oatpp/README.md

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# Oat++ 

**News**  

- ⚠️ Attention! Oat++ main repo is bumping its version to 1.4.0. While 1.4.0 is **IN DEVELOPMENT** use `1.3.0-latest` tag.
- Follow the [changelog](https://github.com/oatpp/oatpp/blob/master/changelog/1.4.0.md) for news and features in version `1.4.0`.
- Consider supporting Oat++ via the [GitHub sponsors](https://github.com/sponsors/oatpp) page.

---

Oat++ is a modern Web Framework for C++. 
It's fully loaded and contains all necessary components for effective production level development. 
It's also light and has a small memory footprint.

**Start**

- [Get Started](https://oatpp.io/docs/start/)
- [Build For Unix/Linux](https://oatpp.io/docs/installation/unix-linux/)
- [Build For Windows](https://oatpp.io/docs/installation/windows/)
- [Examples](#examples)

**About**

- [Website](https://oatpp.io/)
- [Supported Platforms](https://oatpp.io/supported-platforms/)
- Latest Benchmarks: [5 Million WebSockets](https://oatpp.io/benchmark/websocket/5-million/)
- [Contributing to Oat++](CONTRIBUTING.md)

**Join Our Community**

- [Gitter](https://gitter.im/oatpp-framework/Lobby) - Talk to Oat++ developers and to other Oat++ users.
- [Twitter](https://twitter.com/oatpp_io) - Follow Oat++ on Twitter.
- [Reddit](https://www.reddit.com/r/oatpp/) - Follow Oat++ subreddit.
- [StackOverflow (new)](https://stackoverflow.com/questions/tagged/oat%2b%2b) - Post a Question.

## Quick Overview

**Shortcuts:**

- [Oat++ High Level Overview](https://oatpp.io/docs/start/high-level-overview/) - Get a quick overview of Oat++ features.
- [Example Project](https://github.com/oatpp/example-crud) - A complete example of a "CRUD" service (UserService) built with Oat++. REST + Swagger-UI + SQLite.

### Build Powerful API And Document It With Swagger-UI

See [ApiController](https://oatpp.io/docs/components/api-controller/) for more details.

```cpp
ENDPOINT_INFO(getUserById) {
  info->summary = "Get one User by userId";

  info->addResponse<Object<UserDto>>(Status::CODE_200, "application/json");
  info->addResponse<Object<StatusDto>>(Status::CODE_404, "application/json");
  info->addResponse<Object<StatusDto>>(Status::CODE_500, "application/json");

  info->pathParams["userId"].description = "User Identifier";
}
ENDPOINT("GET", "users/{userId}", getUserById,
         PATH(Int32, userId))
{
  return createDtoResponse(Status::CODE_200, m_userService.getUserById(userId));
}
``` 

### Access Databases And Keep Your Data Consistent

See [Oat++ ORM](https://oatpp.io/docs/components/orm/) for more details.

```cpp
QUERY(createUser,
      "INSERT INTO users (username, email, role) VALUES (:username, :email, :role);",
      PARAM(oatpp::String, username), 
      PARAM(oatpp::String, email), 
      PARAM(oatpp::Enum<UserRoles>::AsString, role))
```

## Frequently Asked Questions

### Q: "Oat++" name?

- "Oat" is something light, organic, and green. It can be easily cooked and consumed with no effort. 
- "++" gives a hint that it is "something" for C++.

### Q: What is the main area of Oat++ application?

Oat++ is used for many different purposes, from building REST APIs that run on embedded devices to 
building microservices and highly-loaded cloud applications.

But the majority of use cases appears to be in **IoT** and **Robotics**.

### Q: How portable is Oat++?

Theoretically, Oat++ can be **easily** ported everywhere where you have **threads** and **network stack**.
With an additional comparably small effort, it can be ported almost everywhere depending on how
much you strip it and what would be the final binary size.

See [supported platforms](https://oatpp.io/supported-platforms/) for additional info.

### Q: What is the size of a minimal Oat++ application?

About **1Mb**, depending on C/C++ std-lib and oatpp version.

### Q: Which Oat++ API to choose, Simple or Async?

Always choose **Simple API** wherever possible. Simple API is more developed and makes the code cleaner.

Async API is designed for small, specific tasks that run at high concurrency levels ex.:
- Serving file downloads to a large number of concurrent users (1K users and more).
- Streaming to a large number of clients (1K or more).
- Websocket Chat servers.

For all other purposes use simple API.

## Examples

### REST-API

- [REST Service](https://github.com/oatpp/example-crud) - A complete example of a "CRUD" service (UserService) built with Oat++. REST + Swagger-UI + SQLite.
- [REST Client](https://github.com/oatpp/example-api-client) - Example project of how-to use Retrofit-like client wrapper (ApiClient) and how it works.

### WebSocket

- [Can Chat](https://github.com/lganzzzo/canchat) - Feature-complete rooms-based chat for tens of thousands users. Client plus Server.
- [WebSocket](https://github.com/oatpp/example-websocket) - Collection of oatpp WebSocket examples.
- [YUV Websocket Stream](https://github.com/oatpp/example-yuv-websocket-stream) - Example project how-to create a YUV image stream from a V4L device (i.E. Webcam) using websockets.

### Databases

- [SQLite](https://github.com/oatpp/example-crud) - A complete example of a "CRUD" service. REST + Swagger-UI + SQLite.
- [PostgreSQL](https://github.com/oatpp/example-postgresql) - Example of a production-grade entity service storing information in PostgreSQL. With Swagger-UI and configuration profiles.
- [MongoDB](https://github.com/oatpp/example-mongodb) - Example project how to work with MongoDB using **oatpp-mongo** mondule. Project is a web-service with basic CRUD and Swagger-UI.
 
### IoT

- [Example-IoT-Hue](https://github.com/oatpp/example-iot-hue-ssdp) - Example project how-to create an Philips Hue compatible REST-API that is discovered and controllable by Hue compatible Smart-Home devices like Amazon Alexa or Google Echo.

### Streaming

- [HTTP Live Streaming Server](https://github.com/oatpp/example-hls-media-stream) - Example project on how to build an HLS-streaming server using Oat++ asynchronous API.
- [YUV Websocket Stream](https://github.com/oatpp/example-yuv-websocket-stream) - Example project how-to create a YUV image stream from a V4L device (i.E. Webcam) using websockets.

### TLS

- [TLS With Libressl](https://github.com/oatpp/example-libressl) - Example project how-to setup secure connection and serve via HTTPS.

### Microservices

- [Consul Integration](https://github.com/oatpp/example-consul) - Example project on how to use [oatpp::consul::Client](https://oatpp.io/api/latest/oatpp-consul/rest/Client/). Consul integration.
- [Microservices](https://github.com/oatpp/example-microservices) - Example project on how to build microservices with Oat++, 
and example on how to consolidate those microservices using [monolithization](https://oatpp.io/docs/monolithization/) technique.

### Asynchronous API

- [Async Service](https://github.com/oatpp/example-async-api) - Example project on how to use asynchronous API to handle a large number of simultaneous connections.