TDLib (Telegram Database library) is a cross-platform library for building [Telegram](https://telegram.org) clients. It can be easily used from almost any programming language.
* **Cross-platform**: `TDLib` can be used on Android, iOS, Windows, macOS, Linux, FreeBSD, Windows Phone, WebAssembly, watchOS, tvOS, Tizen, Cygwin. It should also work on other *nix systems with or without minimal effort.
* **Multilanguage**: `TDLib` can be easily used with any programming language that is able to execute C functions. Additionally it already has native Java (using `JNI`) bindings and .NET (using `C++/CLI` and `C++/CX`) bindings.
* **High-performance**: in the [Telegram Bot API](https://core.telegram.org/bots/api), each `TDLib` instance handles more than 24000 active bots simultaneously.
See the [td_api.tl](https://github.com/tdlib/td/blob/master/td/generate/scheme/td_api.tl) scheme or the automatically generated [HTML documentation](https://core.telegram.org/tdlib/docs/td__api_8h.html)
for a list of all available `TDLib` [methods](https://core.telegram.org/tdlib/docs/classtd_1_1td__api_1_1_function.html) and [classes](https://core.telegram.org/tdlib/docs/classtd_1_1td__api_1_1_object.html).
* Build `TDLib` with CMake as explained in [building](#building). You will likely need to manually specify path to the installed OpenSSL to CMake, e.g.,
* Download and install [gperf](https://sourceforge.net/projects/gnuwin32/files/gperf/3.0.1/). Add the path to gperf.exe to the PATH environment variable.
* Td::TdJson, Td::TdJsonStatic — dynamic and static version of a JSON interface. This has a simple C interface, so it can be easily used with any programming language that is able to execute C functions.
See [td_json_client](https://core.telegram.org/tdlib/docs/td__json__client_8h.html) and [td_log](https://core.telegram.org/tdlib/docs/td__log_8h.html) documentation for more information.
* Td::TdStatic — static library with C++ interface for general usage.
See [Client](https://core.telegram.org/tdlib/docs/classtd_1_1_client.html) and [Log](https://core.telegram.org/tdlib/docs/classtd_1_1_log.html) documentation for more information.
See [ClientActor](https://core.telegram.org/tdlib/docs/classtd_1_1_client_actor.html) and [Log](https://core.telegram.org/tdlib/docs/classtd_1_1_log.html) documentation for more information.
See [example/java](https://github.com/tdlib/td/tree/master/example/java) for example of using `TDLib` from Java and detailed build and usage instructions.
`TDLib` provides native .NET interface through `C++/CLI` and `C++/CX`. To enable it, specify option `-DTD_ENABLE_DOTNET=ON` to CMake.
.NET Core doesn't support `C++/CLI`, so if .NET Core is used, then `TDLib` JSON interface should be used through P/Invoke instead.
See [example/csharp](https://github.com/tdlib/td/tree/master/example/csharp) for example of using `TDLib` from C# and detailed build and usage instructions.
See [example/uwp](https://github.com/tdlib/td/tree/master/example/uwp) for example of using `TDLib` from C# UWP application and detailed build and usage instructions for Visual Studio Extension "TDLib for Universal Windows Platform".
When `TDLib` is built with `TD_ENABLE_DOTNET` option enabled, `C++` documentation is removed from some files. You need to checkout these files to return `C++` documentation back:
But for most use cases we suggest to use the JSON interface, which can be easily used with any programming language that is able to execute C functions.
See [td_json_client](https://core.telegram.org/tdlib/docs/td__json__client_8h.html) and [td_log](https://core.telegram.org/tdlib/docs/td__log_8h.html) documentation for detailed JSON interface description,
the [td_api.tl](https://github.com/tdlib/td/blob/master/td/generate/scheme/td_api.tl) scheme or the automatically generated [HTML documentation](https://core.telegram.org/tdlib/docs/td__api_8h.html) for a list of
all available `TDLib` [methods](https://core.telegram.org/tdlib/docs/classtd_1_1td__api_1_1_function.html) and [classes](https://core.telegram.org/tdlib/docs/classtd_1_1td__api_1_1_object.html).
`TDLib` JSON interface adheres to semantic versioning and versions with the same major version number are binary and backward compatible, but the underlying `TDLib` API can be different for different minor and even patch versions.
If you need to support different `TDLib` versions then you can use a value of the `version` option to find exact `TDLib` version and to use appropriate API then.
See [example/python/tdjson_example.py](https://github.com/tdlib/td/tree/master/example/python/tdjson_example.py) and [example/ruby/example.rb](https://github.com/tdlib/td/tree/master/example/ruby/example.rb) for examples of such usage.