# Environments: testing and production

> Testing and production share one host. The mode is switched from the account and verified with the environment field returned by Init().

- kind: concept
- status: stable
- api_version: v1
- last_verified: 2026-10-21
- url: https://tilopay.com/en/developers/entornos

> **Warning:** There is no sandbox host. Testing and production use the same host:
> `app.tilopay.com`. The URL does not tell you which mode you are in.

## How the mode is switched [#como-se-cambia]

The mode is switched **from the account in the Tilopay portal**, not from the integration.
There is no parameter, header or alternate URL that changes it from code.

## How to verify it [#como-se-verifica]

`Tilopay.Init()` returns an **`environment`** field:

| Value | Meaning |
|---|---|
| `"PROD"` | Production |
| `"TEST"` | Testing |

That is the only signal available at runtime. Read it and surface it in your own checkout
while developing.

## The real risk [#riesgo]

> **Warning:** Because the host is the same, an integrator can believe they are testing while actually
> being in production, taking real money. Verify that `environment` is `"TEST"` before assuming
> you are testing; make an unexpected `"PROD"` fail loudly in development.

## Test cards [#tarjetas]

In testing mode you charge with the [test cards](/en/developers/tarjetas-de-prueba): each
one lists the number, brand, expected result and whether it opens the 3DS challenge screen.