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

# Sandbox

> Build and verify against test infrastructure before going live.

The sandbox is a full copy of the API running against test infrastructure, so code that works in the sandbox works in production unchanged. Use it to build and verify your integration before going live.

Create a `mk_test_` key in Settings and send it as your Bearer token. Sandbox accounts are funded with test balances, so you can open and settle Hedges end to end without real money.

<Info>
  Sandbox and production are fully isolated, with separate balances, positions, and history. A test key cannot see or touch production data.
</Info>

## Prices and fees

Prices in the sandbox track the same live FX rates as production. Fees in the sandbox are indicative and may differ from production.