Zoom Scheduler API

# Fix list: Zoom Scheduler API

From Anchor Terminal's listing at https://www.anchorterminal.com/tools/zoom-scheduler, the October 2026 research run, assessed 9 October 2026. Grade D, 50.6 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 Zoom Scheduler 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. Payments & pricing, 25 out of 100, up to 9.4 more on the total

Why it scored 25: No x402, MPP or L402 (0). Seat prices are public, $5.99 a user a month or $4.99 billed yearly, with nothing per call (10). Scheduler Basic is free with no card and a 14-day trial is advertised, but the pricing page lists API access under the paid plan and whether the free plan or the trial can call the API was not established (15). A person signs up and creates a Marketplace app in a browser (0). Total 25.

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, 43 out of 100, up to 9.3 more on the total

Why it scored 43: No field selection was found, and a schedule object runs to several hundred lines of fields. Query parameters could not be read (8). List responses return `next_page_token`, and the changelog records filters by team, account scope and created or updated time. The parameter list itself was not readable (14). Errors carry a status and a short code name such as InvalidArgument, NotFound or Conflict, with a 409 on booking conflicts and little detail (12). No idempotency key or safe-retry guidance for `POST /scheduler/attendee` (3). Booking needs six fields. No official SDK covers Scheduler, and Zoom Rivet 0.3.0 has no Scheduler module (6). Total 43.

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. Security & auth, 54 out of 100, up to 8.1 more on the total

Why it scored 54: OAuth 2.0 with granular scopes per operation, user and admin variants, PKCE, one-hour access tokens and revocation (30). The OAuth docs show refresh tokens and device codes sent in the URL query string as an option, which takes 10 off (20). Read scopes are separate from write, update and delete scopes, and Server-to-Server scopes need an administrator's approval. No confirmation step for cancelling or deleting (14). Booker names, answers and meeting notes written by outsiders reach the model, with no injection guidance found (0). No audit log of API calls was found in the pages read (0). security.txt valid to 31 December 2029, a disclosure policy with safe harbour, a private HackerOne bounty, security bulletins, and a SOC 2 Type 2 report for October 2024 to October 2025 that names Zoom Scheduler and Zoom APIs (20). Total 54.

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.

## 4. Reliability, 63 out of 100, up to 7.4 more on the total

Why it scored 63: Graded as a hosted API. Statuspage site at status.zoom.us (redirects to www.zoomstatus.com) with Zoom Scheduler as its own component and REST API and Webhooks under Zoom Developer Platform (20). The front page shows 25 September to 9 October 2026, with no incident naming Scheduler or the REST API. The developer documentation site was degraded for 1 hour 54 minutes on 3 October. The history page is drawn by script and the status API is closed by robots.txt, so 90 days could not be read (10). Every Scheduler operation is labelled Light, which is 4 a second and 6,000 a day on Free, 30 a second on Pro and 80 a second on Business and above, per account (15). The docs say to wait and retry on 429 and that the daily-limit response carries a header saying when to resume. No `Retry-After` is named and no idempotency key exists for booking writes (8). No SLA found, and the API terms say Zoom does not guarantee uptime (0). No beta label on the Scheduler API, and Zoom's lifecycle page treats an initial release as stable (10). Total 63.

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.

## 5. Schema & documentation, 61 out of 100, up to 6.3 more on the total

Why it scored 61: The reference states OpenAPI version 3.1.1, but no specification file is linked from the page, the API catalogue or llms.txt. A Markdown copy of the whole reference is published (10). llms.txt, Markdown copies of pages and an API catalogue at `/.well-known/api-catalog.json` (10). Most operations carry one line such as "Patches a scheduled event". The available times and booking operations say when to use them (8). Request bodies are typed, with 55 required marks, 38 enumerated fields and email, date and date-time formats. The Markdown copy and the static page omit query and path parameters (9). Every request body has an example and each operation lists its error statuses with a code name, some misspelt (11). The path is versioned v2 and the changelog has dated Scheduler entries (13). Total 61.

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, 28 out of 100, up to 6.3 more on the total

Why it scored 28: The latest Scheduler changelog entry is 17 August 2026, 53 days before this check (20). Two dated entries in the last 90 days, 13 July and 17 August (0). A public changelog with a developer forum thread for each entry and a developer support page. Whether the forum answers was not checked (8). No official SDK covers Scheduler (0). No package to assess (0). Total 28.

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, 69 out of 100, up to 2.7 more on the total

Made of editorial 59, provenance 79.

Why it scored 69: Closed service under the Zoom API Licence and Terms of Use of 16 July 2025 (15). The Privacy Statement of 17 September 2026 gives no fixed retention periods. The Terms of Service delete customer content 30 days after termination, and both documents say communications-like customer content is not used to train AI models. The DPA is a PDF we did not read (18). A lifecycle page describes deprecation and sunset stages and the changelog tags them, but the API terms let Zoom change or deprecate APIs without prior notice, with only commercially reasonable efforts to tell developers (8). The sub-processor list, updated 2 October 2026, names 24 third parties and 23 affiliates with locations and has an email sign-up for changes (18). Total 59.

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: zoom.us, no registry record we could read (0 of 15)
- Terms of service: read, states 7 of the 7 things a reader expects, and has 3 clauses that cost points (4 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.

- Zoom's API terms (section 3.7.9) forbid using the APIs to monitor availability, performance or functionality, or for benchmarking. This matters before any probe is run
- Whether Scheduler Basic (free) or the 14-day trial can call the Scheduler API
- Whether `POST /scheduler/attendee` deduplicates a repeated request
- The registration date of zoom.us (rdap.org answered 404)
- unchecked: query and path parameters of every operation, which the Markdown copy and the static page omit
- unchecked: status history before 25 September 2026 (the history page is drawn by script and robots.txt closes /api/)
- unchecked: the general Using Zoom APIs page (error format and pagination rules), not read within the page budget for the docs host
- unchecked: the Data Processing Addendum (a PDF) and any API call log in the Marketplace or admin console
- unchecked: the main pricing page at zoom.us/pricing, which is drawn by script. Prices come from zoom.us/pricing/scheduler and the product page
- unchecked: ISO 27001 and other certification pages listed in the trust centre sitemap

## Weaknesses

- Zoom's API terms (section 3.7.9) forbid using the APIs to monitor availability or performance, or for benchmarking. This matters before any probe is run
- No operation moves a booking. `PATCH /scheduler/events/{eventId}` changes status, notes and no-show marks only
- No idempotency key or safe-retry guidance for booking writes was found in the reviewed documentation
- No official SDK covers Scheduler. Zoom Rivet 0.3.0 has no Scheduler module
- No downloadable OpenAPI file is linked, and the Markdown reference omits query and path parameters
- The API terms allow Zoom to change or deprecate APIs without prior notice and disclaim any uptime guarantee

## 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 /scheduler/schedules/{scheduleId}/available_times` and book only a spot whose status is `available`
- Send `start_date_time` in ISO 8601 with the booker's IANA `time_zone` to `POST /scheduler/attendee`. Expect 409 on a conflict
- To move a booking, cancel it with `PATCH /scheduler/events/{eventId}` and `status` set to `cancelled`, then book the new slot
- List scheduled events before retrying a booking, because no idempotency key is documented
- Request a new Server-to-Server OAuth token every hour. That grant issues no refresh token

## 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.