API (Application Programming Interface)

Application Programming Interface (API) is a contract between two software systems that specifies how they can request and exchange data. APIs are the connective tissue of modern software architecture, enabling integration across otherwise separate systems.

API Types in Voice Platforms

• REST APIs — web-based endpoints for creating, reading, or updating data (e.g., CRM integration).
• Webhooks — event-driven callbacks that notify external systems of state changes (e.g., call completed).
• Streaming APIs — real-time bi-directional channels for live transcription or sentiment analysis.

APIs in Voice Agent Workflows

AI voice agents rely on APIs to fetch caller context from CRM systems, check appointment availability, look up patient records in EHR, and update records post-call. Without APIs, voice agents would operate in isolation without access to business systems.

Security Considerations

APIs handling sensitive data (PHI, PCI, PII) must enforce authentication (OAuth, API keys), encryption in transit (HTTPS), and audit logging to meet compliance requirements like HIPAA and GDPR.