# Calendar and scheduling APIs for AI agents

> 7 calendars & scheduling listings ranked by the Anchor benchmark. Leader Google Calendar API (A). APIs that read and write calendars across Google and Microsoft, find free time and book meetings, with booking pages and reminders. Compared on the providers covered, availability logic, webhooks and price per connected account.

- Canonical: https://www.anchorterminal.com/categories/scheduling
- Markdown: https://www.anchorterminal.com/categories/scheduling.md (~3,700 tokens)
- Slim: https://www.anchorterminal.com/categories/scheduling.min.md (~480 tokens, same facts, less prose, for token-sensitive contexts)
- JSON: https://www.anchorterminal.com/categories/scheduling.json (this page as data, same URL with Accept: application/json)
- Site index for agents: https://www.anchorterminal.com/llms.txt (full text: https://www.anchorterminal.com/llms-full.txt)
- API: https://www.anchorterminal.com/api/v1/index.json
- Updated: 2026-10-04

APIs that read and write calendars across Google and Microsoft, find free time and book meetings, with booking pages and reminders. Compared on the providers covered, availability logic, webhooks and price per connected account.

- Tools ranked: 7 · agent-ready (BB or better): 2 · accept x402: 0 · hosted endpoints: 7 · desk reviews by the panel: 20
- JSON: https://www.anchorterminal.com/api/v1/tools.json (list) · https://www.anchorterminal.com/api/v1/rankings.json (ranked) · https://www.anchorterminal.com/api/v1/x402.json (payable) · https://www.anchorterminal.com/api/v1/capabilities.json (by capability)
- Grades run AA, A, BB, B, C, D, E, F · methodology: https://www.anchorterminal.com/benchmark/

- Capabilities in this category: calendar.read, calendar.write, calendar.availability, calendar.booking, calendar.webhooks
- https://letme.dev/calendar.read picks the top-graded tool in this list and says how to call it direct; calling through letme comes later (https://www.anchorterminal.com/letme/index.md)

## Ranking

| # | Tool | Vendor | Kind | Category | Grade | Score | Confidence | x402 | Auth | Where | Reviews | Page |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 8 | Google Calendar API | Google | HTTP API | Scheduling | A | 79.5 | medium | no | OAuth | hosted | 4/5 (8) | https://www.anchorterminal.com/tools/google-calendar-api.md |
| 87 | Nylas Calendar and Scheduler API | Nylas | HTTP API | Scheduling | BB | 71.3 | medium | no | OAuth or key | hosted | 3/5 (2) | https://www.anchorterminal.com/tools/nylas-calendar.md |
| 125 | Calendly API + MCP | Calendly | HTTP API | Scheduling | B | 68.4 | medium | no | OAuth or key | hosted | 4/5 (2) | https://www.anchorterminal.com/tools/calendly.md |
| 170 | Microsoft Graph Calendar API | Microsoft | HTTP API | Scheduling | B | 65.6 | medium | no | OAuth | hosted | 3/5 (2) | https://www.anchorterminal.com/tools/microsoft-graph-calendar.md |
| 182 | Cronofy API | Cronofy | HTTP API | Scheduling | B | 64.4 | medium | no | OAuth or key | hosted | 4/5 (2) | https://www.anchorterminal.com/tools/cronofy.md |
| 292 | Cal.com API v2 + MCP | Cal.com | HTTP API | Scheduling | C | 57.5 | medium | no | OAuth or key | hosted + local | 3/5 (2) | https://www.anchorterminal.com/tools/cal-com.md |
| 417 | Apiroc Unified Calendar API | Apiroc | HTTP API | Scheduling | E | 41.3 | medium | no | OAuth or key | hosted | 2/5 (2) | https://www.anchorterminal.com/tools/apiroc.md |

Scores are from public evidence against the published checklist (https://www.anchorterminal.com/benchmark/), with Performance and Task success pending. p95 latency and context cost come from our probes, which haven't run yet.

## Summaries

### 8. Google Calendar API, A (79.5)

Google Calendar's REST API for accessing calendars and managing events. 20 OAuth scopes, including free/busy only and read-only on owned calendars. Google calendars only.

- Page: https://www.anchorterminal.com/tools/google-calendar-api · Markdown: https://www.anchorterminal.com/tools/google-calendar-api.md · JSON: https://www.anchorterminal.com/api/v1/tools/google-calendar-api.json
- Capabilities: calendar.read, calendar.write, calendar.availability, calendar.webhooks · endpoint: `https://www.googleapis.com/calendar/v3`

### 87. Nylas Calendar and Scheduler API, BB (71.3)

Unified calendar API over Google, Microsoft 365 and Outlook, Exchange (EWS) and iCloud. One schema across Google, Microsoft 365, Exchange EWS, iCloud and virtual calendars. API keys can't be scoped, so the MCP and any agent holding a key reach every grant.

- Page: https://www.anchorterminal.com/tools/nylas-calendar · Markdown: https://www.anchorterminal.com/tools/nylas-calendar.md · JSON: https://www.anchorterminal.com/api/v1/tools/nylas-calendar.json
- Capabilities: calendar.read, calendar.write, calendar.availability, calendar.booking, calendar.webhooks · endpoint: `https://api.us.nylas.com/v3`

### 125. Calendly API + MCP, B (68.4)

Calendly's scheduling API for availability, bookings, invitees and webhooks, with a hosted MCP server. Per-resource OAuth scopes for new apps and personal access tokens, plus read and write scopes on the MCP. Booking through the API needs a paid seat, and Free users get a 403.

- Page: https://www.anchorterminal.com/tools/calendly · Markdown: https://www.anchorterminal.com/tools/calendly.md · JSON: https://www.anchorterminal.com/api/v1/tools/calendly.json
- Capabilities: calendar.read, calendar.availability, calendar.booking, calendar.webhooks · endpoint: `https://api.calendly.com`

### 170. Microsoft Graph Calendar API, B (65.6)

Calendar endpoints of Microsoft Graph for Outlook, Microsoft 365 and Exchange Online. findMeetingTimes suggests slots across attendees and rooms, and getSchedule returns free/busy for many people. 4 concurrent requests per app per mailbox.

- Page: https://www.anchorterminal.com/tools/microsoft-graph-calendar · Markdown: https://www.anchorterminal.com/tools/microsoft-graph-calendar.md · JSON: https://www.anchorterminal.com/api/v1/tools/microsoft-graph-calendar.json
- Capabilities: calendar.read, calendar.write, calendar.availability, calendar.webhooks · endpoint: `https://graph.microsoft.com/v1.0`

### 182. Cronofy API, B (64.4)

Calendar sync and scheduling API from a UK company. OAuth scopes as narrow as `free_busy`, with `delete_event` separate from `create_event`. Production pricing starts at $819 a month billed yearly.

- Page: https://www.anchorterminal.com/tools/cronofy · Markdown: https://www.anchorterminal.com/tools/cronofy.md · JSON: https://www.anchorterminal.com/api/v1/tools/cronofy.json
- Capabilities: calendar.read, calendar.write, calendar.availability, calendar.booking, calendar.webhooks · endpoint: `https://api.cronofy.com`

### 292. Cal.com API v2 + MCP, C (57.5)

Scheduling API behind Cal.com's booking pages. OAuth scopes split into READ and WRITE per resource, with 30-minute access tokens and PKCE. API outage of 1 hour 14 minutes on 31 August 2026, with HTTP 500s on slots and bookings.

- Page: https://www.anchorterminal.com/tools/cal-com · Markdown: https://www.anchorterminal.com/tools/cal-com.md · JSON: https://www.anchorterminal.com/api/v1/tools/cal-com.json
- Capabilities: calendar.read, calendar.availability, calendar.booking, calendar.webhooks · endpoint: `https://api.cal.com/v2`

### 417. Apiroc Unified Calendar API, E (41.3)

Unified calendar API over Google Calendar, Microsoft Outlook (Office 365, Exchange and Outlook.com) and iCloud. $0.50 per connected account a month after 50 on Pro, with unlimited requests. No status page history, changelog, OpenAPI spec, llms.txt or security.txt.

- Page: https://www.anchorterminal.com/tools/apiroc · Markdown: https://www.anchorterminal.com/tools/apiroc.md · JSON: https://www.anchorterminal.com/api/v1/tools/apiroc.json
- Capabilities: calendar.read, calendar.write, calendar.availability, calendar.webhooks · endpoint: `https://api.apiroc.com/api/v1`

## How we test this category

An agent finds a free slot across a Google and a Microsoft calendar, books it, moves it and cancels it. We check availability accuracy, time zones, webhook delivery and the cost per connected account. This test hasn't run yet, so Task success is pending and the grades here come from the categories assessed from public evidence.

## Indexed, not reviewed (32)

Sorted into this category from public catalogues, with facts and our own checks but no score, grade or rank (https://www.anchorterminal.com/indexed/index.md).

| Listing | Kind | What it does | Why it's here |
| --- | --- | --- | --- |
| [42min](https://www.anchorterminal.com/tools/42min-meetings.md) | MCP server | Scheduling for AI assistants: bookings, availability, meeting polls and routing forms. | vendor's own |
| [AddCal](https://www.anchorterminal.com/tools/addcal.md) | MCP server | Publish public calendars and events others subscribe to: RSVPs, feeds and add-to-calendar links. | vendor's own |
| [Aether Wealth](https://www.anchorterminal.com/tools/aetherwealth-mcp.md) | MCP server | Aether Wealth MCP for AI assistants: trades, alerts, market data, macro calendar & indicators. | vendor's own |
| [Astrocal](https://www.anchorterminal.com/tools/astrocal-mcp-server.md) | MCP server | AI-native scheduling: check availability, book meetings, cancel and reschedule via MCP | vendor's own |
| [Award Travel Finder](https://www.anchorterminal.com/tools/awardtravelfinder-mcp.md) | MCP server | Search award flight availability and points pricing across 27 airlines and 23 loyalty programs. | vendor's own |
| [Bowmark](https://www.anchorterminal.com/tools/bowmark.md) | MCP server | Do things on live websites: prices, availability, quotes, bookings, anything behind a form or login. | vendor's own |
| [Chronary](https://www.anchorterminal.com/tools/chronary-mcp.md) | MCP server | Calendar API for AI agents: events, availability, Google/Microsoft setup, scheduling, and iCal. | vendor's own |
| [Coordinalo — Service Business Operations](https://www.anchorterminal.com/tools/coordinalo-mcp-server.md) | MCP server | Scheduling, availability, clients, billing and CRM for appointment-based services. | vendor's own |
| [Denik](https://www.anchorterminal.com/tools/denik.md) | MCP server | Book appointments, check availability, list services and create payment links for a Denik business. | vendor's own |
| [domain-radar](https://www.anchorterminal.com/tools/insight-domain-radar.md) | MCP server | High-Speed Domain Keyword Matrix, TLD Coverage & RDAP Availability Radar (Powered by insight.surf) | vendor's own |
| [Forward Email](https://www.anchorterminal.com/tools/forwardemail-mcp-server.md) | MCP server | Privacy-focused email: domains, DNS verification, aliases, SMTP sending, mailboxes and calendars. | vendor's own |
| [heyoden.com MCP server](https://www.anchorterminal.com/tools/heyoden-mcp.md) | MCP server | Talk to your Oden AI todo and calendar account from Claude Code, Cursor, or any MCP client. | vendor's own |
| [icloud-calendar-mcp](https://www.anchorterminal.com/tools/onekash-icloud-calendar-mcp.md) | MCP server | MCP server for iCloud (Apple) Calendar access via CalDAV | vendor's own |
| [INITE Club](https://www.anchorterminal.com/tools/inite-club.md) | MCP server | Ask the agent of someone whose calendar you could not get. No credential needed to try. | vendor's own |
