Built for developers who never want to integrate payments twice.

One REST integration to every acquirer and payment method in your KLAUDE setup. Idempotent requests, signed webhooks, network tokens and a sandbox from day one.

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The API examples on this page are demonstrative. Endpoints, fields and behaviour are illustrative until your production credentials and documentation are issued.

Payments Routing Tokenisation Recurring Webhooks Errors

Payments API

Create a payment with an amount in minor units, a currency and a payment method. Set routing to smart and KLAUDE selects the acquirer; set it to a specific acquirer ID to pin the route. Every request accepts an Idempotency-Key header so retries never double-charge.

Authorise-and-capture or authorise-only
3-D Secure 2 handled inline with exemption logic
Hosted payment page or full API control

POST /v1/payments

// Request
{
  "amount": 25000,
  "currency": "EUR",
  "customer": "cus_9Xp2LmA",
  "payment_method": "pm_card_4Zk1",
  "capture": true,
  "routing": "smart",
  "three_ds": { "mode": "auto" },
  "metadata": { "order_id": "A-10422" }
}

// Response 201
{
  "id": "pay_7Hq3ZtR",
  "status": "succeeded",
  "amount": 25000,
  "currency": "EUR",
  "route": { "acquirer": "acq_eu_02", "attempts": 1 },
  "created": "2026-09-17T10:42:11Z"
}

Routing

Routing rules are configured in the dashboard and can be overridden per request. Each payment response includes the route taken and any cascade attempts, so you always know why a transaction went where it did.

routing object

{
  "routing": {
    "strategy": "smart",          // smart | cost | pinned
    "prefer": ["acq_eu_02", "acq_eu_01"],
    "cascade": true,             // retry soft declines
    "max_attempts": 2
  }
}

// Response route detail
"route": {
  "acquirer": "acq_eu_01",
  "attempts": 2,
  "history": [
    { "acquirer": "acq_eu_02", "result": "soft_decline", "code": "91" },
    { "acquirer": "acq_eu_01", "result": "approved" }
  ]
}

Tokenisation

Card details are captured by KLAUDE's hosted fields or SDK and exchanged for a token. Tokens are acquirer-independent, so you can change providers without re-collecting cards. Network tokens and account updater keep stored credentials valid when cards are reissued.

POST /v1/payment_methods

{
  "type": "card",
  "card_token": "tok_hosted_Fk92…",   // from hosted fields
  "customer": "cus_9Xp2LmA",
  "network_token": true
}

// Response
{
  "id": "pm_card_4Zk1",
  "card": { "brand": "visa", "last4": "4242", "exp": "09/29", "issuing_country": "DE" },
  "network_token": { "status": "active" }
}

Recurring payments

Create a subscription against a stored payment method. KLAUDE flags transactions correctly as merchant-initiated, applies smart retry logic on failed renewals and emits events at each stage so your billing system stays in sync.

POST /v1/subscriptions

{
  "customer": "cus_9Xp2LmA",
  "payment_method": "pm_card_4Zk1",
  "amount": 4900,
  "currency": "EUR",
  "interval": "month",
  "trial_days": 14,
  "retry": { "strategy": "smart", "max_attempts": 4 }
}

Webhooks

Every event is delivered as a signed JSON POST. Verify the Klaude-Signature header (HMAC-SHA256 of the raw body with your endpoint secret), respond with a 2xx, and KLAUDE retries with exponential backoff for up to 72 hours if you don't. Events can be replayed from the dashboard.

payment.succeeded, payment.failed, payment.rerouted
dispute.opened, dispute.alert, dispute.won
subscription.renewed, subscription.retry_scheduled
payout.paid, settlement.completed

webhook payload

{
  "id": "evt_2Nq8sT",
  "type": "payment.rerouted",
  "created": "2026-09-17T10:42:12Z",
  "data": {
    "payment": "pay_7Hq3ZtR",
    "from": "acq_eu_02",
    "to": "acq_eu_01",
    "reason": "soft_decline"
  }
}

// Verify (Node)
const sig = crypto.createHmac('sha256', secret)
  .update(rawBody).digest('hex');
if (!timingSafeEqual(sig, req.headers['klaude-signature'])) throw …

Errors

Conventional HTTP status codes. Errors carry a stable code, a human-readable message and, for declines, the acquirer response code and whether a retry is permitted under scheme rules.

402 Payment Required

{
  "error": {
    "type": "card_declined",
    "code": "insufficient_funds",
    "message": "The card was declined by the issuer.",
    "acquirer_code": "51",
    "retry_allowed": false
  }
}