generated: '2026-07-23'
method: searched
source: https://developers.newline53.com/docs/sandbox-walkthrough
docs_pages:
  - https://developers.newline53.com/docs/sandbox-walkthrough
  - https://developers.newline53.com/docs/synthetic-accounts-1
  - https://developers.newline53.com/docs/transactions-and-transfers
  - https://developers.newline53.com/docs/sandbox-errors
  - https://developers.newline53.com/docs/clearing-the-sandbox
base_url: https://sandbox.newline53.com/api/v1
auth: Identical JWS/HMAC (HS512) token strategy to production
provisioning: HMAC keys issued by the Newline Relationship team over secure email; no self-service sandbox signup yet
test_vs_live:
  separation: separate sandbox host (sandbox.newline53.com); production access is program-scoped
  notes: Sandbox does not contain all production features
staged_fixtures:
  customers: Staged customers are business customers with only name and address populated (no self-serve customer creation in sandbox)
  synthetic_accounts: >-
    Staged general Synthetic Accounts are master accounts with a 1:1 relationship to a Custodial Account
    (a Commercial DDA), pre-loaded with varying balances
simulation:
  mock_transactions:
    endpoint: POST /sandbox/mock_transactions
    purpose: Auto-generate externally originated transactions to validate how they render in your app (sandbox only)
  transfers: Transfers to/from external accounts are simulated; no real money movement occurs
  external_accounts: >-
    Creating ach_external / wire_external / instant_payments_external Synthetic Accounts performs no
    authentication in sandbox (any account/routing number accepted); production requires valid, connectable accounts
  vrns: VRNs can be created off any staged general Synthetic Account (beta in production)
  debit_cards: Debit card interactions can be tested in sandbox, fully simulated (beta in production)
  error_scenarios: Error scenarios can be exercised via the sandbox (see docs/sandbox-errors)
  clear_state: Sandbox state can be reset (see docs/clearing-the-sandbox)
published_test_values: none (no magic card/account numbers published; fixtures are program-staged)