Music API

Generate songs, instrumentals, and BGM. 32 models including Suno V4.5. From $0.018/track.

Async API. Music generation is asynchronous. Submit a job and poll GET /v1/jobs/:id, or use a webhook_url callback.

POST /v1/generations/music

Submit a music generation job. Supports text prompts, lyrics, genre tags, and instrumental mode.

Request body

Field	Type	Required	Description
`model`	string	Yes	Model key (e.g. `"suno-v4-5"`, `"yue-v2"`, `"diffrhythm"`, `"mureka-v7-6"`).
`prompt`	string	Yes	Description or lyrics. Supports `[Verse]`, `[Chorus]` section markers.
`genre`	string	No	Genre tag: `"pop"`, `"jazz"`, `"electronic"`, `"classical"`, etc.
`duration`	number	No	Duration in seconds. Max varies by model (60-480s).
`instrumental`	boolean	No	Set to `true` for instrumental-only (no vocals).
`webhook_url`	string (URL)	No	URL to POST the result to when complete.
`confirm`	boolean	No	Set to `false` for cost estimate only. Default: `true`.

Response fields

Field	Type	Description
`id`	string	Job ID (`job_` prefix).
`status`	string	`"queued"`, `"processing"`, `"completed"`, or `"failed"`.
`url`	string	CDN URL of the generated audio (MP3).
`cost.micro`	integer	Cost in microdollars.
`cost.display`	string	Human-readable cost (e.g. `"$0.10"`).
`metadata.duration`	number	Track duration in seconds.
`metadata.title`	string	AI-generated track title (if applicable).

Code examples

curl

curl -X POST https://api.fairstack.ai/v1/generations/music \
  -H "Authorization: Bearer $FAIRSTACK_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "suno-v4-5",
    "prompt": "An upbeat jazz track with walking bass and brushed drums"
  }'

Python

from fairstack import FairStack

client = FairStack(api_key="fs_live_YOUR_KEY")

# Submit async music generation
job = client.generate.music(
    model="suno-v4-5",
    prompt="An upbeat jazz track with walking bass and brushed drums"
)

# Poll for result
result = job.wait()
print(result.url)    # https://media.fairstack.ai/music/...
print(result.cost)   # $0.10

Node.js

import { FairStack } from "fairstack";

const client = new FairStack({ apiKey: "fs_live_YOUR_KEY" });

const job = await client.generate.music({
  model: "suno-v4-5",
  prompt: "An upbeat jazz track with walking bass and brushed drums",
});

const result = await job.wait();
console.log(result.url);   // https://media.fairstack.ai/music/...
console.log(result.cost);  // { micro: 100000, display: "$0.10" }

Completed response

{
  "id": "job_music_abc",
  "status": "completed",
  "url": "https://media.fairstack.ai/music/.../output.mp3",
  "model": "suno-v4-5",
  "modality": "music",
  "cost": {
    "micro": 100000,
    "display": "$0.10",
    "currency": "USD"
  },
  "metadata": {
    "duration": 120,
    "sample_rate": 44100,
    "title": "Midnight Jazz Walk"
  }
}

Cost estimation

Set confirm: false to get the exact cost before generating.

curl -X POST https://api.fairstack.ai/v1/generations/music \
  -H "Authorization: Bearer $FAIRSTACK_API_KEY" \
  -d '{ "model": "suno-v4-5", "prompt": "test", "confirm": false }'

# Response: { "estimated_cost": { "micro": 100000, "display": "$0.10" } }

Lyrics mode

Pass lyrics with section markers for structured song generation:

{
  "model": "suno-v4-5",
  "prompt": "[Verse 1]\nWalking through the city lights\nEvery shadow feels just right\n\n[Chorus]\nWe are the dreamers tonight",
  "genre": "indie pop",
  "duration": 180
}

Instrumental mode

Set instrumental: true for background music, film scores, and BGM:

{
  "model": "yue-v2",
  "prompt": "Epic orchestral score for a fantasy film trailer",
  "instrumental": true,
  "duration": 60
}

Quality tiers

Tier	Example Model	Price	Max Duration	Best For
Budget	DiffRhythm, ACE-Step	$0.018-0.03	60s	BGM, prototyping, short clips
Standard	YuE V2, Mureka	$0.05-0.08	120s	Content creators, podcasts
Premium	Suno V4.5, Suno V4.5 Plus	$0.10-0.15	480s	Professional tracks, full songs

Next steps

Jobs API -- poll async music generation jobs
Model Catalog -- browse all 32 music models
Error Handling -- retries and idempotency

Voice API Jobs API