The Telephony Server Application Programming Interface (TAPI) is a Microsoft Windows-based programming interface that enables software developers to create applications that interact with and control telephony devices and services. TAPI provides a standardized way for applications to manage voice and data communication functions on Windows-based computers. It was initially developed to enable computer telephony integration (CTI) and has evolved to support various telephony features.
Key features and aspects of TAPI include:
- Device Abstraction: TAPI abstracts the complexities of interacting with different telephony hardware devices, such as modems, telephones, fax machines, and voice processing systems. This allows developers to write applications that work with various devices without needing to know the specific details of each one.
- Call Control: TAPI enables applications to initiate, manage, and terminate voice and data calls. This includes features like call initiation, answering incoming calls, placing calls on hold, transferring calls, and conference calling.
- Call Monitoring: Applications can use TAPI to monitor the state of ongoing calls, including call progress, call duration, and call events.
- Caller ID and Call Logging: TAPI provides capabilities for retrieving caller ID information and logging call details, which can be useful for applications like call centers and customer relationship management (CRM) systems.
- Voice Processing: TAPI supports voice processing functions, including recording and playing back audio, as well as performing basic voice recognition and text-to-speech tasks.
- Faxing: TAPI allows applications to send and receive faxes using fax modems and services.
- Unified Messaging: With advancements in TAPI, it has become capable of integrating with unified messaging systems, allowing applications to work with email, voicemail, and other communication channels.
- CTI Integration: TAPI enables computer telephony integration by allowing applications to connect telephony functions with data from other applications, such as CRM systems, databases, and customer records.
- Supplementary Services: TAPI supports supplementary services like call waiting, call forwarding, and call conferencing.
TAPI has evolved over the years, and there are different versions available. TAPI 2.x and TAPI 3.0 are among the most notable versions, with TAPI 3.0 offering improved features and compatibility.
Developers use TAPI to create a wide range of applications, including call center software, voice response systems, automated attendants, voice messaging systems, and more. TAPI-compliant applications can work with a variety of telephony hardware and services, making it a versatile tool for integrating voice and data communication into Windows-based software.