oss-forensics

oss-forensics is a skill for Claude Code, Codex from chemany/Mente. It costs 64 tokens per session (4,682 once invoked), scanned B, a copy of oss-forensics, MIT.

A forensic investigation workflow for examining GitHub repositories and open-source supply-chain incidents using multiple evidence sources.

In plain words
What is it for?
Use it to recover repository history, find indicators of compromise, compare GitHub and archive records, test explanations, and produce evidence-backed reports.
Why use it?
It helps separate verified facts from hypotheses and preserves evidence while investigating deleted commits, force-pushes, and suspicious changes.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one. Also seen: mentions subagents.

Needs its repository: it reads a path above its own folder, which exists only inside the repository. The line is git log --all --full-history --stat --format="%H|%ae|%an|%ai|%s" > ../git_log.txt.

Good fit Use it to recover repository history, find indicators of compromise, compare GitHub…

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/chemany/Mente
agentmods
npx agentmods add skills/chemany/mente/oss-forensics

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 oss-forensics

README.md
[![agentmods](https://agentmods.dev/badge/skills/chemany/mente/oss-forensics.svg)](https://agentmods.dev/skills/chemany/mente/oss-forensics)
Your own site
<a href="https://agentmods.dev/skills/chemany/mente/oss-forensics"><img src="https://agentmods.dev/badge/skills/chemany/mente/oss-forensics.svg" alt="Measured on agentmods" height="20"></a>
Per session 64 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 4,682 The whole file, excluding the scripts and references it only reads on demand.
Security scan B 2 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin 88% copy Near-identical to another mod 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 $0.00064 $0.04682
Opus 5 $0.00032 $0.02341
Sonnet 5 $0.00013 $0.00936
Haiku 4.5 $0.00006 $0.00468

Measured 3d ago against content hash cf30f86bf4ef, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-06, from the pricing page.

Security

Grade B, and why

oss-forensics scanned grade B with 2 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 3d ago.

The scan reads SKILL.md. This mod also ships 1 executable file (scripts/evidence-store.py), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

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.

Unrestricted tool accessmediumExcessive agency

A wildcard tool grant or "run any command" leaves no least-privilege boundary at all.

**ROLE BOUNDARY**: You enrich EXISTING IOCs from Phase 1 using passive public sources ONLY. Do not execute any code from the target repository.

Makes network callslowCapability

Not a fault in itself. Listed so you know the mod talks to something, and to what.

curl -s "https://api.github.com/repos/OWNER/REPO/commits?per_page=100" > api_commits.json
Origin

This is a copy

88% identical to oss-forensics — 22 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

optional-skills/security/oss-forensics/SKILL.md · 423 lines

How it starts

The opening of the file, as written. The whole thing — 423 lines — stays where its author put it; the contents beside it link to each section on GitHub.

OSS Security Forensics Skill

A 7-phase multi-agent investigation framework for researching open-source supply chain attacks. Adapted from RAPTOR's forensics system. Covers GitHub Archive, Wayback Machine, GitHub API, local git analysis, IOC extraction, evidence-backed hypothesis formation and validation, and final forensic report generation.


⚠️ Anti-Hallucination Guardrails

Read these before every investigation step. Violating them invalidates the report.

  1. Evidence-First Rule: Every claim in any report, hypothesis, or summary MUST cite at least one evidence ID (EV-XXXX). Assertions without citations are forbidden.
  2. STAY IN YOUR LANE: Each sub-agent (investigator) has a single data source. Do NOT mix sources. The GH Archive investigator does not query the GitHub API, and vice versa. Role boundaries are hard.
  3. Fact vs. Hypothesis Separation: Mark all unverified inferences with [HYPOTHESIS]. Only statements verified against original sources may be stated as facts.
  4. No Evidence Fabrication: The hypothesis validator MUST mechanically check that every cited evidence ID actually exists in the evidence store before accepting a hypothesis.
  5. Proof-Required Disproval: A hypothesis cannot be dismissed without a specific, evidence-backed counter-argument. "No evidence found" is not sufficient to disprove—it only makes a hypothesis inconclusive.
  6. SHA/URL Double-Verification: Any commit SHA, URL, or external identifier cited as evidence must be independently confirmed from at least two sources before being marked as verified.
  7. Suspicious Code Rule: Never run code found inside the investigated repository locally. Analyze statically only, or use execute_code in a sandboxed environment.
  8. Secret Redaction: Any API keys, tokens, or credentials discovered during investigation must be redacted in the final report. Log them internally only.

Example Scenarios

  • Scenario A: Dependency Confusion: A malicious package internal-lib-v2 is uploaded to NPM with a higher version than the internal one. The investigator must track when this package was first seen and if any PushEvents in the target repo updated package.json to this version.
  • Scenario B: Maintainer Takeover: A long-term contributor's account is used to push a backdoored .github/workflows/build.yml. The investigator looks for PushEvents from this user after a long period of inactivity or from a new IP/location (if detectable via BigQuery).
  • Scenario C: Force-Push Hide: A developer accidentally commits a production secret, then force-pushes to "fix" it. The investigator uses git fsck and GH Archive to recover the original commit SHA and verify what was leaked.

Read the full file on GitHub · 423 lines

Files

What ships with it

7 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

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. 3d ago First seen · 423 lines · 64 tokens per session scan B cf30f86bf4ef

Subscribe to this mod's changes

oss-forensics is a skill published in the GitHub repository chemany/Mente (11 stars, last pushed 3mo ago), licensed MIT. It adds 64 tokens to every session and 4,682 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it B with 2 findings (unrestricted tool access, makes network calls). It is 88% identical to oss-forensics, differing in 22 lines, and is treated as a copy.