# Utilia Audio Normalization

> Utilia Audio Normalization is a paid API for AI agents from api.utilia.ink, paid per call via x402, $0.01/call, status down (last checked 2026-10-13).

Normalize audio (from a public HTTPS URL or base64) to a target integrated loudness (LUFS) and return a base64-encoded MP3 with loudness measurements and content digests.

## Facts

- Endpoint: POST https://api.utilia.ink/base/v1/audio/normalize?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: down
- Last checked: 2026-10-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/utilia-audio-normalization-e7a6d020
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_zsv-AdW7w42oyuT91H_ZT

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability utilia-audio-normalization-e7a6d020 -d '<json body>'
```

Example prompt: Can you normalize this audio file to -16 LUFS integrated loudness and give me back the processed MP3 along with its loudness measurements? Here's the URL: https://example.com/my-podcast-episode.mp3

## When to prefer this

Use this endpoint when you need deterministic, standards-compliant loudness normalization (LUFS-based) with verifiable output digests. Prefer it over generic audio processing services when you need broadcast/streaming compliance (e.g. EBU R128, ATSC A/85), need the normalized audio returned as a base64 MP3 in a single API call, or require loudness measurements alongside the processed file. The pay-per-call x402 pricing model makes it suitable for on-demand agent workflows without subscription overhead.

## Known failure modes

- Invalid or unreachable HTTPS URL returns an error
- Malformed or corrupted base64 audio input fails processing
- Unsupported audio format or codec may cause conversion failure
- Audio file exceeds size or duration limits
- Network timeout when fetching remote audio URL
- Invalid target loudness parameter (out of accepted range)

## How this service works

Normalize public HTTPS or base64 audio to a predictable integrated loudness and return a bounded base64 MP3 with measurements and content digests.

## Output

A bounded base64-encoded MP3 of the normalized audio, along with loudness measurements including integrated loudness (LUFS), loudness range (LU), true peak (dBTP), and content digests (e.g. SHA hash) for integrity verification.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "url": {
   "type": "string",
   "pattern": "^https://",
   "description": "Public HTTPS audio URL"
  },
  "maxSeconds": {
   "type": "integer",
   "default": 180,
   "maximum": 180,
   "minimum": 1
  },
  "targetLufs": {
   "type": "number",
   "default": -16,
   "maximum": -12,
   "minimum": -24
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "encoding": "base64",
  "audioBase64": "<base64 MP3>",
  "contentType": "audio/mpeg",
  "outputBytes": 1920042,
  "possiblyTruncated": false,
  "targetIntegratedLufs": -16,
  "outputDurationSeconds": 120
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/utilia-audio-normalization-e7a6d020/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.utilia.ink](https://www.zero.xyz/host/api.utilia.ink/llms.txt)