Zoho Books

# Fix list: Zoho Books

From Anchor Terminal's listing at https://www.anchorterminal.com/tools/zoho-books, the October 2026 research run, assessed 8 October 2026. Grade C, 61.1 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 Zoho Books: 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, 30 out of 100, up to 8.8 more on the total

Why it scored 30: No x402, MPP or L402 (0). Plan prices are public, $15 to $240 an organisation a month billed yearly in the US edition. Calls have no unit price, and the API add-on that raises the daily limit has no public price (10). The Free plan includes 1,000 API requests a day per the plan comparison, and the signup steps on the pricing page ask for a company name, email address, phone number and password, with no card mentioned (20). A person signs up in a browser, registers an OAuth client in the developer console and approves scopes (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, 51 out of 100, up to 8 more on the total

Why it scored 51: Graded on the REST API. Lists default to 200 records a page and `per_page` lowers that. No field selection parameter was found (10 of 25). `page`, `per_page` and `has_more_page` in `page_context`, with `filter_by`, `search_text`, `sort_column` and, on 17 operations, `last_modified_time` (18 of 20). Errors return a JSON `code` and `message`, documented thinly (10 of 20). Upsert by a unique custom field on 15 update operations, with no idempotency key on creates (8 of 20). No official SDK for the Books API was found, every call needs `organization_id`, access tokens last one hour and hosts differ by data centre (5 of 15).

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, 71 out of 100, up to 5.8 more on the total

Why it scored 71: Graded on the REST API v3, read as a hosted service. status.zoho.com redirects to us.zohostatus.com, which has a Zoho Books component and incident history back to November 2025 (20). None of the 33 incidents since 10 July 2026 names Books. On 3 September 2026 a Zoho Deluge outage ran 2 hours 34 minutes and the status feed shows the Books component returning to operational in the same second, so we read the record as minor incidents only (20 of 30). Only the US page was read. Limits are published with numbers, 100 requests a minute per organisation, 1,000 to 10,000 a day by plan and 5 or 10 concurrent calls (15). 429 is documented with codes 44, 45 and 1070, but no Retry-After header or backoff guidance was found. `X-Unique-Identifier-Key` with `X-Upsert` makes 15 update operations safe to repeat, and creates have no idempotency key (6 of 15). No SLA found (0). v3 is the current documented version (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. Security & auth, 68 out of 100, up to 5.6 more on the total

Why it scored 68: OAuth 2.0 with scopes per module and operation (81 scope strings in the OpenAPI files, such as `ZohoBooks.invoices.READ`), one-hour access tokens and refresh tokens the user can revoke (30). Less 10 because the documented token and refresh calls carry the client secret and refresh token in the URL query string, and the page tells readers to use the query string (20 of 30). READ scopes per module allow a read-only agent. No approval step for deletes through the API was found (13 of 20). Records hold text from customers and vendors and no prompt-injection guidance was found. The MCP help page asks users to get an admin's approval first and to add tools only when required (3 of 15). The API Usage dashboard lists recent calls by user, module, IP address and application, and plans include an activity log (12 of 15). security.txt valid to 30 June 2028, a bug bounty, SOC 2 Type 2 and ISO/IEC 27001 (20).

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.

## 5. Schema & documentation, 71 out of 100, up to 4.7 more on the total

Why it scored 71: The docs link a downloadable archive, `openapi-all.zip`, holding OpenAPI 3.0.0 files for 45 resources and 885 operations (25). No llms.txt at zoho.com or under the API docs. Every operation in the API docs has a Markdown twin, and the help centre has an llms.txt with 328 pages (8 of 10). Operation descriptions are short (median 47 characters), while parameter descriptions name the call that supplies each ID. Little on when not to use an operation (14 of 20). Required fields are marked, but only 26 enums appear across the 45 files, allowed values sit in prose and `filter_by` is a string grammar (8 of 15). Each operation has request and response examples. The files declare only 200 and 201 responses, and the errors page lists eight HTTP statuses and three sample codes with no error catalogue (8 of 15). The version is in the path. No dated API changelog was found, and the product What's New page is dated and carries some API items (8 of 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. Maintenance & community, 56 out of 100, up to 3.9 more on the total

