Venice Voice Changer (/audio/voice-changer/*)

Speech-to-speech conversion: upload a recording, get the same speech back in a different voice, with the original pacing, emotion and timing preserved. It's asynchronous, with its own quote → queue → retrieve → complete family (parallel to, but separate from, venice-audio-music).

Availability (checked 2026-09-30): the endpoints are in the public API spec, but the only voice-changer model, elevenlabs-voice-changer, is not yet open to regular API keys. It is not listed by GET /models, and regular keys (or no key) get 404 "Specified model not found" from every endpoint below. Before using this skill, confirm that a model with model_spec.voice_changer: true shows up in GET /models?type=music for your key; if none does, the feature isn't available to you.

Method	Path	Auth	Notes
POST	/api/v1/audio/voice-changer/quote	None required (key optional)	Price for a source of N seconds.
POST	/api/v1/audio/voice-changer/queue	Bearer key or x402 (SIWX)	multipart/form-data (file) or JSON (audio_url). Charges and enqueues. 40 req/min per user.
POST	/api/v1/audio/voice-changer/retrieve	Bearer key or x402 (SIWX)	Status JSON or the converted audio. 120 req/min per user.
POST	/api/v1/audio/voice-changer/complete	Bearer key or x402 (SIWX)	Release the provider-held media.

Each endpoint only accepts voice-changer models (400 otherwise, naming the endpoint to use instead), and /audio/quote, /audio/queue, /audio/retrieve, /audio/complete refuse voice-changer models the same way.

Use when

• You have a real recording (voice-over, dialogue, a take) and want it in another voice without re-performing it.
• You want to keep the timing of the original exactly — e.g. dubbing against picture.

For text → speech use venice-audio-speech; to create a reusable voice from a sample, see voice cloning there.

Discover models

There is no ?type=voice-changer filter. Voice-changer models are music-type models whose model_spec carries:

Field	Meaning
voice_changer	true on voice-changer models only.
accepted_audio_formats	Containers accepted for the source, judged from the file's bytes (not its name or Content-Type). mp4 covers M4A.
max_source_audio_duration_seconds	Longest source accepted; longer → 422 before any charge.
supports_background_noise_removal	Whether remove_background_noise is honored.
supports_seed	Whether seed is honored.
voices, default_voice, supports_custom_voice_id	Target voices; with supports_custom_voice_id: true you may pass a provider Voice ID.
pricing.durations	Whole-minute price tiers keyed by source length.

elevenlabs-voice-changer supports: formats mp3, wav, ogg, mp4, aac; max source 300 s; noise removal and seed supported; the curated ElevenLabs voices (Aria default, Roger, Sarah, …) or any ElevenLabs Voice ID; output mp3. Read its price tiers from pricing.durations rather than hard-coding them.

Lifecycle

1. POST /audio/voice-changer/quote

curl https://api.venice.ai/api/v1/audio/voice-changer/quote \
  -H "Content-Type: application/json" \
  -d '{ "model": "elevenlabs-voice-changer", "duration_seconds": 52 }'

Response: { "quote": <USD>, "duration_seconds": 52 }.

Field	Notes
model	Required. A voice-changer model.
duration_seconds	Required. Positive integer or numeric string, ≤ max_source_audio_duration_seconds.

This is an estimate for the length you declare. The actual charge uses the length Venice measures when you queue; if both round up to the same whole minute the price is identical.

2. POST /audio/voice-changer/queue

Supply the source exactly once — a multipart file or a JSON audio_url. Both or neither → 400.

# Upload
curl https://api.venice.ai/api/v1/audio/voice-changer/queue \
  -H "Authorization: Bearer $VENICE_API_KEY" \
  -F "model=elevenlabs-voice-changer" \
  -F "file=@take-03.wav" \
  -F "voice=Roger" \
  -F "remove_background_noise=true"

# By URL
curl https://api.venice.ai/api/v1/audio/voice-changer/queue \
  -H "Authorization: Bearer $VENICE_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "elevenlabs-voice-changer",
    "audio_url": "https://example.com/take-03.mp3",
    "voice": "Roger",
    "seed": 42
  }'

Response:

{ "model": "elevenlabs-voice-changer", "queue_id": "…", "status": "QUEUED", "duration_seconds": 52 }

duration_seconds is the source length measured server-side — the exact quantity billed.

Field	Notes
model	Required.
file	Multipart source recording, max 25 MB.
audio_url	Public http(s) URL. Venice fetches it (30 s timeout, 25 MB cap), validates the bytes, and forwards only the bytes — the URL itself is never passed to the provider.
voice	1–60 chars. A curated voice or provider Voice ID. Defaults to default_voice. Not checked against voices at queue time — an unknown Voice ID fails with 400 at queue or on retrieve.
remove_background_noise	Boolean ("true" / "false" in multipart).
seed	Non-negative integer, for reproducible output.

