MusicGPT API

# Fix list: MusicGPT API

From Anchor Terminal's listing at https://www.anchorterminal.com/tools/musicgpt, the October 2026 research run, assessed 9 October 2026. Grade E, 45.9 out of 100.

This is everything the published grade says the listing lacks, the biggest possible gain to the total first. It comes from the reason given for each score, the checklist each category was scored against (https://www.anchorterminal.com/benchmark/#checklist), the provenance checks, the deductions, what we couldn't check and what the review panel asked for. A fix counts at the next check, once it's public.

For a coding agent working on MusicGPT API: work through the items below in the product, its docs and its public pages. Each category gives the reason for its score, with the points each checklist item earned, and the checklist itself, so the gap is the items that earned less than their points. Change the product, not the wording, and keep a note of what you changed and where it's published.

## 1. Reliability, 37 out of 100, up to 12.6 more on the total

Why it scored 37: Graded as a hosted API. No status page is linked from the docs, the home page or the API page (0). No readable incident history (5). Limits are published per plan, 1, 3 or 10 parallel requests per feature group and 20, 200 or 500 `GET /v1/byId` calls a minute (15). The error page names 429 `TOO_MANY_REQUESTS` and asks for exponential backoff, with no Retry-After header and no idempotency key documented (7). No SLA found. The API page claims 99 per cent server uptime with no terms behind it (0). `POST /v2/MusicAI` is not labelled beta (10).

The checklist (https://www.anchorterminal.com/benchmark/#checklist-reliability):

Hosted APIs, MCP servers, models and platforms.

- 20, a public status page with component history (Statuspage, Instatus, BetterStack or the vendor's own).
- 0 to 30, the incident record for the last 90 days on that page. 30 for a clean record or trivial incidents only, 20 for minor incidents only, 10 for one major outage (an hour or more of a core API down, or errors across the board), 0 for several. 5 when there's no history we could read, and the note says so.
- 15, rate limits documented with numbers.
- 15, documented 429 or overload handling (Retry-After, backoff guidance), and idempotency keys or safe-retry guidance where writes are involved.
- 10, an SLA published for any paid tier.
- 10, the surface agents use is generally available, not beta or preview.

Local packages, SDKs, frameworks and stdio MCP servers.

- 20, installs from an official package with supported runtimes stated.
- 25, a public CI and test suite, passing on the default branch.
- 0 to 25, open crash or regression issues relative to activity (25 for few and handled, 0 for many, old and unanswered).
- 15, semver discipline and breaking changes called out in a changelog.
- 15, version 1.0 or later, or declared stable.

Protocols are read from their reference implementations, the public facilitators or servers, spec stability and test vectors.

## 2. Security & auth, 35 out of 100, up to 11.4 more on the total

Why it scored 35: Named API keys created in the API dashboard and sent as the raw `Authorization` header value. No scopes, expiry or rotation are documented (20). No read-only or restricted key (0). Output is generated audio, lyrics and transcripts of the caller's own files, so no third-party content (10). Each conversion can be fetched by ID with its `conversion_cost`, and no audit log was found (5). `/.well-known/security.txt` answers 404, and no disclosure policy, bug bounty or certification was found on the pages read. No webhook signature is documented (0).

The checklist (https://www.anchorterminal.com/benchmark/#checklist-security):

- 0 to 30, the credential model. 30 for OAuth 2.1 with scopes, or scoped and revocable keys with rotation. 20 for plain revocable API keys. 10 for one all-powerful key. 10 off when a secret can travel in a URL query string as a documented option.
- 0 to 20, read-only or least-privilege modes, and confirmation or approval for destructive actions.
- 0 to 15, prompt-injection posture where the tool returns untrusted content (documented mitigations or guidance). A tool that returns no untrusted content gets 10.
- 0 to 15, audit logs or per-call visibility for the operator.
- 0 to 20, a security programme. security.txt or a disclosure policy, a bug bounty, SOC 2 or ISO 27001, advisories handled in public.

Models are read for retention, whether API data trains models (and whether that's off by default), zero-retention options and certifications. Frameworks for telemetry defaults, approval hooks, guardrails and sandboxing.

## 3. Payments & pricing, 30 out of 100, up to 8.8 more on the total

Why it scored 30: No x402, MPP or L402 in the docs, the OpenAPI file or the pricing page (0). Per-request prices for every feature on three plans are public (20). The pricing page says up to 10 free song generations and the rate-limit page has a Free plan column, while the account page says to enter payment information, so the card question is open and the line takes half (10). A person signs up in a browser by email code or social login and creates the key in a dashboard (0).

The checklist (https://www.anchorterminal.com/benchmark/#checklist-payments):

The published rubric, also on the [x402 page](https://www.anchorterminal.com/x402/).

