mobile-developer

A set of guidelines for building mobile apps with React Native and Expo, tools for creating cross-platform iOS and Android applications.

In plain words
What is it for?
Use it to build screens and navigation, connect native features, add push notifications, support offline use, and handle mobile-specific user interfaces.
Why use it?
It helps keep mobile screens, navigation, authentication, and platform-specific behavior consistent with the project's existing structure.

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/mtnyilmaz/agents/mobile-developer
Any agent
npx skills add mtnyilmaz/agents --skill mobile-developer
Clone the repo
git clone --depth 1 https://github.com/mtnyilmaz/agents

Made for: Claude Code, Codex.

Per session 53 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,200 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 $0.00053 $0.01200
Opus 5 $0.00026 $0.00600
Sonnet 5 $0.00011 $0.00240
Haiku 4.5 $0.00005 $0.00120

Measured 2d ago against content hash b8133fcf32b1, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

mobile-developer 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.

.agents/skills/mobile-developer/SKILL.md · 140 lines

How it starts

The opening of the file, as written. The whole thing — 140 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Mobile Developer

Expert in building production-grade mobile apps with React Native and Expo.

Reference Documentation

Read these docs when needed:

  • .agents/rules/design-system.md — Tokens, component layering, loading/empty/error UX (bundled for Expo installs)
  • .agents/rules/native-ux-design.md — Safe area, touch targets, platform patterns, parity with web
  • .agents/rules/frontend-patterns.md — Mobile sections (Expo Router, components, state)
  • .agents/rules/project-architecture.md — See apps/mobile section
  • .agents/rules/project-architecture.md — tRPC mobile client, shared Zod schemas
  • .agents/rules/auth-patterns.md — JWT flow for mobile, SecureStore token management
  • .agents/rules/project-architecture.md — Package versions

Expo Official Guides (References)

Official detailed instructions from the Expo team. Read these for specialized topics:

  • references/expo/building-native-ui/ — Native view creation
  • references/expo/expo-api-routes/ — API routes in Expo
  • references/expo/expo-cicd-workflows/ — CI/CD via EAS
  • references/expo/expo-deployment/ — Apple/Google stores deploy
  • references/expo/expo-tailwind-setup/ — NativeWind & Tailwind setup
  • references/expo/native-data-fetching/ — Fetching on native
  • references/expo/upgrading-expo/ — Expo SDK upgrades

App Structure (Expo Router)

apps/mobile/
  app/
    _layout.tsx          ← root layout (providers, fonts, theme)
    (auth)/
      _layout.tsx
      login.tsx
      register.tsx
    (tabs)/
      _layout.tsx        ← bottom tab navigator
      index.tsx          ← home tab
      profile.tsx
    (modals)/
      confirm.tsx
  components/            ← mobile-specific components
  hooks/                 ← mobile hooks (useCamera, useLocation, etc.)
  lib/
    secure-store.ts      ← Token CRUD (single source of truth)
    api-client.ts        ← REST client with token interceptor + 401 handler
    trpc.ts              ← tRPC client (reads from same tokenStore)
  services/              ← Endpoint functions (never handle tokens)
  store/                 ← Zustand stores

Read the full file on GitHub · 140 lines

Files

What ships with it

1 file 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 · 140 lines · 53 tokens per session scan A b8133fcf32b1

Subscribe to this mod's changes

mobile-developer is a skill published in the GitHub repository mtnyilmaz/agents (6 stars, last pushed 3mo ago), licensed MIT. It adds 53 tokens to every session and 1,200 once invoked, about $0.0003 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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