BiG API Access — Open Banking for Portugal | open-banking.io

BiG — Banco de Investimento Global — is one of Portugal's specialist investment and savings banks, and open-banking.io lets you reach its account data without the usual PSD2 red tape. There are no eIDAS certificates to buy, no sandbox onboarding, and no waiting on a developer portal. You sign up, and your BiG balances and transactions flow into a dashboard where only you hold the key that can decrypt them.

That last part matters. open-banking.io is zero-knowledge: your encryption keys are generated on your own device, and the service stores only your public key. It can relay ciphertext but can never read a single BiG transaction. Coverage spans 2,600+ EU and UK banks, so the same setup works if you later add accounts elsewhere.

How to connect BiG

Connecting happens entirely in 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 open the dashboard.
  2. Set an encryption passphrase. Your private decryption key is created locally on your device at this moment; nobody else, including open-banking.io, ever sees it.
  3. Pick BiG from the bank list and choose the account type you need — BiG supports both business and personal accounts (BIC BDIGPTPLXXX).
  4. Approve on BiG's own secure login. You are redirected to the bank's PSD2 consent screen to authorise access directly with BiG. Your consent lasts up to 180 days, after which you simply renew it.
  5. Your BiG accounts then sync into your dashboard automatically.

Access your data

Reading BiG data programmatically is an optional step you take after the connection exists. On the Developers page, create an API key and export a credentials.json — this bundles the 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. Requests authenticate with the X-Api-Key header, and every response is decrypted locally with your own key. Without that private key, the API key alone returns only ciphertext — which is exactly the point.

All of this runs on flat pricing of roughly EUR 3/month, with no per-call or certificate fees.

FAQ

Do I connect BiG using an API key?

No. You connect BiG in the dashboard by approving access on BiG's own login screen. API keys exist only for optionally reading data later.

Can open-banking.io see my BiG transactions?

No. The service is zero-knowledge and holds only your public key. Data is decrypted on your device with a key only you possess.

How long does my BiG access last?

BiG grants consent for up to 180 days per authorisation. When it expires, you re-approve it in the dashboard.

Ready to start? Visit open-banking.io.