How do I install the Hash Verifier skill?

Run npx skillmds@latest add rationaleyes/hash-verifier in your terminal (requires Node.js), paste this page's agent-chat prompt into Claude, Cursor, or any MCP-connected agent, or download the SKILL.md file and copy it into your agent's skills directory.

Is Hash Verifier safe to use?

This skill has not completed SkillMD's automated safety review yet. Capability flags: executes scripts. SkillMD never runs a skill's scripts for you; review the SKILL.md before installing.

Which AI agents work with Hash Verifier?

This skill is tagged as working with Claude Code, Claude.ai, OpenAI Codex. SKILL.md is an open format, so most agents that read a skills directory can load it too.

Is Hash Verifier free to use?

Yes. Installing skills from SkillMD is free, and the skill stays under its author's original license.

Who published Hash Verifier?

RationalEyes (@rationaleyes) published this skill. Their other Agent Skills are listed on their SkillMD profile.

Hash Verifier by rationaleyes — Agent Skill

Name: Hash Verifier
Rating: 4.2 (5 reviews)
Author: RationalEyes

Hash Verifier

Skill integrity verifier. Checks that all installed Claude Skills match their known-good cryptographic hashes and alerts on any modifications, new unexpected files, or missing files. Use this skill to detect skill tampering, rug-pull attacks, or unauthorized post-install changes. Invoke with: "verify skill integrity", "check skill hashes", "run hash verification", or "detect skill tampering".

RationalEyes Updated Sep 22, 2026

File contents

Hash Verifier Skill

This skill detects unauthorized modifications to installed Claude Skills by comparing current file hashes against a known-good manifest (hashes.json). It provides cryptographic integrity verification to detect unauthorized modifications to installed skills.

What This Skill Does

On first run, the verifier creates a hashes.json manifest capturing SHA-256 hashes of every file in every skill directory. On subsequent runs, it compares current state against the manifest and reports:

Modified files — existing files whose content has changed
New files — files added after the manifest was created
Deleted files — files present in the manifest but no longer on disk

This directly addresses the "rug-pull" attack pattern, where a skill appears benign during initial review but is silently modified later to introduce malicious behavior. It also catches supply-chain poisoning where a trusted skill repository pushes an update containing injected content.

Invocation

To verify all installed skills against the stored manifest:

Please run the hash verifier to check skill integrity.

To create or refresh the manifest (do this immediately after installing a skill you have manually reviewed):

Please generate a new skill hash manifest for the current skills.

First-Time Setup

Install and review all skills you want to trust.
Run: python3 scripts/generate_manifest.py --paths ~/.claude/skills .claude/skills
Store hashes.json in a trusted location (or commit it to version control).
Run the verifier before each session: python3 scripts/verify_hashes.py

Interpreting Results

PASS: All files match the manifest. No changes detected.
MODIFIED: One or more files have changed since the manifest was created. This could be a legitimate update OR tampering. Compare with the upstream source to determine which.
NEW FILE: A file was added that was not in the manifest. Inspect it before continuing.
MISSING: A file in the manifest is gone. This may indicate a partial update or deletion attack.

Manifest Storage

The manifest is stored at the location specified by --manifest (default: ~/.claude/skill-hashes.json). For maximum security, store it in a location that is:

Version-controlled (git tracks changes with attribution)
Read-only for the Claude process during normal operation
Backed up separately from the skill directories themselves

Running Manually

# Generate initial manifest
python3 ~/.claude/skills/hash-verifier/scripts/generate_manifest.py \
    --paths ~/.claude/skills \
    --manifest ~/.claude/skill-hashes.json

# Verify on subsequent runs
python3 ~/.claude/skills/hash-verifier/scripts/verify_hashes.py \
    --paths ~/.claude/skills \
    --manifest ~/.claude/skill-hashes.json

Part of the Claude Skills Defense Suite.

Execution

Run hash verification against all discoverable skill locations:

python3 "$(dirname "$0")/scripts/verify_hashes.py" \
    --paths ~/.claude/skills ./.claude/skills \
    --manifest ~/.claude/skill-hashes.json

---name: hash-verifierdescription: Skill integrity verifier. Checks that all installed Claude Skills match their known-good cryptographic hashes and alerts on any modifications, new unexpected files, or missing files. Use this skill to detect skill tampering, rug-pull attacks, or unauthorized post-install changes. Invoke with: "verify skill integrity", "check skill hashes", "run hash verification", or "detect skill tampering".---# Hash Verifier SkillThis skill detects unauthorized modifications to installed Claude Skills bycomparing current file hashes against a known-good manifest (`hashes.json`).It provides cryptographic integrity verification to detect unauthorizedmodifications to installed skills.## What This Skill DoesOn first run, the verifier creates a `hashes.json` manifest capturing SHA-256hashes of every file in every skill directory. On subsequent runs, it comparescurrent state against the manifest and reports:- **Modified files** — existing files whose content has changed- **New files** — files added after the manifest was created- **Deleted files** — files present in the manifest but no longer on diskThis directly addresses the "rug-pull" attack pattern, where a skill appearsbenign during initial review but is silently modified later to introducemalicious behavior. It also catches supply-chain poisoning where a trustedskill repository pushes an update containing injected content.## InvocationTo verify all installed skills against the stored manifest:```Please run the hash verifier to check skill integrity.```To create or refresh the manifest (do this immediately after installinga skill you have manually reviewed):```Please generate a new skill hash manifest for the current skills.```## First-Time Setup1. Install and review all skills you want to trust.2. Run: `python3 scripts/generate_manifest.py --paths ~/.claude/skills .claude/skills`3. Store `hashes.json` in a trusted location (or commit it to version control).4. Run the verifier before each session: `python3 scripts/verify_hashes.py`## Interpreting Results- **PASS**: All files match the manifest. No changes detected.- **MODIFIED**: One or more files have changed since the manifest was created. This could be a legitimate update OR tampering. Compare with the upstream source to determine which.- **NEW FILE**: A file was added that was not in the manifest. Inspect it before continuing.- **MISSING**: A file in the manifest is gone. This may indicate a partial update or deletion attack.## Manifest StorageThe manifest is stored at the location specified by `--manifest` (default:`~/.claude/skill-hashes.json`). For maximum security, store it in a locationthat is:- Version-controlled (git tracks changes with attribution)- Read-only for the Claude process during normal operation- Backed up separately from the skill directories themselves## Running Manually```bash# Generate initial manifestpython3 ~/.claude/skills/hash-verifier/scripts/generate_manifest.py \ --paths ~/.claude/skills \ --manifest ~/.claude/skill-hashes.json# Verify on subsequent runspython3 ~/.claude/skills/hash-verifier/scripts/verify_hashes.py \ --paths ~/.claude/skills \ --manifest ~/.claude/skill-hashes.json```---*Part of the Claude Skills Defense Suite.*## ExecutionRun hash verification against all discoverable skill locations:```bashpython3 "$(dirname "$0")/scripts/verify_hashes.py" \ --paths ~/.claude/skills ./.claude/skills \ --manifest ~/.claude/skill-hashes.json```

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