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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 API Current version Proto files Documentation
ASRaaS Recognizer v1 Download gRPC setup
Training Download
NLUaaS Runtime v1 Download gRPC setup
Wordset Download
DLGaaS DialogService v1 Download gRPC setup
TTSaaS Synthesizer and Storage v1 Download gRPC setup

gRPC-web support

This table lists the Mix runtime services that are gRPC-Web compliant.

Service gRPC-Web

URLs to runtime services

Service Production URLs1
Event logs
  1. For v1 APIs

Authorization URL

Server URL
Nuance OAuth server

See Authorize your client application for more information.

Authorization scopes

Service Scopes
ASRaaS asr: Provides access to the ASRaaS runtime API and resources
asr.wordset: Allows client applications to upload ASR wordsets
NLUaaS nlu: Provides access to the NLUaaS runtime API and resources
nlu.wordset: Allows client applications to upload NLU wordsets
DLGaaS dlg: Provides access to the DLGaaS runtime API and resources
TTSaaS tts: Provides access to the TTSaaS runtime API and resources
Event logs log: Provides access to event logs

See Authorize your client application for more information.

Access token lifetime

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

URN format

Mix.asr DLM, Mix.nlu model, and Mix.dialog resource URNs



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.

ASR and NLU wordset URNs


For example, to upload the Mix.asr cities_wordset application-level wordset, specify the URN as follows: