Plaid Link test harness
Test the connect-a-bank popup and your onSuccess / onExit / onEvent wiring with no Plaid account. Two modes below.
1. Mock popup No account
A faithful re-creation of the Plaid Link flow. Runs entirely offline and fires the same callbacks your app expects — wire and watch your integration today.
Sandbox test login pre-filled: user_good / pass_good
2. Real Plaid Link Token
Loads Plaid's official link-initialize.js. Paste a sandbox link_token to open the genuine popup. Leave it blank and it opens then fails — fine as a smoke test.
Plaid script loads on first click.
How to get a free sandbox link_token (when you're ready)
Plaid Sandbox is free and signup only asks for an email + company name — no banking data, no payment, no SSN. With your client_id and a Sandbox secret, mint a token from any terminal:
curl -s -X POST https://sandbox.plaid.com/link/token/create \
-H 'Content-Type: application/json' \
-d '{
"client_id": "YOUR_CLIENT_ID",
"secret": "YOUR_SANDBOX_SECRET",
"client_name": "Brook Test",
"country_codes": ["US"],
"language": "en",
"user": { "client_user_id": "test-user-1" },
"products": ["auth", "transactions"]
}'
Paste the returned link_token above and click Open real Plaid Link. In the sandbox bank login use user_good / pass_good (any MFA code works). To force a specific failure, log in as user_custom with password { "force_error": "INVALID_LINK_TOKEN" }.
A link_token can only be created server-side because it needs your secret — that's why the genuine popup can't be fully real without an account. The mock covers the popup + flow; the sandbox token covers the real UI when you want it.