# Plaid Fintech

> Expert patterns for Plaid API integration including Link token flows, transactions sync, identity verification, Auth for ACH, balance checks, webhook handling, and fintech compliance best practices. Use when: plaid, bank account linking, bank connection, ach, account aggregation.

- Skill: `whd4/plaid-fintech` (Agent Skill)
- Install (CLI): `npx skillmds add whd4/plaid-fintech`
- Raw SKILL.md: https://api.skillmd.com/api/skills/whd4/plaid-fintech/raw
- Safety review: pending (external: skill-scanner PASS, skillspector PASS)
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Integrations & APIs
- Author: whd4 (https://skillmd.com/u/whd4)
- Updated: 2026-08-19
- Page: https://skillmd.com/skills/whd4/plaid-fintech

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# 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

| Issue | Severity | Solution |
|-------|----------|----------|
| Issue | critical | See docs |
| Issue | high | See docs |
| Issue | high | See docs |
| Issue | high | See docs |
| Issue | medium | See docs |
| Issue | medium | See docs |
| Issue | medium | See docs |
| Issue | medium | See docs |