plaid

Plaid Banking API Expert

Plaid connects applications to users' bank accounts for financial data access, payments, and identity verification.

When to Use

• Connecting bank accounts in fintech apps
• Implementing Plaid Link flow
• Retrieving transactions, balances, or account info
• Setting up ACH transfers
• Identity/income verification
• Handling Plaid webhooks

Core Products

Product	Purpose
Auth	Bank account/routing numbers for ACH
Transactions	Transaction history (up to 24 months)
Identity	Verify user via bank account ownership
Balance	Real-time account balances
Investments	Holdings from investment accounts
Liabilities	Loan and credit card data

Quick Start

1. Install SDK

npm install plaid react-plaid-link

2. Create Plaid Client

import { Configuration, PlaidApi, PlaidEnvironments } from "plaid";

const client = new PlaidApi(
  new Configuration({
    basePath: PlaidEnvironments.sandbox,
    baseOptions: {
      headers: {
        "PLAID-CLIENT-ID": process.env.PLAID_CLIENT_ID,
        "PLAID-SECRET": process.env.PLAID_SECRET,
      },
    },
  })
);

3. Create Link Token (Server)

// POST /api/plaid/create-link-token
export async function POST(req: Request) {
  const response = await client.linkTokenCreate({
    user: { client_user_id: userId },
    client_name: "Your App",
    products: ["auth", "transactions"],
    country_codes: ["US"],
    language: "en",
  });

  return Response.json({ link_token: response.data.link_token });
}

4. Plaid Link (Client)

import { usePlaidLink } from "react-plaid-link";

function ConnectBank({ linkToken }) {
  const { open, ready } = usePlaidLink({
    token: linkToken,
    onSuccess: async (public_token, metadata) => {
      // Exchange for access_token on server
      await fetch("/api/plaid/exchange-token", {
        method: "POST",
        body: JSON.stringify({ public_token }),
      });
    },
  });

  return (
    <button onClick={() => open()} disabled={!ready}>
      Connect Bank Account
    </button>
  );
}