music-generation

AI music generation via micropayments. No API keys needed.

Generate full-length music tracks with lyrics, instrumental, or custom style prompts — paid per track with USDC on Base.

Note: MiniMax always generates a ~3 minute track per call. Generation takes 1-3 minutes. Plan accordingly.

Available Models

Model	Price	Notes
minimax/music-2.5+	$0.1575	Latest MiniMax flagship, best quality
minimax/music-2.5	$0.1575	Stable version, same quality

Endpoint

POST /api/v1/audio/generations

Request

{
  "model": "minimax/music-2.5+",
  "prompt": "upbeat synthwave with warm neon pads and a driving beat",
  "instrumental": true,
  "lyrics": "optional lyrics if not instrumental",
  "duration_seconds": 30
}

Parameters

Field	Type	Required	Description
`model`	string	No	Model ID (default: `minimax/music-2.5+`)
`prompt`	string	Yes	Music style, mood, or description
`instrumental`	boolean	No	Generate without vocals (default: false)
`lyrics`	string	No	Custom lyrics. Cannot be used with `instrumental: true`
`duration_seconds`	integer	No	Target duration hint 5-240s (default: 30). MiniMax ignores this — output is always ~3 min.

Response

{
  "created": 1775488202,
  "model": "minimax/music-2.5+",
  "data": [
    {
      "url": "https://...",
      "duration_seconds": 186
    }
  ]
}

The url is a time-limited CDN link (expires in ~24h). Download immediately if you need to store the file.

Payment

Same x402 flow as all BlockRun endpoints:

Call without payment → 402 with price + payment requirements
Sign USDC authorization locally (EIP-712)
Call again with X-Payment header → music generated + payment settled

// 402 response body
{
  "error": "Payment Required",
  "price": { "amount": "0.157500", "currency": "USD" },
  "generation_info": {
    "output_duration": "~3 minutes of audio per track",
    "generation_time": "~2 minutes to generate"
  },
  "paymentInfo": { "network": "base", "asset": "USDC", "x402Version": 2 }
}

Usage with Python SDK

import blockrun_llm
from blockrun_llm.x402 import parse_payment_required, create_payment_payload
from eth_account import Account
import requests

wallet_key = blockrun_llm.load_wallet()
account = Account.from_key(wallet_key)

# Step 1: get payment requirements
resp = requests.post(
    "https://blockrun.ai/api/v1/audio/generations",
    json={"model": "minimax/music-2.5+", "prompt": "chill lo-fi beats", "instrumental": True},
)
pr = parse_payment_required(resp.headers["PAYMENT-REQUIRED"])
acc = pr["accepts"][0]

# Step 2: sign & pay
payload = create_payment_payload(
    account=account,
    recipient=acc["payTo"],
    amount=str(acc["amount"]),
    network=acc["network"],
    resource_url=pr["resource"]["url"],
    resource_description="BlockRun music generation",
    max_timeout_seconds=acc["maxTimeoutSeconds"],
    extra=acc.get("extra"),
)

# Step 3: generate (takes 1-3 minutes)
result = requests.post(
    "https://blockrun.ai/api/v1/audio/generations",
    json={"model": "minimax/music-2.5+", "prompt": "chill lo-fi beats", "instrumental": True},
    headers={"X-Payment": payload},
    timeout=200,
)
track_url = result.json()["data"][0]["url"]
print(f"Track: {track_url}")
print(f"Tx: {result.headers['X-Payment-Receipt']}")

Usage with curl

# Step 1: get 402
curl -s -X POST https://blockrun.ai/api/v1/audio/generations \
  -H "Content-Type: application/json" \
  -d '{"model": "minimax/music-2.5+", "prompt": "epic orchestral film score", "instrumental": true}'

# Step 2: pay and generate (use SDK for signing)

Via BlockRun MCP (Claude Code)

claude mcp add blockrun -- npx @blockrun/mcp

Then in Claude:

Generate an upbeat pop track with lyrics about crypto and the future

Create an instrumental ambient track for a meditation app

Limitations

Output is always ~3 minutes — MiniMax does not support duration control
Generation takes 1-3 minutes — do not set client timeout below 200s
MP3 only — no WAV output currently
1 track per request — batching not supported
No image reference inputs — prompt-only generation

Pricing Details

Model	MiniMax Cost	BlockRun Price	Margin
music-2.5+	¥1.0 (~$0.138)	$0.1575	~14%
music-2.5	¥1.0 (~$0.138)	$0.1575	~14%

Prices in USD, paid in USDC on Base network.

Wallet Requirements

Funded wallet on Base mainnet. Recommended balance: $5+ for ~30 tracks.

# Check balance
python3 -c "from blockrun_llm import get_wallet_address; print(get_wallet_address())"

Troubleshooting

"Music generation timed out"

Generation can take up to 3 minutes. Increase your client timeout to at least 200 seconds.

"Payment verification failed"

Insufficient USDC balance. Check your wallet on Basescan.

"Cannot specify lyrics when instrumental=true"

Remove lyrics field or set instrumental: false.