generated: '2026-08-27'
method: searched
source: https://docs.klarna.com/
sources:
  - https://docs.klarna.com/api/kn/direct-partner/security/
  - https://docs.klarna.com/klarna-network-distribution/web-sdk/
  - https://docs.klarna.com/conversion-boosters/on-site-messaging/
  - https://docs.klarna.com/conversion-boosters/sign-in-with-klarna/before-you-start/
description: >-
  Klarna's client-side surface is larger than its server-side one. Where Klarna ships no
  server-side REST SDK in any language, it ships several browser-loaded JavaScript libraries and
  native mobile in-app SDKs, all authenticated with a non-secret client-id
  (klarna_<live|test>_client_<random>) rather than an API key. Every loader below was probed live
  on 2026-08-27.
authentication: client-id (not the API key) — see authentication/klarna-authentication.yml

families:
  - name: Klarna Payments widget
    kind: hosted-iframe
    loader: https://x.klarnacdn.net/kp/lib/v1/api.js
    probed: {date: '2026-08-27', status: 200, bytes: 484379, content_type: application/javascript}
    pinned: false
    description: >-
      Loads the Klarna payment-method widget into the merchant checkout against a client_token
      returned by createCreditSession, then produces an authorization token via authorize().
    api_surface: [Klarna.Payments.init, Klarna.Payments.load, Klarna.Payments.authorize]
    docs: https://docs.klarna.com/payments/web-payments/integrate-with-klarna-payments/
  - name: Klarna Web SDK
    kind: javascript-sdk
    loader: https://js.klarna.com/web-sdk/v1/klarna.js
    probed: {date: '2026-08-27', status: 200, bytes: 75766, content_type: application/javascript}
    pinned: false
    description: >-
      The newer unified browser SDK for the Klarna Network surface, covering payment buttons,
      messaging placements, identity/sign-in and integration metadata. Documented as an SDK
      reference (Config, IntegrationMetadata, Payment, Messaging, Identity namespaces) alongside
      the REST APIs in the Klarna Network documentation.
    docs: https://docs.klarna.com/klarna-network-distribution/web-sdk/
  - name: On-site Messaging
    kind: web-component
    loader: https://osm.klarnaservices.com/lib.js
    probed: {date: '2026-08-27', status: 200, bytes: 57696, content_type: application/javascript}
    pinned: false
    element: <klarna-placement data-key="..." data-locale="...">
    description: >-
      Promotional placements rendered on product, cart and checkout pages showing the shopper the
      available Klarna payment options before checkout. Customisable through the Merchant Portal
      for merchants without CSS access.
    docs: https://docs.klarna.com/conversion-boosters/on-site-messaging/
  - name: Express Checkout
    kind: hosted-button
    description: >-
      A Klarna-hosted express-purchase button placed on product and cart pages that collects
      shopper details from the Klarna account and short-circuits the checkout form.
    docs: https://docs.klarna.com/conversion-boosters/express-checkout/
  - name: Sign in with Klarna
    kind: hosted-button + OIDC
    description: >-
      Consumer identity button backed by the OAuth 2.0 / OIDC authorization-code flow at
      login.klarna.com. Returns verified profile claims (including verified name and date of
      birth) under the scopes catalogued in scopes/klarna-scopes.yml.
    docs: https://docs.klarna.com/conversion-boosters/sign-in-with-klarna/before-you-start/
  - name: Hosted Payment Page (HPP)
    kind: hosted-page
    description: >-
      A fully Klarna-hosted checkout page created via createHppSession and optionally distributed
      to the shopper by Klarna over email or SMS (distributeHppSession). Requires no client-side
      library at all — the merchant redirects or shares a URL.
    spec: openapi/klarna-hpp-api-openapi.yml
    docs: https://docs.klarna.com/payments/other-products/hosted-payment-page/
  - name: Klarna Mobile SDK
    kind: native-sdk
    platforms: [android, ios, react-native, flutter]
    packages: packages/klarna-packages.yml
    description: >-
      In-app rendering of the same payment, messaging and sign-in surfaces for native apps.
    docs: https://docs.klarna.com/payments/mobile-payments/integrate-with-mobile-sdk/

pinning_finding: >-
  All three browser loaders are served from unpinned major-line URLs (…/v1/…). A merchant cannot
  determine, and cannot lock, the build being executed in their checkout page. Klarna's versioning
  policy covers the REST APIs and the SDK packages; it does not cover these CDN-delivered scripts.
maintainers:
  - FN: Kin Lane
    email: kin@apievangelist.com