Runtime event logs

The Mix ASR, NLU, TTS, NR, and Dialog runtime services generate event logs that can be used by Nuance customers to troubleshoot deployments, monitor operational data, produce reports, generate billing records, track usage, and so on.

Mix offers two REST APIs to help customers access and use this data:

  • The Nuance Kafka Consumer API provides access to the event logs generated by the services. Customers can use this API to pull the data that they need and then manipulate and process this data for their use cases; for example, for reporting or troubleshooting.
  • The Nuance Audio File Storage Service (AFSS) API provides access to the audio files.

Note: Before you can use the Mix logging APIs, Nuance must enable event logs in your application. Please contact your Nuance representative for more information.

Kafka API essentials

Standard Kafka concepts and terminology used by the Nuance Kafka Consumer API.


Authorize your client application using the OAuth 2.0 protocol.

Consumer lifecycle

Recommended practices for using the API in a real-life scenario.

Best practices

Best practices for using the Kafka API.


Tips and workarounds to common issues when working with the Kafka API.

About payloads

Describes the top-level structure of each event log message.

ASR payloads

ASR event logs.

NR payloads

NR event logs.

NLU payload

NLU event logs.

Dialog payloads

Dialog event logs.

TTS payload

TTS event logs.

NTTS payload

Neural TTS event logs.

ForgetMe payload

ForgetMe event logs.

Managing sensitive information in an application

Mark sensitive information in an application to redact information in the logs.

Correlating event logs

Recommended approaches for correlating event logs.

Inject content into the payloads

Inject content such as client data, user ID, and request ID in the payloads.

Kafka consumer API

Use the Kafka consumer API to access event logs.


Use the Audio File Storage Service API to download audio files of utterances sent for recognition to ASRaaS and NRaaS.

ForgetMe gRPC API

Use the ForgetMe gRPC API to request the removal of customer data.