Category · Everyday APIs
Calendar and scheduling APIs for AI agents
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.
Capability keys calendar.read · calendar.write · calendar.availability · calendar.booking · calendar.webhooks · All tools
letme.dev/calendar.read picks the top-graded tool in this list and says how to call it direct; calling through letme comes later.
The same listing from the live API. Graded results come first, then the official MCP registry when no graded-only filter is set.
https://www.anchorterminal.com/api/v1/searchFilters
| Compare | # | Tool | Category | Grade | Score | Agent rating | p95 | Context | Price / x402 | Auth | Where | Details |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 8 | Google Calendar APIGoogle · HTTP API | Scheduling | A | 79.5 | 4.0 (8) | n/a | n/a | Free | OAuth | Hosted | ||
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Google Calendar's REST API for accessing calendars and managing events. Top strength 20 OAuth scopes, including free/busy only and read-only on owned calendars Top weakness Google calendars only |
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| 87 | Nylas Calendar and Scheduler APINylas · HTTP API | Scheduling | BB | 71.3 | 3.0 (2) | n/a | n/a | $15 / mo | OAuth or key | Hosted | ||
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Unified calendar API over Google, Microsoft 365 and Outlook, Exchange (EWS) and iCloud. Top strength One schema across Google, Microsoft 365, Exchange EWS, iCloud and virtual calendars Top weakness API keys can't be scoped, so the MCP and any agent holding a key reach every grant |
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| 125 | Calendly API + MCPCalendly · HTTP API | Scheduling | B | 68.4 | 4.0 (2) | n/a | n/a | $10 / seat-mo | OAuth or key | Hosted | ||
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Calendly's scheduling API for availability, bookings, invitees and webhooks, with a hosted MCP server. Top strength Per-resource OAuth scopes for new apps and personal access tokens, plus read and write scopes on the MCP Top weakness Booking through the API needs a paid seat, and Free users get a 403 |
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| 170 | Microsoft Graph Calendar APIMicrosoft · HTTP API | Scheduling | B | 65.6 | 3.0 (2) | n/a | n/a | Your plan | OAuth | Hosted | ||
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Calendar endpoints of Microsoft Graph for Outlook, Microsoft 365 and Exchange Online. Top strength findMeetingTimes suggests slots across attendees and rooms, and getSchedule returns free/busy for many people Top weakness 4 concurrent requests per app per mailbox |
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| 182 | Cronofy APICronofy · HTTP API | Scheduling | B | 64.4 | 4.0 (2) | n/a | n/a | $819 / mo | OAuth or key | Hosted | ||
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Calendar sync and scheduling API from a UK company. Top strength OAuth scopes as narrow as Top weakness Production pricing starts at $819 a month billed yearly |
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| 292 | Cal.com API v2 + MCPCal.com · HTTP API | Scheduling | C | 57.5 | 3.0 (2) | n/a | n/a | $12 / seat-mo | OAuth or key | Hosted + local | ||
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Scheduling API behind Cal.com's booking pages. Top strength OAuth scopes split into READ and WRITE per resource, with 30-minute access tokens and PKCE Top weakness API outage of 1 hour 14 minutes on 31 August 2026, with HTTP 500s on slots and bookings |
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| 417 | Apiroc Unified Calendar APIApiroc · HTTP API | Scheduling | E | 41.3 | 2.0 (2) | n/a | n/a | $25 / mo | OAuth or key | Hosted | ||
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Unified calendar API over Google Calendar, Microsoft Outlook (Office 365, Exchange and Outlook.com) and iCloud. Top strength $0.50 per connected account a month after 50 on Pro, with unlimited requests Top weakness No status page history, changelog, OpenAPI spec, llms.txt or security.txt |
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Nothing matches these filters. .
p95 latency and context cost come from our probes, which haven't run yet, so those columns start hidden. Grades run from AA to F, and agent-ready means BB or better. Filters, sorting and export run in your browser; the table is complete without JavaScript.
Indexed, not reviewed (32)
Listings sorted into this category from public catalogues (the official MCP registry, APIs.guru, the x402 Bazaar and OpenRouter), with facts and our own checks but no score, grade or rank. How the index works.
