Async

Async is a low-latency text-to-speech API designed for building real-time voice applications and AI agents. It focuses on delivering natural-sounding speech with minimal delay, enabling responsive, conversational experiences across web, mobile, and back-end systems. The platform is built for production workloads, with predictable performance and reliability suitable for customer-facing deployments.

Async supports 15 languages and offers a 24/7 service-level agreement (SLA), making it appropriate for teams that need consistent uptime and support. Its API is optimized for streaming scenarios, allowing developers to generate and deliver audio on the fly rather than waiting for full file generation. Native integrations with tools like Pipecat, n8n, and LiveKit simplify orchestration, workflow automation, and real-time communication use cases. Pricing starts from $0.50 per hour of audio, which provides clear cost visibility for scaling applications.