Plaid Fintech

Patterns

Link Token Creation and Exchange

Create a link_token for Plaid Link, exchange public_token for access_token. Link tokens are short-lived, one-time use. Access tokens don’t expire but may need updating when users change passwords.

Transactions Sync

Use /transactions/sync for incremental transaction updates. More efficient than /transactions/get. Handle webhooks for real-time updates instead of polling.

Item Error Handling and Update Mode

Handle ITEM_LOGIN_REQUIRED errors by putting users through Link update mode. Listen for PENDING_DISCONNECT webhook to proactively prompt users.

Anti-Patterns

❌ Storing Access Tokens in Plain Text

❌ Polling Instead of Webhooks

❌ Ignoring Item Errors

⚠️ Sharp Edges