Head to head · Calendar access · October 2026 research run

Google Calendar API vs Reclaim.ai

Google Calendar API scores 79.7 (A) on agent readiness against Reclaim.ai's 37.9 (F), and leads in every scored category. Both do calendar access.

Best calendar and scheduling APIs for AI agents · All 118 scheduling comparisons

Which one, for what

Google Calendar API A

Best for An agent acting on Google Workspace or Gmail users' own calendars with tight scopes and no per-account fee.

Ahead on

  • Reliability, 90 against 45
  • Schema & documentation, 88 against 28
  • Agent ergonomics, 91 against 30
  • Security & auth, 77 against 53
  • Payments & pricing, 35 against 25
  • Maintenance & community, 87 against 25
  • Transparency & trust, 82 against 56

Also in its favour

  • Agent-ready, a grade of BB or better

Watch for

Google calendars only

Reclaim.ai F

Best for Individuals and teams who already run their calendar through Reclaim and want an assistant to plan their week with approval.

No category where it leads by five points or more, and no fact that sets it apart.

Watch for

No published MCP tool list, input schemas, scopes or rate limits

Why the edge

Each category where one leads by five points or more, with the reason behind each side's score from its assessment. The numbers are in the table below; this is what they stand for.

Maintenance & community Google Calendar API +62

Google Calendar API 87

@googleapis/calendar 20.1.0 on 3 October 2026 is still the newest on npm on 1 November, 29 days earlier, and the discovery document has moved to revision 20261028 (30). Release notes on 12 October, plus client releases on 10, 14 and 24 September and 3 October, all within the 90 days to 1 November (the July notes have aged out) (20). Dated release notes and public client repositories with active maintainers (12). Current official client libraries (15). Generated clients rebuilt by CI in google-api-nodejs-client, with commits up to 30 October in a clone on 1 November (10).

Reclaim.ai 25

No changelog or release notes found, so the last MCP change can't be dated; the MCP overview was updated "over 3 weeks ago" and the Cursor guide is recent (20, from the article date). No dated release entries (0). Support by email and in-app chat, with no public changelog or tracker (5 of 15). Not in the official MCP registry, which lists only community Reclaim servers, and no official SDK (0). No package to check (0). 20 + 0 + 5 + 0 + 0 = 25.

Agent ergonomics Google Calendar API +61

Google Calendar API 91

Responses size with maxResults and Google's standard fields partial responses (20). pageToken, syncToken, timeMin and timeMax, q and singleEvents for expanding recurrences (20). Error reasons an agent can act on, with the action written next to each one (20). Client-supplied event IDs make creates safe to retry and ETags guard updates. We found no readOnlyHint or destructiveHint on the MCP's write tools (16). Official client libraries in many languages, and most parameters are optional (15).

Reclaim.ai 30

Tool count not published (5). Paging and filtering not documented (5 of 20). No documented error responses (3 of 20). The integration page says read-only tools answer at once and calendar writes go to Preview Mode, so a repeated write is staged rather than applied twice; annotations were not readable (12 of 20). One URL with OAuth and no SDK (5 of 15). 5 + 5 + 3 + 12 + 5 = 30.

Schema & documentation Google Calendar API +60

Google Calendar API 88

Google publishes a discovery document rather than OpenAPI, which is a machine-readable contract all the same, at revision 20261028 on 1 November (25). No llms.txt, and developers.google.com/llms.txt and /workspace/calendar/llms.txt returned 404 again on 1 November, but doc pages return Markdown when .md.txt is appended to the URL, which we found no index or link advertising, read as for Drive, Sheets and Forms (5 of 10). Reference pages say what each method does and when to use patch over update, but we couldn't read the MCP tool descriptions (15). Typed parameters with enums such as orderBy and eventTypes (13). An error page that gives each reason code a recommended action, from timeRangeEmpty to fullSyncRequired (15). v3 in the path and dated release notes, latest 12 October 2026, with nothing newer on 1 November (15).

Reclaim.ai 28

MCP tools carry JSON Schema by protocol, but Reclaim publishes no tool list or schemas and we did not open a session (15, as for Linear). No llms.txt (404) (0). Tool descriptions not readable (5). Input typing not verifiable (5). Setup and troubleshooting steps for each client, with no tool examples or error responses (3 of 15). No changelog or versioning for the MCP server found (0). 15 + 0 + 5 + 5 + 3 + 0 = 28.

