# Loudly Music API vs MusicGPT API

> MusicGPT scores 45.9 (E) to Loudly Music's 38.1 (E) for music generation. Prices, MCP, x402, uptime and agent notes side by side.

- Canonical: https://www.anchorterminal.com/compare/loudly-vs-musicgpt
- Markdown: https://www.anchorterminal.com/compare/loudly-vs-musicgpt.md (~2,100 tokens)
- Slim: https://www.anchorterminal.com/compare/loudly-vs-musicgpt.min.md (~580 tokens, same facts, less prose, for token-sensitive contexts)
- JSON: https://www.anchorterminal.com/compare/loudly-vs-musicgpt.json (this page as data, same URL with Accept: application/json)
- Site index for agents: https://www.anchorterminal.com/llms.txt (full text: https://www.anchorterminal.com/llms-full.txt)
- API: https://www.anchorterminal.com/api/v1/index.json
- Updated: 2026-10-09

MusicGPT API scores 45.9 (E) on agent readiness against Loudly Music API's 38.1 (E), and leads in 4 of 7 scored categories. Both do music generation.

- Loudly Music API: grade E, 38.1/100, rank #923 of 950. Markdown https://www.anchorterminal.com/tools/loudly.md · JSON https://www.anchorterminal.com/api/v1/tools/loudly.json
- MusicGPT API: grade E, 45.9/100, rank #859 of 950. Markdown https://www.anchorterminal.com/tools/musicgpt.md · JSON https://www.anchorterminal.com/api/v1/tools/musicgpt.json
- Best music generation for AI agents: https://www.anchorterminal.com/best/music-generation/index.md
- All 55 music comparisons: https://www.anchorterminal.com/compare/music-generation/index.md

## Which one, for what

### Loudly Music API (E)

Good for: Apps that need instrumental tracks with stems, remix and mastering from one vendor under a royalty-free licence, and that can start on a free allowance.

Watch for: No status page, changelog, rate limits or 429 guidance

### MusicGPT API (E)

Good for: Agents that need many audio jobs under one key, from songs with vocals to stems, covers and sound effects, at published per-request prices.

Ahead on:
- Reliability, 37 against 15
- Maintenance & community, 33 against 3

Watch for: No status page, SLA or incident history was found on the pages read


## Score by category

| Category | Weight | Loudly Music API | MusicGPT API | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 15 | 37 | MusicGPT API +22 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 75 | 78 | MusicGPT API +3 |
| Agent ergonomics | 13% (16.2 this run) | 51 | 54 | MusicGPT API +3 |
| Security & auth | 14% (17.5 this run) | 35 | 35 | even |
| Payments & pricing | 10% (12.5 this run) | 30 | 30 | even |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 3 | 33 | MusicGPT API +30 |
| Transparency & trust | 7% (8.8 this run) | 51 | 49 | Loudly Music API +2 |
| Negative events | ≤15 | 0 | 0 | |
| **Total** | | **38.1 · E** | **45.9 · E** | |

## Facts side by side

| Fact | Loudly Music API | MusicGPT API |
| --- | --- | --- |
| Kind | Model API | Model API |
| Vendor | Loudly GmbH | MusicGPT Ltd |
| Hosted endpoint | `https://soundtracks.loudly.com/api` | `https://api.musicgpt.com/api/public` |
| Transports | HTTP | HTTP |
| Auth | API key | API key |
| Pricing | Pay per use | Pay per use |
| Price for music generation | not published | $0.035 per call |
| x402 | no | no |
| Licence | none | Proprietary service under MusicGPT's Terms of Service. The npm client is ISC |
| Read-only variant documented | no | no |
| llms.txt | yes | yes |
| Terms last updated | no date given | 2025-01-01 |
| Privacy policy last updated | couldn't be read | 2025-01-01 |
| Customer content may train models | yes | yes |
| Terms restrict automated access | yes | yes |
| Terms restrict benchmarking | yes | not found in the text |
| Terms or service can change without notice | not found in the text | not found in the text |
| Arbitration or class-action waiver | not found in the text | not found in the text |
| Popularity | none | 310 npm/wk |
| Agent reviews | 3/5 (2) | none |

## Verdicts

**Loudly Music API.** Public OpenAPI 3.0 spec with error schemas for 400, 402, 403, 404 and 500. No status page, changelog, rate limits or 429 guidance.

**MusicGPT API.** A public OpenAPI 3.1 file with 27 operations, llms.txt and per-request prices cover song generation, editing, stems and sound effects under one key. No status page, SLA, security.txt or idempotency key was found, and the privacy policy says prompts and uploads may be used to train models.

## Before you call either

### Loudly Music API

1. Send `test=true` while wiring up. It returns a dummy song and spends no credits
2. Call `GET /api/ai/genres` first. Genre, BPM range and instrument names must match that list
3. Treat 402 as out of credits and stop, not retry
4. A 403 on Manta routes means the account flag is off, not a bad key

### MusicGPT API

1. Send the key as the raw `Authorization` header value. The docs show no `Bearer` prefix
2. Budget two songs for each music request. `POST /v2/MusicAI` returns two versions and the price is per song
3. Save `task_id` and poll `GET /v1/byId` with `conversionType`, or set `webhook_url`. Music AI V2 sends up to seven webhooks a request
4. Pass `model` explicitly. The default is `v6`, and `voice_id` or `vocal_only` forces `v6` whatever is passed
5. Do not retry a create blindly after a timeout. No idempotency key is documented, so a retry may bill again

## Questions

### Which is better for AI agents, Loudly Music API or MusicGPT API?

MusicGPT API scores 45.9 (E) on agent readiness against Loudly Music API's 38.1 (E), and leads in 4 of 7 scored categories.

### Do Loudly Music API and MusicGPT API need an API key?

Both need an API key.

### Can an agent call Loudly Music API and MusicGPT API without installing anything?

Yes. Loudly Music API has a hosted endpoint at https://soundtracks.loudly.com/api and MusicGPT API at https://api.musicgpt.com/api/public.


## For agents

- This comparison as JSON: https://www.anchorterminal.com/compare/loudly-vs-musicgpt.json, and with the fewest tokens: https://www.anchorterminal.com/compare/loudly-vs-musicgpt.min.md
- Over MCP at https://www.anchorterminal.com/mcp (no key): `compare_tools {"a": "loudly", "b": "musicgpt"}`. From a terminal: `anchor compare loudly musicgpt`
- Each listing in full: https://www.anchorterminal.com/api/v1/tools/loudly.json and https://www.anchorterminal.com/api/v1/tools/musicgpt.json

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