horizon-shield

A read-only service for reviewing Japanese construction and renovation estimates against the public JCCDB cost dataset. It produces independently checkable fair-price records anchored to Bitcoin.

In plain words
What is it for?
Use its /audit, /red-flags, and /verify commands to review estimates, find warning signs, and verify the resulting fair-price records.
Why use it?
It helps identify potentially unusual prices in an estimate and provides a record that others can recompute and verify. It does not require an API key according to the supplied description.

Plugin for Claude Code

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Claude Code
/plugin marketplace add ogasurfproject-jpg/horizon-shield
agentmods
npx agentmods add plugins/ogasurfproject-jpg/horizon-shield/plugin
Clone the repo
git clone --depth 1 https://github.com/ogasurfproject-jpg/horizon-shield

Made for: Claude Code.

Per session not measured What this adds to a session before it is invoked.
When invoked not measured Not applicable: nothing here is loaded into a session.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Security

Grade A, and why

horizon-shield scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

plugin/.claude-plugin/plugin.json · 16 lines

What it actually says

{
  "name": "horizon-shield",
  "displayName": "HORIZON SHIELD",
  "version": "1.1.0",
  "description": "Audit Japanese construction and renovation estimates against the open JCCDB dataset and return Bitcoin-anchored, independently recomputable fair-price receipts. Read-only remote MCP, no API key. Adds /audit, /red-flags, /verify commands.",
  "author": {
    "name": "Toshikatsu Oga",
    "email": "[email protected]",
    "url": "https://shield.the-horizons-innovation.com"
  },
  "homepage": "https://shield.the-horizons-innovation.com",
  "repository": "https://github.com/ogasurfproject-jpg/horizon-shield",
  "license": "MIT",
  "keywords": ["mcp", "construction", "estimate", "audit", "japan", "real-estate", "fair-price", "verifiable"]
}
Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 2d ago First seen · 16 lines scan A 7a7b0b3f0df5

Subscribe to this mod's changes

horizon-shield is a plugin published in the GitHub repository ogasurfproject-jpg/horizon-shield (1 stars, last pushed 3d ago), licensed MIT. Its token cost is not measured: this kind of file is read by the harness, not the model. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.