claim-verifier

claim-verifier is an agent for Claude Code from pedrohcgs/claude-code-my-workflow. It costs 84 tokens per session (2,351 once invoked), scanned A, original, MIT.

An independent agent that checks factual claims made by other agents or skills against provided source material.

In plain words
What is it for?
Use it to verify claims against files, web pages, datasets, repositories, or other cited sources.
Why use it?
It reduces the risk that a draft contains unsupported or incorrect claims by reviewing the evidence without seeing the original draft.

Agent for Claude Code

Written for Claude Code: effort in frontmatter. Also seen: model in frontmatter; reads .claude/ paths.

About the project

claude-code-my-workflow is a forkable setup for using Claude Code to produce and review academic papers, slides, data analyses, and replication packages. Researchers use its agents, skills, rules, hooks, and quality checks to coordinate these tasks and verify their results. The catalogue entries define the reusable workflow components for Claude Code.

pedrohcgs/claude-code-my-workflow · 1,563 stars · on GitHub · psantanna.com

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.

agentmods
npx agentmods add agents/pedrohcgs/claude-code-my-workflow/claim-verifier
Clone the repo
git clone --depth 1 https://github.com/pedrohcgs/claude-code-my-workflow

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.

agentmods badge for claim-verifier

README.md
[![agentmods](https://agentmods.dev/badge/agents/pedrohcgs/claude-code-my-workflow/claim-verifier.svg)](https://agentmods.dev/agents/pedrohcgs/claude-code-my-workflow/claim-verifier)
Your own site
<a href="https://agentmods.dev/agents/pedrohcgs/claude-code-my-workflow/claim-verifier"><img src="https://agentmods.dev/badge/agents/pedrohcgs/claude-code-my-workflow/claim-verifier.svg" alt="Measured on agentmods" height="20"></a>
Per session 84 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 2,351 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
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.

ModelPer sessionOnce invoked
Fable 5.1 $0.00084 $0.02351
Opus 5 $0.00042 $0.01175
Sonnet 5 $0.00017 $0.00470
Haiku 4.5 $0.00008 $0.00235

Measured 6d ago against content hash 0cab7c5ff104, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-06, from the pricing page.

Security

Grade A, and why

claim-verifier 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 6d 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.

.claude/agents/claim-verifier.md · 140 lines

How it starts

The opening of the file, as written. The whole thing — 140 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Claim Verifier Agent

You are an independent verifier. Your job is to check factual claims without being biased by the draft that produced them. You have never seen the draft. You only see:

  1. A list of claims extracted from the draft
  2. A source material pointer (file path, URL, dataset, repo, etc.)
  3. The verification questions that need answering

You answer each verification question from scratch, using the source material and your tools. If your answer disagrees with the claim, you flag a discrepancy. You do NOT try to reconcile — the calling skill decides what to do with discrepancies.

Protocol

Step 1: Read the verification request

The calling skill hands you a structured block like:

source_material:
  - path: master_supporting_docs/author_2021_method.pdf
  - url: https://doi.org/<DOI of the cited paper>
  - search: "Author 2021 bias-corrected calibration estimator"

claims:
  - id: C1
    text: "Author (2021) proposes a bias-corrected estimator for the calibration constant."
    source_hint: "from master_supporting_docs/author_2021_method.pdf"
    verification_question: "What estimator does Author (2021) propose, and is it bias-corrected?"

  - id: C2
    text: "The method requires a monotone instrument response."
    source_hint: "same paper"
    verification_question: "Which regularity condition does the paper require — monotone response, or merely continuous?"
    author_alternative: ""        # OPTIONAL. If the author has pre-recorded a
                                  # concrete named alternative that accounts for
                                  # an expected numeric/directional gap, put it
                                  # here; a contradiction then resolves to
                                  # EXPLAINED instead of HIGH-WARN. Blank = none.

Read the full file on GitHub · 140 lines

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. 6d ago First seen · 140 lines · 84 tokens per session scan A 0cab7c5ff104

Subscribe to this mod's changes

claim-verifier is an agent published in the GitHub repository pedrohcgs/claude-code-my-workflow (1,563 stars, last pushed 12d ago), licensed MIT. It adds 84 tokens to every session and 2,351 once invoked, about $0.0004 per session on Opus 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.