Sparkasse Westerwald-Sieg Open Banking & API Access

Pulling your Sparkasse Westerwald-Sieg balances and transactions into your own tools no longer means wrestling with eIDAS certificates or a bank sandbox. open-banking.io gives you PSD2 access to Sparkasse Westerwald-Sieg (BIC MALADE51AKI) across a network of 2,600+ EU and UK banks, and it does so as a zero-knowledge service: your data is encrypted with a key that never leaves your device, so only you can read it. Both business and personal accounts are supported, and a single consent stays valid for up to 180 days before you renew it.

How to connect Sparkasse Westerwald-Sieg

Connecting happens entirely inside the open-banking.io dashboard — there is no API call, code, or key involved in this step.

  1. Sign up for open-banking.io and set your encryption passphrase. Your keys are generated locally on your own device at this moment.
  2. In the dashboard, pick Sparkasse Westerwald-Sieg from the bank list and choose the account type you need — business or personal.
  3. You are redirected to Sparkasse Westerwald-Sieg's own secure login, where you approve access on the bank's PSD2 consent screen.
  4. Your accounts sync back into the dashboard, ready to view. That's the whole flow — no certificate to buy, nothing to self-host.

Access your data

Once a Sparkasse Westerwald-Sieg connection exists, developers can optionally read it programmatically. On the Developers page, create an API key and export a credentials.json file — this bundles your API key together with your private decryption key. From there use the CLI (openbanking accounts, openbanking transactions, openbanking sync), an SDK, or the REST API directly. Requests authenticate with the X-Api-Key header, and every response is decrypted locally with your own key. The CLI and SDK only read and sync connections you already approved in the dashboard — there is no connect command, because connecting is a bank-side consent step, not an API operation. An API key on its own returns only ciphertext; without your private key, nobody — not even open-banking.io — can read it.

At roughly EUR 3/month, you get certificate-free access with genuinely private, locally-decrypted data.

Do I need a developer account to connect Sparkasse Westerwald-Sieg?

No. Connecting is done in the dashboard by approving consent on Sparkasse Westerwald-Sieg's login page. The API key and credentials.json are only needed if you later want to read the data in code.

Can open-banking.io see my Sparkasse Westerwald-Sieg transactions?

No. The service is zero-knowledge and holds only your public key. Your transactions are decrypted locally with a private key that stays on your device.

Up to 180 days per PSD2 rules. When it expires, re-approve on the bank's consent screen from the dashboard to keep syncing.

Ready to start? Visit open-banking.io.