Sonilo Text-to-Music

Generate music from a text description alone — no video involved. The prompt IS the input, so the brief carries everything: genre, mood, energy arc, instrumentation, and what must not appear. Every track is licensed (music licensed via Shutterstock) and cleared for commercial use on social, brand content, and advertising.

Setup: See the setup-api-key skill to connect the Sonilo MCP server and authenticate — sonilo login (no key) or SONILO_API_KEY.

⚠️ Cost: this tool makes an API call that may incur charges. Only call it when the user has actually asked for a generation. Check get_account_services (see the account skill) if you're unsure whether free-trial runs remain.

Scoring a video instead? Use video-to-music — it matches pacing, motion, and emotion to the actual cut, which a text prompt cannot do.

Transport: MCP or CLI

Pick one at the start of the session and stay on it. Do not mix the two inside a single job, and do not announce the choice.

1. Sonilo MCP tools visible in this session (text_to_music and friends) — use them. This is the preferred path: it needs no shell, and it is the only one that survives a very long generation. If a call fails to authenticate — rather than failing on its inputs — this transport is not usable in this session: go to 2 instead of retrying it.
2. No usable Sonilo MCP tools, but sonilo account exits 0 — use the CLI commands below. Same API, same account, same credential file. Probe with sonilo account, not sonilo whoami: whoami exits 0 even when signed out, so it cannot tell the two states apart.
3. Neither — stop and run the setup-api-key skill. Do not call api.sonilo.com with curl to work around it; both transports handle uploads, polling and retries that a bare request does not.

Quick Start

MCP tool call (recommended)

text_to_music(
    prompt="A chill lo-fi hip hop beat with jazzy piano chords",
    duration=30
)

Saves the generated file(s) to SONILO_MCP_BASE_PATH (~/Desktop by default) and returns the saved path(s) as text.

Python (pip install sonilo)

from sonilo import Sonilo

client = Sonilo()  # reads SONILO_API_KEY

track = client.text_to_music.generate(prompt="A chill lo-fi hip hop beat with jazzy piano chords", duration=30)
track.save("output.mp3")

JavaScript / TypeScript (npm install sonilo)

import { SoniloClient } from "sonilo";

const client = new SoniloClient(); // reads SONILO_API_KEY

const track = await client.textToMusic.generate({
  prompt: "A chill lo-fi hip hop beat with jazzy piano chords",
  duration: 30,
});

CLI (npm install -g sonilo-cli or pip install sonilo-cli)

sonilo text-to-music --prompt "A chill lo-fi hip hop beat with jazzy piano chords" --duration 30

cURL (raw REST API, no MCP host)

curl -X POST "https://api.sonilo.com/v1/text-to-music" \
  -H "Authorization: Bearer $SONILO_API_KEY" \
  --data-urlencode "prompt=A chill lo-fi hip hop beat with jazzy piano chords" \
  --data-urlencode "duration=30" \
  --output output.m4a

Tool

Parameters

Stems

stems=true additionally returns each generated track split into four separated instrument tracks — drums, bass, vocals, other — free of charge. The full mix is untouched; the stems arrive alongside it in the task result as a stems array next to audio:

"stems": [
  {
    "stream_index": 0,
    "drums":  { "url": "…", "content_type": "audio/mp4", "file_size": 2913044 },
    "bass":   { "url": "…", "content_type": "audio/mp4", "file_size": 2870211 },
    "vocals": { "url": "…", "content_type": "audio/mp4", "file_size": 2794560 },
    "other":  { "url": "…", "content_type": "audio/mp4", "file_size": 3011830 }
  }
]

What matters when you use it:

• Async only on REST. stems=true requires mode=async (a 400 otherwise): you get a 202 + task_id and poll /v1/tasks/{task_id}. The MCP tools are always async, so on the hosted server the param just works.
• Available on every surface (verified 2026-08-17): REST, the hosted MCP server, the local sonilo-mcp package (>= 0.18.0), the SDKs (sonilo npm >= 0.16.0, PyPI >= 0.15.0), and the CLIs (--stems, npm sonilo-cli >= 0.15.0, PyPI sonilo-cli >= 0.14.0).
• Match stems to tracks by stream_index, never by array position. A stream whose separation failed is simply absent, so stems can be shorter than audio.
• stems_error is not a failed generation. When separation failed wholly or partly, or was skipped, the task carries a stems_error string — possibly alongside a partial stems array. The generation itself succeeded and every audio URL is valid: treat missing stems as a missing extra, never as a reason to retry or refund.
• Timing: separation runs after generation finishes — typically another 2–6 min, giving up after 30 min (then stems_error).
• The four stem names are fixed (htdemucs separation): melodic instruments — piano, synths, guitar, strings — land in other, and on instrumental tracks vocals is near-silent. That is correct behavior, not a bug.
• Formats: stems normally follow output_format; trust each stem's content_type for what was actually delivered.

# REST: submit with stems, then poll the task
curl -X POST "https://api.sonilo.com/v1/text-to-music" \
  -H "Authorization: Bearer $SONILO_API_KEY" \
  --data-urlencode "prompt=A chill lo-fi hip hop beat with jazzy piano chords" \
  --data-urlencode "duration=30" \
  --data-urlencode "mode=async" \
  --data-urlencode "stems=true"
# → {"task_id": "…"} — poll GET /v1/tasks/{task_id} for audio + stems

Prompting

The prompt is the only input — there is no footage to lean on. Describe genre, mood, tempo, instrumentation, and the energy arc; "A driving synthwave track with arpeggiated leads" beats "electronic music." Describe structure in words too ("builds for 10 s, drops, outro"), since there is no cut to infer it from. Name exclusions explicitly — the sounds that must not appear.

The same craft vocabulary applies as for video scoring, minus the video pre-flight: references/music-prompting.md.

Generate once and iterate on the prompt, not on rerolls — failed runs auto-refund, but your own retry is a new charge.

Workflow Tips

• If the user has a finished video, you are in the wrong skill. video-to-music syncs to the actual cut instead of producing a generic track of matching length.
• Duration is required here. Don't guess it — ask if the user hasn't said.
• Several takes in one go: variants_num=3 returns three distinct directions for one request instead of three re-rolls. It costs 3×, and it is never free-trial covered — say the price before calling.
• User wants the track's instruments as separate files (to remix, re-balance, or drop one)? stems=true — it's free, but async-only and not on every surface yet; see Stems.
• Content restriction: prompts cannot reference specific artists, bands, or copyrighted lyrics.

Recovering a Timed-Out Call

text_to_music streams its result in one call unless output_format="wav", variants_num above 1, or stems=true triggers the backend's async mode. If an async variant times out, the error message includes a task_id; the generation keeps running (and is already charged) on the backend. Call get_sfx_task(task_id) — get_generation_task(task_id) on the hosted server — to retrieve the result; see the task-recovery skill.

Output Files

.m4a by default (.wav if requested), named from the prompt (slugified) or sonilo-<timestamp>.m4a. Multiple parallel streams get a -<index> suffix.

Error Handling

Common errors: 401 invalid key, 402 insufficient balance / trial exhausted, 422 invalid parameters (e.g. duration out of range), 429 rate limit. See the account skill to check trial/usage before a call.