Initialize Plaid Link with the auth product; for institutions that support instant auth (OAuth or credential-based), the user will complete Link and you can call the Auth endpoint immediately to retrieve account and routing numbers
For institutions where instant auth is unavailable, Plaid will offer same-day micro-deposit verification; the user enters their account details manually, and Plaid initiates two small deposits to the account
After initiating micro-deposits, store the item_id and set the account status to pending_verification in your system; do not enable ACH origination until verification completes
Send the user to a verification screen; when the user submits the two micro-deposit amounts, call the Auth verify endpoint with the item_id and the two amounts to complete verification
Handle verification failures: if the amounts do not match, Plaid returns a VERIFICATION_EXPIRED or invalid amounts error; you have a limited number of attempts before the verification link expires and must be re-initiated
On successful verification, call the Auth endpoint to retrieve the finalized account and routing numbers and update the account status to verified in your system
Known gotchas
Same-day micro-deposit verification requires same-day ACH availability; if initiated after the last Same-Day ACH window, the deposits arrive the following business day, extending the user's wait and potentially increasing drop-off
Plaid's micro-deposit verification has a maximum number of incorrect attempts before locking; implement attempt tracking and warn the user before they exhaust their attempts rather than letting the link expire unexpectedly
Plaid may return account and routing numbers through instant auth that differ from what the user sees on a check (e.g., the account number on the check may be a sub-account number, not the DDA number Plaid returns); communicate this possibility to users who report a mismatch
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