Sumsub

# Fix list: Sumsub

From Anchor Terminal's listing at https://www.anchorterminal.com/tools/sumsub, the October 2026 research run, assessed 8 October 2026. Grade B, 68.5 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 Sumsub: 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. Payments & pricing, 25 out of 100, up to 9.4 more on the total

Why it scored 25: No x402, MPP or L402 (0). Per-verification prices are public for two plans ($1.35 and $1.85, with $149 and $299 monthly minimums). Business verification, transaction monitoring and fraud prevention are quoted by sales (15). Sandbox mode is free without a card and returns test results only. The trial of 50 real checks asks for bank card details (10). Signup, token creation and MCP sign-in all need a person in a browser (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.

## 2. Agent ergonomics, 60 out of 100, up to 6.5 more on the total

Why it scored 60: `fields` on 8 operations and limit and offset on 16 let responses be sized. The MCP tool list couldn't be read without an account (13). Offset paging, a cursor on audit events, case filters and transaction queries, but not on every list (16). Errors return code, description and correlationId, with errorCode and errorName for 139 documented cases (18). No idempotency keys. A caller's own externalUserId can be used to look an applicant up before retrying a create. MCP annotations weren't readable (6). No server SDK, and every request needs an HMAC signature over timestamp, method, path and body. Signing examples exist in seven languages (7).

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.

## 3. Reliability, 80 out of 100, up to 4 more on the total

Why it scored 80: Graded on the REST API, hosted lines. Statuspage at status.sumsub.com with API, WebSDK and MobileSDK components for three regions (20). In the 90 days to 8 October 2026 it shows a complete outage of 13 minutes on 31 August, 13 minutes of SDK 403 errors on 14 July, 75 minutes of AML screening errors on 20 July, Dashboard search errors on 14 September and an open minor incident for some networks in Vietnam, none an hour of core API downtime (20). Limits published as 300 GET and 50 POST per 5 seconds (15). 429 is documented, but no Retry-After, backoff guidance or idempotency key was found (5). 99.5 per cent monthly availability in Annex 1 of the public terms (10). The API is generally available (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.

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

Why it scored 78: Public OpenAPI 3.0.1 spec at api.sumsub.com/openapi.json with 157 operations (25). llms.txt on docs and API hosts, and every docs page as Markdown (10). Reference pages give an overview, required permission and field tables per method, but only 24 of 157 operations in the spec carry a summary or description, and when not to use a method is rarely stated (12). 1,119 schemas with 132 enums and 319 required lists, though 189 of 5,343 properties are described (10). Request and response examples on reference pages and a table of 139 error codes, while 154 operations declare only a default response (11). A weekly dated changelog, but the spec stays at version 1.0.0 with no version in the path (10).

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.

## 5. Security & auth, 80 out of 100, up to 3.5 more on the total

Why it scored 80: App tokens with per-token permissions, IP allowlist, optional expiry, disable and delete, and HMAC signing so the secret never travels. MCP uses OAuth with PKCE and dynamic client registration (30). View and manage permissions are separate, source keys limit a token to a group of applicants, and a role permission gates MCP. No confirmation step for destructive calls was found (15). The API returns applicant-supplied text and document data. No injection guidance was found. Sumsub's skills refuse non-sandbox tokens (4). Audit trail events API with IP and user agent, 30-day usage per token, and an email on token creation (13). security.txt valid to 31 December 2027, a Bugcrowd engagement, SOC 2 Type 2, ISO/IEC 27001 and PCI DSS listed. No public advisories page found (18). Judgement call, no deduction for the webhook digest test endpoint, which takes a webhook secret in the query string, because the API credential itself can't.

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.

## 6. Maintenance & community, 74 out of 100, up to 2.3 more on the total

Why it scored 74: The changelog's latest entry covers 28 September to 2 October 2026, and agent skills 1.5.0 shipped on 3 October (30). Weekly changelog entries through July, August and September (20). Closed service with a dated changelog, a support site and a feedback tool in the MCP server. Response times weren't measurable (10). The WebSDK on npm is at 2.9.0 and mobile SDKs have their own changelogs, but there is no server SDK and no entry in the official MCP registry (8). The skills repository has had five releases since 3 July, and the signing examples took dependency updates until 11 June 2026. No CI workflows in either (6).

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.

## 7. Transparency & trust, 74 out of 100, up to 2.3 more on the total

Made of editorial 52, provenance 96.

Why it scored 74: Closed service with public terms dated 21 May 2026 naming the contracting entities. Skills and WebSDK are MIT (16). The data processing agreement is Annex 3 of the terms and the privacy notice is dated 19 March 2026. Customers set retention, and data is deleted after a year of inactivity following cancellation. Clause 6.9 lets Sumsub use personal data to develop fraud detection with machine learning, which is disclosed but broad (20). The API reference says breaking changes are versioned and existing endpoints aren't affected. Mobile SDK versions are supported for one year. The older audit endpoint is marked for deprecation without a date (8). Hosting regions EU, UAE and SGP appear on the status page. The subprocessor list is in the Dashboard, not public (8).

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):

- Terms of service: read, states 7 of the 7 things a reader expects, and has 2 clauses that cost points (6 of 10)

## 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 MCP server's tool list, count, input schemas and annotations (tools/list needs a signed-in Sumsub account)
- unchecked: whether signing up for a Sandbox-only account asks for a card. The docs ask for card details only when activating the trial
- unchecked: GitHub stars and open issues for sumsub/agent-skills (GitHub web pages weren't fetched)
- Whether 429 responses carry a Retry-After header. None is documented
- The subprocessor list and data hosting locations are in the Dashboard and weren't read
- Whether the SLA in Annex 1 carries service credits, which weren't found in the text reviewed

## Weaknesses

- No idempotency keys and no Retry-After or backoff guidance found in the reviewed documentation
- Only 24 of 157 operations in the OpenAPI spec carry a summary or description, and 154 declare only a default response
- No official server-side SDK. Sumsub publishes request-signing examples in seven languages instead
- The 14-day trial of 50 real checks needs a bank card, and production opens after Sumsub checks the integration
- Terms clause 6.9 permits Sumsub to use customers' personal data to develop fraud detection, including machine learning models
- The subprocessor list is published in the Dashboard, not on a public page

## 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.

- Sign every request. X-App-Access-Sig is the lowercase hex HMAC-SHA256 of timestamp, uppercase method, path with query and raw body, and the timestamp must be within one minute of server time
- Use a sandbox token (prefix sbx) for agent work. Sandbox and production tokens are separate, and Sumsub's own skills refuse any other prefix
- Stay under 300 GET and 50 POST requests per 5 seconds, and under 500 new applicants per 24 hours in Sandbox
- Token permissions can't be edited after creation. Generate a new token with the narrower set and delete the old one
- Subscribe to the applicantReviewed webhook for results and verify x-payload-digest against the raw body before trusting it

## 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.