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.

Zcal publishes 3 API contracts indexed on the APIs.io network: Scheduling Links, Bookings, and Integrations and Webhooks. Tagged areas include Scheduling, Calendar, Booking, Meetings, and Webhook.

Zcal’s developer surface includes documentation, engineering blog, and 7 more developer resources.

🌐 Visit website 📡 Profile data on GitHub

18.3/100 emerging ▬ flat Agent 14/100 agent aware Front door AI 1/6 silent saas Full breakdown ↓
scored 2026-11-13 · rubric v0.28.0 · Show this score on your site →

AccessFreemium

1 published contract

Scheduling Calendar Booking Meetings Webhook

Kin Score

Kin Score How this is scored →
scored 2026-11-13 · rubric v0.28.0

Composite quality — 18.3/100 · emerging

Contract Quality 7.3 / 21

Developer Ergonomics 2.0 / 17

Access Clarity 2.2 / 17

Operational Transparency 0.5 / 11

Contract Governance 0.0 / 10

Discoverability 4.9 / 9

Regulatory Posture 0.7 / 15

Agent readiness — 14/100 · agent aware

Machine-Readable Contract 18 / 18

Agentic Access Contract 0 / 10

Documented Reversibility 0 / 6

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

A2A Agent Card 0 / 8

Dry-Run / Simulate Mode 0 / 4

Delegated User Identity 0 / 6

Protected Resource Metadata 0 / 5

Registration Without a Human 0 / 6

Agentic Commerce Well-Known Document 0 / 5

Pagination 5 / 5

Distinct Operations 3 / 3

MCP Tool Quality 6 / 6

Regulatory Posture applies to this provider. Its tags matched the Horizontal (data, software, accessibility, platform) regime, so Regulatory Posture carries 15 points of the composite. If this regime is wrong for your business, say so on your provider repo — the applicability map is public and we will correct it.

Create-or-Update Ergonomics does not apply to this provider. The published contracts declare no write operations, and a read-only API cannot create-or-update. The facet is excluded from this provider's denominator entirely — not scored zero. A reference or data API is not deficient for being unable to upsert.

The six quality facets above are damped to 85 points between them, because the conditional facet above carries the other 15. That is why each facet's contribution is shown against a damped maximum: raising a quality facet moves the composite by 85% of its nominal weight, not 100%. The full arithmetic is at apis.io/rating/.

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Agent readiness — checks not met, largest first (exact, from this profile):

MCP Server +12 pts — deployment.mode + probe verdict on the mcp/ manifest, not the pointer; an unprobed slug falls back to authorship Ask about this →
Agentic Access Contract +10 pts — agentic_access artifact present (x-agentic-access), graded by author Ask about this →
Machine-Readable Auth +10 pts — a served openid-configuration/oauth-authorization-server carrying `issuer` (served), else the securitySchemes class in the provider OpenAPIs — bound (mutualTLS, DPoP, Signature) > negotiable (oauth2 authorizationCode/clientCredentials, openIdConnect) > bearer (http bearer, apiKey) Ask about this →
Idempotency +9 pts — OpenAPI mutating operations declare an idempotency key — a header, a request-body property, or a named de-duplication token whose own description says so (verified); else common[].type matches /idempoten/i (documented) Ask about this →
Stable Error Semantics +8 pts — OpenAPI $refs a shared error schema across 4xx/5xx responses (verified), else common[].type includes ErrorCatalog / ErrorCodes / DeclineCodes Ask about this →
A2A Agent Card +8 pts — a2a/-a2a.yml manifest, graded on conformance.grade against A2A 1.0.0 Ask about this →

11 more unmet checks in the Agent Readiness table above.

Kin Score — facets with the most composite points still available (weight × headroom):

Developer Ergonomics scores 11.9 — up to +17.6 composite points Ask about this →
Access Clarity scores 12.8 — up to +17.4 composite points Ask about this →
Contract Quality scores 34.4 — up to +16.4 composite points Ask about this →

Each check links to what satisfies it. Publish the artifact, or tell us where it already lives, and the score moves on the next scoring run.

Not sure how this applies to your stack? Ask about any one item. Kin Lane reads every question, looks at your profile and your situation, and replies with what a fix would take — scoped to that one area, priced up front, yours whether you ship it or not. Ask a question →

Improve this rating by publishing the missing artifacts — every area above can be raised, and the full rubric is at apis.io/rating/. Every facet and dimension name above is a link: it opens that measurement's own page — what it means, the exact checks that feed it, how the whole catalog distributes on it, and the providers at the top of it. This rating is computed from the provider profile at artifacts.apis.io/zcal/apis.yml: open an issue on github.com/api-evangelist/zcal to ask a question or point us at an artifact you publish. Submit an artifact on GitHub — free → Manage your own listing — the Influence plan, $499/mo →

Markets this provider is in provisional

The Kin Score Market layer reads a provider inside its market: its position, and how deep its integrations go. Depth is only comparable within a position. Provisional and unweighted: not part of the Kin Score or agent readiness.

Market	Position	Depth	Registered MCP server	Declares compatibility
Zoom App Marketplace and Partner Ecosystem (builders and partners on Zoom)	builds-on	19.7 (thin)	-	-

Registered MCP server and declares compatibility are report only — not weighted. Undeclared means we found nothing we can read, so there is no number: we never infer integrations.

Standards implemented 1

Standards this provider implements or carries. De facto ones are profiled and measured by the API Commons; formal ones come from the standards directory and are linked by the provider's own tags. The evidence column says how each claim was established — not that it was made.

OpenAPI

measured — observed by APIs.io (published)

APIs 3

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 API collections (OpenAPI-derived and Bruno).

