A VASP-licensed company needed to offer both traditional fiat banking services and crypto custody under one roof. The challenge was integrating fiat account management (EUR, USD, GBP) with Fireblocks-powered crypto wallets, while maintaining full AML/KYT compliance. Finhost deployed the unified platform with exchange operations, real-time transaction monitoring, and a custom-branded interface.
Objectives
- Unify fiat accounts and crypto custody in a single platform.
- Integrate Fireblocks for secure crypto wallet management.
- Enable exchange operations with competitive rates.
- Maintain real-time KYT monitoring and full AML compliance.
What We Built (Scope)
- Web apps: unified client interface combining fiat accounts and crypto portfolio in one branded experience.
- Fiat accounts: EUR, USD, and GBP accounts powered by regulated banking partners.
- Crypto custody: Fireblocks integration for secure wallet management with multi-network support.
- Exchange: crypto-fiat and crypto-crypto exchange operations with real-time quotes.
- Onboarding & compliance: KYC/KYB with real-time KYT (Know Your Transaction) monitoring for all transfers.
- Back-office: admin dashboard for operations, compliance alerts, and transaction oversight.
Customer Journey
The client held a VASP license and was operating crypto custody services using a patchwork of internal tools. They wanted to add fiat banking (EUR, USD, GBP accounts) to their offering — giving customers a single platform where they could hold both crypto and fiat, exchange between them, and make fiat payments.
The key requirement was architectural unity. They didn’t want two separate systems stitched together with API calls — they wanted a single ledger that understood both fiat balances and crypto positions, with one onboarding flow, one compliance engine, and one back-office.
We started by integrating Fireblocks for crypto custody — connecting their existing vault structure to Finhost’s account model. This meant mapping Fireblocks vault accounts to Finhost user accounts, handling multi-network deposits (ERC-20, TRC-20, native chains), and displaying real-time crypto balances alongside fiat.
The exchange engine was built on top of Kraken’s API for crypto-fiat and crypto-crypto pairs. We implemented real-time quote fetching, slippage protection, and fee calculation — all integrated into the same transaction flow as fiat payments.
The compliance layer was the most critical piece. With both fiat and crypto transactions flowing through the platform, the client needed real-time KYT (Know Your Transaction) monitoring for every crypto transfer, alongside standard AML screening for fiat payments.
Challenges We Faced
- Unified ledger for fiat and crypto: Fiat accounts use traditional double-entry bookkeeping with IBANs and account numbers. Crypto uses vault addresses, UTXOs, and network confirmations. We built a unified account abstraction layer that presents both as “accounts” to the user while maintaining separate settlement logic underneath.
- Fireblocks integration depth: Fireblocks is powerful but complex. We had to handle webhook-driven deposit detection across multiple networks, manage gas fee estimation for withdrawals, implement address whitelisting, and build a VASP name resolution flow for Travel Rule compliance.
- Exchange rate volatility: Crypto-fiat exchange requires real-time quotes with short validity windows. We implemented a quote-lock mechanism: the user sees a rate, has 30 seconds to confirm, and the system either executes at that rate or refreshes.
- KYT false positives: Real-time crypto transaction monitoring generates a significant number of alerts — many of which are false positives. We built a tiered alert system in the back-office: low-risk alerts auto-resolve, medium-risk go to a review queue, and high-risk freeze the transaction pending manual investigation.
- Regulatory complexity: The VASP operated across multiple jurisdictions, each with different Travel Rule requirements. We configured the compliance engine to apply different rules per jurisdiction — some requiring originator/beneficiary data for all crypto transfers, others only above certain thresholds.
Architecture Snapshot
- Finhost white-label core as the unified application backbone.
- Banking partner integrations for fiat accounts and payment rails.
- Fireblocks integration for crypto custody and wallet operations.
- Exchange engine for quotes, conversion, and settlement.
- KYT monitoring with real-time transaction screening and compliance alerts.
Implementation Timeline
- Discovery & design: ~1–2 weeks (flows, provider scoping, compliance mapping).
- Build & integrations: ~3–4 weeks (fiat, crypto, exchange, KYT).
- Go-live: full platform deployed in ~6 weeks with 24/7 KYT monitoring active.
Successful Launch
The unified platform went live in 6 weeks. The client now offers a single branded experience where customers hold EUR, USD, and GBP fiat accounts alongside BTC, ETH, and stablecoin wallets. The exchange engine processes crypto-fiat conversions with real-time Kraken pricing. 24/7 KYT monitoring screens every crypto transaction in real-time, with the tiered alert system reducing compliance team workload by filtering false positives automatically. The back-office gives the operations team a unified view of all fiat and crypto activity. The client has successfully positioned themselves as a “one-stop shop” for customers who need both traditional banking and digital asset services.
Launch a Similar App with Finhost
Finhost is a white-label core banking platform. We deliver the apps, the back-office, and the integrations you need to bridge fiat and crypto quickly — without building separate systems for each.
Talk to Finhost about launching your own crypto-fiat platform on a fast timeline.