CustomsLens – Building a complete customs platform, from scratch

Where it began

With CustomsLens, we're solving a clear problem: customs handling takes too much time and goes wrong too often. Their customers – importers, exporters, freight forwarders – were losing hours to administration that was largely repetitive.

The question was simple: can you automate this?

What we built

We started with the biggest pain points. First invoice processing, since that's where most of the time was being wasted.

The AI extraction

This is where it got interesting. We use OpenAI's Vision API to read commercial invoices. Not just the text – the AI understands the structure. It knows that the amount in the bottom right is usually the total, that the table in the middle contains the line items, and that the address in the top left is the exporter.

It doesn't work perfectly. Sometimes it picks up the wrong field, sometimes it misses a line. But in 90%+ of cases it's correct, and the user only has to make corrections instead of typing everything in themselves. That's the difference between 20 minutes and 2 minutes per invoice.

The TARIC integration

HS codes are the classification codes for goods at customs. There are thousands of them, and choosing the right one is crucial – the wrong code means the wrong import duties.

We built a direct link to the EU TARIC database. You search by description ("hardwood garden furniture") or by code ("9403.60"), and you immediately see the tariff and any restrictions. No more digging through PDFs.

The rest of the platform

Around that, we built what you'd expect from a modern SaaS platform:

• Document management with categories and status tracking
• Digital signing via DocuSeal
• Shipment wizard that guides you through the process
• Dashboard with filters, search, and bulk actions
• Location tracking via Google Maps
• Team management with invitations and roles

The integrations

This project once again taught us how much work external integrations are. We connected with:

• OpenAI Vision (document AI)
• EU TARIC API (customs tariffs)
• DocuSeal (signing)
• Google Places (locations)
• KVK API (NL company data)
• VAT Sense (EU VAT validation)
• Twilio (SMS verification)
• SendGrid (email)

Every integration has its own quirks. Rate limits, authentication flows, error handling, edge cases. It's never "just hooking up an API."

The technical choices

Supabase as the backend – We wanted to build quickly without writing a complete backend. Supabase gives you PostgreSQL, authentication, and storage out-of-the-box. Row Level Security ensures that data from different organizations stays strictly separated.

Next.js 14 with App Router – Server components where possible, client components where necessary. Good performance, good developer experience.

Tailwind + shadcn/ui – No time wasted on custom design systems. shadcn gives you solid components that you can customize.

What we learned

Every project teaches you something. With CustomsLens:

1. AI is powerful but not magic – You have to catch edge cases, build in feedback loops, and accept that it won't be 100%
2. Domain knowledge is essential – We spent a lot of time understanding how customs handling works. Without that knowledge, you build the wrong things
3. Multi-tenant is complex – Five user roles with different permissions, combined with organization-level permissions. You need to design that properly from the start

Where it stands now

CustomsLens is now used by companies that deal with customs on a daily basis. The feedback is positive – the AI extraction and the HS code search function are mentioned most often.

There's still plenty to build. More automation, smarter suggestions, better reporting. But the foundation is there, and that foundation works.