Zcal

OPEN COLLECTION

Zcal API pricing

Not yet checked against Zcal's own pricing page. Compiled by API Evangelist on 2026-06-21 from zcal.co/pricing; confirm before you rely on a figure. A free plan or tier is listed.

Plan	Price
Free free	Free
Pro paid	—
Business paid	—

Plan details, limits and sources →

Rate limits

Inbound REST API Rate Limit: not applicable requests
Outbound Webhook Delivery: not documented events

Compiled by API Evangelist, not yet checked against Zcal's documentation. Rate-limit details →

Pricing Plans 1

Published pricing tiers and plan structures.

Zcal Plans Pricing

3 plans

PLANS

Rate Limits 1

Documented rate limits and quota policies.

Zcal Rate Limits

2 limits

RATE LIMITS

FinOps 1

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

Zcal Finops

FINOPS

Security Posture 2

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

Documentation 1

Reference material describing how the API behaves

Documentation

Documentation

Access & Security 2

Authentication, authorization, and security posture

TrustCenter

TrustCenter

DomainSecurity

DomainSecurity

Operate 1

Status, limits, changes, and where to get help

RateLimits

RateLimits

Commercial 2

Pricing, plans, and the legal terms of use

Plans

Plans

FinOps

FinOps

Company 3

The organization behind the API

LinkedIn

Website

Website

Blog

Blog

Source (apis.yml)

aid: zcal
url: https://raw.githubusercontent.com/api-evangelist/zcal/refs/heads/main/apis.yml
name: Zcal
kind: company
description: 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.
deliveryModel:
  model: saas
  open_source: false
  commercial: true
  callable_host: false
  label: Hosted service · you call their endpoint
  confidence: medium
  source:
  - pricing
  generated: '2026-08-28'
  method: derived
accessModel:
  pricing: freemium
  onboarding: unknown
  trial: false
  try_now: false
  public: false
  label: Freemium
  confidence: low
  source:
  - plans
  - security
  generated: '2026-11-13'
  method: derived
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/icons/zcal.png
x-docs-platform: gitbook
x-docs-platform-confidence: medium
x-docs-platform-checked: 2026-10-17
tags:
- Scheduling
- Calendar
- Booking
- Meetings
- Webhook
tags_raw:
- Scheduling
- Calendar
- Booking
- Meetings
- Webhooks
created: '2026-06-21'
modified: '2026-06-21'
specificationVersion: '0.23'
apis:
- aid: zcal:scheduling-links
  name: Zcal Scheduling Links
  tags:
  - Scheduling
  - Booking
  - Links
  image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg
  humanURL: https://help.zcal.co/
  properties:
  - url: https://help.zcal.co/
    type: Documentation
  - url: https://zcal.co/
    type: Website
  - url: openapi/_original/zcal-openapi.yml
    type: OpenAPI
  description: 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 application; there is no documented public REST API for
    creating or managing scheduling links programmatically.
- aid: zcal:bookings
  name: Zcal Bookings
  tags:
  - Booking
  - Event
  - Attendees
  tags_raw:
  - Bookings
  - Events
  - Attendees
  image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg
  humanURL: https://help.zcal.co/
  properties:
  - url: https://help.zcal.co/
    type: Documentation
  - url: https://zcal.co/
    type: Website
  - url: openapi/_original/zcal-openapi.yml
    type: OpenAPI
  description: Bookings (events) capture timing, hosts, attendees, location, and custom question responses. Booking data is
    surfaced to external systems through outbound webhooks rather than a queryable public REST API.
- aid: zcal:integrations-webhooks
  name: Zcal Integrations and Webhooks
  tags:
  - Webhook
  - Integration
  - Automation
  tags_raw:
  - Webhooks
  - Integrations
  - Automation
  image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg
  humanURL: https://help.zcal.co/integrations/webhooks
  properties:
  - url: https://help.zcal.co/integrations/webhooks
    type: Documentation
  - url: https://help.zcal.co/integrations/webhooks/webhook-payload
    type: Documentation
  - url: openapi/_original/zcal-openapi.yml
    type: OpenAPI
  description: 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 via the x-zcal-webhook-signature header. Connectors such
    as Zapier and Make, plus native Zoom, Stripe, Google Analytics, and Meta Pixel integrations, extend automation without
    a public REST API.
common:
- type: TrustCenter
  url: security/zcal-trust-center.yml
- type: DomainSecurity
  url: security/zcal-domain-security.yml
- type: LinkedIn
  url: https://www.linkedin.com/company/zcal
- type: Website
  url: https://zcal.co/
- type: Documentation
  url: https://help.zcal.co/
- type: Plans
  url: plans/zcal-plans-pricing.yml
- type: RateLimits
  url: rate-limits/zcal-rate-limits.yml
- type: FinOps
  url: finops/zcal-finops.yml
- type: Blog
  url: https://zcal.co/blog
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com

Zcal API — frequently asked questions

Does Zcal have an API?

Yes. APIs.io lists 3 APIs from Zcal, including Zcal Scheduling Links, Zcal Bookings and Zcal Integrations and Webhooks.

Is there an OpenAPI specification for the Zcal API?

Yes. APIs.io indexes 3 OpenAPI specifications for Zcal, each linked for download from this page.

How much does the Zcal API cost?

APIs.io lists 3 pricing plans for Zcal, with each plan's price, limits and inclusions under Pricing on this page.

Is the Zcal API ready for AI agents?

Zcal has a Kin Score of 18.3 out of 100 (emerging) and an Agent Readiness score of 13.6 (agent-aware), scored by API Evangelist on 2026-11-13.

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