> ## Documentation Index > Fetch the complete documentation index at: https://docs.crossmint.com/llms.txt > Use this file to discover all available pages before exploring further. # Buy from Authenticated Stores > Let the agent sign in to the user's account at a merchant to use saved addresses, saved payment methods, and account pricing. Some purchases only work when you're **logged in** to the merchant: a saved cart, member pricing, subscription reorders, or a card and address already stored on the account. **Authenticated stores** let the agent check out inside the user's signed-in session at the merchant, rather than as a guest. With an authenticated session, the agent can: * Use the user's **saved payment methods** — a card already on file at the merchant, so there's no card for you to submit. * Use **saved addresses** and account defaults. * See **account-specific pricing**, carts, and eligibility. This is what makes "pay with a card on file" (see [Choose a Payment Method](/agents/payment-flows/agent-checkouts-payment-method)) possible: the payment method lives in the merchant account, and the agent selects it during the logged-in checkout. **Closed beta.** Buying from authenticated stores is in closed beta and enabled per project. [Reach out to Crossmint](https://www.crossmint.com/contact/sales) to request access.