Seal Verification & Security Log: Catch a Broken Seal Before the Trailer Rolls
Record the seal number at the loading dock, verify it at the gate, flag any mismatch on the spot, and keep a photo-backed chain-of-custody log — with a security supervisor approving every discrepancy resolution before the trailer moves.
An internal web tool where dock staff record the seal number and a photo at load, gate staff scan or type the seal at exit, the tool instantly flags any mismatch, your security supervisor reviews and approves every discrepancy resolution before the trailer is released, and you keep a tamper-evident, photo-backed chain-of-custody log ready for a C-TPAT audit.
Before you start
- A Supabase account (free)
- A Vercel account (free)
- A phone or tablet that can take photos at the dock and gate
- Your current seal log (a clipboard sheet or spreadsheet is fine)
- Claude Code or any AI coding agent
The problem this kills
A loaded trailer gets a high-security bolt seal at the dock. Someone writes the seal number on a clipboard. Hours later it rolls up to the gate, and a guard is supposed to read the seal, compare it to the number on the paperwork, and make sure nobody cracked it open in between. That comparison — the seal verification — is the whole point of a sealed load. It's also where things quietly fall apart.
The number gets transposed. The clipboard sheet walks off. A digit looks like another digit at dusk. A guard waves the truck through because the line is backing up. And when a customs officer or a C-TPAT auditor asks you to prove a specific trailer's seal was intact end to end — with evidence, with names, with timestamps — you're flipping through a binder hoping the right page is there. A broken or swapped seal that slips through isn't a paperwork problem; it's a stolen-load, contaminated-shipment, lost-certification problem.
You don't need a six-figure yard-management system to fix this. You can build the seal log yourself, this afternoon.
What you'll build
An internal web tool your dock and gate staff open on a phone or tablet. At the dock, the person sealing the trailer records the seal number, the trailer, and a photo of the seal in place. At the gate, the guard pulls up that trailer, reads the seal, and types or scans it — and the tool compares the two on the spot. Match: the trailer is cleared and the whole event is logged. Mismatch, broken seal, or no seal on file: it stops, flags the discrepancy with the reason, and nobody can release the trailer until your security supervisor reviews the evidence and approves a resolution.
Behind every event is a complete chain-of-custody log: who sealed it, when, with what number and photo; who verified it, when, what they read; and every supervisor decision in between. It handles the messy real cases too — a seal legitimately replaced at an inspection (with a new number and a reason), a re-sealed trailer after a customs exam, and the same trailer/seal event being entered twice by accident.
What's inside the Implementation Plan
The downloadable plan is a single markdown file you paste into an AI coding agent. It opens by interviewing you about your own yard and security process — how you number and source your seals, who seals and who verifies, what's on your current log sheet, your normal and peak truck volumes, your C-TPAT and customs rules, and your real exceptions like authorized re-sealing — and then it reads a short spec back for your thumbs-up before it builds anything. That's the difference between a tool shaped to your gate and a generic template you have to fight.
From there it walks the agent through the data model (trailers, seal-at-load records, seal-at-gate verifications, discrepancies, and the audit trail), the load-side capture with photo upload, the gate-side verify-and-compare, the mismatch flagging, the supervisor approval gate, and the chain-of-custody report. Every step ends with a ready-to-copy prompt. There's a full "No API yet?" path: import from a CSV or your current log sheet and export a clean chain-of-custody CSV, so you can ship today without touching any existing system.
The governance it includes (this is the point)
This is cargo security — the controls are the product. The plan builds them in: a login so only your team can use it; row-level security so each site or organization only ever sees its own trailers and seals; a complete, append-only audit trail of who sealed, who verified, and who approved each resolution, with timestamps and photos; a hard human-approval gate so a flagged trailer physically cannot be marked released until your security supervisor signs off; and duplicate guards keyed on trailer + seal event so the same seal can't be logged twice. That's the C-TPAT chain-of-custody story your compliance lead and your customs broker want to see.
Who it's for
Gate guards, dock and shipping staff, security supervisors, and the compliance person who owns your C-TPAT program. If you can explain to a new guard how a seal gets checked and what makes one worth stopping the truck for, you can build this — no developer required.
You've got this — open the plan, paste the first prompt, answer a few questions about how your yard actually runs, and you'll watch your first seal verification light up green or red.