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Zcal

Zcal is a free scheduling platform for booking meetings via shareable scheduling links, meeting polls, and team pages (round-robin and collective). Zcal does not publish a general-purpose public REST API; programmatic integration is delivered through outbound webhooks (event.created, event.rescheduled, event.cancelled) and no-code connectors such as Zapier and Make, plus native integrations including Zoom, Stripe, Google Analytics, and Meta Pixel.

agent aware

Limited machine-readable signal and partial portal coverage — documentation a human can read, but little a machine or agent can consume without scraping.

Kin Score

API Evangelist profiles Zcal the way a machine reads it — 9 machine-readable artifacts across 3 APIs, pulled from the provider's own public surface and indexed so a developer, an analyst, or an AI agent can evaluate it against every other provider on the network.

Every provider in the network is reduced to the same set of machine-readable artifacts — OpenAPI contracts, event specifications, GraphQL schemas, runnable collections, pricing and rate-limit signals, security posture, OAuth scopes, and the agent surfaces (MCP servers and skills) that let software drive the API on its own. We profile them because the interface is the part of a company you can actually inspect: it is a truer signal of what a provider does than any marketing page. From those artifacts we compute the Kin Score — Zcal scores 32.6/100 (thin), with a separate agent-readiness read of 24/100 (agent aware). The full breakdown is below, followed by every artifact we hold — each card links through to its machine-readable definition on apis.io.

Kin Score

This is the API Evangelist rating — a single, repeatable read computed from the artifacts on this page. Green fill is points earned; the red track is points possible, so every bar shows earned-versus-possible at a glance.

Kin Score Kin Score How this is scored →
scored 2026-07-27 · rubric v0.5
Composite quality — 32.6/100 · thin
Contract Quality 9.4 / 25
Developer Ergonomics 2.2 / 20
Commercial Clarity 9.5 / 20
Operational Transparency 2.7 / 13
Governance 0.0 / 12
Discoverability 8.8 / 10
Agent readiness — 24/100 · agent aware
Machine-Readable Contract 18 / 18
Agentic Access Contract 0 / 15
MCP Server 0 / 12
Machine-Readable Auth 0 / 10
Idempotency 0 / 9
Stable Error Semantics 0 / 8
Request/Response Examples 0 / 7
Rate-Limit Signaling 7 / 7
Typed Event Surface 0 / 6
Agent Skills 0 / 5
Well-Known Catalog 0 / 4
Consent & Bot Identity 0 / 3

How we profile Zcal

Each block below is one kind of artifact we hold for Zcal. For each we say what it is and why it earns a place in the profile, then list every one we've indexed — capped at two rows, scroll within the panel for the rest.

APIs 3

Each API is captured as its own OpenAPI definition — every operation, parameter, and response. This is the single most useful machine-readable description of what an API does, and it's what lets us score, lint, mock, and generate against it without asking the provider for anything.

Individual APIs this provider publishes, each with its own machine-readable definition.

Zcal Scheduling Links

Unlimited shareable scheduling links, meeting polls, and customizable booking pages let invitees self-serve a time. This is a product surface managed through the Zcal web applic...

Zcal Bookings

Bookings (events) capture timing, hosts, attendees, location, and custom question responses. Booking data is surfaced to external systems through outbound webhooks rather than a...

Zcal Integrations and Webhooks

Outbound webhooks POST a JSON payload to a subscriber URL when a booking is created, rescheduled, or cancelled. Payloads can be verified with an optional HMAC SHA-256 signature ...

Open Collections 1

Open, tool-agnostic collections carry the same runnable value as Postman without locking you to one client — the portable, forkable form of the same exercise.

Open, tool-agnostic API collections (OpenAPI-derived and Bruno).

Zcal

OPEN COLLECTION

Pricing Plans 1

Pricing is part of the interface. Machine-readable plans tell you what a tier costs and includes before you commit — one of the six things the Kin Score reads for commercial clarity.

Published pricing tiers and plan structures.

Zcal Plans Pricing

3 plans

PLANS

Rate Limits 1

Rate limits are the difference between a demo that works and a production integration that doesn't fall over. Publishing them is an operational-transparency signal — and a hard requirement for any agent that plans its own throughput.

Documented rate limits and quota policies.

Zcal Rate Limits

2 limits

RATE LIMITS

FinOps 1

Cost, billing, and metering signals let a buyer model the financial operations of an API before it's live. We profile them for the same reason we profile pricing: the money is part of the contract.

Cost, billing, and metering signals for API financial operations.

Zcal Finops

FINOPS

Security Posture 2

Authentication, domain security, vulnerability disclosure, and trust-center signals — the evidence that a provider takes security seriously enough to document it. We profile it because you can't govern what you can't see.

Authentication, domain security, vulnerability disclosure, and trust-center signals.

Zcal Domain Security

TLSv1.3 · HSTS · DMARC

SECURITY

Zcal Trust Center

SOC 2, ISO 27001

SECURITY

Resources

Every other property we hold for Zcal — documentation, portals, status pages, policies, and corporate surface — grouped by the job it does, following the integrator's arc from getting started to running in production.

Documentation 1

Reference material describing how the API behaves

Access & Security 2

Authentication, authorization, and security posture

Operate 1

Status, limits, changes, and where to get help

Commercial 2

Pricing, plans, and the legal terms of use

Company 3

The organization behind the API

← All providers · Data indexed from github.com/api-evangelist/zcal · machine-readable index on apis.io