Calcal.com
Cal's API program has strong foundations in discovery and schema design, but two areas risk slowing partner adoption and blocking AI agent integration entirely. The most critical gaps are missing runnable examples with test coverage and absent agent-facing instruction context — meaning partners and their coding agents lack the concrete, executable material they need to integrate confidently.
API DesignA clean, typed, well-governed API contract agents can reason about3 pass1 warn1 fail84A
| Signal | Points | Findings | Rationale | |
|---|---|---|---|---|
| pass | Machine-readable, versioned contractvia spec | 25/25 | Versioning declared (info.version="1.0.0") and header-versioning detected. Investigated: spec 100%, docs 100%. | A current OpenAPI version with a declared versioning scheme lets agents reason about the contract. |
| pass | Auth declared & discoverablevia docs | 25/25 | authentication documented in the docs site at https://cal.com/authentication. Investigated: docs 100%, spec 50%. | Agents can only authenticate when auth is declared, scoped, and discoverable. |
| warn | Schema coverage & depthvia spec | 16.7/25 | Only 12% of operations have documented schemas. Investigated: spec 67%, sdk 0%. | Typed, complete request/response schemas are what make agent function-calling possible. |
| pass | Security & governance hygienevia spec | 15/15 | No credential-shaped strings detected in spec. Investigated: spec 100%, wellknown 100%. | No leaked secrets, no critical lint violations, no OWASP API Top-10 spec smells, and a published vulnerability-disclosure channel. |
| fail | Example coveragevia spec | 0/10 | 18% example coverage. Investigated: spec 0%, docs 0%, sdk 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 fail75B
| Signal | Points | Findings | Rationale | |
|---|---|---|---|---|
| pass | Self-service developer portalvia docs | 29/29 | Self-service signup at https://app.cal.com/signup; no free tier or sandbox language detected. Investigated: docs 100%. | Self-serve key/account creation is the fast first call for partners, with no sales gate. |
| pass | Description completenessvia spec | 15/15 | 79% description completeness (target 90%+). Investigated: spec 100%. | Complete descriptions are the context humans and agents need to use endpoints. |
| pass | Changelog publishedvia sdk | 13/13 | Newest official SDK activity 1 day(s) ago. Investigated: sdk 100%, spec 0%, docs 0%. | A published changelog lets partners track changes without surprise. |
| warn | Quickstart presentvia docs | 12.5/25 | Quickstart page reachable (1 variants scanned starting at https://cal.com/getting-started) but no runnable code sample detected in HTML or .md variant. Investigated: docs 50%. | A quickstart is the fastest path from landing page to first successful call. |
| fail | Code samples in docsvia docs | 0/18 | No detectable code samples across 19 sampled docs pages. Investigated: docs 0%. | Multi-language samples shorten time-to-first-call. |
Agent DiscoveryPartners and their agents can find your APIs — llms.txt, registries, crawlable and reachable docs2 pass2 warn0 fail92A+
| Signal | Points | Findings | Rationale | |
|---|---|---|---|---|
| pass | Docs reachable, not hard auth-gatedvia docs | 30/30 | All 1 pages are publicly accessible. Investigated: docs 100%. | Agents can only index and fetch docs they can reach — past auth gates and over correct HTTP semantics. |
| pass | Registry & SDK presencevia docs | 28/28 | Indexed on Context7 (websites/cal, 2298 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. |
| warn | llms.txt present, valid & comprehensivevia docs | 24/30 | llms.txt contains parseable links but doesn't fully follow the proposed structure: https://cal.com/docs/llms.txt: No blockquote summary found. Investigated: docs 80%. | A valid, comprehensive llms.txt is the machine-readable entry point for agents. |
| warn | Crawlable / AEOvia wellknown | 9/12 | Sitemap present (7 entries) but carries no lastmod values. Investigated: wellknown 75%. | Bots allowed plus a fresh sitemap make docs findable by agent crawlers. |
Agent UnderstandingAgents can correctly interpret your APIs — machine-readable errors, consistent descriptions, structured data, parseable docs3 pass2 warn1 fail81A
| Signal | Points | Findings | Rationale | |
|---|---|---|---|---|
| pass | Machine-readable errors (RFC 9457)via docs | 28/28 | 5 distinct 4xx/5xx response codes documented. Investigated: docs 100%, spec 50%. | RFC 9457 problem details and a documented error-code inventory let agents parse failures without burning tokens. |
| pass | Agent-navigable, token-efficient docsvia docs | 22/22 | All 1 pages contain server-rendered content. Investigated: docs 100%. | Server-rendered, clean, small-footprint docs are what an agent can cheaply fetch and parse correctly. |
| warn | Operation purpose clarityvia spec | 18.8/25 | 80% of operations are agent-inferable (target 90%+). Investigated: spec 75%. | Agents select the right endpoint from its summary + operationId; clear, named operations make tool-selection reliable — the strongest driver of correct tool choice. |
| pass | Docs structured datavia docs | 8/8 | JSON-LD Article markup on 19/19 assessed pages (100%) with dateModified present. Investigated: docs 100%. | 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. |
| warn | Description consistency across surfaces | 0.9/7 | Mean pairwise description similarity across 2 surfaces (docs, sdk) is 5% (threshold 35% for full credit). | Every surface tells the same story about what the product is. |
| fail | Agent instructions file (AGENTS.md)via wellknown | 0/10 | No AGENTS.md at the site root or /.well-known/. Investigated: 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. |
Agent UsabilityAgents have the context to use your APIs reliably, not just find them4 pass0 warn1 fail92A+
| Signal | Points | Findings | Rationale | |
|---|---|---|---|---|
| pass | Idempotency documentedvia spec | 27/27 | idempotency documented in the docs site at https://cal.com/docs/api-reference/v2/credits/charge-credits. Investigated: spec 100%, docs 100%. | Documented idempotency lets agents retry safely. |
| pass | Rate-limit signalingvia spec | 22/22 | rate-limit behavior documented in the docs site at https://cal.com/docs/api-reference/v2/bookings-guests/add-guests-to-an-existing-booking. Investigated: spec 100%, docs 100%. | Machine-readable rate-limit headers let agents throttle adaptively. |
| pass | Pagination documented & consistentvia docs | 22/22 | Pagination params detected on 71 list endpoint(s). Investigated: docs 100%, spec 75%. | Consistent, documented pagination lets agents traverse collections. |
| pass | Sandbox separationvia spec | 20/20 | sandbox documented in the docs site at https://cal.com/sandbox. Investigated: spec 100%, docs 100%. | An isolated environment lets agents exercise destructive operations safely. |
| fail | Runnable collection with test scriptsvia platform | 0/9 | No public Postman workspace discovered for the org. Investigated: platform 0%. | A public, maintained collection with assertions is runnable truth agents validate against. |
Resources Discovered
The public resources we found for Cal — the evidence behind the score. All discovered from public sources; nothing here requires access to your systems.
| Agent hints | Context7 (2,298) |
|---|---|
| APIs analyzed | 2 — Cal.com API v2, @calcom/api: Public API for Cal.com |