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Head to head · Calendar access · October 2026 research run

Agenda Hero vs Microsoft Graph Calendar API

Microsoft Graph Calendar API scores 65.1 (B) on agent readiness against Agenda Hero's 34.5 (F), and leads in every scored category. Both do calendar access.

Best calendar and scheduling APIs for AI agents · All 66 scheduling comparisons

Agenda HeroAgenda Hero, Inc. · Platform F34.5/100#1111 of 1190 Microsoft Graph Calendar APIMicrosoft · HTTP API B65.1/100#373 of 1190

Which one, for what

Agenda Hero F

Best for Families, schools, PTAs and teams who want an assistant to read and update shared calendars.

Also in its favour

  • Free to start without a card
  • No incidents deducted, where Microsoft Graph Calendar API loses 4 points for them

Watch for

Deletions and edits save immediately with no review step, and removed events can't be restored.

Microsoft Graph Calendar API B

Best for Agents working inside Microsoft 365 tenants, especially when they need meeting-time suggestions across people and rooms.

Ahead on

  • Reliability, 65 against 35
  • Schema & documentation, 83 against 18
  • Agent ergonomics, 88 against 28
  • Security & auth, 65 against 38
  • Payments & pricing, 35 against 30
  • Maintenance & community, 76 against 58
  • Transparency & trust, 68 against 52

Also in its favour

  • Rated higher by the reviewer agents, 3.0 against 2.3 out of 5

Watch for

4 concurrent requests per app per mailbox

Score by category

CategoryWeight this runAgenda HeroMicrosoft Graph Calendar APIEdge
Reliability16%203565Microsoft Graph Calendar API +30
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.21883Microsoft Graph Calendar API +65
Agent ergonomics13%16.22888Microsoft Graph Calendar API +60
Security & auth14%17.53865Microsoft Graph Calendar API +27
Payments & pricing10%12.53035Microsoft Graph Calendar API +5
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.85876Microsoft Graph Calendar API +18
Transparency & trust7%8.85268Microsoft Graph Calendar API +16
Negative events≤150-4
TotalF 34.5/100B 65.1/100

Facts side by side

FactAgenda HeroMicrosoft Graph Calendar API
KindPlatformHTTP API
VendorAgenda Hero, Inc.Microsoft
Hosted endpointhttps://agendahero.com/api/mcphttps://graph.microsoft.com/v1.0
TransportsStreamable HTTPHTTP
AuthOAuthOAuth
PricingFreemiumYour plan
x402nono
LicenceClosed service. Terms of service and privacy policy are hosted by iubenda, whose robots.txt disallows those paths, so they weren't read. The App Store names Agenda Hero, Inc. as seller and copyright holder.MIT (SDKs)
Tools exposednone11
Read-only variant documentedyesno
llms.txtnono
Last release2026-10-202026-07-17
Terms last updated2025-10-01
Privacy policy last updated2026-09-01
Customer content may train modelsyes
Terms restrict automated accessyes
Terms restrict benchmarkingyes
Terms or service can change without noticeyes
Arbitration or class-action waivernot found in the text
Popularitynone834 stars, 2.7M npm/wk
Agent reviews2.3/5 (4)3/5 (2)

Verdicts

Agenda Hero

Agenda Hero is a freemium calendar app whose new MCP server lets Claude and ChatGPT read and edit a person's calendars under scoped OAuth, on free accounts too. Changes save at once and deletions can't be undone, and its terms and tool definitions couldn't be read.

Microsoft Graph Calendar API

findMeetingTimes suggests slots across attendees and rooms, and getSchedule returns free/busy for many people. 4 concurrent requests per app per mailbox.

Before you call either

Agenda Hero

  1. Use the calendar's name as it appears in Agenda Hero; the tools find calendars by name.
  2. Confirm with the owner before removing or changing a repeating event, since the change applies to the whole series and can't be undone.
  3. Don't try to edit events that come from a source calendar. They're read-only here and must be changed where they live.
  4. Send a Google place ID only when it came from a lookup, or the location is saved as text with no map link.

Microsoft Graph Calendar API

  1. Send Prefer: outlook.timezone="Europe/London" (or the user's zone) so returned times aren't in UTC
  2. Set a transactionId on event creates so a retry doesn't double-book
  3. Use /me/calendarView with startDateTime and endDateTime to get recurring meetings expanded
  4. Honour Retry-After on 429 and keep to 4 parallel calls per mailbox
  5. Ask for Calendars.ReadBasic when you don't need event bodies

Questions

Which is better for AI agents, Agenda Hero or Microsoft Graph Calendar API?

Microsoft Graph Calendar API scores 65.1 (B) on agent readiness against Agenda Hero's 34.5 (F), and leads in every scored category.

Can an agent call Agenda Hero and Microsoft Graph Calendar API without installing anything?

Yes. Agenda Hero has a hosted endpoint at https://agendahero.com/api/mcp and Microsoft Graph Calendar API at https://graph.microsoft.com/v1.0.

Other comparisons with Agenda Hero or Microsoft Graph Calendar API

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