Developer documentation

Implementation guide — by topic

The implementation guide covers end-to-end integration workflows. Jump straight to a topic:

• First requestAuthenticate and make your first API call.
• Personal onboardingKYC and account creation for individual users.
• Business onboardingKYB and setup for business customers.
• Accounts & IBANsOpen multi-currency accounts with dedicated IBANs.
• CardsIssue, activate, and manage virtual and physical cards.
• Top up & unloadMove funds onto and off cards and accounts.
• IBAN payoutsSend payouts to external IBANs over SEPA and SWIFT.
• TransactionsQuery, filter, and reconcile transaction data.
• Budgets & FXManage budgets and convert between currencies.
• TransfersMove money between users, accounts, and programmes.
• CryptoCrypto on/off-ramp flows and crypto-enabled cards.
• ProgramsConfigure card programmes and product settings.
• OperationsOperational tooling: statuses, limits, and controls.
• API catalogueThe full endpoint catalogue at a glance.
• Go liveProduction checklist and the path from sandbox to launch.

Frequently asked questions

What can I build with the HOPPA API?

Embedded finance products: branded card programmes (virtual and physical), multi-currency accounts and wallets with dedicated IBANs, SEPA and SWIFT payouts, currency exchange, and crypto on/off-ramp flows. Typical builds include neobank apps, expense platforms, payroll cards, and marketplaces adding financial features to an existing product.

How do I get sandbox access?

Sandbox access is granted on request rather than self-service. Submit the form at hoppa.global/sandbox with your company name and use case, and the HOPPA team will set you up with an API key and the sandbox base URL. Access requests are typically reviewed within a few business days.

What authentication does the HOPPA API use?

Every request is authenticated with an API key sent in the x-api-key HTTP header. Sandbox keys work against the sandbox base URL provided with your access; production keys are issued as part of go-live. Keys are scoped to your programme, so keep them server-side and never expose them in client code.

How long does an integration take?

A first working flow — create a user, issue a card, fund it, transact — takes four API calls and can run the same day you receive sandbox access. A production launch depends on your programme scope and compliance onboarding; Ready-to-Launch packages ship in weeks, while custom builds vary with requirements.

What card types can I issue?

Virtual and physical cards under your own brand, covering corporate cards, individual payment cards, and crypto-enabled cards. Cards support top-ups, spending controls, and transaction queries through the same API. Available card products depend on your programme, region, and licensing route — the team will confirm options for your use case.

Which regions are supported?

HOPPA focuses on the UK and EU rails: SEPA and SWIFT payments, UK and EU IBANs, and card programmes for European use cases. Service availability varies by region and is subject to eligibility, so tell the team where your customers are and they will confirm coverage for your programme.