expo

A set of coding rules for Expo projects, which are applications built with React Native. It covers project settings, development, builds, updates, permissions, navigation, and publishing.

In plain words
What is it for?
Use it when editing Expo or React Native files such as TypeScript, JavaScript, and app configuration. It guides work on app setup, development builds, production builds, updates, and store submissions.
Why use it?
Mobile projects can become inconsistent when configuration, builds, and release settings are handled differently. These rules give the agent project-specific standards to follow.

Cursor rule for Cursor

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 rules/jimmypocock/cursor-rules/expo
Clone the repo
git clone --depth 1 https://github.com/jimmypocock/cursor-rules

Made for: Cursor.

Per session 3 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 852 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 $0.00003 $0.00852
Opus 5 $0.00002 $0.00426
Sonnet 5 $0.00001 $0.00170
Haiku 4.5 $0.00000 $0.00085

Measured 3d ago against content hash 3d32eb230461, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

expo 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 3d 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.

.cursor/rules/expo.mdc · 144 lines

How it starts

The opening of the file, as written. The whole thing — 144 lines — stays where its author put it; the contents beside it link to each section on GitHub.


Description: Expo Development Standards Globs: **/.tsx, **/.jsx, **/.ts, **/.js, **/expo.config.js, **/app.json

Expo Development Standards

@base.mdc @typescript.mdc @react-native.mdc

Project Configuration

  • Use app.json/app.config.js for configuration
  • Implement proper versioning strategy
  • Configure proper app identifiers
  • Set up splash screen and app icon properly
  • Configure proper orientation settings
  • Implement proper permissions handling
  • Set up proper navigation structure
  • Configure build settings appropriately

Expo Workflow

  • Use Expo CLI for development
  • Implement proper environment variables
  • Configure development build correctly
  • Use Expo Go for rapid development
  • Implement proper production builds
  • Create custom development clients when needed
  • Use proper publishing workflows
  • Implement proper version control with Expo

EAS (Expo Application Services)

  • Use EAS Build for production builds
  • Implement EAS Update for over-the-air updates
  • Configure proper EAS profiles
  • Set up appropriate build triggers
  • Use EAS Submit for store submissions
  • Implement proper environment secrets
  • Configure proper build cache settings
  • Use EAS Metadata for store listings

Expo Libraries

  • Use Expo SDK modules appropriately
  • Implement proper module version compatibility
  • Use Expo Router for navigation when appropriate
  • Implement proper media handling with Expo
  • Use Expo's notification system properly
  • Implement proper authentication with Expo Auth
  • Configure Expo FileSystem for storage
  • Use Expo's asset system for resources

Authentication

  • Implement secure authentication flows
  • Use Expo Auth Session appropriately
  • Configure proper auth providers
  • Implement secure token storage
  • Create proper authentication state management
  • Implement proper session management
  • Configure proper authentication error handling
  • Create proper authentication UI flows
  • Use Expo Router or React Navigation
  • Implement proper deep linking
  • Configure proper navigation state persistence
  • Create type-safe navigation
  • Implement proper navigation guards
  • Use proper stack management
  • Create appropriate transition animations
  • Implement proper navigation context

Read the full file on GitHub · 144 lines

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. 3d ago First seen · 144 lines · 3 tokens per session scan A 3d32eb230461

Subscribe to this mod's changes

expo is a cursor rule published in the GitHub repository jimmypocock/cursor-rules (8 stars, last pushed 1y ago), licensed MIT. It adds 3 tokens to every session and 852 once invoked, about $0.0000 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.