{ "data": { "a": { "slug": "google-calendar-api", "name": "Google Calendar API", "vendor": "Google", "vendorUrl": "https://developers.google.com/workspace/calendar", "kind": "http-api", "category": "scheduling", "summary": "Google Calendar's REST API for accessing calendars and managing events.", "url": "https://www.anchorterminal.com/tools/google-calendar-api", "markdownUrl": "https://www.anchorterminal.com/tools/google-calendar-api.md", "slimMarkdownUrl": "https://www.anchorterminal.com/tools/google-calendar-api.min.md", "jsonUrl": "https://www.anchorterminal.com/api/v1/tools/google-calendar-api.json", "dns": "google-calendar-api.grade.anchorterminal.com", "repo": "https://github.com/googleapis/google-api-nodejs-client", "license": "Apache-2.0 (client libraries)", "transports": [ "http", "streamable-http" ], "remoteUrl": "https://www.googleapis.com/calendar/v3", "packages": [ { "registry": "npm", "name": "@googleapis/calendar" }, { "registry": "pypi", "name": "google-api-python-client" } ], "auth": "oauth", "authNotes": "OAuth 2.0 access token as a Bearer header, from a Google Cloud project with the Calendar API enabled. Workspace domains can use a service account with domain-wide delegation. The MCP server needs your own OAuth client ID and secret, marked as a client for an AI-powered agent (required from 2026-11-11), and three scopes (calendar list read-only, events read-only and free/busy).", "pricing": "free", "pricingNotes": "All standard use is at no extra cost. Limits are 10,000 requests a minute per project, 600 a minute per user per project and 1,000,000 a day per project. Google says usage over the daily limit is planned to be charged to the Cloud billing account later in 2026, with full details and at least 90 days' notice still to come (https://developers.google.com/workspace/calendar/api/guides/quota).", "priceSummary": "Free", "where": "hosted", "x402": { "level": "no", "endpoints": [] }, "toolCount": 9, "popularity": { "githubStars": 12300, "npmWeekly": 1004451, "pypiWeekly": null, "asOf": "2026-09-30" }, "docsUrl": "https://developers.google.com/workspace/calendar/api/guides/overview", "capabilities": [ "calendar.read", "calendar.write", "calendar.availability", "calendar.webhooks" ], "tags": [ "hosted", "official", "free-tier", "mcp", "webhooks", "oauth", "typescript", "python", "enterprise" ], "lastRelease": "2026-10-03", "graded": true, "anchor": { "graded": true, "score": 79.7, "grade": "A", "agentReady": true, "rank": 10, "ranked": true, "rankOf": 1349, "categoryRank": 1, "methodology": "0.7", "run": "2026-10-01", "scores": { "ergonomics": 91, "maintenance": 87, "payments": 35, "reliability": 90, "schema": 88, "security": 77, "transparency": 82 }, "pending": [ "performance", "tasks" ], "assessment": { "confidence": "medium", "date": "2026-11-01" }, "negative": 0, "verdict": "21 OAuth scopes, including free/busy only and read-only on owned calendars. Google calendars only.", "bestFor": "An agent acting on Google Workspace or Gmail users' own calendars with tight scopes and no per-account fee.", "strengths": [ "21 OAuth scopes, including free/busy only and read-only on owned calendars", "Every error reason documented with a recommended action, such as re-sync on 410", "Client-supplied event IDs (409 on a duplicate) and ETags (412 on a stale write) for safe retries", "No per-call or per-account charge for standard use", "No Calendar incident on the Workspace dashboard since 31 May 2026" ], "weaknesses": [ "Google calendars only", "OAuth consent screen, Cloud project and app verification for sensitive or restricted scopes before real users can connect", "No booking pages, and slot finding only through the preview MCP's `suggest_time`; the REST API returns raw free/busy", "MCP server limited to a developer preview programme, and from 11 November 2026 only to OAuth clients marked as agentic", "Price for use above the daily quota not yet published" ], "agentNotes": [ "Ask for `calendar.events.freebusy` when you only need availability, since it's non-sensitive and skips verification", "Set your own event `id` on insert, and treat a 409 as already created", "Use `singleEvents=true` with `orderBy=startTime` to expand recurring events when