# Take payments

You connect your own provider account. The shopper's money settles into that account,
not into a Mercemur balance you later withdraw from.

<Info>
  **There is no per-transaction platform fee.** No application fee is added to a Stripe
  charge, no Route transfer is attached to a Razorpay order, no split is attached to an
  Adyen payment, and nothing is skimmed in between. Mercemur is paid through your
  subscription, not your sales.
</Info>

## Choose a provider

<Columns cols={3}>
  <Card title="Stripe" icon="stripe">
    Your own account, via a restricted key. Best coverage outside India.
  </Card>
  <Card title="Razorpay" icon="indian-rupee-sign">
    Your own account. UPI, cards and netbanking for India.
  </Card>
  <Card title="Dodo Payments" icon="globe">
    Merchant of record. Dodo handles tax and chargebacks and remits the rest.
  </Card>
  <Card title="Adyen" icon="building-columns">
    Your own account, via an API key. Card acquiring with 3D Secure and built-in
    risk scoring.
  </Card>
</Columns>

Dodo is the odd one out: as merchant of record it takes on the tax and compliance
work, and charges you for that directly. It cannot serve a cart that needs shipping,
so it suits digital catalogues.

## Connect it

1. Open **Settings → Payments** in the dashboard and paste the credential for your
   provider.
2. Mercemur calls the provider with that key before storing it. A key that does not
   work is refused at that moment rather than at a shopper's checkout.
3. Set the webhook secret for the same provider. Without it, settlement events cannot
   be verified and orders stay pending.

Credentials are encrypted at rest and are never returned by any endpoint, including
to you. A field that expects a public key refuses a secret key, so a paste into the
wrong box fails loudly.

## Which provider a checkout uses

If you have connected more than one, Mercemur uses the provider you marked as
preferred, as long as it is active and can serve that cart. Otherwise it falls back in
a fixed order: Stripe, then Razorpay, then Dodo, then Adyen.

If none can serve the cart, the order completes as **pending** with a note explaining
why. That is deliberate. The alternative to failing closed is charging the wrong
account, which is worse than a delay.

## What the shopper is charged

The total is recomputed on the server in integer minor units. Gift card, store credit
and loyalty balances come off first, and the remainder is what the provider is asked
for. When that remainder is zero the order completes without contacting a provider at
all.

At settlement both the webhook and the reconciler re-check the amount and currency
against the order before marking it paid, so a short payment cannot settle an order.

## Verify it end to end

Place a real order with a total above zero.

<Warning>
  Test with a **non-zero** total. A free order skips the payment step entirely, so a
  zero-total test passes while paid checkout is broken. That exact blind spot hid a
  two-month outage.
</Warning>

## Reference

- `POST /hooks/{provider}` receives settlement events. One route, per-store signature
  verification, and a body cap.
- [Money and rounding](/requests/money) for how amounts are represented.
- [Idempotency](/requests/idempotency) for safe retries on writes.
- The **Money** tab in the reference for refunds, payments and payouts.