cross-validation

cross-validation is a skill for Claude Code, Codex from paruff/uFawkesAI. It costs 2 tokens per session (1,004 once invoked), scanned A, original, MIT.

A consistency-checking skill that compares specifications, designs, code builds, and tests across a software development workflow.

In plain words
What is it for?
Use it to verify specification-to-build coverage, specification-to-test coverage, design compliance, and whether tests can run successfully.
Why use it?
It catches cases where implementation misses a requirement, tests do not cover an acceptance condition, or code contradicts the approved design.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one. Also seen: installed under .agents/ (shared by several agents).

Needs its repository: it runs a file that does not travel with it, so clone the repository first. The line is bash .agents/assertions/cross-validation-runner.sh \.

Good fit Use it to verify specification-to-build coverage, specification-to-test coverage, design compliance, and whether tests can run successfully.

Compare 6 skills from other repositories ↓
Install

Getting it into your agent

It runs from inside its repository, so the clone comes first — what it calls does not travel with the file alone.

Clone the repo
git clone --depth 1 https://github.com/paruff/uFawkesAI
agentmods
npx agentmods add skills/paruff/ufawkesai/cross-validation

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 cross-validation

README.md
[![agentmods](https://agentmods.dev/badge/skills/paruff/ufawkesai/cross-validation.svg)](https://agentmods.dev/skills/paruff/ufawkesai/cross-validation)
Your own site
<a href="https://agentmods.dev/skills/paruff/ufawkesai/cross-validation"><img src="https://agentmods.dev/badge/skills/paruff/ufawkesai/cross-validation.svg" alt="Measured on agentmods" height="20"></a>
Per session 2 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,004 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 $0.00002 $0.01004
Opus 5 $0.00001 $0.00502
Sonnet 5 $0.00000 $0.00201
Haiku 4.5 $0.00000 $0.00100

Measured 7d ago against content hash 51645d498496, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, from the pricing page.

Security

Grade A, and why

cross-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 7d 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.

.agents/skills/cross-validation/SKILL.md · 143 lines

How it starts

The opening of the file, as written. The whole thing — 143 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Cross-Validation Skill

The cross-validation skill enables the cross-validation agent to validate consistency between agent outputs and their sources. It provides the rules registry and validation runner that check pairwise consistency across the agent pipeline.

Skill Purpose

This skill implements cross-validation of the uFawkesAI agent pipeline. It validates that:

  1. Spec ↔ Build Consistency — All spec requirements are addressed in build output
  2. Spec ↔ Test Coverage — All spec acceptance criteria have corresponding tests
  3. Design ↔ Build Compliance — Build follows architecture decisions from design
  4. Test ↔ Test-Execution Viability — All tests are viable and passing in test-execution

Note: The review agent now consolidates review, build-review, and security capabilities. Review findings are validated as part of the build process.

How to Load

Load this skill when you need to validate cross-agent consistency:

Load `.agents/skills/cross-validation/SKILL.md`

Validation Rules Registry

The skill uses .agents/registry/cross-validation.yaml as the rules registry. This file defines:

  • Which agent pairs need validation
  • What specific consistency checks to perform
  • How to extract and compare information from agent reports

Validation Runner

The skill provides .agents/assertions/cross-validation-runner.sh which:

  1. Reads the cross-validation rules from the registry
  2. Extracts relevant sections from agent reports (spec, design, build, test, test-execution, review)
  3. Applies each validation rule
  4. Generates a unified cross-validation report
  5. Returns PASS if all rules pass, FAIL otherwise

Usage Examples

Loading the Skill

Load `.agents/skills/cross-validation/SKILL.md`

Running Validation

bash .agents/assertions/cross-validation-runner.sh \
  --spec-report path/to/spec-report.md \
  --design-report path/to/design-report.md \
  --build-report path/to/build-report.md \
  --test-report path/to/test-report.md \
  --test-execution-report path/to/test-execution-report.md \
  --review-report path/to/review-report.md

Read the full file on GitHub · 143 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. 7d ago First seen · 143 lines · 2 tokens per session scan A 51645d498496

Subscribe to this mod's changes

cross-validation is a skill published in the GitHub repository paruff/uFawkesAI (2 stars, last pushed 15d ago), licensed MIT. It adds 2 tokens to every session and 1,004 once invoked, about $0.0000 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 2026-08-31.

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