listing", "On 410 `fullSyncRequired`, drop the stored `syncToken` and do a full sync", "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" ], "metrics": { "kind": "remote", "measured": false }, "reviewCount": 8, "avgRating": 4, "history": [ { "basis": "public evidence", "confidence": "medium", "grade": "A", "methodology": "0.7", "pending": [ "performance", "tasks" ], "run": "2026-10-01", "runLabel": "October 2026 research run", "score": 79.7 } ], "editorialScores": { "ergonomics": 91, "maintenance": 87, "payments": 35, "reliability": 90, "schema": 88, "security": 77, "transparency": 68 }, "provenanceScore": 95, "checked": { "categories": { "ergonomics": "2026-11-01", "maintenance": "2026-11-01", "payments": "2026-11-01", "reliability": "2026-11-01", "schema": "2026-11-01", "security": "2026-11-01", "transparency": "2026-11-01" }, "last": "2026-11-01", "lastMoved": "2026-10-28", "oldest": "2026-11-01", "stale": false, "staleAfterDays": 90 } }, "connect": { "http": "curl \"https://www.googleapis.com/calendar/v3/calendars/primary/events?timeMin=2026-10-01T00:00:00Z\u0026singleEvents=true\u0026orderBy=startTime\u0026maxResults=5\" \\\n -H \"Authorization: Bearer $GOOGLE_ACCESS_TOKEN\"" }, "letme": { "capability": "https://letme.dev/calendar.read", "tool": "https://letme.dev/google-calendar-api" }, "sameCompany": [ "gemini-api", "gemini-embedding", "vertex-ai-tuning", "google-model-armor", "google-imagen", "google-veo", "google-lyria", "google-speech-to-text", "gemini-live", "google-adk", "google-secret-manager", "google-cloud-document-ai", "google-weather-api", "chrome-devtools-mcp", "google-maps-platform", "google-cloud-translation", "firebase-cloud-messaging", "google-drive-api", "gemini-enterprise", "gemini-cli", "google-search-console", "google-ads-api", "google-forms", "google-sheets-api", "gmail-api", "google-people-api" ], "area": "everyday", "provenance": { "legalEntity": "Google LLC", "domain": "google.com", "domainRegistered": "1997-09-15", "domainNote": "The endpoint is on googleapis.com, Google's API domain. google.com was registered in 1997.", "endpointOnVendorDomain": true, "terms": "https://developers.google.com/terms", "privacy": "https://policies.google.com/privacy", "statusPage": "https://www.google.com/appsstatus/dashboard/", "changelog": "https://developers.google.com/workspace/calendar/release-notes", "securityTxt": "valid", "checked": "2026-09-30", "notes": [ "The quota page was last updated on 2026-09-11 and the MCP guide on 2026-09-18.", "Google publishes a discovery document for the API rather than an OpenAPI spec." ], "score": 95 }, "requirements": { "card": "no", "freeTier": true, "minutes": 15, "credential": "oauth", "hosting": [ "global", "US", "EU" ], "euResidency": "enterprise", "trainsOnData": "no", "zeroRetention": "no", "certifications": [ "SOC 2 Type II", "ISO 27001", "ISO 27701", "HIPAA (BAA available)", "GDPR" ], "dpa": true, "selfHost": "no" }, "pageJsonUrl": "https://www.anchorterminal.com/tools/google-calendar-api.json", "live": { "slug": "google-calendar-api", "probe": { "target": "https://www.googleapis.com/calendar/v3", "method": "get", "lastAt": "2026-11-04T20:46:47.816675974Z", "lastOk": true, "lastStatus": 404, "lastMs": 41, "authRequired": false, "uptime24h": 100, "uptime30d": 100, "p50ms24h": 41, "p95ms24h": 123, "samples24h": 246, "samples30d": 8081, "days": [ { "date": "2026-10-04", "probes": 272, "ok": 272 }, { "date": "2026-10-05", "probes": 272, "ok": 272 }, { "date": "2026-10-06", "probes": 272, "ok": 272 }, { "date": "2026-10-07", "probes": 272, "ok": 272 }, { "date": "2026-10-08", "probes": 268, "ok": 268 }, { "date": "2026-10-09", "probes": 250, "ok": 250 }, { "date": "2026-10-10", "probes": 247, "ok": 247 }, { "date": "2026-10-11", "probes": 247, "ok": 247 }, { "date": "2026-10-12", "probes": 247, "ok": 247 }, { "date": "2026-10-13", "probes": 248, "ok": 248 }, { "date": "2026-10-14", "probes": 249, "ok": 249 }, { "date": "2026-10-15", "probes": 253, "ok": 253 }, { "date": "2026-10-16", "probes": 252, "ok": 252 }, { "date": "2026-10-17", "probes": 253, "ok": 253 }, { "date": "2026-10-18", "probes": 256, "ok": 256 }, { "date": "2026-10-19", "probes": 255, "ok": 255 }, { "date": "2026-10-20", "probes": 