- 40, a machine payment protocol (x402, MPP or L402) on the tool's own endpoints. 10 to 30 when it covers only some endpoints or only goes through a third party, and the note says which.
- 20, per-call or per-unit pricing published without a login. 10 for public plan-only pricing, 0 for "contact sales" or prices behind a login.
- 20, a free tier or trial that doesn't need a card.
- 20, autonomous onboarding, meaning an agent can get access without a person signing up in a browser (keyless use, x402, a programmatic key API).

Payment platforms and agent wallets rarely charge for their own API over a machine protocol, so the first line has steps for them, and the highest one that applies counts. 40 when x402, MPP or L402 runs on all their own endpoints, 30 when it runs on part of their own API, 25 when their merchants can accept one, 20 for running a facilitator, 15 for paying as a buyer, and 0 when the only protocol is their own. Merchant acceptance sits above a facilitator because the platform's own customers can charge agents through it, while a facilitator settles for sellers who wire up the protocol themselves. The counter-argument (a facilitator does more for the protocol as a whole) has a point. Each note says which step applied.

Open-source software you run yourself is scored on its hosted or paid option if it has one. A free, self-hosted package with nothing to buy gets 20, 20 and 20 for the last three lines, and 0 to 40 for the first only if it ships a payment protocol.

## 4. Agent ergonomics, 54 out of 100, up to 7.5 more on the total

Why it scored 54: Creates return a small JSON task with an `eta` and a `credit_estimate`, but music requests always make two versions and Music AI V2 sends up to seven webhooks a request (15). `limit` and `page` on the two voice lists, polling by `task_id` or `conversion_id`, and no call that lists past conversions (10). One error body with `error_code` and `message` and 11 documented codes (16). No idempotency key is documented and 409 `CONFLICT` is described only in general terms (3). `/v2/MusicAI` has no required field and defaults to `v6`. SDKs are published for Node and Python, and the npm package dates from 16 June 2025 (10).

The checklist (https://www.anchorterminal.com/benchmark/#checklist-ergonomics):

- 0 to 25, context cost. For MCP, the number and size of the tool definitions (25 for ten or fewer compact tools, 15 for 11 to 30, 5 for more than 30, plus up to 10 back for toolsets, dynamic loading or read-only subsets). For APIs, whether responses can be sized (field selection, limits, summaries).
- 20, pagination, filtering and output-size controls.
- 20, actionable, documented error responses, codes and messages an agent can recover from.
- 20, idempotency or safe retries, and for MCP the `readOnlyHint` and `destructiveHint` annotations.
- 15, sensible defaults, few required parameters, and official SDKs in at least two languages.

Models are read for tool use, structured output, prompt caching, context length, batch and SDKs. Frameworks for how much code and how many defaults a tool-calling agent with MCP needs.

## 5. Maintenance & community, 33 out of 100, up to 5.9 more on the total

Why it scored 33: The newest changelog entry is labelled September 2026 with no day, so recency is scored within 90 days (20). Two entries fall in the last 90 days, August and September 2026 (0). A public changelog and an API support address with a stated 24 hour response, with no public issue tracker (8). Official SDKs exist on npm and PyPI, but npm `musicgpt` 1.0.1 dates from 16 June 2025 and names no repository (5). No public repository or CI to judge (0).

The checklist (https://www.anchorterminal.com/benchmark/#checklist-maintenance):

- 0 to 30, time since the last release, or the last published model or API change for a closed service. 30 within 30 days, 20 within 90, 10 within 180, 0 older.
- 20, at least three releases or dated changelog entries in the last 90 days.
- 0 to 25, responsiveness. Issues and pull requests answered on GitHub (the open issues and how recent the replies are). For closed services, a public changelog and a support or community channel that answers, 0 to 15.
- 15, presence in the official MCP registry under a verified namespace (MCP servers), or current official SDKs (APIs and models).
- 10, package health, current dependencies and CI.

Models are read for deprecation notice periods and model churn rather than release counts.

## 6. Transparency & trust, 49 out of 100, up to 4.5 more on the total

Made of editorial 32, provenance 65.

Why it scored 49: Closed service under one 14-section Terms of Service dated 1 January 2025 that covers the whole platform, with no API-specific terms. Paid plans carry commercial rights to output (12). The privacy policy is ten short sections. It says prompts and uploads may be used to train models after anonymisation and gives no retention periods. The changelog says MP3 files are kept 90 days and WAV files 7 days. No DPA found (10). The changelog gives dated notices, such as WAV files leaving webhooks on 9 February 2026 and new prices from 1 August, with no written policy and no removal date for Music AI V1 (10). No sub-processor list or data locations found (0).