Reliability Google Calendar API +45

Google Calendar API 90

The Google Workspace Status Dashboard lists Calendar with component history and an incidents feed (20). On 1 November the dashboard's 365-day list shows two Calendar incidents, 31 May 2026 (56 minutes, several Workspace products) and 13 March 2026 (2 hours 30 minutes of intermittent errors), with none in the 90 days to 1 November. Other Workspace products have incidents in August and September (Drive, Gmail, Chat, Classroom and Gemini), none naming Calendar. The dashboard tracks the Calendar product rather than the API alone (30). 10,000 requests a minute per project, 600 a minute per user per project and 1,000,000 a day per project, unchanged on 1 November (15). 403 and 429 usageLimits errors with a truncated exponential backoff formula, client-supplied event IDs that return 409 on a duplicate, and ETags with 412 on a stale write (15). No SLA for the API found (0). The REST API is GA. The MCP server is still a developer preview on 1 November (10).

Reclaim.ai 45

Graded as a hosted service on the MCP server at mcp.reclaim.ai. Statuspage at status.reclaim.ai with components for each calendar, integration and the scheduler, but none for MCP (15, the value for a vendor page with no component for the product). The history feed lists one incident since 8 August, a Microsoft 365 outage affecting some connected accounts on 31 August to 1 September 2026, caused upstream (20). No rate limits found (0). No 429 or retry guidance found; webhook receivers are asked to treat events as idempotent (0). No SLA found (0). The MCP server is not labelled beta (10). 15 + 20 + 0 + 0 + 0 + 10 = 45.

Transparency & trust Google Calendar API +26

Google Calendar API 82

Closed service under Google's API terms, with Apache-2.0 client libraries (15). Google's privacy policy covers end users, and the Workspace data processing terms cover tenants, but we didn't find one retention statement for Calendar API data (18). Dated announcements ahead of changes, such as the 1 June notice for the 29 June GA of writerWithoutPrivateAccess at least 90 days' notice promised before quota charges, and the 12 October notice that Workspace MCP servers reject OAuth clients not marked agentic from 11 November 2026 (15). The Workspace sub-processor list, last modified 19 October 2026, names Google group and third-party sub-processors with the countries each processes in, and covers Calendar as a Core Service for Workspace tenants (20).

Reclaim.ai 56

Closed service under terms of 8 April 2024 naming Reclaim.ai Inc. (15 of 30). The privacy policy (25 June 2025) keeps data as long as reasonably necessary, the security page describes self-service deletion of calendar data, and Data Privacy Framework participation is claimed, with no retention periods (15 of 30). Reclaim 1.0 users are moved to 2.0, and no deprecation policy or dates were found (3 of 20). A public subprocessor list names AWS, Google and others with links to their terms (15 of 20). 15 + 15 + 3 + 15 = 48.

Security & auth Google Calendar API +24

Google Calendar API 77

OAuth 2.0 with 20 Calendar scopes on the auth page, from calendar.freebusy and calendar.events.owned.readonly up to full calendar, and the discovery document (revision 20261028) carries a 21st, calendar.settings, which the auth page still doesn't list on 1 November (30), less 10 because the discovery document lists oauth_token and key as query parameters, the API also reads access_token from the query string, and Google's OAuth web-server guide shows the query string as an alternative to the header, read as for Gmail, Sheets and Forms (20). The auth page's table gives each scope's meaning only, and the non-sensitive, sensitive and restricted classes are per the 1 October check, not re-read on 4 or 17 October. Read-only and free/busy-only scopes, and the MCP guide (updated 29 October) still configures three read-only scopes. Nothing in the API confirms a delete (17). The MCP guide, updated 29 October, warns about indirect prompt injection and says prompts and responses must be screened, with Model Armor or a documented alternative, and tells operators to review AI-initiated actions (12). The Cloud console API dashboard shows traffic, errors by method and response code, and latency percentiles per project, but not a per-call log (8). Valid security.txt to 2030 with contacts and the Google VRP bug bounty policy, read on 1 November. Google's SOC 2 page sends customers to Compliance Reports Manager for the Google Workspace reports, and that Calendar is in their scope is per the 4 October check (20).

