Source Validation

Source Validation is a skill for Claude Code, Codex from zgbrenner/agentcounsel. It costs 49 tokens per session (3,430 once invoked), scanned A, original, MIT.

A claim-by-claim check of whether sources, legal authorities, quotations, dates, and factual statements in draft legal work are supported by the available materials. It classifies what is supported, uncertain, missing, or contradicted.

In plain words
What is it for?
Use it to review legal memos, contracts, research summaries, and other drafts before relying on their citations or factual claims.
Why use it?
It helps reveal citations or claims that do not actually support what the draft says. It also separates source checking from independent legal research and attorney judgment.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Good fit Use it to review legal memos, contracts, research summaries, and other drafts before relying on their citations or factual claims.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/zgbrenner/agentcounsel/source-validation
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.

Any agent
npx skills add zgbrenner/agentcounsel --skill source-validation
Clone the repo
git clone --depth 1 https://github.com/zgbrenner/agentcounsel

Made for: Claude Code, Codex.

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 Source Validation

README.md
[![agentmods](https://agentmods.dev/badge/skills/zgbrenner/agentcounsel/source-validation/github.svg)](https://agentmods.dev/skills/zgbrenner/agentcounsel/source-validation)
Your own site
<a href="https://agentmods.dev/skills/zgbrenner/agentcounsel/source-validation"><img src="https://agentmods.dev/badge/skills/zgbrenner/agentcounsel/source-validation/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.

agentmods 80×15 button for Source Validation

Your own site · 80×15
<a href="https://agentmods.dev/skills/zgbrenner/agentcounsel/source-validation"><img src="https://agentmods.dev/badge/skills/zgbrenner/agentcounsel/source-validation.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 49 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 3,430 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.

ModelPer sessionOnce invoked
Fable 5.1 $0.00049 $0.03430
Opus 5 $0.00024 $0.01715
Sonnet 5 $0.00010 $0.00686
Haiku 4.5 $0.00005 $0.00343

Measured 9d ago against content hash e69969e4703d, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-12, from the pricing page.

Security

Grade A, and why

Source Validation 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 9d 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.

skills/legal-methodology/source-validation/SKILL.md · 191 lines

How it starts

The opening of the file, as written. The whole thing — 191 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Source Validation

Purpose

This source-validation check now uses a claim-by-claim support taxonomy. For each material factual or legal claim, classify support as source-supported, source-mentioned but insufficient, unsupported, contradicted by source, legal authority required, or attorney judgment required. These classifications organize attorney review; they do not independently verify current law or certify that a legal conclusion is correct.

Apply a systematic method for checking that every cited source, authority, quotation, date, and factual claim in a draft legal work product actually exists and says what is claimed. The skill enumerates every citation and claim in the draft, classifies each by source tier using the hierarchy in core/source-and-citation-discipline.md, and marks each as verified, unverified, or unverifiable. It produces a source-by-source validation table and a list of unresolved items that must be checked before the draft is relied upon.

This skill does not and cannot substitute for independent legal research. It does not confirm whether an authority is current, controlling, or correctly interpreted. Model background knowledge is never treated as a source, even when it appears to confirm a citation. Verification means tracing a claim to a user-provided document or a source independently retrieved and confirmed in the current session — nothing else qualifies.

Use When

  • A draft legal work product contains citations, quotations, authority references, or factual claims that need to be checked before the draft is finalized or passed to attorney review.
  • A user asks to "verify the sources," "check the citations," "confirm these quotes are real," or "validate the authority in this draft."
  • The Red-Team Verifier (or any review process) has flagged specific citations or claims as unverified and a dedicated source check is needed.
  • A legal research memo, brief section, or analysis contains cases, statutes, regulations, or secondary sources that were gathered during research and need to be confirmed before attorney reliance.
  • A draft quotes from a source document (contract, filing, policy, statute) and the quotations need to be checked against the provided text.
  • The user wants a complete audit trail showing which sources in a draft are confirmed and which require additional verification.

Read the full file on GitHub · 191 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. 9d ago First seen · 191 lines · 49 tokens per session scan A e69969e4703d

Subscribe to this mod's changes

Source Validation is a skill published in the GitHub repository zgbrenner/agentcounsel (19 stars, last pushed 1mo ago), licensed MIT. It adds 49 tokens to every session and 3,430 once invoked, about $0.0002 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 2026-09-03.

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