> ## Documentation Index
> Fetch the complete documentation index at: https://docs.open.cx/llms.txt
> Use this file to discover all available pages before exploring further.

> Upload an immutable WAV recording for a native call flow using base64 audio and workflow write permission.

# Upload asset

Requires `workflows:write`, with telephony and Classical IVR enabled. Send the WAV bytes as base64 in `wavBase64` and a recording name in `name`.

Supports mono or stereo, 16-bit PCM, A-law or mu-law WAV files at 8, 16, 24, 32, 44.1 or 48 kHz. The decoded file must be at most 20 MB and five minutes long. Invalid or unsupported audio is rejected.

The response contains the recording ID, name, sample rate, channels, duration in seconds and creation time. Use the ID in a Classical IVR node. Every upload creates a new recording; it does not replace an existing recording, activate a workflow or change number routing. See [WAV recordings](/phone/call-flows#wav-recordings).