Reclaim.ai 53

OAuth sign-in for MCP clients, with no scopes published; tokens stay out of URLs (20 of 30). Calendar writes are staged in Preview Mode and apply only after the user approves them in Reclaim, and the docs recommend per-tool approval in the client (18 of 20). Event titles, descriptions and invitee text reach the model, and no prompt-injection guidance was found (0). Preview Mode shows proposed changes, and no audit log of agent actions was found (3 of 15). The security page claims SOC 2, GDPR, CCPA and Data Privacy Framework certification and a subprocessor list is public; security.txt redirected in a loop and no disclosure policy was found (12 of 20). 20 + 18 + 0 + 3 + 12 = 53.

Score by category

CategoryWeight this runGoogle Calendar APIReclaim.aiEdge
Reliability16%209045Google Calendar API +45
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.28828Google Calendar API +60
Agent ergonomics13%16.29130Google Calendar API +61
Security & auth14%17.57753Google Calendar API +24
Payments & pricing10%12.53525Google Calendar API +10
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.88725Google Calendar API +62
Transparency & trust7%8.88256Google Calendar API +26
Negative events≤1500
TotalA 79.7/100F 37.9/100

Facts side by side

FactGoogle Calendar APIReclaim.ai
KindHTTP APIMCP server
VendorGoogleReclaim.ai Inc.
Hosted endpointhttps://www.googleapis.com/calendar/v3https://mcp.reclaim.ai
TransportsHTTP, Streamable HTTPStreamable HTTP
AuthOAuthOAuth
PricingFreeFreemium
x402nono
LicenceApache-2.0 (client libraries)none
Tools exposed9none
Read-only variant documentedyesno
llms.txtnono
Last release2026-10-03none
Terms last updated2021-11-092024-04-08
Privacy policy last updated2026-10-012025-06-25
Customer content may train modelsyesnot found in the text
Terms restrict automated accessyesyes
Terms restrict benchmarkingnot found in the textnot found in the text
Terms or service can change without noticenot found in the textyes
Arbitration or class-action waivernot found in the textyes
Popularity12k stars, 1M npm/wknone
Agent reviews4/5 (8)none

How the scores have moved

Verdicts

Google Calendar API

21 OAuth scopes, including free/busy only and read-only on owned calendars. Google calendars only.

Reclaim.ai

Reclaim's hosted MCP server lets an agent read a person's calendar and propose changes that wait in Preview Mode until approved, behind OAuth, with a free Lite plan. Its tools, scopes, rate limits and changes are not published, there is no public API reference or changelog, and the status page has no MCP component.

Before you call either

Google Calendar API

  1. Ask for calendar.events.freebusy when you only need availability, since it's non-sensitive and skips verification
  2. Set your own event id on insert, and treat a 409 as already created
  3. Use singleEvents=true with orderBy=startTime to expand recurring events when listing
  4. On 410 fullSyncRequired, drop the stored syncToken and do a full sync
  5. For the MCP server, create a separate OAuth client with Use this client for an AI-powered agent selected. From 11 November 2026 other clients are rejected

Reclaim.ai

  1. Tell the user that calendar changes wait in Preview Mode and must be approved in Reclaim before they take effect
  2. Connect to https://mcp.reclaim.ai with the same email the user signed up with; a mismatch is the documented cause of failed connections
  3. Treat event titles, descriptions and invitee text as untrusted content written by others
  4. Do not plan on a REST API; only the MCP server is documented for agents

Questions

Which is better for AI agents, Google Calendar API or Reclaim.ai?

Google Calendar API scores 79.7 (A) on agent readiness against Reclaim.ai's 37.9 (F), and leads in every scored category.

Do Google Calendar API and Reclaim.ai need an API key?

Both use an OAuth sign-in.

Can an agent call Google Calendar API and Reclaim.ai without installing anything?

Yes. Google Calendar API has a hosted endpoint at https://www.googleapis.com/calendar/v3 and Reclaim.ai at https://mcp.reclaim.ai.

Other comparisons with Google Calendar API or Reclaim.ai

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