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.
npx skills add simiancraft/simiancraft-skills --skill expo-developer-toolsgit clone --depth 1 https://github.com/simiancraft/simiancraft-skillsWrote 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.
[](https://agentmods.dev/skills/simiancraft/simiancraft-skills/expo-developer-tools)<a href="https://agentmods.dev/skills/simiancraft/simiancraft-skills/expo-developer-tools"><img src="https://agentmods.dev/badge/skills/simiancraft/simiancraft-skills/expo-developer-tools/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.
<a href="https://agentmods.dev/skills/simiancraft/simiancraft-skills/expo-developer-tools"><img src="https://agentmods.dev/badge/skills/simiancraft/simiancraft-skills/expo-developer-tools.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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 | $0.00168 | $0.00603 |
| Opus 5 | $0.00084 | $0.00302 |
| Sonnet 5 | $0.00034 | $0.00121 |
| Haiku 4.5 | $0.00017 | $0.00060 |
Grade A, and why
expo-developer-tools 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 10d 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.
What it actually says
Expo Developer Tools (shared iOS + Android)
The in-app developer tooling of an Expo / React Native app: the developer menu and the React Native DevTools it opens. This surface is a React Native feature, so it is the same on iOS and Android; the only platform-divergent part is the gesture that opens the menu. That is why this is a shared skill: ios-simulator / expo-ios-simulator and android-emulator-harness each say how to open the menu on their platform, then point here for what the items and panels mean.
This skill is the interpretive field guide: what each tool shows and how an agent reads it. It is not a driver; driving the app lives in the platform simulator/emulator skills.
Layout (in the order you meet the tools)
references/opening.md: the open-gesture matrix (the one platform-divergent thing).references/dev-menu.md: the developer-menu items, top to bottom as the app presents them.references/react-native-devtools.md: the panels behind "Open DevTools".references/rozenite.md: Rozenite plugins, the escape hatch when a built-in panel is not enough.references/techniques.md: cross-tool techniques (named after the technique), at the bottom.
Out of scope
Driving the app (tapping, typing, screenshots) -> the platform skills. Web debugging (Chrome DevTools, Playwright) -> the web skills; the web diverges from this mobile menu entirely.
What ships with it
5 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.
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.
- 10d ago First seen · 44 lines · 168 tokens per session scan A 9b637fe372e4
expo-developer-tools is a skill published in the GitHub repository simiancraft/simiancraft-skills (7 stars, last pushed 6d ago), licensed MIT. It adds 168 tokens to every session and 603 once invoked, about $0.0008 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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