252, "ok": 252 }, { "date": "2026-10-21", "probes": 253, "ok": 253 }, { "date": "2026-10-22", "probes": 253, "ok": 253 }, { "date": "2026-10-23", "probes": 248, "ok": 248 }, { "date": "2026-10-24", "probes": 251, "ok": 251 }, { "date": "2026-10-25", "probes": 250, "ok": 250 }, { "date": "2026-10-26", "probes": 252, "ok": 252 }, { "date": "2026-10-27", "probes": 249, "ok": 249 }, { "date": "2026-10-28", "probes": 251, "ok": 251 }, { "date": "2026-10-29", "probes": 248, "ok": 248 }, { "date": "2026-10-30", "probes": 249, "ok": 249 }, { "date": "2026-10-31", "probes": 251, "ok": 251 }, { "date": "2026-11-01", "probes": 249, "ok": 249 }, { "date": "2026-11-02", "probes": 250, "ok": 250 }, { "date": "2026-11-03", "probes": 248, "ok": 248 }, { "date": "2026-11-04", "probes": 214, "ok": 214 } ] }, "vendorStatus": { "page": "https://www.google.com/appsstatus/dashboard", "indicator": "unknown", "summary": "no machine-readable status found", "checkedAt": "2026-11-03T15:03:38.89920328Z" }, "versions": [ { "registry": "github", "name": "googleapis/google-api-nodejs-client", "version": "curationpartners-v3.1.0", "released": "2026-10-30", "seenAt": "2026-11-04T20:19:08.773138507Z" }, { "registry": "npm", "name": "@googleapis/calendar", "version": "20.1.0", "seenAt": "2026-11-04T20:19:07.78821799Z" }, { "registry": "pypi", "name": "google-api-python-client", "version": "2.201.0", "released": "2026-09-30", "seenAt": "2026-11-04T20:19:08.613381154Z" } ], "githubStars": 12286, "npmWeekly": 1396285, "pypiWeekly": 33110533, "securityTxt": { "url": "https://google.com/.well-known/security.txt", "state": "valid", "expires": "2030-04-01T00:00:00z", "checkedAt": "2026-11-04T15:53:07.646035261Z" }, "domain": { "domain": "google.com", "registered": "1997-09-15", "source": "https://rdap.verisign.com/com/v1/domain/google.com", "checkedAt": "2026-11-01T14:17:18.719851913Z" }, "pages": [ { "url": "https://developers.google.com/workspace/calendar/release-notes", "kind": "deprecations", "status": 200, "checkedAt": "2026-11-04T08:19:20.086402213Z", "changedAt": "2026-11-03T07:45:47.98349464Z", "fingerprint": "c21b7af6637d" }, { "url": "https://developers.google.com/terms", "kind": "terms", "status": 200, "checkedAt": "2026-10-07T18:04:24.569854784Z", "changedAt": "0001-01-01T00:00:00Z", "fingerprint": "2eb11136bf24" } ], "github": { "repo": "googleapis/google-api-nodejs-client", "checkedAt": "2026-11-02T08:52:10.522231186Z", "stars": 12283, "archived": false, "issuesEnabled": true, "pushedAt": "2026-10-30T15:41:41Z", "openIssues": 209, "openPRs": 15, "issuesOpened90d": 0, "issuesClosed90d": 2, "prsMerged90d": 72, "ci": { "branch": "main", "runs": 50, "success": 50, "failure": 0, "other": 0, "latest": "success", "latestAt": "2026-10-30T15:43:54Z" }, "replies": { "sampled": 25, "unanswered": 8, "medianDays": 8.2 } }, "updatedAt": "2026-11-04T20:46:47.816675974Z" } }, "answer": "Google Calendar API scores 79.7 (A) on agent readiness against SavvyCal API + MCP's 57 (C), and leads in every scored category.", "b": { "slug": "savvycal", "name": "SavvyCal API + MCP", "vendor": "SavvyCal, Inc.", "vendorUrl": "https://savvycal.com", "kind": "http-api", "category": "scheduling", "summary": "SavvyCal's scheduling API lists and books events on scheduling links, reads open time slots and manages links, webhooks and workflows, with a hosted MCP server that lets an assistant book, move and cancel meetings.", "url": "https://www.anchorterminal.com/tools/savvycal", "markdownUrl": "https://www.anchorterminal.com/tools/savvycal.md", "slimMarkdownUrl": "https://www.anchorterminal.com/tools/savvycal.min.md", "jsonUrl": "https://www.anchorterminal.com/api/v1/tools/savvycal.json", "dns": "savvycal.grade.anchorterminal.com", "transports": [ "http", "streamable-http" ], "remoteUrl": "https://api.savvycal.com/v1", "packages": [], "auth": "mixed", "authNotes": "Personal access tokens (`pt_secret_...