expo-examples

Files (3)

• SKILL.md
• openai.yaml · agents/
• catalog.md · references/

SKILL.md (first lines)

# Expo Examples

[expo/examples](https://github.com/expo/examples) is Expo's official library of ~70 **integration examples** — directories named `with-<library>` (e.g. `with-stripe`, `with-maps`), each built around **one** library or service. These are not full apps: they're **managed** projects (no `ios/`/`android/` dirs — native setup is via config plugins), and the typical one is a **single screen of ~100–200 lines**. Mine them for the canonical integration *pattern* — the dependency set, `app.json` config plugins, and minimal wiring Expo maintains against the current SDK — and adapt that into the user's app. Don't expect to lift an application architecture from them.

Reach for an example before hand-rolling an integration. (Kinds — full-stack, showcases, starters — are noted in `./references/catalog.md`.)

## Two modes

1. **Inspiration / adapt** (most common) — the user already has a project. Find the matching example, read its key files, and apply the *pattern* to their code.
2. **Scaffold** — greenfield. Start a fresh project directly from the example.

## Workflow

### 1. Find the right example

Map the user's need to an example name (e.g. payments → `with-stripe`, auth → `with-clerk`). `./references/catalog.md` is a categorized snapshot for fast triage — but it drifts, so confirm against the live list:

```bash
# Live example names:
gh api repos/expo/examples/contents --jq '.[] | select(.type=="dir" and (.name|startswith(".")|not)) | .name'
# Aliases (renamed) + deprecated (dead/moved) examples — check before recommending:
gh api repos/expo/examples/contents/meta.json --jq '.content' | base64 -d
```

`meta.json` is the source of truth for what's renamed or dead (deprecated examples are removed from the repo tree but still listed here, each with a `message`). If an example is in its `deprecated` map, don't recommend it — follow the `message` to the modern path. If it's in `aliases`, use the `destination`.

### 2a. Inspiration mode — study without touching the user's project

The common case: the user already has an app and wants to see how Expo does something. Read the example as **reference** and apply the patterns by hand — never scaffold an example on top of their project.

**First, list the whole example in one call.** Integration code is often nested (e.g. Stripe's server routes live in `app/api/`), so a one-level listing misses the important files:

```bash
gh api 'repos/expo/examples/git/trees/master?recursive=1' \
  --jq '.tree[].path | select(startswith("with-stripe/"))'
```

**Then read the high-signal files first:** `README.md` (setup) → `package.json` (deps) → `app.json` (config plugins / permissions) → the integration code the manifest revealed → `.env` (required secrets). Per file:

```bash
gh api repos/expo/examples/contents/with-stripe/utils/stripe-server.ts --jq '.content' | base64 -d
# No gh? Raw URL (branch is master):
curl -s https://raw.githubusercontent.com/expo/examples/master/with-stripe/utils/stripe-server.ts
```

**Reading more than a couple of files?** Many integrations are spread across server routes, a client provider, and config (Stripe is). Skip the per-file calls — pull the whole example into a **throwaway/gitignored dir (not the user's project)** and read it freely with Grep/Read, then apply by hand:

```bash
npx degit expo/examples/with-stripe /tmp/expo-ref/with-stripe   # clean copy, no git history
# fallback without degit (sparse-checkout, no full ~64 MB clone):
git clone --depth 1 --filter=blob:none --sparse https://github.com/expo/examples.git /tmp/expo-ref/examples \
  && (cd /tmp/expo-ref/examples && git sparse-checkout set with-stripe)
```

Read from there with Grep/Read; delete the scratch dir when done.

### 2b. Scaffold mode — new project from an example

```bash
npx create-expo --example with-stripe   # short form:  npx create-expo -e with-stripe
bun create expo --example with-stripe    # with bun
```

### 3. Adapt into the user's app — non-destructively (critical)

When the user already has an app, **add only what the example introduces; never overwrite their setup.**

- **Version-align — don't copy pinned versions.** Examples track the **latest** SDK, so their `package.json` pins won't match an older project. Add only the *missing* deps with `npx expo install <pkg>` (it resolves SDK-correct versions) instead of copying exact versions.
- **Merge config, don't replace it.** Add only the `app.json`/`app.config.*` plugins and permissions the example introduces that the user lacks — keep their existing config block intact.
- **Port the integration code.**
- **Recreate env vars** from the example's `.env` shape — it holds placeholders, never working secrets.

**Done when** the integration code is ported and every dependency, config plugin, permission, and env var it needs is accounted for in the user's app — not when it merely *looks* wired up.

## Gotchas

- **Default branch is `master`,** not `main` (matters for raw URLs and sparse checkout).
- **Single-click deploy.** Every example has a launch URL: `https://launch.expo.dev/?github=https://github.com/expo/examples/tree/master/<example>`.

## Related skills

- Native UI components (@expo/ui package) → `expo-ui`
- Styling and native-feeling screens → `expo-native-ui`
- Navigation and routing → `expo-router`
- Authoring a native module → `expo-module`
- Upgrade the SDK before adopting a latest-SDK example → `expo-upgrade`

## References

- `./references/catalog.md` — categorized snapshot of the example library for fast triage.

## Submitting Feedback
If you encounter errors, misleading or outdated information in this skill, report it so Expo can improve:
```bash
npx --yes @expo/agent-cli@latest feedback --category skills --subject "expo-examples" "<actionable feedback>"
```
Only submit when you have something specific and actionable to report. Include as much relevant context as possible.
If an agent repeatedly fails at an Expo task or the user has to step in, submit a brief report of the task, expected result, and what went wrong using `--category evals` and the relevant Expo package or command as `--subject`.

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