The Audio File Storage Service (AFSS) API lets you download audio files of the utterances that were sent for recognition to ASRaaS and NRaaS.

AFSS version: v1

This document covers v1 of the Nuance AFSS Rest API.



The API requires the URN of the resource to download, in the following format:


For ASRaaS and NRaaS, this is obtained from the audioUrn field in the asr-callsummary payload or nrc-callsummary payload event logs.

For example, consider the following event log:

"absEndTime": 1616532498670,
"IP!S3Events": "L4sFrmz...9MMxM0EC2s=",
"audioDump": "http://minio-prod.fabric-prod.svc.cluster.local:9000/afss/fd228157ac40497a6f9a51f43f476b8c40dc270de6d3f218810745104242b098/asraas/44620fec-4c48-4d41-82d9-68fd8732f84f",
"audioUrn": "urn:nuance-mix:log:service:audio/asraas/44620fec-4c48-4d41-82d9-68fd8732f84f"

To get the audio file for this URN, the REST endpoint would look something like this:


Your client application must provide an access token to access the AFSS API. This access token can be shared between the AFSS and the Kafka APIs. See Authorization for details.

Audio resources

Get audio resources

GET /api/v1/audio

Retrieve the audio file that corresponds to the URN specified.


Name In Type Description
urn query string URN of the resource to download. For ASRaaS and NRaaS, this is obtained with the audioUrn field.


Status Meaning Description Schema
200 OK Success Inline