The TeamTalk 4 SDK enables software developers to easily implement features for sending and receiving multiple audio and video streams over the Internet. The SDK consists of a client DLL and a standalone server which can be used in both LAN and WAN environments. It comes with wrapper classes for .NET Framework and a C-API which allows development on both Windows and Linux.

Here is a list of the main features in the TeamTalk 4 SDK:

- Multiple active real time audio and video streams
- Share desktop applications
- Instant text messaging
- File sharing
- Tree structure for grouping clients
- Audio capture supported by DirectSound, WinMM, ALSA and CoreAudio
- Video capture supported by DirectShow, Video4Linux (V4L) and QuickTime
- CELT and Speex audio codecs for both high and low bandwidth usage
- Automatic Gain Control (AGC) and 3D-sound positioning
- Audio transmission using push-to-talk (PTT) and voice activation (VAD)
- Echo cancellation
- Store all audio transmissions to either .wav or .mp3 format
- Video codec supporting variable (VBR) and constant (CBR) bitrate as well as configurable quality
- User account system for server authentication
- Secure data transmission using TLS and BlowFish encryption