> ## Documentation Index
> Fetch the complete documentation index at: https://docs.lead.bank/llms.txt
> Use this file to discover all available pages before exploring further.

# Core Objects in Sandbox

> What core accounts, balances, and transactions return in sandbox, and what you can and cannot test against them.

<Note>
  Beta access for sandbox functionality is targeted for October 9, 2026.
</Note>

## What exists

Your sandbox program has core accounts, core balances, and core transactions you can list and retrieve the same way as in production:

```text theme={null}
GET /v2/core_accounts
GET /v2/core_balances?core_account_id={id}
GET /v2/core_transactions?core_balance_id={id}
```

## How balances and transactions behave

Sandbox returns a static response for core balances and core transactions. The figures and entries you read are fixed sample data.

New activity in sandbox does not reach the core objects. Simulated ACH, wires, instant payments, and internal transfers do not create core transactions and do not change any core balance.

Use the sandbox core endpoints to test how your integration reads these objects, not to reconcile simulated payments.

## What you can test

* Requesting the `core_account/read`, `core_balance/read`, and `core_transaction/read` scopes and calling each endpoint with them.
* Parsing every field on the three objects, including `amounts`, `overdraft`, and `interest` on a balance.
* List filters and cursor pagination: `type` on accounts, `core_account_id` on balances, `core_balance_id`, `type`, and the `created_at` window on transactions.
* Error handling.

## What you cannot test

* A balance changing in response to a simulated payment.
* A core transaction appearing for a simulated payment, or joining a payment's core transaction ID to a core transaction.
* Status changes. Core accounts and balances stay `active` in sandbox, and there is no simulate endpoint to deactivate or close one.

## Related

[Sandbox Environment](/get-started/sandbox) · [ACH Sandbox Testing](/products/ach/sandbox) · [The Core Balance Object](/products/core-balance/core-balance-object) · [The Core Transaction Object](/products/core-transaction/core-transaction-object)


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