expo/skills is a collection of instructions that help AI coding agents build, deploy, upgrade, and debug Expo applications. Developers use these skills when working with Expo, EAS, React Native, iOS, and Android workflows.
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 expo/skills --skill expo-migrate-modulegit clone --depth 1 https://github.com/expo/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/expo/skills/expo-migrate-module)<a href="https://agentmods.dev/skills/expo/skills/expo-migrate-module"><img src="https://agentmods.dev/badge/skills/expo/skills/expo-migrate-module/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/expo/skills/expo-migrate-module"><img src="https://agentmods.dev/badge/skills/expo/skills/expo-migrate-module.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- Socket pass
- Snyk pass
- NVIDIA SkillSpector warn
SkillSpector: 2 findings, up to medium
These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →
- medium Excessive Agency · line 77 Skill enables autonomous high-impact decisions without human-in-the-loop verification. Critical operations (destructive commands, financial transactions, data deletion) should require explicit user confirmation.Fix: Add human-in-the-loop confirmation for destructive, irreversible, or high-impact operations. Never auto-execute commands that modify files, send data, or alter system state.
- medium MCP Rug Pull · line 110 npx commands without a version suffix (e.g. @1.0.0) create a rug-pull risk if the upstream server is compromised and publishes a malicious update.Fix: Pin the version: npx @scope/[email protected]
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 | $0.00103 | $0.01668 |
| Opus 5 | $0.00051 | $0.00834 |
| Sonnet 5 | $0.00021 | $0.00334 |
| Haiku 4.5 | $0.00010 | $0.00167 |
Grade A, and why
expo-migrate-module 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 9d 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.
How it starts
The opening of the file, as written. The whole thing — 114 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Migrate an Expo Module
Migrate the Swift side of an existing Expo module without changing its observable JS API. Treat the current JS/TypeScript surface and tests as the compatibility contract. Leave Kotlin on the 1.0 DSL unless the user explicitly expands the task.
Prerequisite
The Expo Modules API 2.0 macros require expo 57.0.7 or newer. Before editing, check the target's installed version (expo in package.json/lockfile, or npm ls expo). If it is older, stop and tell the user to upgrade first; do not attempt the migration against an unsupported version. This is a floor, not a guarantee: the exact macro and core surface still varies within 57.x, so step 2 must still verify the checked-out source.
References
- Read
references/migration-map.mdbefore changing source. It contains the 1.0-to-2.0 mappings, semantic traps, and mixed-mode rules. - Read
references/example.mdfor a full before/after walkthrough of one module through mixed mode to a complete migration. Consult it when you need to see how the per-member rules compose. - Read
references/compatibility.mdwhen the checked-outexpo-modules-coreversion or branch is not known to support every requested macro. It explains how to verify the actual compile-time and runtime surface instead of guessing from an SDK number.
Workflow
1. Establish the contract
Inspect repository instructions and the worktree before editing. Locate the Swift module classes, records, shared objects, native views, JS/TS bindings, tests, example app, podspec, and installed or checked-out expo-modules-core.
Inventory every exported item before rewriting it:
- module and shared-object JS names
- function names, arity, labels, defaults, nullability, sync/async behavior, errors, and queue semantics
- property names, mutability, and constant caching behavior
- event wire names and payload shapes
- record field names, defaults, requiredness, and nullability
- shared-object constructors and instance/static placement
- lifecycle hooks and views
What ships with it
4 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.
- 9d ago First seen · 114 lines · 103 tokens per session scan A d19060a823b3
expo-migrate-module is a skill published in the GitHub repository expo/skills (2,507 stars, last pushed today), licensed MIT. It adds 103 tokens to every session and 1,668 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 2026-08-30.
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