Audio

Upload and download audio recordings from mapping and testing runs, and generate voice clips from text for your tests to play.

6 endpoints

Get an upload URL

POST/audio/upload-url

Generate a pre-signed URL for uploading an audio file to S3.

Body Parameters

Name	Type	Required	Description
filename	string	required	Name of the audio file. Note the all-lowercase spelling — the API rejects fileName
category	string	required	test, map, voice, or transcript. Use voice for audio your tests play (profile voice items).
associatedId	string	optional	Run, job or voice id this file belongs to. Defaults to the generated audioId
contentType	string	required	MIME type (e.g., audio/wav, audio/mp3)

Request

bash

curl -X POST -H "x-api-key: YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"filename":"recording.wav","contentType":"audio/wav","category":"voice"}' \
  https://api.nopaque.co.uk/audio/upload-url

Response

json

{
  "uploadUrl": "https://s3.eu-west-2.amazonaws.com/...",
  "audioId": "aud_abc123",
  "expiresIn": 3600
}

Get a download URL

GET/audio/download-url

Generate a pre-signed URL for downloading an audio file.

Query Parameters

Name	Type	Required	Description
audioId	string	required	Audio file ID

Request

bash

curl -H "x-api-key: YOUR_API_KEY" \
  "https://api.nopaque.co.uk/audio/download-url?audioId=aud_abc123"

Response

json

{
  "downloadUrl": "https://s3.eu-west-2.amazonaws.com/...",
  "expiresIn": 3600
}

List audio files

GET/audio

List all audio files in the workspace.

Query Parameters

Name	Type	Required	Description
limit	number	optional	Maximum items to return (default 50)
nextToken	string	optional	Pagination token from previous response

Request

bash

curl -H "x-api-key: YOUR_API_KEY" \
  https://api.nopaque.co.uk/audio

Response

json

{
  "audioFiles": [
    {
      "id": "aud_abc123",
      "filename": "recording.wav",
      "contentType": "audio/wav",
      "createdAt": "2026-04-10T12: 00: 00Z"
    }
  ],
  "count": 1
}

Get an audio file

GET/audio/{id}

Get metadata for a specific audio file.

Path Parameters

Name	Type	Required	Description
id	string	required	Audio file ID

Request

bash

curl -H "x-api-key: YOUR_API_KEY" \
  https://api.nopaque.co.uk/audio/aud_abc123

Response

json

{
  "id": "aud_abc123",
  "filename": "recording.wav",
  "contentType": "audio/wav",
  "sizeBytes": 1048576,
  "createdAt": "2026-04-10T12: 00: 00Z"
}

Delete an audio file

DELETE/audio/{id}

Delete an audio file and its S3 object.

Path Parameters

Name	Type	Required	Description
id	string	required	Audio file ID

Request

bash

curl -X DELETE -H "x-api-key: YOUR_API_KEY" \
  https://api.nopaque.co.uk/audio/aud_abc123

Response

json

{
  "message": "Audio file deleted successfully"
}

Generate a voice clip

POST/audio/generate

Speak `text` in one of the enabled voices (List voices, on the Mission Tests page) and store the result as an MP3 voice clip in your workspace. To use it in a test, add its `audioId` to a profile as a voice item. This costs money: it is billed per character of `text`, markup included, and every generation is billed, including repeats of the same text. Each workspace has a monthly character limit (402 `TTS_MONTHLY_LIMIT_REACHED` once it is reached). 404 when the voice is not available. 502 when the speech provider failed; nothing was stored or billed, so try again. The published SDKs (0.13.0) have no method for this, so the sample is curl only.

Body Parameters

Name	Type	Required	Description
voiceId	string	required	An enabled voice id from List voices
text	string	required	1-1,000 characters. Ultra voices (ids starting Telnyx.Ultra.) also accept a pause, <break time="1s" /> (0.1 s to 10 s, in s or ms), and an emotion, <emotion value="sad" />
settings	object	optional	Delivery settings, Ultra voices only. Sending them for another voice is a 400
└ speed	number	optional	Speaking rate; above 1 is faster
└ volume	number	optional	Loudness
└ emotion	string	optional	neutral, happy, sad, angry, fearful, disgusted or surprised
name	string	optional	Display name for the clip. Defaults to the start of the text

Request

bash

curl -X POST -H "x-api-key: YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"voiceId":"Telnyx.Ultra.0ee8beaa-6a0b-4c3e-9f1d-2b7c5e4a8d61","text":"Hi, I would like to check my balance, please.","name":"Balance enquiry"}' \
  https://api.nopaque.co.uk/audio/generate

Response

json

{
  "audioId": "aud_abc123",
  "url": "https://s3.eu-west-2.amazonaws.com/...",
  "expiresInSecs": 300,
  "characters": 45,
  "sizeBytes": 38912,
  "durationSecs": 2.4,
  "voiceId": "Telnyx.Ultra.0ee8beaa-6a0b-4c3e-9f1d-2b7c5e4a8d61",
  "name": "Balance enquiry"
}