connect a US bank account and list transactions with the Teller API

Steps

1. Embed Teller Connect (the client-side JS widget) in your app and configure it with your application_id from the Teller dashboard.
2. Handle the onSuccess callback, which returns an enrollment object containing an access_token and an array of accounts; store the access_token server-side.
3. Call GET /accounts using HTTP Basic auth with the access_token as the username and an empty password to retrieve the list of linked accounts.
4. For each account, call GET /accounts/{account_id}/transactions to retrieve paginated transactions; use the count and from_id query parameters to page through results.
5. Parse each transaction object for amount, date, description, and status fields; note that pending transactions appear with status 'pending'.
6. Handle certificate-pinned mTLS requirements in production by downloading Teller's client certificate bundle and configuring your HTTP client accordingly.