Sell on the web

Your app and your payment provider run the checkout. Your server chooses the price, by currency, region or pricing experiment, creates the checkout at the provider and sends the buyer to it. Voidhash learns what was sold afterwards, from Stripe's events or from your backend's reports, and grants the Voidhash product the sold price is mapped to. Any number of prices can map to one product, in each environment.

The one thing Voidhash needs from you is the buyer's distinct ID on the payment. With it, the purchase, its renewals and its refunds are credited to that person and to the campaign that brought them.

Send the distinct ID to your server

getDistinctId() returns the anonymous visitor's ID, or your user ID once you called identify(). Send it with your checkout request:

import { voidhash } from "./lib/voidhash";

export async function buy(plan: string) {
  // Resolves at once when the client has started; before that, there is no ID yet.
  await voidhash.initialize();

  const response = await fetch("/api/checkout", {
    body: JSON.stringify({ distinctId: voidhash.getDistinctId(), plan }),
    headers: { "content-type": "application/json" },
    method: "POST",
  });
  const { url } = await response.json();
  window.location.assign(url);
}

A signed-in user's distinct ID is your own user ID, so your server often has it already. Call identify() before the checkout, so the browser's ID matches it.

A visitor who buys before signing up is fine too. The purchase lands on the anonymous visitor, and when they later sign up and you call identify(), it moves to the user with the rest of their history.

Put it on the payment

• Stripe: set metadata.voidhash_distinct_id on the Checkout Session, and for a subscription subscription_data.metadata.voidhash_distinct_id too, so its renewals carry it. Or set it on the Stripe customer's metadata, which covers all of that customer's later payments. See Stripe revenue.
• Another provider: store the distinct ID with your order, for example in the checkout's custom data, and report the payment with it as distinctId once the provider says it was paid. See Sell on your website.

Stripe Payment Links, the pricing table and the Buy Button cannot carry a distinct ID for each buyer. Their purchases are recorded on a placeholder person for the Stripe customer, and move to your user only from the customer's next event after your backend sets its voidhash_distinct_id. To tie anonymous visitors to their purchases, create Checkout Sessions on your server.

Test it

Use the test publishable key (vh_pk_test_…) on your staging site, and create its checkouts in Stripe test mode or your provider's sandbox, reported with a test secret key. Test purchases appear under Test in Studio and never unlock access in production. See Environments.

Example

The web example sends the distinct ID to a stand-in checkout endpoint of your own backend.