# Test mode > Test keys run the partner API against test invites only: no email, no free pass, no real person. Test keys (`i100x_test_…`) see only test objects. A test practice invite (`pi_test_…`) gets the same request checks as a live one — including the country rule and the `Idempotency-Key` — and its `url` opens a test page, `/test/practice/{token}`, with **Simulate sign-up** (sends `practice.signed_up` to your test webhooks), **Simulate plan created** and **Simulate a practice session** (these only change your test stats). Test stats are exact (`"rounded": false`) and every answer carries `"livemode": false`. A live key naming a test object, or a test key naming a live one, answers `403 TEST_MODE_ONLY`. Live events never reach an endpoint created with a test key.