Sparkasse Mainz API Access & Open Banking Data

Sparkasse Mainz serves Rheinhessen from its base in Rhineland-Palatinate, and if you keep business or personal accounts there you can reach that data through open-banking.io without touching a single line of bank integration code. open-banking.io is a certificate-free bridge to more than 2,600 EU and UK banks that keeps the whole thing zero-knowledge: your account information is decrypted on your own device with a key that never leaves your hands. The service holds only your public key, so it can move ciphertext but can never read it.

Sparkasse Mainz (BIC MALADE51MNZ) supports both business and personal accounts, and a single PSD2 consent stays valid for up to 180 days before you renew it.

How to connect Sparkasse Mainz

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

  1. Sign up for open-banking.io and set your encryption passphrase. Your cryptographic keys are generated locally on your device at this moment.
  2. In the dashboard, choose Sparkasse Mainz and select whether you are linking a business or personal account.
  3. You are redirected to Sparkasse Mainz's own secure login, where you authenticate and approve access on the bank's PSD2 consent screen.
  4. Once you confirm, your accounts sync back into the open-banking.io dashboard, ready to view.

That consent governs the link for up to 180 days, after which you simply repeat the approval on the bank's side.

Access your data

Reading Sparkasse Mainz data programmatically is an optional step you take after the account is already connected. On the Developers page, create an API key and export a credentials.json file — it bundles the API key together with your private decryption key. From there you can use the CLI (openbanking accounts, openbanking transactions, openbanking sync), an SDK, or the REST API. Every request sends the X-Api-Key header, and each response is decrypted locally with your own key. An API key on its own only ever returns ciphertext; without your private key there is nothing readable to see. The CLI and SDK read and sync existing connections — they never create one.

All of this runs for roughly EUR 3 per month, with no eIDAS certificate and no bank-specific onboarding to arrange.

Do I need a developer account to use Sparkasse Mainz?

No. Connecting and viewing accounts is done in the dashboard. API keys and credentials.json are only for developers who want programmatic reads.

Can open-banking.io see my Sparkasse Mainz balances?

No. The platform stores only your public key. Data is decrypted on your device, so the servers hold ciphertext they cannot open.

Up to 180 days per PSD2 authorisation. When it expires, re-approve access on Sparkasse Mainz's own consent screen.

Start at open-banking.io.