# Testing (/docs/sign/testing)

Requests made with a sandbox (`coss_test_…`) key work end to end: sessions open the real signing
page, signers sign, and the request is sealed and completed. What's different:

- **No emails reach anyone.** Invitations, reminders and copies go through the sandbox's fake
  provider: read them in the dashboard's emails page instead.
- **The signing page says it's a test** ("signing it has no legal effect"), and so does the
  certificate.
- **Nothing is billed.**
- **`allowed_origins` can include `http://localhost`** for embedding while you develop.

Test PDFs need nothing special; put anchors like `{{signature:signer_1}}` in them to place fields
without coordinates. Webhooks (`sign_request.*`) are delivered as in live environments, and
`coss trigger sign_request.completed` sends a sample one.