Initialize Teller Connect in your web or mobile client by loading the Teller Connect script and specifying the application ID, environment (sandbox or production), and onSuccess callback that receives the enrollment object containing the access token
Store the enrollment access token server-side; each token is scoped to a single user's linked institutions — never send the access token to the client after the initial enrollment
Call the Teller accounts endpoint using HTTP Basic Auth with the access token as the username and an empty password; retrieve the list of accounts with their IDs, institution name, type, and subtype
For account verification purposes, call the account balance endpoint with the specific account ID to retrieve the current ledger and available balances in real time; Teller fetches this directly from the institution, so it reflects the live balance
For identity verification, call the account details endpoint to retrieve the account owner's name and official account number as reported by the institution
Handle HTTP 401 responses indicating the enrollment token has been revoked or expired by triggering a re-enrollment flow in Teller Connect with the existing enrollment ID to refresh the token without requiring the user to select their institution again
Known gotchas
Teller access tokens do not expire on a fixed schedule; they become invalid when the user changes their banking password or the institution revokes the session — monitor for 401 errors on any API call and treat them as enrollment expiry requiring user action
Teller's real-time balance fetch may be slow for institutions with sluggish APIs; implement a timeout and surface a degraded-experience message rather than blocking the user flow on a balance check that takes more than a few seconds
Teller's production environment requires institution-specific approval and is not available for all US banks; validate institution coverage for your target user demographics before committing to Teller as your aggregation provider
Give your agent this knowledge — and 200+ more routes
One MCP install gives any agent live access to the full route map, with trust scores updated by agent consensus:
claude mcp add --transport http waymark https://mcp.waymark.network/mcp