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+# AGENTS.md
+
+This file contains guidelines for agentic coding agents working in the Grimoire repository.
+
+## Quick Reference
+
+For detailed project architecture, patterns, and conventions, see **[CLAUDE.md](./CLAUDE.md)**.
+
+## Build Commands
+
+### Development
+```bash
+npm run dev          # Start development server with HMR
+npm run build        # TypeScript check + production build
+npm run preview      # Preview production build locally
+```
+
+### Code Quality
+```bash
+npm run lint         # Run ESLint (fails on errors)
+npm run lint:fix     # Auto-fix ESLint issues + formatting
+npm run format       # Format with Prettier
+npm run format:check # Check formatting without changes
+```
+
+### Testing
+```bash
+npm test             # Run tests in watch mode
+npm run test:ui      # Visual test explorer
+npm run test:run     # Single test run (CI mode)
+```
+
+**Single Test**: Use `vitest run` with file pattern:
+```bash
+npm run test:run src/lib/nostr-utils.test.ts
+```
+
+### Verification
+Always run before committing:
+```bash
+npm run lint && npm run test:run && npm run build
+```
+
+## Code Style Guidelines
+
+### Imports & Dependencies
+- **Path Alias**: Use `@/` for `src/` directory (configured in Vite & Vitest)
+- **Import Order**: External libs → Applesauce → Local `@/` modules → Relative imports
+- **Applesauce**: Prefer helpers from `applesauce-core/helpers` and `applesauce-common/helpers`
+- **No Default Exports**: Use named exports for better tree-shaking
+
+```typescript
+// ✅ Correct import order
+import { useState } from "react";
+import { use$ } from "applesauce-react/hooks";
+import { getProfileContent } from "applesauce-core/helpers";
+import { cn } from "@/lib/utils";
+import { UserName } from "./components/UserName";
+```
+
+### TypeScript & Types
+- **Strict Mode**: Project uses strict TypeScript configuration
+- **No `any`**: ESLint rule disabled, but prefer proper types
+- **Applesauce Types**: Use types from `applesauce-core` and `nostr-tools`
+- **Local Types**: Extend in `src/types/` when needed
+
+```typescript
+// ✅ Use proper types from Applesauce
+import type { NostrEvent, ProfileContent } from "applesauce-core/helpers";
+import type { EventPointer } from "nostr-tools/nip19";
+```
+
+### React Patterns
+- **React 19**: Use latest features (hooks, concurrent rendering)
+- **No Default Exports**: Components use named exports
+- **Props Interface**: Always define props interface with JSDoc comments
+- **Destructured Props**: Destructure props in function signature
+
+```typescript
+// ✅ Component pattern
+interface QuotedEventProps {
+  /** EventPointer with optional relay hints */
+  eventPointer?: EventPointer;
+  /** Depth level for nesting */
+  depth?: number;
+}
+
+export function QuotedEvent({ eventPointer, depth = 0 }: QuotedEventProps) {
+  // Component logic
+}
+```
+
+### Performance & Caching
+- **Applesauce Helpers**: Cache internally - NO `useMemo` needed
+- **Custom Helpers**: Use `useMemo` for complex transformations
+- **Stable References**: Use `useStableValue`/`useStableArray` for filters/options
+
+```typescript
+// ❌ WRONG - Unnecessary memoization
+const title = useMemo(() => getArticleTitle(event), [event]);
+
+// ✅ CORRECT - Helpers cache internally
+const title = getArticleTitle(event);
+```
+
+### Styling
+- **TailwindCSS**: Primary styling approach
+- **CSS Variables**: Theme tokens in HSL format (see `index.css`)
+- **Utility Function**: Use `cn()` from `@/lib/utils` for class merging
+- **Dark Mode**: Default (controlled via HTML class)
+
+```typescript
+// ✅ Styling pattern
+import { cn } from "@/lib/utils";
+
+const className = cn(
+  "flex items-center gap-2 p-2 rounded-lg",
+  isActive && "bg-primary text-primary-foreground",
+  className
+);
+```
+
+### File Organization
+- **By Domain**: Group files by feature/domain (`nostr/`, `ui/`, `services/`, `hooks/`)
+- **Colocated Tests**: Test files next to source files (`*.test.ts`)
+- **Barrel Exports**: Use `index.ts` for clean imports
+- **Pure Functions**: Business logic in `src/core/logic.ts`
+
+### Naming Conventions
+- **Components**: PascalCase with descriptive names (`LiveActivityRenderer`)
+- **Hooks**: camelCase with `use` prefix (`useAccount`, `useProfile`)
+- **Utilities**: camelCase with descriptive names (`getDisplayName`, `canAccountSign`)
+- **Constants**: UPPER_SNAKE_CASE for exports
+- **Files**: kebab-case for utilities, PascalCase for components
+
+## Testing Guidelines
+
+### Test Environment
+- **Vitest**: Test framework with Node environment
+- **Polyfills**: IndexedDB, WebSocket, localStorage pre-configured
+- **Setup File**: `src/test/setup.ts` contains browser API polyfills
+
+### What to Test
+- **Parsers**: All argument parsing logic and edge cases
+- **Pure Functions**: State mutations and business logic
+- **Utilities**: Helper functions and data transformations
+- **Not UI Components**: React components tested manually
+
+### Test Structure
+```typescript
+describe("parseReqCommand", () => {
+  describe("kind flag (-k, --kind)", () => {
+    it("should parse single kind", () => {
+      const result = parseReqCommand(["-k", "1"]);
+      expect(result.filter.kinds).toEqual([1]);
+    });
+  });
+});
+```
+
+## Critical Rules
+
+1. **Singleton Services**: Never create new EventStore, RelayPool, or RelayLiveness instances
+2. **Verification**: Always run full verification before committing changes
+3. **Applesauce Caching**: Don't use `useMemo` with Applesauce helpers
+4. **Account Signing**: Always check `canSign` before signing operations
+5. **Error Boundaries**: Wrap event renderers in error boundaries
+6. **Path Alias**: Use `@/` for all internal imports
+
+## Project Context
+
+Grimoire is a Nostr protocol explorer with a tiling window manager interface. Each window is a Nostr "app" (profile viewer, event feed, NIP documentation, etc.). Commands are launched Unix-style via Cmd+K palette.
+
+**Stack**: React 19 + TypeScript + Vite + TailwindCSS + Jotai + Dexie + Applesauce
+
+---
+
+*See [CLAUDE.md](./CLAUDE.md) for detailed architecture, patterns, hooks, and conventions.*
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