Quaderno

# Fix list: Quaderno

From Anchor Terminal's listing at https://www.anchorterminal.com/tools/quaderno, the October 2026 research run, assessed 8 October 2026. Grade C, 59.5 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 Quaderno: 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. Security & auth, 39 out of 100, up to 10.7 more on the total

Why it scored 39: An API key sent as the Basic auth username. The docs say anyone holding it can read and modify everything the account has access to. Connect apps use OAuth 2.0 authorisation code with two scopes, read_only (the default) and read_write, access tokens that expire after 25 days and refresh tokens (20). The read_only scope and custom team roles with view-only access to six areas give some least privilege. Invoices can't be deleted through the API, only credited or voided. No confirmation step was found (11). Returns customer names, notes and metadata written by others, with no injection guidance (3). No API audit log was found in the reviewed documentation (0). A security policy page, TLS 1.2 and a Visma Security Program Gold claim. The bug bounty is marked temporarily closed, security.txt returns 404 and the Visma Trust Centre lists no certificates for Quaderno (5).

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.

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

Why it scored 30: No x402, MPP or L402 (0). Four plans are public by month, Hobby $29, Startup $49, Business $99 and Growth $149, each with a transaction allowance, and Enterprise on request. That is plan-only pricing (10). A 7-day trial with no card, stated on the pricing page and in the terms, plus a free sandbox (20). Signup is a browser form (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.

## 3. Agent ergonomics, 56 out of 100, up to 7.2 more on the total

Why it scored 56: No MCP server from the vendor, so this is the REST API. Lists return 25 objects by default and up to 100 with `limit`. There is no field selection, though the tax calculation returns one small object (12). Cursor paging with `created_before` plus X-Pages-HasMore and X-Pages-NextPage headers, and filters by text, date range, state, contact and processor_id on document lists (17). Standard status codes with a JSON `error` message and 422 on invalid state changes, without a catalogue of error codes (11). No idempotency keys. A duplicate can be checked by processor_id before a retry (5). Tax calculation needs only `to_country` and falls back to account defaults. Official Ruby and PHP libraries, the Ruby gem last released on 29 July 2024, and every call needs the account subdomain (11).

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.

## 4. Maintenance & community, 28 out of 100, up to 6.3 more on the total

Why it scored 28: The newest public API version is 20241028. The PHP library's v2.1.4 came out on 4 July 2026, 96 days before the check, and the OpenAPI files were republished on 10 August 2026 with a preview of version 20260309 (10). No three dated releases or changelog entries in the last 90 days (0). Closed service. The API changelog stops at October 2024 and the product changelog at July 2025, with a help centre and support contact (6). Official Ruby and PHP libraries. The Ruby gem is 3.0.1 from 29 July 2024 (8). The Ruby repository has a test workflow. The PHP one has tests and no CI workflow (4).

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. Schema & documentation, 77 out of 100, up to 3.7 more on the total

Why it scored 77: OpenAPI 3.1 spec for version 20241028 at developers.quaderno.io/redocusaurus/openapi-v20241028.yaml, 92 operations (25). quaderno.io/llms.txt routes agents to the developer docs, but the docs site has no llms.txt of its own and no Markdown pages (7). 91 of 92 operations carry a description, mostly one sentence, with fuller guidance in the reference's opening section on conventions and in the guides (12). 61 enums and required fields are marked, but amounts and dates are plain strings with no formats, patterns or length limits (9). Examples throughout, one table of status codes for the whole API, and only 9 operations document a response other than success (9). Date-named versions selectable by Accept header and a public API changelog (15).

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.

## 6. Transparency & trust, 76 out of 100, up to 2.1 more on the total

Made of editorial 69, provenance 83.

Why it scored 76: Closed service under terms updated on 15 September 2026 that name Recrea Systems, SL and Spanish law. The Ruby library is MIT (17). The privacy policy and the terms both say account content is deleted within 6 months of cancellation, and the terms add a 30-day API retrieval period. The DPA lets the processor use customer data in aggregated and anonymised form for improvement, research and training (20). Old API versions are sunset with at least one month's notice, and deprecated behaviour carries a `Deprecation: true` header. No fixed schedule (12). The Visma Trust Centre lists hosting by DigitalOcean in the Netherlands and AWS in Ireland, and each processor with its country (20).

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 6 of the 7 things a reader expects, and has 3 clauses that cost points (3.1 of 10)
- security.txt: not found (0 of 10)

## 7. Reliability, 91 out of 100, up to 1.8 more on the total

Why it scored 91: Graded on the public REST API. Statuspage at quaderno.statuspage.io with two components, Quaderno Web Application and Quaderno APIs (20). Its incident feed lists nothing after a brief API outage on 16 July 2025, so the last 90 days are clean (30). The limit is published as 100 API calls per 15 seconds, with a monthly cap of ten times the plan's transactions (15). 429 is documented with X-RateLimit-Limit, Remaining and Reset headers, but no Retry-After or backoff guidance was found, there are no idempotency keys and the docs say retry logic is the integration's responsibility (6). The SLA page promises 99.99 per cent monthly uptime with service credits to customers on Quaderno Premium, a tier the pricing page doesn't name (10). GA (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.

## 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: whether an API key can be revoked or rotated, and whether a Custom role's view-only permissions limit that user's API key. The API keys page needs a login
- Which plan the SLA's Quaderno Premium refers to. The pricing page lists Hobby, Startup, Business, Growth and Enterprise
- Whether a 429 response carries Retry-After. The docs name only the X-RateLimit headers
- When API version 20260309, shown as a preview, becomes available
- Whether exemption certificates can be managed through the API. The spec has tax ID validation and an exempt tax code, and no certificate object
- Prices are shown with a dollar sign outside the EU and a euro sign inside it, with the same figures, per the pricing page's script. We read the figures from the page data, not a rendered page

## Weaknesses

- One API key reads and writes everything its user can reach. Scopes exist only on Connect OAuth tokens (read_only, read_write)
- No idempotency keys, and the docs say retry logic is the integration's responsibility
- The newest public API version is 20241028. A preview of 20260309 is in the docs but not yet available
- No security.txt, the bug bounty is marked temporarily closed, and no SOC 2 or ISO 27001 report was found for Quaderno itself
- Registration and filing are a done-for-you service booked by call, not API operations. Monthly API calls are capped at ten times the plan's transactions

## 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.

- Call GET https://quadernoapp.com/api/authorization first. Its `href` gives the account subdomain that every other call needs
- Before retrying a failed POST /transactions, list invoices by `processor_id` to check whether the sale was recorded. There is no idempotency key
- Treat GET /invoices/{id}/deliver as a write. It emails the invoice to the customer
- Correct a final invoice with a credit note. DELETE on invoices returns 410 and PUT accepts only notes, tags, metadata and address fields
- Read X-RateLimit-Remaining and X-RateLimit-Reset, and page with `created_before` and `limit` up to 100

## 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.