Increasing demand for advanced voice-and-facsimile network services has motivated the recent introduction of an important, new, programmable network element: AT&T's A-I-Net™ service-circuit node. This new network element complements existing network switching and database elements by providing internal network access to a programmable node that has highly specialized service circuits. These circuits support network services that involve the synthesis, interpretation, repetition, or translation of voiceband information. Although the central-office and operations-support interfaces we describe are designed for the United States market, the service-circuit node provides a flexible base for supporting interfaces that are appropriate for other markets, too. As service-circuit technology continues to advance to support complex, image-processing functions (e.g., facsimile or speaker recognition), service providers will require greater flexibility for developing services that use these functions. An applications-development environment, based on application-oriented-language technology, enables service providers to introduce new capabilities rapidly into existing networks.