Calendlycalendly.com
Calendly's API program shines on contract quality and schema design — partners and agents can build against a clean, well-typed surface. The two areas that need urgent attention are onboarding access and operational reliability for AI agents.
API DesignA clean, typed, well-governed API contract agents can reason about3 pass2 warn0 fail91A+
| Signal | Points | Findings | Rationale | |
|---|---|---|---|---|
| pass | Auth declared & discoverablevia spec | 25/25 | Authentication is required across the API (declared globally or on every operation), so an agent knows credentials are needed. Investigated: spec 100%, docs 100%. | Agents can only authenticate when auth is declared, scoped, and discoverable. |
| warn | Schema coverage & depthvia spec | 20.8/25 | Operations take 2.3 parameters each on average and some use nested-object or request-body schemas, which are harder for an agent to fill correctly. Investigated: spec 83%, sdk 67%. | Typed, complete request/response schemas are what make agent function-calling possible. |
| warn | Machine-readable, versioned contractvia spec | 18.8/25 | The API sets a version ("1.0.0") but exposes no versioning scheme in the URL, a header, or the media type, so an agent can't pin to a specific version. Investigated: spec 75%, docs 50%. | A current OpenAPI version with a declared versioning scheme lets agents reason about the contract. |
| pass | Security & governance hygienevia spec | 15/15 | No credential-shaped strings detected in spec. Investigated: spec 100%, sdk 100%, wellknown 100%. | No leaked secrets, no critical lint violations, no OWASP API Top-10 spec smells, and a published vulnerability-disclosure channel. |
| pass | Example coveragevia docs | 10/10 | Docs show code samples in 4 language(s) (top: typescript, javascript, ruby), and 2 of 20 sampled pages offer ≥ 2 languages side by side. Investigated: docs 100%, sdk 100%, spec 0%. | Examples carry shape semantics schemas under-specify — for humans and agents alike. |
Developer ExperienceThe context both developers and agents need to integrate fast — onboarding, code samples, complete descriptions and worked examples3 pass1 warn1 fail67C
| Signal | Points | Findings | Rationale | |
|---|---|---|---|---|
| pass | Code samples in docsvia docs | 18/18 | Docs show code samples in 4 language(s) (top: typescript, javascript, ruby), and 2 of 20 sampled pages offer ≥ 2 languages side by side. Investigated: docs 100%. | Multi-language samples shorten time-to-first-call. |
| pass | Description completenessvia spec | 15/15 | Only 75% of operations and parameters have substantive descriptions (2 of 4 ops, 5 of 5 params; target 90%+). Investigated: spec 100%, sdk 0%. | Complete descriptions are the context humans and agents need to use endpoints. |
| pass | Changelog publishedvia spec | 13/13 | changelog is documented on the docs site at https://developer.calendly.com/release-notes, even though it isn't declared in the API spec. Investigated: spec 100%, docs 100%. | A published changelog lets partners track changes without surprise. |
| warn | Quickstart presentvia docs | 12.5/25 | Quickstart page is reachable at https://developer.calendly.com/docs/getting-started/overview (7 variants scanned) but has no runnable code sample in its HTML or .md variant, so there's nothing to copy and run. Investigated: docs 50%. | A quickstart is the fastest path from landing page to first successful call. |
| fail | Self-service developer portalvia docs | 0/29 | The signup page is sales-gated (contact-sales / request-access language detected), so an agent can't self-serve. Investigated: docs 0%. | Self-serve key/account creation is the fast first call for partners, with no sales gate. |
Agent DiscoveryPartners and their agents can find your APIs — llms.txt, registries, crawlable and reachable docs3 pass0 warn0 fail100A+
| Signal | Points | Findings | Rationale | |
|---|---|---|---|---|
| pass | llms.txt present, valid & comprehensivevia docs | 30/30 | A full-corpus llms-full.txt is published at https://developer.calendly.com/llms-full.txt, so agents can ingest all your docs in one fetch. Investigated: docs 100%, sdk 0%. | A valid, comprehensive llms.txt is the machine-readable entry point for agents. |
| pass | Registry & SDK presencevia docs | 28/28 | Indexed on Context7 (websites/developer_calendly, 1030 snippets). Investigated: docs 100%, sdk 75%, cli 0%, mcp 0%, wellknown 0%. | Listing in MCP registries and publishing SDKs puts the API where agents and their tooling look. |
