Cimplify Link

Link is Cimplify's shopper identity and saved-details layer: saved addresses, saved payment methods, cross-merchant sessions, and checkout acceleration.

Cimplify Link gives shoppers a faster checkout across Cimplify-powered merchants. It is not a generic auth-as-a-service product; it is the customer identity and saved-details layer used by checkout.

Product Surfaces

Checkout acceleration: checkout can recognize a verified Cimplify shopper and load saved addresses/payment methods after verification.
Hosted OAuth: auth.cimplify.io verifies shoppers for storefront sign-in and checkout.
Direct API/SDK access: client.link.* powers custom account pages and dashboard-style views in a merchant storefront.

How Shoppers Join Link

Enrollment happens when a shopper checks out and opts to remember their details. Later checkouts can use those saved details after the shopper verifies through Cimplify.

Privacy invariant: saved details, account names, and membership-specific UI become available only after verification.

How Merchants Opt In

Merchants opt in by using a checkout integration that supports Cimplify Link:

Pass enroll_in_link: false to checkout processing only when the merchant does not want to offer saved details for future 1-click checkout.

Authentication Model

There are two auth paths. Pick the one that matches the product surface:

Surface	Host	Used by	What happens
Storefront OAuth	`auth.cimplify.io`	`CimplifySignInButton`, `startSignIn`, checkout sign-in	Hosted passkey/OTP/consent. Returns an OAuth code, then the merchant callback sets storefront session cookies.
Direct Link API	`api.cimplify.io/v1/link/auth/*`	Cimplify-hosted customer surfaces, custom account surfaces, SDK `client.link.*`	Request/verify OTP directly and receive Link access/refresh tokens.

For merchant storefront checkout, use Storefront OAuth. The checkout component collects the contact inline, sends that contact as a login hint, and loads saved details only after Cimplify verifies the shopper.

Smallest Checkout Embed

import { CimplifyClient } from "@cimplify/sdk";
import { CimplifyCheckout } from "@cimplify/sdk/react";

const client = new CimplifyClient({
  publicKey: "cpk_live_…",
  credentials: "include",
});

<CimplifyCheckout client={client} cartId={cart.id} onComplete={handleComplete} />

Also add the OAuth callback routes from Sign in with Cimplify. Those routes complete Cimplify saved-details sign-in during checkout.

The shopper dashboard at link.cimplify.io is a Cimplify-hosted customer product, not a merchant integration surface. Merchant account pages should use SDK-rendered account components backed by storefront auth and client.link.*.

CheckoutElement: The checkout iframe
SDK: Link: Direct client.link.* API