Plaid integration for bank account verification, balance checks, and transaction data.
Plaid Link, webhook handling, and the transaction data pipeline for fintech applications — implemented correctly with proper tokenization, webhook security, and the error handling that financial data requires.
Fintech application that needs bank account linking, ACH payment verification, or transaction data access — and needs Plaid implemented securely and correctly
Plaid is the leading bank account data aggregation platform for fintech applications. It enables applications to verify bank accounts, check balances, and access transaction history via bank connections. The implementation is more involved than a typical API integration:
Token security. Plaid uses a two-token model: the Link token (frontend, short-lived) and the access token (server-side, long-lived). Access tokens must never reach the client. They must be stored server-side, encrypted, and accessed only by server-side code.
Link flow. Plaid Link is a JavaScript widget that handles the bank login flow in an iframe. The frontend receives a public_token on completion, which must be exchanged server-side for an access token. The exchange must happen over HTTPS and never client-side.
Webhook handling. Plaid sends webhooks for transaction updates, account errors, and item status changes. The webhook endpoint must verify Plaid's JWT signature to prevent spoofing. Transaction webhooks need to trigger data sync; error webhooks need to prompt user re-authentication.
Transaction pagination and sync. The Plaid Transactions API returns transactions in paginated batches. Initial transaction sync requires fetching all historical transactions; ongoing sync uses the incremental sync API. This is a multi-step process with error handling.
Item re-authentication. Bank connections expire. Users whose connection has expired receive an ITEM_LOGIN_REQUIRED error and must re-authenticate via a new Link session. The UX for this recovery flow is critical.
Plaid integration with Link flow, webhook handling, transaction data access, and the security patterns that financial data access requires
Link flow implementation
Frontend Plaid Link configuration and initialization. `public_token` to `access_token` exchange server-side. Access token encrypted storage.
Account data
Bank account and routing number retrieval for ACH payment setup. Account balance retrieval. Account identity information.
Transaction sync
Initial transaction fetch. Incremental sync using Plaid's transactions/sync API. Transaction storage and categorization.
Webhook handling
Webhook endpoint with Plaid JWT verification. Transaction update handler. Item error and re-authentication prompt.
Re-authentication flow
Detection of expired connections. User prompt with new Link session. Token refresh without losing transaction history.
One honest number to start.
Fixed-scope, fixed-price. The number below is the starting point — final scope is built from your brief.
Plaid integration with Link flow, webhook handling, transaction data access, and the security patterns that financial data access requires
Three steps, every time.
The same repeatable engagement on every project. No surprises, no mystery, no billable ambiguity.
Brief & discovery.
We send you questions, then get on a call. Output: a written scope with every step, feature, and integration listed.
Build & ship.
Fixed schedule, weekly reviews. No scope creep unless you change the scope — and if you do, we reprice it transparently.
Warranty & retainer.
30-day warranty on every launch. Most clients stay on a monthly retainer for ongoing features and maintenance.
Why Fixed-Price Matters Here
Plaid integration scope is defined by the Plaid products used (Auth, Transactions, Identity, Assets). Fixed price.
Related engagements.
Questions, answered.
Bank account verification for ACH: Plaid Auth (instant account/routing number retrieval) or Plaid Identity Verification. Transaction data for expense tracking or financial analysis: Plaid Transactions. Balance checks for lending: Plaid Balance. Income verification: Plaid Income.
Plaid production access requires completing Plaid's developer review process, which includes a security review and compliance questionnaire. The process takes 2–4 weeks. Sandbox access is available immediately for development.
Plaid integration is part of the fintech application build. Full fintech app from $25k. Fixed-price.
Tell Ryel about your project.
Describe what you’re building and what outcome you need. You’ll have a written, fixed-price scope within the week.