| pass | Crawlable / AEOvia wellknown | 12/12 | robots.txt lets all monitored AI crawlers reach the docs paths. Investigated: wellknown 100%. | Bots allowed plus a fresh sitemap make docs findable by agent crawlers. |
| na | Docs reachable, not hard auth-gated | —/30 | No surface produced evidence for this capability in this run. | Agents can only index and fetch docs they can reach — past auth gates and over correct HTTP semantics. |
Agent UnderstandingAgents can correctly interpret your APIs — machine-readable errors, consistent descriptions, structured data, parseable docs2 pass2 warn0 fail89A
| Signal | Points | Findings | Rationale | |
|---|---|---|---|---|
| pass | Machine-readable errors (RFC 9457)via docs | 28/28 | Documents 7 distinct 4xx/5xx error response codes, so an agent can branch on specific failures instead of guessing. Investigated: docs 100%, spec 50%. | RFC 9457 problem details and a documented error-code inventory let agents parse failures without burning tokens. |
| pass | Operation purpose clarityvia spec | 25/25 | 94% of operations (59 of 63) have both a clear summary and a descriptive name, so an agent can pick the right endpoint. Investigated: spec 100%, sdk 100%. | Agents select the right endpoint from its summary + operationId; clear, named operations make tool-selection reliable — the strongest driver of correct tool choice. |
| warn | Agent instructions file (AGENTS.md)via sdk | 5/10 | No agents.md or skill.md context file found (nice-to-have for agent operation). Investigated: sdk 50%, wellknown 0%. | An AGENTS.md gives coding agents explicit setup, auth, and usage instructions to interpret and operate the API — beyond llms.txt's link index. |
| warn | Docs structured datavia docs | 4/8 | JSON-LD markup on only 20 of 20 assessed pages, and coverage is sparse or dateModified is missing. Investigated: docs 50%. | Structured data (JSON-LD/schema.org) on docs pages gives agents an unambiguous parse target and is what answer engines cite. Detected on the JS-rendered head (Firecrawl) for a bounded page budget, so JS-injected JSON-LD is now caught; pages we can't render are excluded rather than failed. |
| na | Agent-navigable, token-efficient docs | —/22 | No surface produced evidence for this capability in this run. | Server-rendered, clean, small-footprint docs are what an agent can cheaply fetch and parse correctly. |
| na | Description consistency across surfaces | —/7 | Only 1 surface description(s) with ≥6 tokens available; need at least 2 to compare. | Every surface tells the same story about what the product is. |
Agent UsabilityAgents have the context to use your APIs reliably, not just find them2 pass1 warn1 fail63C
| Signal | Points | Findings | Rationale | |
|---|---|---|---|---|
| pass | Rate-limit signalingvia spec | 22/22 | rate-limit behavior is documented on the docs site at https://developer.calendly.com/api-docs/overview/rate-limits, even though it isn't declared in the API spec. Investigated: spec 100%, docs 100%. | Machine-readable rate-limit headers let agents throttle adaptively. |
| warn | Sandbox separationvia sdk | 10/20 | No test-mode flag or sandbox environment is exposed. Investigated: sdk 50%, spec 0%, docs 0%. | An isolated environment lets agents exercise destructive operations safely. |
| pass | Runnable collection with test scriptsvia sdk | 9/9 | README is present and includes a runnable quickstart. Investigated: sdk 100%, platform 50%. | A public, maintained collection with assertions is runnable truth agents validate against. |
| fail | Idempotency documentedvia spec | 0/27 | Only 0% of mutating operations (0 of 22) document idempotency, so an agent's retries can create duplicate writes. Investigated: spec 0%, docs 0%, sdk 0%. | Documented idempotency lets agents retry safely. |
| na | Pagination documented & consistent | —/22 | No surface produced evidence for this capability in this run. | Consistent, documented pagination lets agents traverse collections. |
Resources Discovered
The public resources we found for Calendly — the evidence behind the score. All discovered from public sources; nothing here requires access to your systems.
| Agent hints | Context7 (1,030) |
|---|---|
| APIs analyzed | 2 — Calendly API, Calendly OAuth |