_id, public_key, secret key

Step 2: Install Plaid Library

Install the Plaid library in your Project using Nu-Get Package Manager for interacting with Plaid banking APIs.

Step 3: Integrate Plaid link

Plaid Link is the easiest way to integrate with the Plaid API. Plaid Link is a drop-in module that handles authentication and credential verification. It works with all browsers and platforms including Android and iOS.
Plaid.create accepts configuration objects and returns two functions open and exit.
Open will display the “Select bank” view and close will exit from the Plaid window.
Response: Public token, selected account ID

Step 4: Exchange Token flow

Once the user has successfully logged in the Plaid link, the public token can be fetched on the client-side via onsuccess callback. The public_token is transitory and expires after 30 minutes. A public token is revoked once it has been successfully exchanged for an access token.
API: POST item/public_token/exchange
Response: Access token

Step 5: Selected account information flow

Bypassing the access token and the selected account Id you’ll get all the account information.
API: POST auth/get
Result: List of all connected verified account Ids and each account Id retrieves each account’s bank name, routing number, account number, current balance