NAV Navbar

Runtime APIs: Quick Reference

icon This page summarizes the main resources for using the gRPC APIs to interact with the automatic speech recognition (ASR), natural language understanding (NLU), Dialog, and text-to-speech (TTS) runtime services.

API versions and proto files

Service Current version Proto files Documentation
ASRaaS v1 Download Installation
NLUaaS v1 Download Installation
DLGaaS v1 Download Installation
TTSaaS v1 Download Installation

URLs to runtime services

Service Production URLs1
  1. For v1 APIs

Authentication URL

Server URL
Mix OAuth server

See Obtain authentication for services for more information.

Access token lifetime

The access token expires after 15 minutes so must be regenerated frequently.

URN format



For example, to load the resource for the American English coffee_app application configuration, specify the URN as follows:

Service URN
Mix.asr urn:nuance-mix:tag:model/coffee_app/mix.asr?=language=eng-USA
Mix.nlu urn:nuance-mix:tag:model/coffee_app/mix.nlu?=language=eng-USA
Mix.dialog urn:nuance-mix:tag:model/coffee_app/mix.dialog

The legacy form of the URN is supported but deprecated.