Audio normalize (EBU R128)

Loudness-normalize any audio/video URL to a target LUFS with ffmpeg's loudnorm (EBU R128) and return MP3 — consistent levels for podcasts, clips, and TTS output. Body: {"url":"https://…/audio.wav","targetLufs":-16?}.

Input

Field	Type	Description
url *	string	Public URL of the media file (max 30MB)
targetLufs	number	Integrated loudness target, -36 to -8 (default -16)

Example output

{
  "format": "mp3",
  "targetLufs": -16,
  "truePeakDb": -1.5,
  "bytes": 2210000,
  "mp3Base64": "SUQzBAAAAA…"
}

Try it — see the 402 challenge (free)

curl -i -X POST https://agent402.tools/api/audio-normalize \
  -H "Content-Type: application/json" \
  -d '{"url":"https://example.com/episode.wav"}'

The response is HTTP 402 Payment Required with exact payment requirements. Any x402 v2 client pays automatically and retries:

Paid call (JavaScript agent)

import { wrapFetchWithPayment } from "@x402/fetch";
import { x402Client } from "@x402/core/client";
import { registerExactEvmScheme } from "@x402/evm/exact/client";
import { privateKeyToAccount } from "viem/accounts";

const client = new x402Client();
registerExactEvmScheme(client, { signer: privateKeyToAccount(KEY) });
const payFetch = wrapFetchWithPayment(fetch, client);

const res = await payFetch("https://agent402.tools/api/audio-normalize", {
  method: "POST",
  headers: { "Content-Type": "application/json" },
  body: JSON.stringify({
    "url": "https://example.com/episode.wav"
  }),
});

Wallet-only. This tool reaches the network/browser/storage, so it is paid in USDC via x402 (no proof-of-work tier).

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