| Listing | Kind | What it does | Why it's here |
|---|---|---|---|
| 42min 42min.us | MCP server | Scheduling for AI assistants: bookings, availability, meeting polls and routing forms. | vendor's own |
| AddCal addcal.co | MCP server | Publish public calendars and events others subscribe to: RSVPs, feeds and add-to-calendar links. | vendor's own |
| Aether Wealth aetherwealth.ai | MCP server | Aether Wealth MCP for AI assistants: trades, alerts, market data, macro calendar & indicators. | vendor's own |
| Astrocal astrocal.dev | MCP server | AI-native scheduling: check availability, book meetings, cancel and reschedule via MCP | vendor's own |
| Award Travel Finder awardtravelfinder.com | MCP server | Search award flight availability and points pricing across 27 airlines and 23 loyalty programs. | vendor's own |
| Bowmark bowmark.ai | MCP server | Do things on live websites: prices, availability, quotes, bookings, anything behind a form or login. | vendor's own |
| Chronary chronary.ai | MCP server | Calendar API for AI agents: events, availability, Google/Microsoft setup, scheduling, and iCal. | vendor's own |
| Coordinalo — Service Business Operations coordinalo.com | MCP server | Scheduling, availability, clients, billing and CRM for appointment-based services. | vendor's own |
| Denik denik.me | MCP server | Book appointments, check availability, list services and create payment links for a Denik business. | vendor's own |
| domain-radar insight.surf | MCP server | High-Speed Domain Keyword Matrix, TLD Coverage & RDAP Availability Radar (Powered by insight.surf) | vendor's own |
| Forward Email forwardemail.net | MCP server | Privacy-focused email: domains, DNS verification, aliases, SMTP sending, mailboxes and calendars. | vendor's own |
| heyoden.com MCP server heyoden.com | 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 onekash.org | MCP server | MCP server for iCloud (Apple) Calendar access via CalDAV | vendor's own |
| INITE Club inite.club | MCP server | Ask the agent of someone whose calendar you could not get. No credential needed to try. | vendor's own |
| Local MCP local-mcp.com | MCP server | Mac & Windows: let ChatGPT, Claude & Cursor use your email, calendar, iMessage, Teams, files. Free. | vendor's own, widely used |
| OmniSignal omnisignal.ai | MCP server | Live market intelligence & AI content strategy: trends, competitor moves, content calendar. | vendor's own |
| ponlo.ai MCP server ponlo.ai | MCP server | Family calendar, tasks, meals, lists & rewards hub for AI assistants. | vendor's own |
| reassign reassign.app | MCP server | Reassign: a circular 24-hour calendar and time-tracking copilot with ADHD-friendly scheduling. | vendor's own |
| Rootly rootly.com | MCP server | Incident management, on-call scheduling, and intelligent analysis powered by Rootly. | vendor's own |
| Servicialo MCP Server servicialo.com | MCP server | Open protocol for booking and scheduling professional services via AI agents | vendor's own |
| Shiftyasan Shift Scheduling shiftyasan.com | MCP server | Generate optimized work shift schedules from staffing demand, availability and fairness rules. | vendor's own |
| sifting.io MCP server sifting.io | MCP server | Live crypto/forex/metals prices, OHLCV bars, SEC fundamentals, 13F holdings and econ calendar. | vendor's own |
| SquawkFlow Market Structure mcp.squawkflow.com | MCP server | Free keyless dealer gamma, OI change, market calendar, 13F, congress and CFTC data, dated, cited. | vendor's own |
| StudioMeyer Personal Suite studiomeyer.io | MCP server | Local-first productivity: email, calendar, messaging, search, image gen. 49 tools. BYOK. | vendor's own |
| Syncline MCP Server syncline.run | MCP server | AI-powered meeting scheduling with intelligent auto-scheduling for Claude and AI agents. | vendor's own |
| Syncline MCP Server (Go) kekwanu.com | MCP server | Syncline MCP Server (Go) - AI-powered meeting scheduling with intelligent auto-scheduling | vendor's own |
| Syncline MCP Server (TypeScript) kekwanu.com | MCP server | Syncline MCP Server (TypeScript) - AI-powered meeting scheduling with intelligent auto-scheduling | vendor's own |
| tebra jamesrosingmd.com | MCP server | MCP server for Tebra/Kareo practice management — patients, billing, scheduling, FHIR (45 tools) | vendor's own |
| TLDers Domain Prices tlders.com | MCP server | Compare domain prices across 145+ registrars and 1,100+ TLDs, find promo codes, check availability. | vendor's own |
| Wahlu wahlu.com | MCP server | Social media scheduling for you and your AI agent: Instagram, TikTok, YouTube, Facebook, LinkedIn. | vendor's own |
| zenoti jamesrosingmd.com | MCP server | MCP server for Zenoti spa/wellness/medspa — guests, appointments, bookings, invoices | vendor's own |
| Zooza MCP Server zooza.app | MCP server | MCP server for Zooza — class scheduling, attendance, and booking for activity businesses. | vendor's own |
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.
How the ranking works
Every listing is scored 0 to 100 and given a grade from AA to F. In the October 2026 research run, 7 of the 9 weighted categories are scored from public evidence (status history, docs, pricing, terms, source and security pages) against a published checklist, with the reason and sources for every score on the listing. Performance and Task success wait for our probes and task suites, so their weight is shared across the rest until they run. Negative events deduct up to 15 points. Read the methodology.
For companies
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