# Oat++ — Zero-Dependency C++ Web Framework

> Oat++ (oatpp) is a light, zero-dependency C++ web framework for building high-performance REST APIs, WebSocket services, and microservices with a clean object-mapping API.

## Install

Save in your project root:

# Oat++ — Zero-Dependency C++ Web Framework

## Quick Use
```bash
git clone https://github.com/oatpp/oatpp.git
cd oatpp && mkdir build && cd build
cmake .. && make -j$(nproc) && sudo make install
# Start with the starter project:
git clone https://github.com/oatpp/oatpp-starter.git
cd oatpp-starter && mkdir build && cd build
cmake .. && make -j$(nproc) && ./crud-exe
```

## Introduction
Oat++ is a modern C++ web framework designed for high-performance HTTP services with zero external dependencies. It provides object mapping, Swagger integration, and connection handling out of the box, making it practical for production C++ APIs and microservices.

## What Oat++ Does
- Serves HTTP/1.1 requests with async and blocking execution models
- Maps C++ objects to JSON and back using code-generated DTOs
- Provides built-in Swagger/OpenAPI documentation generation
- Supports WebSocket connections for real-time communication
- Handles database interaction through typed ORM-style query builders

## Architecture Overview
Oat++ uses a layered design: an HTTP connection handler dispatches to a router, which maps requests to controller endpoints. Data Transfer Objects (DTOs) define typed request and response bodies. The framework compiles without any third-party library, relying only on the C++ standard library and OS sockets.

## Self-Hosting & Configuration
- Build from source with CMake; no package manager dependencies needed
- Define API endpoints in controller classes using macro-based routing
- Configure server port, connection limits, and threading in the AppComponent
- Enable Swagger UI by adding the oatpp-swagger module
- Choose between simple (blocking) and async (coroutine-based) server modes

## Key Features
- Truly zero external dependencies; compiles on any platform with a C++11 compiler
- Built-in Swagger UI generation from annotated endpoints
- Async server mode using coroutines for high-concurrency scenarios
- Typed DTO system catches serialization mismatches at compile time
- Modular ecosystem with extensions for PostgreSQL, SQLite, WebSocket, and more

## Comparison with Similar Tools
- **Drogon** — Drogon offers similar performance with a broader async ecosystem; Oat++ emphasizes zero dependencies and simpler bootstrapping
- **Crow** — Crow is a microframework with Flask-like simplicity; Oat++ provides more structure with DTOs and Swagger support
- **cpp-httplib** — cpp-httplib is header-only for simple cases; Oat++ adds routing, serialization, and API documentation
- **Pistache** — Pistache focuses on REST; Oat++ extends to WebSocket and database layers

## FAQ
**Q: Does Oat++ require Boost or any other library?**
A: No. Oat++ has zero external dependencies. Optional modules like oatpp-postgresql add specific integrations.

**Q: How does Oat++ handle JSON serialization?**
A: You define DTO classes with macros like DTO_FIELD. The framework generates serializers that map between C++ objects and JSON automatically.

**Q: Is Oat++ suitable for production use?**
A: Yes. Oat++ is used in production services and benchmarks competitively with other C++ frameworks.

**Q: What platforms does Oat++ support?**
A: Linux, macOS, Windows, and FreeBSD. Any platform with a C++11 compiler and POSIX or WinSock sockets.

## Sources
- https://github.com/oatpp/oatpp
- https://oatpp.io/docs/start/

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Source: https://tokrepo.com/en/workflows/asset-f554ac6c
Author: AI Open Source