| [Local MCP](https://www.anchorterminal.com/tools/local-mcp.md) | MCP server | Mac & Windows: let ChatGPT, Claude & Cursor use your email, calendar, iMessage, Teams, files. Free. | vendor's own, widely used |
| [OmniSignal](https://www.anchorterminal.com/tools/omnisignal.md) | MCP server | Live market intelligence & AI content strategy: trends, competitor moves, content calendar. | vendor's own |
| [ponlo.ai MCP server](https://www.anchorterminal.com/tools/ponlo-server.md) | MCP server | Family calendar, tasks, meals, lists & rewards hub for AI assistants. | vendor's own |
| [reassign](https://www.anchorterminal.com/tools/reassign.md) | MCP server | Reassign: a circular 24-hour calendar and time-tracking copilot with ADHD-friendly scheduling. | vendor's own |
| [Rootly](https://www.anchorterminal.com/tools/rootly-mcp-server.md) | MCP server | Incident management, on-call scheduling, and intelligent analysis powered by Rootly. | vendor's own |
| [Servicialo MCP Server](https://www.anchorterminal.com/tools/servicialo-mcp-server.md) | MCP server | Open protocol for booking and scheduling professional services via AI agents | vendor's own |
| [Shiftyasan Shift Scheduling](https://www.anchorterminal.com/tools/shiftyasan-mcp-server.md) | MCP server | Generate optimized work shift schedules from staffing demand, availability and fairness rules. | vendor's own |
| [sifting.io MCP server](https://www.anchorterminal.com/tools/sifting-mcp.md) | MCP server | Live crypto/forex/metals prices, OHLCV bars, SEC fundamentals, 13F holdings and econ calendar. | vendor's own |
| [SquawkFlow Market Structure](https://www.anchorterminal.com/tools/squawkflow-market-structure.md) | MCP server | Free keyless dealer gamma, OI change, market calendar, 13F, congress and CFTC data, dated, cited. | vendor's own |
| [StudioMeyer Personal Suite](https://www.anchorterminal.com/tools/studiomeyer-personal-suite.md) | MCP server | Local-first productivity: email, calendar, messaging, search, image gen. 49 tools. BYOK. | vendor's own |
| [Syncline MCP Server](https://www.anchorterminal.com/tools/syncline-mcp-server.md) | MCP server | AI-powered meeting scheduling with intelligent auto-scheduling for Claude and AI agents. | vendor's own |
| [Syncline MCP Server (Go)](https://www.anchorterminal.com/tools/kekwanu-syncline-mcp-server-go.md) | MCP server | Syncline MCP Server (Go) - AI-powered meeting scheduling with intelligent auto-scheduling | vendor's own |
| [Syncline MCP Server (TypeScript)](https://www.anchorterminal.com/tools/kekwanu-syncline-mcp-server.md) | MCP server | Syncline MCP Server (TypeScript) - AI-powered meeting scheduling with intelligent auto-scheduling | vendor's own |
| [tebra](https://www.anchorterminal.com/tools/jamesrosingmd-tebra.md) | MCP server | MCP server for Tebra/Kareo practice management — patients, billing, scheduling, FHIR (45 tools) | vendor's own |
| [TLDers Domain Prices](https://www.anchorterminal.com/tools/tlders-domain-prices.md) | MCP server | Compare domain prices across 145+ registrars and 1,100+ TLDs, find promo codes, check availability. | vendor's own |
| [Wahlu](https://www.anchorterminal.com/tools/wahlu-mcp-server.md) | MCP server | Social media scheduling for you and your AI agent: Instagram, TikTok, YouTube, Facebook, LinkedIn. | vendor's own |
| [zenoti](https://www.anchorterminal.com/tools/jamesrosingmd-zenoti.md) | MCP server | MCP server for Zenoti spa/wellness/medspa — guests, appointments, bookings, invoices | vendor's own |
| [Zooza MCP Server](https://www.anchorterminal.com/tools/zooza-mcp-server.md) | MCP server | MCP server for Zooza — class scheduling, attendance, and booking for activity businesses. | vendor's own |