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Leaving Products blank enables every product this connection supports: transactions auth identity investments liabilities assets statements income_verification. That default needs Statements Start Date, Statements End Date and Client User ID, so fill all three or the connection fails. If you type your own Products list, fill only the fields its products need: the dates for statements, and Client User ID for income_verification.

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Pick a Sandbox institution

Plaid Sandbox simulates real banks. Each simulated bank has an ID that starts with ins_, and the institution you pick decides which kinds of accounts the connection links.

  • Copy one of these Institution ID values across.
  • ins_109508: First Platypus Bank
  • ins_109509: First Gingham Credit Union
  • ins_109510: Tattersall Federal Credit Union
  • ins_109511: Tartan Bank
  • ins_109512: Houndstooth Bank
  • The full list, with the products each institution supports, is in the Plaid Sandbox institutions docs. The institution must support every product in your Products list.

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Copy the Sandbox test credentials

Sandbox Username and Sandbox Password are a simulated bank login used to sign in to the Sandbox institution. They are not your Plaid Dashboard login.

1

Open Sandbox Studio

In the Plaid Dashboard left sidebar, under Build, click Sandbox to open Sandbox Studio.

  • In the Credentials box, pick a test user from the User list. Default user works for most products.
  • Click Copy next to Username and copy the Sandbox Username across.
  • Click Copy next to Password and copy the Sandbox Password across.
  • Other test users for specific scenarios are listed in the Plaid Sandbox test credentials docs.
Plaid Sandbox Studio with Sandbox in the sidebar, the User list and the Username and Password copy buttons highlighted

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Choose the Products

A Plaid product is a group of related API endpoints. The products you list are enabled on the Sandbox bank link this connection creates, and they decide which actions work. Enter one or more products, separated by spaces, for example transactions auth identity.

1

Check the supported products

This connection supports the following products. Leave Products blank to enable all of them.

  • transactions: transactions and recurring transactions.
  • auth: account and routing numbers.
  • identity: account holder names, emails, phone numbers and addresses.
  • investments: holdings and investment transactions.
  • liabilities: credit card, student loan and mortgage details.
  • assets: asset reports.
  • statements: bank statements.
  • income_verification: bank income.
  • The institution you picked must also support every product you list, otherwise Plaid rejects the connection.
2

Select the products for your actions

Enables actions: Create Asset Report, Download Statement, Enrich Transactions, Filter Asset Report, Get Asset Report, Get Asset Report PDF, Get Auth, Get Bank Income, Get Bank Income PDF, Get Credit Sessions, Get Identity, Get Investment Holdings, Get Investment Transactions, Get Liabilities, Get Recurring Transactions, Get Transactions, List Statements, Refresh Asset Report, Refresh Statements, Refresh Transactions, Remove Asset Report, Sync Transactions

Pick only the products that back the actions you plan to run, and copy the Products list across.

3

Check the values Plaid rejects

Plaid rejects balance and enrich as products, and income is a legacy product no action reads.

  • balance: included on every bank link automatically. Run the balance action on any connection.
  • enrich: needs no bank link. The enrich action sends your own transaction data.
  • income: the Income actions use Plaid’s income_verification product instead.

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Fill the Statements dates

Fill both dates when Products is blank or includes statements. Leave them empty otherwise, because they are ignored.

  • Format: YYYY-MM-DD
  • Example: Start Date 2025-01-01, End Date 2025-12-31
  • Fill both Statements Start Date and Statements End Date. Plaid rejects the connection when only one is filled.
  • The end date cannot be in the future, and it cannot be earlier than the start date.

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Fill the Client User ID

Income data belongs to a Plaid User (a person), not to the bank link. When Products includes income_verification, StackOne creates a Plaid User from the Client User ID, links the Sandbox bank to it and attaches simulated bank income.

  • Enter your own stable ID for this person, for example their ID in your system. StackOne sends it to Plaid as the User’s client_user_id. Do not use an email, phone number or other personal data.
  • Fill it when Products is blank or includes income_verification. Without it the connection fails.
  • Reusing a Client User ID on another connection reuses the same Plaid User.

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Limitations

Check these before you rely on this connection.

  • Only bank income is supported. The income history is fixed at 90 days and cannot be changed from the connection. Payroll income is not supported, because Plaid accepts it only when income_verification is the only product.
  • When Products includes income_verification, the connection creates the Plaid User from the Client User ID only. No identity details (name, date of birth, address) are sent, so set them later with Update User if a flow needs them.
1

Connect

  • Click Connect.
  • If applicable, the provider will redirect you to a sign-in or authorization page. Complete the provider’s authorization flow.
  • Once authorization is successful, you will see a confirmation popup.
2

Use Actions

Connect an AI platform to the linked account’s actions. See AI Platforms.Other ways to call actions are listed in Protocols & SDKs.

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Next Steps

Webhooks setup

Configure receiving Events for Plaid into StackOne.