Imported from utk2602/B3-Decentapp (AGENTS.md). Install upstream with npx skills add utk2602/B3-Decentapp. Copyright stays with the author.

Repository Guidelines

Project Structure & Module Organization

• app/: Expo React Native client (Expo Router) with assets, components, and constants; entry via app/app/index.tsx.
• web/: Next.js marketing/site code under src/, with components in src/components and styles in src/app/globals.css.
• api/: Express + TypeScript fee-payer API; source in src/, built output in dist/.
• programs/key-registry/: Anchor/Solana program code (Rust) with instructions in src/lib.rs; configured by Anchor.toml.
• Root Cargo.toml defines the workspace for on-chain programs; target/ is build output (avoid committing).

Build, Test, and Development Commands

• App: from app/, install with npm install; run npm start (Expo bundler), npm run ios/android for simulators, npm run web for browser preview.
• Web: from web/, npm install then npm run dev (Next dev server), npm run build for production, npm run start to serve the build, npm run lint to check TS/JS.
• API: from api/, npm install, npm run dev for watch mode, npm run build to emit dist/, npm start to run compiled server, npm test (Vitest).
• Programs: from repo root, anchor build to compile on-chain code, anchor test to run Anchor/ts-mocha tests (uses Anchor.toml provider settings).

Coding Style & Naming Conventions

• TypeScript/TSX everywhere; prefer 2-space indentation, semicolons optional but stay consistent with touched files.
• React components: PascalCase filenames and exports; hooks/utilities in camelCase; keep modules co-located with feature folders.
• Linting via Next’s ESLint config in web/; run lint before PRs. For Rust programs, run cargo fmt && cargo clippy before pushing.
• Environment values come from .env/.env.local (never commit secrets).

Testing Guidelines

• API: Vitest for unit/integration; add tests alongside code under api/src/**/__tests__ or *.test.ts; ensure deterministic data and mocked RPC calls.
• Programs: prefer anchor test with deterministic keypairs; document test accounts and airdrops used.
• Frontends: add lightweight component tests when feasible (e.g., React Testing Library) and manual smoke (navigation, critical flows) before merges.

Commit & Pull Request Guidelines

• Commits: concise, imperative subjects (e.g., Add wallet validation, Fix fee payer rate limit). Squash noisy WIP commits before merging.
• PRs: include what/why, linked issues, and testing notes/outputs (npm test, anchor test, manual checks). Add screenshots for UI-facing changes.
• Keep diffs minimal and isolated per domain (app, web, api, programs). Update relevant configs/docs when adding env vars or migrations.

Security & Configuration Tips

• Keys and RPC endpoints belong in env files; prefer placeholders in commits. Rotate any leaked keys immediately.
• When running against Solana devnet/localnet, confirm Anchor.toml provider cluster and wallet paths; avoid using production wallets for tests.