The checklist (https://www.anchorterminal.com/benchmark/#checklist-transparency):

- 0 to 30, source availability and licence clarity. 30 for open source under an OSI licence, 15 for closed with clear terms, 0 for unclear terms.
- 0 to 30, data handling and retention statements that agree with each other (privacy policy, DPA, retention periods, subprocessors).
- 0 to 20, a deprecation policy or notices with dates.
- 0 to 20, telemetry disclosed with an opt-out (local software), or subprocessors and data locations disclosed (hosted).

The other half of Transparency and trust is the provenance score, computed from checked facts (below). The category score is the mean of the two.

Provenance checks not met in full (half of this category, computed from checked facts):

- Domain age: musicgpt.com, registered 2021-11-04 (4 years) (7 of 15)
- Terms of service: read, states 5 of the 7 things a reader expects, and has 1 clause that costs points (6.3 of 10)
- Privacy policy: read, states 6 of the 8 things a reader expects, and has 1 clause that costs points (6.5 of 10)
- Status page: not found (0 of 10)
- security.txt: not found (0 of 10)

## 7. Schema & documentation, 78 out of 100, up to 3.6 more on the total

Why it scored 78: A public OpenAPI 3.1 file with 27 operations (25). llms.txt and a Markdown copy of every page (10). Each operation has a one-line purpose and the guides add notes such as `voice_id` forcing the `v6` model, with little on when not to use an endpoint (11). Schemas are inline with no shared components, 12 of 23 request bodies name required fields, and `gender` on `/v2/MusicAI` is a free string although the guide lists three values. Stems travel as a JSON string inside a form field (9). Every operation has an example, and the error page lists 11 codes, while the file documents only 402, 422 and 500 (11). `/v1` and `/v2` paths and a changelog dated by month (12).

The checklist (https://www.anchorterminal.com/benchmark/#checklist-schema):

APIs and MCP servers.

- 25, a machine-readable contract (a public OpenAPI file or similar; for MCP, typed JSON Schema inputs on every tool).
- 10, llms.txt or Markdown docs served for agents.
- 0 to 20, descriptions that say what a tool is for, when to use it and when not to, read from the tool definitions in the source or the API reference.
- 0 to 15, typed inputs with enums, constraints and required fields, and no free-form JSON blobs.
- 0 to 15, examples and documented error responses.
- 15, versioning and a public changelog.

Models are read from the API reference, the OpenAPI file, llms.txt, the structured-output and tool-use docs and the model cards. Frameworks from docs a model can follow, typed interfaces, examples and the API reference.

## What we couldn't check

What we couldn't read counted as absent. Publishing it on a page a plain HTTP fetch can read (not only in a browser) lets the next check count it.

- unchecked: the PyPI project page for `musicgpt` answered with a client challenge, so the Python SDK's version and release date are unknown.
- unchecked: the API dashboard is behind a sign-in, so key revocation, usage logs and whether the free allowance needs a card were not seen.
- unchecked: the 22 feature guides other than Music AI V2 and the prompt guideline were not read. Their parameters were taken from the OpenAPI file.
- Whether a status page exists. None is linked from the docs, the home page or the API page.
- The changelog of January 2026 mentions song length control in Music AI. No length parameter appears in the `/v2/MusicAI` schema or guide, and no maximum song length is published.
- The terms name MusicGPT Ltd. Singapore with no registration number or address. The npm maintainer account and a sample audio bucket carry the name Lalals, and the relation was not established.
- The terms bar building scrapers or similar programs to gain access to MusicGPT's technology. Recorded as a fact with no deduction. It matters before any probe is run.
- The API page carries a paragraph of placeholder Latin text and claims 99 per cent uptime and latency under 180 ms with no source.
- Process notes. robots.txt was read first on musicgpt.com and docs.musicgpt.com (both 200, both allow the pages read). registry.npmjs.org answered the robots.txt path with a package document and pypi.org allows `/project/`. The robots.txt requests to rdap.verisign.com (400) and api.npmjs.org (404) were sent in one command, which the brief asks to keep apart.

## Weaknesses

- No status page, SLA or incident history was found on the pages read
- No idempotency key is documented, and music requests bill two songs each by default
- The privacy policy says prompts and uploads may be used to train models, with no opt-out stated
- No security.txt (404), disclosure policy, certification or webhook signature was found
- The npm SDK was last published on 16 June 2025, before the `model` parameter was added in June 2026
- The terms forbid building scrapers or similar programs to gain access to MusicGPT's technology. This matters before any probe is run

## What costs an agent a turn today

The notes we give agents before they call it. Each one is a workaround an agent shouldn't need.

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

## When it's done

Send what changed and where it's published as a dispute (https://www.anchorterminal.com/builders/#disputes, or `POST https://www.anchorterminal.com/api/v1/contact` with `"kind": "dispute"`). Disputes are answered in public, and the listing is checked again by the same checklist. Paying for an audit or a listing claim changes nothing here.