Why it scored 56: The OpenAPI archive was last modified on 7 October 2026, one day before this check, though we could not tell what changed in it. The newest dated entry on the product What's New page is 31 July 2026 (25 of 30). That page has entries on 14, 17, 22, 29, 30 and 31 July 2026, inside the last 90 days (20). A dated product changelog, a community forum and support by email, which we did not test for replies (8 of 25). No official SDK for the Books API was found. An official Zoho Books MCP connection exists through Zoho MCP and a Claude connector, and no Zoho server appears in the official MCP registry (3 of 15). No package to assess (0 of 10).

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, 75 out of 100, up to 2.2 more on the total

Made of editorial 54, provenance 95.

Why it scored 75: Closed service under the Zoho Terms of Service, last updated 2 March 2022 (15 of 30). The privacy policy of 22 December 2025 says Zoho does not sell personal information, and that data is deleted from the active database within six months of account termination and from backups three months later. The DPA is sent on request by email (24 of 30). No API deprecation policy or dated retirement notice was found. The help centre notes a new API domain from 1 June 2024 without an end date for the old one (0). A sub-processor page exists, but its directory loads by script and we could not read the list. The data centre page names locations and their certifications (15 of 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 1 clause that costs points (7.1 of 10)
- Privacy policy: read, states 8 of the 8 things a reader expects, and has 1 clause that costs points (8 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 tools of the Zoho Books MCP connection. The help page refers to a Tools list it does not show, and the Zoho MCP setup guide on help.zoho.com loads by script
- unchecked: the sub-processor directory at zoho.com/privacy/sub-processors.html, which loads by script
- unchecked: status pages for data centres other than the US
- unchecked: whether the Books API was affected during the Deluge outage of 3 September 2026
- unchecked: what changed in the OpenAPI archive on 7 October 2026. Only its modification date was read
- unchecked: GitHub. The shell could not list Zoho's repositories, so the absence of an official Books SDK rests on the API docs naming none
- The US pricing page lists API Access under Standard, while the plan comparison and the API docs give the Free plan 1,000 requests a day. We followed the comparison and the docs
- The price of the API add-on that raises the daily limit is shown only inside the product
- No SLA page, API deprecation policy or dated API changelog was found
- The Terms of Service forbid using the services for any form of competitive or benchmarking purposes, which matters before our probes run. Recorded as a fact, with no deduction
- The Markdown help pages open with a line addressed to AI readers telling them to read the help llms.txt first. Recorded as a fact, with no deduction
- The lead was right on the vendor, URL, docs link, OAuth 2.0 and the limits. It was wrong on reports, since no report endpoint is documented, and it did not mention the MCP connection

## Weaknesses

- No profit and loss, balance sheet or other report endpoint appears in the API docs or the OpenAPI files
- The documented token and refresh calls put the client secret and refresh token in the URL query string
- Daily caps are low, 1,000 requests on Free and 10,000 on the top three plans
- No official SDK, SLA, API deprecation policy or dated API changelog found in the reviewed pages
- 429 is documented without a Retry-After header or backoff guidance

## 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 `organization_id` as a query parameter on every call. Read it from `GET /organizations` first
- Use the `api_domain` returned with the token, since each of the nine data centres has its own host (zohoapis.com, zohoapis.eu, zohoapis.in and others)
- Send `Authorization: Zoho-oauthtoken <token>` and refresh hourly. Each user keeps at most 20 refresh tokens and the oldest is deleted
- Stay under 100 requests a minute and the plan's daily cap. Codes 44, 45 and 1070 on a 429 mean minute, day and concurrency limits
- To repeat an update safely, send `X-Unique-Identifier-Key`, `X-Unique-Identifier-Value` and `X-Upsert` with a unique custom field. Creates have no idempotency key

## 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.