A session-inspection tool that records which Codex instructions and skills were loaded, then displays that information in a browser viewer. It is launched through the /skillscope command.

Capturing session details, identifying loaded or merely discovered skill files, generating a skillscope.capture.json bundle, and opening the SkillScope coverage view.

It helps you see what guidance affected a Codex session and whether the expected instruction files were actually used.

skillscope — Skill for Claude Code and Codex by mathieu0905/skilllens

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 mathieu0905/skilllens --skill skillscope

Clone the repo

git clone --depth 1 https://github.com/mathieu0905/skilllens

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.

README.md

[![agentmods](https://agentmods.dev/badge/skills/mathieu0905/skilllens/skillscope/github.svg)](https://agentmods.dev/skills/mathieu0905/skilllens/skillscope)

Your own site

<a href="https://agentmods.dev/skills/mathieu0905/skilllens/skillscope"><img src="https://agentmods.dev/badge/skills/mathieu0905/skilllens/skillscope/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.

Your own site · 80×15

<a href="https://agentmods.dev/skills/mathieu0905/skilllens/skillscope"><img src="https://agentmods.dev/badge/skills/mathieu0905/skilllens/skillscope.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 31 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 633 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.

Model	Per session	Once invoked
Fable 5.1	$0.00031	$0.00633
Opus 5.5	$0.00012	$0.00253
Sonnet 5.5	$0.00006	$0.00127
Haiku 4.5	$0.00003	$0.00063

Measured 2mo ago against content hash 0009ac8d9f69, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

skillscope 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 2mo 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.

integrations/skillscope-codex/skills/skillscope/SKILL.md · 70 lines

How it starts

The opening of the file, as written. The whole thing — 70 lines — stays where its author put it; the contents beside it link to each section on GitHub.

SkillScope For Codex

Use this skill when the user asks to run /skillscope, capture Codex skill coverage, inspect which skill instructions were followed, or open the SkillScope browser view for the current Codex session.

User Entry

The user entry is the Codex slash prompt:

/skillscope

That slash prompt should call the repository launcher:

npm --prefix <skillscope-repo> run codex -- --project-cwd "$(pwd)"

Capture Contract

Identify the Codex rollout JSONL for the active or requested session.
Prefer the session whose session_meta.payload.cwd matches the current project.
Identify SKILL.md, CLAUDE.md, AGENTS.md, or *.skill.md files that the trace proves were read or used.
If no loaded skill can be proven from tool traces, fall back to project skill discovery and mark those files as discovered rather than confirmed loaded.
Preserve task prompt, result metadata, model, cwd, agent version, session ID, and inferred session segments when available.
Generate a skillscope.capture.json bundle before running analysis.
Run SkillScope analysis with the generated bundle, not with separately guessed skill and trace files.
Open the browser viewer after capture unless SKILLSCOPE_NO_OPEN=1 or --no-open is set.

Commands For Codex To Run

From any user project, the slash prompt should run:

npm --prefix <skillscope-repo> run codex -- --project-cwd "$(pwd)"

If the active session cannot be inferred, ask for an explicit trace path and run:

npm --prefix <skillscope-repo> run codex -- \
  --project-cwd "$(pwd)" \
  --trace <codex-rollout.jsonl>

Optional precise inputs:

npm --prefix <skillscope-repo> run codex -- \
  --project-cwd "$(pwd)" \
  --trace <codex-rollout.jsonl> \
  --skill <path-to-SKILL.md> \
  --task <optional-task.md> \
  --result <optional-result.json>

Analysis Boundary

The current default analyzer is heuristic: constraint extraction, trace normalization, keyword overlap, and structured tool signals.
Do not describe heuristic findings as AI judgment.
The launcher is responsible for provenance: which session and which skill artifacts are being compared.
The browser "启动分析" action can run an agent-native judge after the user selects a skill-use window.
Agent judge runs must follow skills/skillscope-analyzer/SKILL.md: judge only the provided local artifacts and cite concrete trace event IDs.
Do not call a separate model API for SkillScope judge. Codex captures should use Codex; Claude Code captures should use Claude Code.

Read the full file on GitHub · 70 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.

2mo ago First seen · 70 lines · 31 tokens per session scan A 0009ac8d9f69

Subscribe to this mod's changes

skillscope is a skill published in the GitHub repository mathieu0905/skilllens (2 stars, last pushed 4mo ago), licensed MIT. It adds 31 tokens to every session and 633 once invoked, about $0.0001 per session on Opus 5.5. 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.

Building agents

skillscope next to 6 skills from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
skillscopemathieu0905/skilllens	Skill	2	4mo ago	MIT	A	31	Claude Code, Codex
imagegenopenai/codex	Skill	133k	yesterday	Apache-2.0	A	113	Codex
playwright-climicrosoft/playwright	Skill	99k	yesterday	Apache-2.0	A	19	Claude Code
local-ai-agentsmicrosoft/ai-agents-for-beginners	Skill	79k	4d ago	MIT	A	200	Claude Code, Codex
systematic-debuggingobra/superpowers	Skill	313k	3d ago	MIT	A	21	Claude Code
next-cache-components-adoptionvercel/next.js	Skill	143k	yesterday	MIT	A	95	Claude Code
next-partial-prefetching-adoptionvercel/next.js	Skill	143k	yesterday	MIT	A	103	Claude Code