A security review guide that asks structured questions about login, sessions, tokens, secrets, permissions, payments, user data, uploads, and webhooks. It can guide the design of new features or audit existing code.

Use it when planning or reviewing authentication, authorization, token handling, payment flows, webhooks, file uploads, or other features an attacker might target.

Security risks are often hidden in assumptions about who can do what and where sensitive data is stored. The questions expose those gaps before they become vulnerabilities.

security — Skill for Claude Code by Tiltely/lens

Install

Getting it into your agent

This one installs as part of its plugin. Adding the marketplace and installing the plugin brings it with everything else the plugin ships.

Claude Code

/plugin marketplace add Tiltely/lens

Claude Code

/plugin install lens

Made for: Claude Code.

Or install lens, the plugin that ships this one along with the rest of its 11 skills, 1 hook.

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/tiltely/lens/security/github.svg)](https://agentmods.dev/skills/tiltely/lens/security)

Your own site

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

Per session 68 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 1,123 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	$0.00068	$0.01123
Opus 5.5	$0.00027	$0.00449
Sonnet 5.5	$0.00014	$0.00225
Haiku 4.5	$0.00007	$0.00112

Measured 1mo ago against content hash b23b04802b62, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

security 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 1mo 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/security/SKILL.md · 106 lines

How it starts

The opening of the file, as written. The whole thing — 106 lines — stays where its author put it; the contents beside it link to each section on GitHub.

The Lens of Security

Read first: ${CLAUDE_PLUGIN_ROOT}/core/protocol.md and ${CLAUDE_PLUGIN_ROOT}/core/dossier.md.

Mode selection

Explicit argument wins ("audit" / "design").
Otherwise infer: planning new work → design; reviewing existing code → audit. Confirm your inference in one line before starting.
Audit mode: below.

Before asking anything

Read the dossier if valid — resolve it per dossier.md (the branch-scoped path). For every battery question already answered there, SKIP it and print the skip line.
Ensure stack: is known (core/stack-detection.md) — it selects Tier 2.

Question battery — design mode

Ask one at a time; follow answers per protocol.md. Append answers to the dossier.

Tier 1 — framing (always)

What is at stake here — what data or capability would an attacker want from this feature? (money, PII, account takeover, reputation)
Who are the actors? (anonymous users, authenticated users, admins, third-party services, internal jobs)

Tier 2 — stack-conditional

If nextjs-web (any flavor): 3. Where does the session/token live — httpOnly cookie, memory, or localStorage? Why there? (localStorage → follow up: XSS steals it; what mitigates that?) 4. How does a session end — expiry, refresh rotation, explicit logout? What happens to in-flight requests when it does? 5. If cookies: what is the CSRF story? (SameSite value, CSRF tokens, or "we accept the risk because…")

If nestjs-api: 6. Which layer decides AUTHORIZATION (not authentication)? Guard, service, query filter? Can a controller be added tomorrow that forgets it? 7. Are inbound webhooks signature-verified before any side effect? Replay protection? 8. Where do secrets live at runtime, and what would leak them? (env injection at deploy per Tiltely practice — confirm nothing persists in repo or droplet .env)

If expo-mobile: 9. Are tokens in SecureStore/Keychain (not AsyncStorage)? What is the story when the device is lost? 10. Do deep links / universal links accept parameters that reach privileged screens?

Read the full file on GitHub · 106 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.

1mo ago First seen · 106 lines · 68 tokens per session scan A b23b04802b62

Subscribe to this mod's changes

security is a skill published in the GitHub repository Tiltely/lens (5 stars, last pushed 2mo ago), licensed MIT. It adds 68 tokens to every session and 1,123 once invoked, about $0.0003 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.

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