Sylter Bank API Access & Open Banking Integration

Want programmatic, privacy-first access to your Sylter Bank accounts? open-banking.io lets you link the Sylter Bank cooperative (BIC GENODEF1SYL) and pull balances and transactions into a single dashboard — with the added guarantee that only you can ever read the data. There are no eIDAS certificates to obtain, no bank sponsorship to negotiate, and no PSD2 licence to hold. Sylter Bank supports both business and personal accounts, and a single consent stays valid for up to 180 days before you renew it.

Unlike raw bank APIs, open-banking.io is built around local encryption: your keys are generated on your own device from a passphrase you set, and the service stores only your public key. That means even open-banking.io's own servers cannot decrypt what they hold.

How to connect Sylter Bank

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

  1. Sign up at open-banking.io and set your encryption passphrase. Your private decryption key is created locally and never leaves your device.
  2. In the dashboard, search for Sylter Bank and choose the account type you hold — business or personal.
  3. You are redirected to Sylter Bank's own secure login, where you approve access under PSD2 (Strong Customer Authentication on the bank's side).
  4. Once you confirm, your selected accounts sync back into your open-banking.io dashboard and refresh automatically for the duration of your 180-day consent.

That's the whole flow — no developer redirect, and the account holder always authorises on Sylter Bank's own screen.

Access your data

Programmatic access is an optional step after your Sylter Bank connection is live. On the Developers page, create an API key and export a credentials.json — this bundles your API key and your private decryption key. From there you can 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. An API key alone only ever returns ciphertext — without your private key the data stays unreadable, which is what makes the model zero-knowledge.

All of this runs on the standard plan at roughly EUR 3/month.

Do I need a certificate or PSD2 licence for Sylter Bank?

No. open-banking.io is certificate-free — you approve access directly on Sylter Bank's login, no eIDAS setup required.

Can open-banking.io read my Sylter Bank data?

No. Decryption happens on your device with a key only you hold; the servers store only your public key.

Does the CLI connect my bank?

No. The CLI and SDK only read and sync connections you have already approved in the dashboard — there is no connect command.

Ready to start? Link Sylter Bank at https://open-banking.io.