Soundverse API by Soundverse Inc.

# Fix list: Soundverse API

From Anchor Terminal's listing at https://www.anchorterminal.com/tools/soundverse, the October 2026 research run, assessed 1 October 2026. Grade E, 42.2 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 Soundverse 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, 27 out of 100, up to 14.6 more on the total

Why it scored 27: No status page found (0). No readable incident history (5). Limits are enforced per tool and per model, hourly and daily, but no numbers are published (0). A 429 returns a `RateLimited` error with `retryable: true`, with no Retry-After or rate-limit headers (5), and an `Idempotency-Key` header makes retried creates safe (7). No SLA (0). The Enterprise API isn't 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: Plain bearer keys with an `sksoundverse_` prefix from the self-serve platform dashboard, with no scopes, expiry or rotation documented (20). No least-privilege mode (0). Returns generated audio and copyright-check results, no third-party content (10). Each generation has an ID and is charged to a wallet, with no audit log found (5). No security.txt, disclosure policy, bug bounty or certification found (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, 20 out of 100, up to 10 more on the total

Why it scored 20: No x402, MPP or L402 (0). Per-call USD prices by capability and licence tier on the platform pricing page, per the listing's check of 2026-09-30 (20). No free tier published (0). A person signs up and funds a wallet (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. Maintenance & community, 3 out of 100, up to 8.5 more on the total

Why it scored 3: No dated release, changelog entry or model launch date found for the API (0). No dated entries in the last 90 days (0). No public changelog. Support is through the help site (3). No official SDK (0). No package 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.

## 5. Transparency & trust, 46 out of 100, up to 4.7 more on the total

Made of editorial 30, provenance 62.

Why it scored 46: Closed service, and output rights are chosen per call, from royalty-free to full ownership of the master, which makes the licence for each file explicit (15). The privacy notice names Soundverse Inc. (US) and SonicLabs AI Private Limited (India), and the whitepaper says training uses only licensed or consented material. We didn't check retention periods (10). Older versioned routes still work through a compatibility layer, but there are no dated deprecation notices (5). No subprocessor 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: soundverse.ai, registered 2023-02-10 (3 years) (7 of 15)
- Status page: not found (0 of 10)
- Changelog: not found (0 of 10)
- security.txt: not found (0 of 10)

## 6. Agent ergonomics, 72 out of 100, up to 4.6 more on the total

Why it scored 72: Creates return a small JSON task at once and outputs arrive as file IDs, but song length isn't a documented parameter and downloads take a second call (15). Polling plus an SSE progress stream on `/v1/generations/{id}/stream` (10). Errors name the cause and say whether to retry (20). `Idempotency-Key` on creates returns the original task without billing again (20). The licence defaults to royalty-free and one endpoint covers every capability (7), no official SDK (0).

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.

## 7. Schema & documentation, 75 out of 100, up to 4.1 more on the total

Why it scored 75: OpenAPI document published on the help site (25). llms.txt on the help site (10). The docs explain the single generations endpoint and the async flow, but say little about when to pick one `tool_id` over another (12). The `license` field is an integer from 0 to 5 with a default of 1, and the capability is chosen by `tool_id` with a per-tool parameters object, which is looser than a typed field per capability (9). A structured error model with named errors (`RateLimited`, `DependencyUnavailable`, `UNAUTHENTICATED`, `INVALID_API_KEY`) and a `retryable` flag (14). `/v1` routes plus a compatibility layer for older versioned routes, no changelog (5).

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.

- We couldn't load the pricing page, OpenAPI document or privacy policy on 2026-10-01, so prices, the OpenAPI and the entity split rest on the listing's check of 2026-09-30.
- Song length limits aren't published.
- When the v7 models shipped, and whether any older model versions are scheduled for retirement.

## Weaknesses

- No status page, changelog or security.txt
- Rate limits enforced hourly and daily per tool with no numbers and no headers
- Song length isn't a documented parameter, and outputs need a second download call
- No official SDK, and no free tier

## 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.

- Always set `Idempotency-Key` on creates, so a retry after a 429 doesn't bill twice
- Retry only errors with `retryable: true` (`RateLimited`, `DependencyUnavailable`). 401 and 403 won't fix themselves
- Pass `license` explicitly. The default is 1, royalty-free, which doesn't cover sync or distribution
- Fetch audio through `GET /v1/files/{file_id}/download`, then poll `GET /v1/generations/{id}` or open `/stream` for progress

## What the review panel asked for

- Rate-limit headers
- A duration parameter
- Publish rate-limit numbers

## 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.