What is fact-checker?

A fact-checking agent that compares quotations and numbers in a book with primary sources, such as official guides or source repositories. It marks claims as PASS or UNVERIFIED when a primary source cannot be accessed.

Use it to extract citations and figures from book text, cross-check them against primary sources, and add verification labels or observation notes to run reports.

It helps prevent unsupported citations and numbers from being presented as verified. Differences are reported separately, while the original figures remain unchanged.

fact-checker — Agent for Claude Code by revfactory

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.

Clone the repo

git clone --depth 1 https://github.com/revfactory/harness-engineering-with-cc

Made for: Claude Code.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

README.md

[![agentmods](https://agentmods.dev/badge/agents/revfactory/harness-engineering-with-cc/fact-checker/github.svg)](https://agentmods.dev/agents/revfactory/harness-engineering-with-cc/fact-checker)

Your own site

<a href="https://agentmods.dev/agents/revfactory/harness-engineering-with-cc/fact-checker"><img src="https://agentmods.dev/badge/agents/revfactory/harness-engineering-with-cc/fact-checker/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

Your own site · 80×15

<a href="https://agentmods.dev/agents/revfactory/harness-engineering-with-cc/fact-checker"><img src="https://agentmods.dev/badge/agents/revfactory/harness-engineering-with-cc/fact-checker.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 59 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.

When invoked 293 The whole file, excluding the scripts and references it only reads on demand.

Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.

Origin original No closer match found in the catalogue.

Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

Model	Per session	Once invoked
Fable 5.1	$0.00059	$0.00293
Opus 5.5	$0.00024	$0.00117
Sonnet 5.5	$0.00012	$0.00059
Haiku 4.5	$0.00006	$0.00029

Measured 2mo ago against content hash ddff3e24fa3a, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

fact-checker 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 2mo 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.

ex-06-15-292-agent-incident/.claude/agents/fact-checker.md · 26 lines

What it actually says

fact-checker

목표

책에 등장한 외부 출처(예: "클로드 코드 내부 사고 사례, 오케스트레이션 패턴 가이드")의 수치를 1차 자료로 대조.

작업

책 본문에서 인용·수치 추출.
(가능 시) 공식 가이드 URL 또는 GitHub 저장소 cross-ref.
검증되면 PASS, 1차 자료 미접근 시 UNVERIFIED로 표시.
책 수치는 절대 변형하지 않는다 — 항상 본문 그대로 보존.
차이가 있으면 별도 "관찰 메모"로 사용자에게 보고.

출력

run/incident.md (또는 대상 예제의 run/*.md)에 UNVERIFIED/관찰 메모 부착.

팀 통신 프로토콜

송신: 차이 발견 시 리더에게 보고. 수신: 없음.

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.

2mo ago First seen · 26 lines · 59 tokens per session scan A ddff3e24fa3a

Subscribe to this mod's changes

fact-checker is an agent published in the GitHub repository revfactory/harness-engineering-with-cc (123 stars, last pushed 5mo ago), licensed Apache-2.0. It adds 59 tokens to every session and 293 once invoked, about $0.0002 per session on Opus 5.5. 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 2026-08-30.

Research

fact-checker next to 6 agents from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
fact-checkerrevfactory/harness-engineering-with-cc	Agent	123	5mo ago	Apache-2.0	A	59	Claude Code
playwright-test-generatormicrosoft/playwright	Agent	99k	today	Apache-2.0	A	151	Claude Code
.NET-Notebook-Migration-Agentmicrosoft/ai-agents-for-beginners	Agent	79k	today	MIT	A	33	Claude Code
AVM Owner Triagegithub/awesome-copilot	Agent	41k	today	MIT	A	61	Claude Code
Ultimate Transparent Thinking Beast Modegithub/awesome-copilot	Agent	41k	today	MIT	A	11	Claude Code
code-revieweranthropics/claude-cookbooks	Agent	54k	2d ago	MIT	A	52	Claude Code
Pimcore Expertgithub/awesome-copilot	Agent	41k	today	MIT	A	26	Claude Code

fact-checker

Getting it into your agent

Wrote this? Show the measurements

What it costs to keep this loaded

Grade A, and why

Nothing flagged

What it actually says

fact-checker

목표

작업

출력

팀 통신 프로토콜

What this file has done since we first saw it

fact-checker compared with agents from other repositories