HORIZON SHIELD

The evidence.
Not opinion. Verifiable.

Every claim below links to a source you can open yourself. The data is public. The records are on Bitcoin. The papers are archived where I cannot quietly edit them.

I started as a carpenter at 15. Thirty years on site. Then I taught myself to build AI. I made this so a homeowner does not need those 30 years to know if a price is fair.

The world is unfair, and too comfortable with it. The people who get overcharged are the ones who were never given the means to know. I think a person has the right to know whether their price is fair. So I built the means.

Nothing here asks for trust. Open the links. Check the hashes. Re-verify the timestamps. If something does not hold up, it does not belong here.

01 / The dataset

An open construction-cost vocabulary

JCCDB v2.0 catalogues 65,729 items across 398 categories. Item names, categories, and units. No prices are baked into the schema. Pricing lives in a separate reference layer, so the open vocabulary cannot be mistaken for a price quote. Published openly under CC BY 4.0.

Item schema65,729 items / 398 categories (no prices)
Compositionverified core 11,250 + extended 54,479
LicenseCC BY 4.0 (core) / CC BY-NC 4.0 (extended)
Replication data & codeZenodo 10.5281/zenodo.20522847

02 / The cryptographic anchor

Records timestamped on Bitcoin

A government office, an industry body, or a university server can quietly edit a record later. Bitcoin cannot. Not even by me. The fingerprints below are confirmed in Bitcoin blocks. Anyone can re-verify them at opentimestamps.org.

PTKA protocol declarationblock 949356 · 2026-05-14
VRQ working paper v1.4block 950337 · 2026-05-21
VRQ working paper v2.2block 950372 · 2026-05-21
VRQ working paper v2.4block 950912 · 2026-05-25
JCCDB Extended (this paper)block 951871 · 2026-06-01

Each consumer PDF report also carries a per-diagnostic SHA-256 audit hash, so the same input always reproduces the same fingerprint.

03 / The academic record

Archived, open, citable

The method is written up and archived in places that issue permanent identifiers. These are preprints. Open to scrutiny, not hidden behind a paywall.

JCCDB origin (mirror)engrXiv 7007
Audit-hash & macro-correctionSSRN 6738701
Phantom-overcharge extensionZenodo 10.5281/zenodo.20370618
Phantom-overcharge extensionZenodo 10.5281/zenodo.20370618
VRQ working paperSSRN 6807738

04 / What the data shows

Findings, stated honestly

These come from a self-selected sample of homeowners who already suspected overcharging. They describe what the tool surfaces, not population averages. Said plainly, on purpose.

Largest gap, same jobup to 91% (98 cases, self-selected)
Phantom overcharge · fixedfoot-bath & studio-mirror reversed black→white
Real concern surfaced insteadoverhead ratios 12.5% / 17.4%
Free AI diagnosticlive now · HORIZON SHIELD

05 / Who built this

A builder, not an institution

Toshikatsu Oga. Carpenter at 15 in Osaka, 1993. Site supervisor, then construction manager, then self-taught AI engineer. Thirty years on the tools before a line of this code.

CompanyThe HORIZ音s Co., Ltd. · Hiratsuka, Japan

Last verified 2026-06-03. All links checked live.
HORIZON SHIELD · shield.the-horizons-innovation.com