The body is strict — unknown fields → 400. Format, length, seed and balance are checked before you're charged. A voice the provider rejects at queue time returns 400, and any charge is refunded immediately.

3. POST /audio/voice-changer/retrieve

curl https://api.venice.ai/api/v1/audio/voice-changer/retrieve \
  -H "Authorization: Bearer $VENICE_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"model":"elevenlabs-voice-changer","queue_id":"..."}' \
  --output converted.mp3

• Still running: 200 {"status":"PROCESSING","average_execution_time":<ms>,"execution_duration":<ms since queued>}.
• Done: 200 with the audio bytes, plus x-venice-audio-format, x-venice-inference-time (s), x-venice-model-id, x-venice-model-name, and x-venice-audio-duration when known.
• Failed: an error status with { "error": "…", "credits_refunded": true|false }. If the provider accepted then failed the job, the charge is refunded; when credits_refunded is false, the message says whether anything is owed. The verdict is stored, so later polls return the same answer without a second refund.
• delete_media_on_completion: true releases the provider copy as soon as the audio is returned.

The audio is delivered once. After a successful download, the next retrieve for that queue_id returns 404. Save the bytes on the first success.

4. POST /audio/voice-changer/complete

curl https://api.venice.ai/api/v1/audio/voice-changer/complete \
  -H "Authorization: Bearer $VENICE_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"model":"elevenlabs-voice-changer","queue_id":"..."}'

Returns {"success": true} once the provider-held media is released (false if the delete didn't go through). Safe to call more than once. Skip it if you retrieved with delete_media_on_completion: true.

Full loop (TypeScript)

import fs from 'node:fs/promises'

const base = 'https://api.venice.ai/api/v1'
const auth = { Authorization: `Bearer ${process.env.VENICE_API_KEY}` }
const model = 'elevenlabs-voice-changer'

async function convert(path: string, voice: string) {
  const form = new FormData()
  form.append('model', model)
  form.append('voice', voice)
  form.append('file', new Blob([await fs.readFile(path)]), 'source.wav')

  const queued = await fetch(`${base}/audio/voice-changer/queue`, { method: 'POST', headers: auth, body: form })
  if (!queued.ok) throw new Error(`queue ${queued.status}: ${await queued.text()}`)
  const { queue_id, duration_seconds } = await queued.json()
  console.log('billed seconds:', duration_seconds)

  while (true) {
    const res = await fetch(`${base}/audio/voice-changer/retrieve`, {
      method: 'POST',
      headers: { ...auth, 'Content-Type': 'application/json' },
      body: JSON.stringify({ model, queue_id, delete_media_on_completion: true }),
    })
    if (!res.ok) throw new Error(`retrieve ${res.status}: ${await res.text()}`)
    if (!(res.headers.get('content-type') ?? '').startsWith('application/json')) {
      await fs.writeFile('converted.mp3', Buffer.from(await res.arrayBuffer()))
      return
    }
    await new Promise(r => setTimeout(r, 3000))
  }
}

Errors

Code	Meaning
400	Strict-body error; both or neither of file / audio_url; audio_url unreachable or unusable; source not in accepted_audio_formats, has a video track, or its length can't be read; voice rejected by the provider (at queue, or later on retrieve — then refunded); non-voice-changer model; unknown / foreign queue_id ("Request ID is invalid.").
401	Authentication failed.
402	Insufficient balance (checked against the price for the measured length). Wallet callers above the $0.10 floor but below the price get the plain {"error":"Insufficient USD or Diem balance…"} body, not PAYMENT_REQUIRED.
403	A PRIVATE_ONLY key calling an anonymized model, or region restriction.
404	Model not found (today: every regular API key); on retrieve, media expired or already delivered.
413	Uploaded file over 25 MB.
422	Source longer than max_source_audio_duration_seconds (at queue, not charged); or, on retrieve, a provider content-policy rejection (refunded).
429	Rate limited (40/min queue, 120/min retrieve, per user).
500	Inference failure; body carries credits_refunded on retrieve.
503	Model at capacity.
504	On retrieve: the provider never accepted the job and it can no longer complete (after ~10 min); charge refunded.

See venice-errors for general body shapes.

Gotchas

• Check availability first — see the note at the top. A 404 on quote with a correct model id means your key can't use it.
• Billing is on the source length, measured server-side and rounded up to whole minutes. A 61 s clip costs the 2-minute tier; trim silence before uploading.
• Don't blindly retry a queue call: a 200 means you've been charged. Keep the queue_id and poll instead.
• Save the audio on the first successful retrieve — there's no second download.
• Mislabelled files are fine (the bytes decide the format); a video file is rejected even if it's an MP4 with audio — extract the audio track first.