CLAUDE.md — Rust + Axum + SQLx

# CLAUDE.md

## Project Overview
{{project_name}} — {{one-line description}}

## Tech Stack
- Language: Rust (latest stable)
- Web framework: Axum 0.7+
- Database: PostgreSQL via SQLx (compile-time checked queries)
- Serialization: serde + serde_json
- Error handling: thiserror + anyhow
- Auth: {{auth_approach}}
- Tracing: tracing + tracing-subscriber

## Commands
```bash
cargo run                    # Dev server
cargo test                   # Run tests
cargo clippy -- -D warnings  # Lint
sqlx migrate run             # Apply migrations
sqlx prepare                 # Prepare offline query cache
```

## Directory Structure
```
src/
├── main.rs              # Server setup + routing
├── routes/              # Axum handler functions
├── models/              # Database models (FromRow)
├── services/            # Business logic
├── extractors/          # Custom Axum extractors
├── error.rs             # App error type + IntoResponse
└── config.rs            # Environment config
migrations/              # SQLx migrations
```

## Conventions
- Use typed extractors (Json<T>, Path<T>, Query<T>)
- Custom AppError type that implements IntoResponse
- All DB queries via sqlx::query_as! (compile-time checked)
- Use Arc<AppState> for shared state
- Prefer &str over String in function parameters
- No unwrap() in production code — use ? operator
- Run `sqlx prepare` before committing if queries changed