# CLAUDE.md

This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.

## Project Overview

AnKao is a Go web application built using the standard library's `net/http` package. The project follows a clean architecture pattern with clear separation of concerns.

## Architecture

### Request Flow
1. HTTP requests arrive at the server running on port 8080
2. Requests pass through the `Logger` middleware (in `internal/middleware/`)
3. The router (`http.NewServeMux`) directs requests to appropriate handlers
4. Handlers (in `internal/handlers/`) process requests and return JSON responses

### Middleware Pattern
Middleware functions wrap the main handler using the standard middleware pattern:
```go
func Middleware(next http.Handler) http.Handler
```
Middleware is applied in [cmd/server/main.go:20](cmd/server/main.go#L20) before starting the server.

### Module Structure
- **cmd/server/** - Application entry point, server configuration and routing setup
- **internal/handlers/** - HTTP request handlers, all return JSON responses
- **internal/middleware/** - HTTP middleware chain (currently: logging)
- **internal/models/** - Data models (directory exists but not yet populated)
- **pkg/config/** - Configuration management (directory exists but not yet populated)

## Common Commands

### Development
```bash
# Run the server
go run cmd/server/main.go

# Install/update dependencies
go mod tidy

# Format code
go fmt ./...

# Vet code for common issues
go vet ./...
```

### Building
```bash
# Build binary to bin/server
go build -o bin/server cmd/server/main.go

# Run built binary (Windows)
.\bin\server.exe

# Run built binary (Unix)
./bin/server
```

### Testing
```bash
# Run all tests
go test ./...

# Run tests with coverage
go test -cover ./...

# Run tests in a specific package
go test ./internal/handlers/
```

## Key Implementation Details

- The server listens on port **:8080** (hardcoded in main.go:23)
- All responses are JSON with appropriate Content-Type headers
- Import paths use the module name `ankao` (defined in go.mod)
- When adding new handlers, register them in [cmd/server/main.go](cmd/server/main.go) using `mux.HandleFunc()`
- Middleware wraps the entire mux, so it applies to all routes