Music Generation API

POST https://blockrun.ai/api/v1/audio/generations          # submit (returns 200 inline or 202 + poll_url)
GET  https://blockrun.ai/api/v1/audio/generations/{id}     # poll an async job (settles on first completed poll)
GET  https://blockrun.ai/api/v1/audio/models               # list music models (free, rate-limited)

{
  "model": "minimax/music-2.5+",
  "prompt": "upbeat synthwave with warm neon pads and a driving beat",
  "instrumental": true,
  "duration_seconds": 30
}

{
  "created": 1775488202,
  "model": "minimax/music-2.5+",
  "data": [
    {
      "url": "https://blockrun.ai/api/media/audios/2026/08/12/<id>.mp3",
      "duration_seconds": 186,
      "lyrics": "..."
    }
  ]
}

{
  "id": "<job id>",
  "object": "audio.generation.job",
  "status": "queued",
  "model": "minimax/music-2.5+",
  "price": { "amount": "0.158500", "currency": "USD" },
  "payment_status": "verified",
  "created": 1775488202,
  "poll_url": "/api/v1/audio/generations/<job id>",
  "poll_instructions": "Slow model — generation exceeded the inline window. Send GET to poll_url with an x-payment header signed by the SAME wallet …"
}

{
  "id": "<job id>",
  "object": "audio.generation.job",
  "status": "in_progress",
  "model": "minimax/music-2.5+",
  "payment_status": "verified",
  "note": "Generation in progress. Poll again in 3-10s. No charge until status=completed."
}

{
  "id": "<job id>",
  "object": "audio.generation.job",
  "status": "completed",
  "model": "minimax/music-2.5+",
  "created": 1775488202,
  "data": [
    { "url": "https://blockrun.ai/api/media/audios/2026/08/12/<id>.mp3", "duration_seconds": 186, "lyrics": "..." }
  ],
  "price": { "amount": "0.158500", "currency": "USD" },
  "payment": { "status": "settled", "tx_hash": "0x…", "network": "base" }
}

curl -X POST http://localhost:8402/v1/audio/generations \
  -H "Content-Type: application/json" \
  -d '{
    "model": "minimax/music-2.5+",
    "prompt": "chill lo-fi hip hop, late night study vibes",
    "instrumental": true
  }'

URL=$(curl -s -X POST http://localhost:8402/v1/audio/generations \
  -H "Content-Type: application/json" \
  -d '{"model":"minimax/music-2.5+","prompt":"chill lo-fi hip hop","instrumental":true}' \
  | python3 -c "import sys,json; print(json.load(sys.stdin)['data'][0]['url'])")

curl -L "$URL" -o track.mp3

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

wallet_key = load_wallet()
account = Account.from_key(wallet_key)
BASE = "https://blockrun.ai"
body = {
    "model": "minimax/music-2.5+",
    "prompt": "epic orchestral film score, dramatic strings",
    "instrumental": True,
}

def sign(resp):
    """Sign the x402 challenge carried by a 402 response."""
    pr = parse_payment_required(resp.headers["PAYMENT-REQUIRED"])
    acc = pr["accepts"][0]
    return 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 1: get the challenge, sign it, submit (waits up to ~60s inline)
challenge = requests.post(f"{BASE}/api/v1/audio/generations", json=body)
result = requests.post(
    f"{BASE}/api/v1/audio/generations",
    json=body,
    headers={"X-Payment": sign(challenge)},
    timeout=100,
)

# Step 2: fast path returned the track inline; slow path returned 202 + poll_url
if result.status_code == 202:
    poll_url = BASE + result.json()["poll_url"]
    while True:
        time.sleep(5)
        # An unsigned poll returns its own 402 — sign it with the SAME wallet
        poll = requests.get(poll_url, timeout=100)
        if poll.status_code == 402:
            poll = requests.get(poll_url, headers={"X-Payment": sign(poll)}, timeout=100)
        job = poll.json()
        if poll.status_code == 200 and job.get("status") == "completed":
            result = poll
            break
        if job.get("status") == "failed":
            raise RuntimeError(f"generation failed, not charged: {job.get('error')}")

track = result.json()["data"][0]
print(f"Track URL: {track['url']}")
print(f"Duration: {track.get('duration_seconds')}s")
print(f"Tx: {result.headers.get('X-Payment-Receipt')}")

body = {
    "model": "minimax/music-2.5+",
    "prompt": "upbeat pop with piano",
    "lyrics": "Sunshine in the morning\nBrightens up my day\nEvery step I'm taking\nLeads me on my way",
    "instrumental": False,
}
# then run the same sign → submit → (poll) loop as above

✅ "upbeat pop with piano and synth bass, energetic chorus"
✅ "dark ambient drone, slow evolving pads, cinematic tension"
✅ "jazz trio, upright bass, brushed snare, bebop swing"

✅ "120 BPM, danceable, happy summer vibes"
✅ "slow and melancholic, solo piano, minor key"

{
  "model": "minimax/music-2.5+",
  "prompt": "pop song about chasing dreams",
  "instrumental": false
}