security-mobile

security-mobile is a skill for Claude Code, Codex from kouroshez/coding-os. It costs 105 tokens per session (3,875 once invoked), scanned A, original, Apache-2.0.

A mobile-app security guide for React Native apps on iOS and Android, based on OWASP MASVS, a standard for checking mobile security. It covers protections for stored secrets, network connections, login actions, links, and native app interfaces.

In plain words
What is it for?
Use it when storing tokens, choosing certificate pinning, adding biometric checks or root/jailbreak detection, protecting deep links, reviewing native modules and third-party SDK permissions, or preparing an app-store submission.
Why use it?
It helps prevent common mobile risks such as stolen sessions after a lost phone, phishing, unsafe logs, and insecure app settings. It gives developers a way to review security before releasing an app.

Skill for Claude CodeCodex

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.

agentmods
npx agentmods add skills/kouroshez/coding-os/security-mobile
Any agent
npx skills add kouroshez/coding-os --skill security-mobile
Clone the repo
git clone --depth 1 https://github.com/kouroshez/coding-os

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 security-mobile

README.md
[![agentmods](https://agentmods.dev/badge/skills/kouroshez/coding-os/security-mobile.svg)](https://agentmods.dev/skills/kouroshez/coding-os/security-mobile)
Your own site
<a href="https://agentmods.dev/skills/kouroshez/coding-os/security-mobile"><img src="https://agentmods.dev/badge/skills/kouroshez/coding-os/security-mobile.svg" alt="Measured on agentmods" height="20"></a>
Per session 105 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 3,875 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
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 $0.00105 $0.03875
Opus 5 $0.00053 $0.01937
Sonnet 5 $0.00021 $0.00775
Haiku 4.5 $0.00011 $0.00387

Measured 2d ago against content hash 52e4e1073f44, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

security-mobile 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 2d 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.

src/core/skills/security-mobile/SKILL.md · 395 lines

How it starts

The opening of the file, as written. The whole thing — 395 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Mobile Security — MASVS-Aligned Patterns

For React Native bare apps targeting iOS 16+ and Android 14+. Aligned with OWASP MASVS v2.0 (the 2024 update). Targets the realistic threat model of a consumer mobile app — not a banking app under nation-state attack, but a real app with payments, PII, and user accounts where a breach hurts.

When to Use This Skill

  • Storing tokens / credentials / secrets on the device.
  • Choosing certificate pinning strategy (or whether to pin at all).
  • Adding root/jailbreak detection.
  • Designing biometric prompts for sensitive ops.
  • Reviewing native-module surface area.
  • Planning what NOT to log/screenshot/leak.
  • Auditing third-party SDKs for risky permissions.
  • Pre-flight before App Store / Play Store submission.

For server-side / API-side security, see security-web. For auth flows specifically, see auth-patterns.

The Threat Model — Realistic Priorities

Mobile threat ranking for a consumer app (high → low priority):

  1. Lost device, no biometric / weak passcode → app session compromised. Mitigation: biometric gate on launch + on sensitive ops; idle timeout; remote logout.
  2. Phishing → credential theft → standard password takeover. Mitigation: passkeys (phishing-proof), magic-link with same-device check.
  3. Malicious / compromised library on the client → can read in-memory state. Mitigation: minimize deps, audit weekly, prefer first-party libs.
  4. Insecure data at rest → device backup or filesystem inspection leaks tokens / PII. Mitigation: Keychain/Keystore for all secrets, encrypted DB for sensitive PII.
  5. MITM on hostile networks → tampered responses. Mitigation: TLS + (selectively) certificate pinning; refuse insecure connections.
  6. Reverse engineering for cloning / cheating → app logic exposed. Mitigation: server-authoritative gameplay, minimal client trust, R8/ProGuard for Android.
  7. Replay of intercepted requests → repeated actions. Mitigation: TLS, idempotency keys (api-design skill).
  8. Side-channel via screenshots / app switcher → sensitive data leaks via screenshots, voice-over, etc. Mitigation: redact sensitive views in inactive state.

Read the full file on GitHub · 395 lines

Files

What ships with it

2 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. 2d ago First seen · 395 lines · 105 tokens per session scan A 52e4e1073f44

Subscribe to this mod's changes

security-mobile is a skill published in the GitHub repository kouroshez/coding-os (6 stars, last pushed 2d ago), licensed Apache-2.0. It adds 105 tokens to every session and 3,875 once invoked, about $0.0005 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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