The Upstox sandbox is a request-response simulation environment. The sandbox is purely a simulation layer. That means when you place an order in sandbox, it doesn’t actually create a virtual position or reflect in any holdings or order book. There are no virtual funds or portfolio tracking — it simply returns a mock success response to help you test if your API requests are formatted correctly and working as expected.
To verify order placement in sandbox, you should rely entirely on the API response, as nothing gets processed on the backend. There’s no live order book, no trade fills, and no execution logic involved.
Also, Upstox offers a really useful tool called the “Same Endpoint Tester” in their developer documentation. It lets you try out the exact same request formats (like placing an order or modifying it) against either the live or sandbox environment directly from the browser. This is great for checking how your payloads behave before coding them into your app.
So, if you’re just testing integration or learning the request structure, sandbox + the endpoint tester is the way to go. For any real data testing like P&L, slippage, or holdings — that has to happen in production.