Seed Audio 1.0

Endpoint

POST https://api.roasos.com/v1/audio/seed-audio-1.0

Send your API key as a bearer token. The key needs the scope api:write. Every paid request also needs an Idempotency-Key header.

The envelope fields quote_only, quote_id, webhook_url and wait_timeout_seconds behave the same on each model endpoint. Refer to Jobs and Quotes and credits.

Good at

The only audio model in the roster that takes references. Give it up to three reference audio clips, name them @Audio1, @Audio2, @Audio3 in the prompt, and it matches that timbre and delivery. Give it one reference image instead, and it reads the scene. fal lists it as text-to-audio, so the prompt can direct a whole piece: "Generate a short suspense radio drama in a late-night convenience store." It is the only audio endpoint that exposes output_format and sample_rate, so use it when you need WAV or PCM. It does not clone a voice into a saved voice_id, and it does not accept avatar_id.

Pricing

The unit is one characters. Pricing key: seed-audio-1.0.

The credits come from the roasOS pricing table. No other field changes the price. To get the exact price of your request, send it with quote_only: true first.

Modes

• text-to-speech

Provider endpoints: bytedance/seed-audio-1.0.

Request fields

The schema is strict. A field that is not in this table gets 400 unsupported_option. The field names are the roasOS role names. One role has one name in every family.

Media

This endpoint accepts these media roles:

• image_url — first frame (or the single source image)
• audio_urls — reference or driving audio

Every other role is refused: avatar_id, elements, product_id, product_images, references, reference_images, end_image_url, scene_id, scene_image, video_urls, video_url, audio_url, voice_id. A refused role gets 400 unsupported_option.

Prompt

text limit 10,000 characters. roasOS adds no wrapper and no tags.

• Tag syntax: @Audio1, @Audio2, @Audio3, each once, in the order of audio_urls: "Read this in the voice of @Audio1: …".
• With no reference, write the spoken words and pick a voice whose suffix includes the language of the text.
• For scene audio, describe the place, the mood, and the speakers in one sentence before the lines.
• For a multi-voice read, label the speakers in the text and give one reference clip per speaker.
• Keep speed near 1; the reservation assumes 12.5 characters per second.
• Choose output_format: "wav" and sample_rate: 48000 for a master you will edit further.

Not exposed

These catalog entries describe omitted inputs, pinned values and source constraints. They do not imply that the provider accepts every listed field.

• multilingual — pinned to false.
• audio_urls — these values are not available: PCM containers, Ogg Opus containers.
• references — not accepted by this public endpoint.
• avatar_id — not accepted by this public endpoint.
• product_id — not accepted by this public endpoint.
• video_urls — not accepted by this public endpoint.
• voice_id — pinned to the model has no provider voice-clone registry.
• language — not accepted by this public endpoint.
• emotion — not accepted by this public endpoint.
• temperature — not accepted by this public endpoint.

Result

The result kind is audio. Always present: url. Present when the run makes it: timestamps.

{
  "data": {
    "id": "gen_…",
    "kind": "audio",
    "model": "seed-audio-1.0",
    "status": "completed",
    "result": {
      "timestamps": [
        {}
      ],
      "url": "https://cdn.roasos.com/workspaces/ws_01/result"
    }
  }
}

The files are immutable objects on https://cdn.roasos.com. A result URL is a valid media input for your next request.

Example

The three steps are always the same: quote, run, poll.

# 1. Quote. Nothing is spent.
curl -X POST https://api.roasos.com/v1/audio/seed-audio-1.0 \
  -H "Authorization: Bearer roasos_sk_live_..." \
  -H "Idempotency-Key: 0f1c9e2a-seed-audio-1.0-0001" \
  -H "Content-Type: application/json" \
  -d '{"quote_only":true,"text":"Two drops, morning and night. That is the whole routine."}'
# 200 { "data": { "kind": "quote", "quote_id": "q_7Hk...", "credits": 3, "expires_at": "...",
#        "confirmation": { "model": "seed-audio-1.0", "example": "1000_characters" } } }

# 2. Run. Same body, same Idempotency-Key, quote_id in place of quote_only.
curl -X POST https://api.roasos.com/v1/audio/seed-audio-1.0 \
  -H "Authorization: Bearer roasos_sk_live_..." \
  -H "Idempotency-Key: 0f1c9e2a-seed-audio-1.0-0001" \
  -H "Content-Type: application/json" \
  -d '{"quote_id":"q_7Hk...","text":"Two drops, morning and night. That is the whole routine."}'
# 201 { "data": { "id": "gen_...", "status": "queued", "credits_reserved": 3 } }

# 3. Poll, then read the result.
curl https://api.roasos.com/v1/jobs/gen_.../status -H "Authorization: Bearer roasos_sk_live_..."
curl https://api.roasos.com/v1/jobs/gen_.../result -H "Authorization: Bearer roasos_sk_live_..."

The deprecated path

POST /v1/generations still reaches this model for one minor version. It is deprecated. This is how it maps:

POST /v1/audio/seed-audio-1.0 is the endpoint. POST /v1/generations still works with { "type": "audio", "model": "seed-audio-1.0", "prompt": "<text>", "options": { "voice": "kian_en_zh", "audio_urls": ["…"], "output_format": "wav", "sample_rate": "44100", "speed": 1, "volume": 1, "pitch": 0 } }; there the script goes in prompt. Every reference must be a workspace-owned cdn.roasos.com object on both surfaces. options.stability must be 0.5 and options.similarity_boost must be 0.75 (no-op).

See also

• llms.txt for this model — the same facts as one plain-text file for an agent.
• GET https://api.roasos.com/v1/catalog/seed-audio-1.0 — the machine-readable form: enums, defaults, limits and prices. Refer to the API reference.
• Jobs — how to poll a job and read its result.
• Provider endpoints: bytedance/seed-audio-1.0.