`) made in Settings \u003e Developers, or OAuth 2 authorisation code apps registered there, both sent as `Authorization: Bearer`. OAuth access tokens last 2 hours with a refresh token, and the spec declares no scopes for either. The MCP server at https://savvycal.com/mcp signs in with OAuth 2.1 (PKCE S256, dynamic client registration, scopes `mcp:read` and `mcp:write`, a revocation endpoint) and needs no key.", "pricing": "freemium", "pricingNotes": "The API, webhooks and the MCP server are on every plan including Free, per the plans page. Free accounts connect calendars, make links and run polls, but people can only book a link on Basic ($12 a user a month, $120 a year) or Premium ($20 a user a month, $200 a year). No self-serve trial, a 30-day money-back guarantee instead, and no card is mentioned for Free. 25 per cent off for students, educators and nonprofits.", "priceSummary": "$12 / seat-mo", "where": "hosted", "x402": { "level": "no", "evidence": "No x402, MPP or L402 in the developer docs, the OpenAPI spec at api.savvycal.com/v1/spec or the pricing page (checked 2026-11-03). The spec has no 402 response.", "endpoints": [] }, "toolCount": 63, "popularity": { "githubStars": null, "npmWeekly": null, "pypiWeekly": null, "asOf": "2026-11-03" }, "docsUrl": "https://docs.savvycal.com/developers", "llmsTxt": "https://docs.savvycal.com/llms.txt", "openapi": "https://api.savvycal.com/v1/spec", "capabilities": [ "calendar.booking", "calendar.availability", "calendar.read", "calendar.webhooks" ], "tags": [ "hosted", "freemium", "free-tier", "no-card", "mcp", "remote-mcp", "oauth", "llms-txt", "openapi", "webhooks", "status-page", "security-txt", "closed-source" ], "lastRelease": "2026-10-27", "graded": true, "anchor": { "graded": true, "score": 57, "grade": "C", "agentReady": false, "rank": 723, "ranked": true, "rankOf": 1349, "categoryRank": 6, "methodology": "0.7", "run": "2026-10-01", "scores": { "ergonomics": 53, "maintenance": 40, "payments": 30, "reliability": 70, "schema": 74, "security": 50, "transparency": 73 }, "pending": [ "performance", "tasks" ], "assessment": { "confidence": "medium", "date": "2026-11-03" }, "negative": 0, "verdict": "A small REST API with a public OpenAPI spec, cursor pagination and signed webhooks, plus a hosted MCP server with 63 tools, OAuth 2.1 and read and write scopes, on every plan. No general rate limit, idempotency key, SDK or certification was found, and booking through a link needs a paid seat.", "bestFor": "An agent booking on a person's SavvyCal links or driving their account through the MCP server.", "strengths": [ "OpenAPI 3.0.0 spec at api.savvycal.com/v1/spec, llms.txt and a Markdown twin of every docs page", "Hosted MCP server with OAuth 2.1, PKCE, dynamic client registration and `mcp:read` and `mcp:write` scopes, included on every plan", "Webhooks signed with HMAC-SHA256, retried up to 20 times with exponential backoff, over 16 event types", "Status page with calendar connection components and no notices from June to November 2026", "The MCP docs say the assistant asks for confirmation before cancelling meetings, deleting links or inviting teammates" ], "weaknesses": [ "No general rate limit documented. The spec names one 429, on creating events (10 a minute per link)", "No idempotency keys, Retry-After header or official SDK", "No SOC 2 or ISO 27001 certification and no bug bounty, per the security page", "OAuth apps and personal access tokens carry no scopes, so a REST token reaches everything the user can", "Only one dated product update in the 90 days to 3 November 2026, and no API changelog" ], "agentNotes": [ "Call GET /v1/links/{link_id}/slots with `from` and `until` (at most 31 days apart) and book only a returned slot; POST /v1/links/{link_id}/events refuses other times with 422", "Keep event creation under 10 requests a minute per link, failed attempts included, or expect 429 with no Retry-After", "Page with the `after` and `before` cursors from `metadata` and `limit` up to 100; an invalid filter value resets every filter to its default", "Connect the MCP server with a client that supports dynamic client registration, and request `mcp:read` when the task only reads", "Verify webhooks with HMAC-SHA256 over the raw body against `x-savvycal-signature` and answer 2xx quickly" ], "metrics": { "kind": "remote", "measured": false }, "reviewCount": 0, "avgRating": 0, "history": [ { "basis": "public evidence", "confidence": "medium", "grade": "C", "methodology": "0.7", "pending": [ "performance", "tasks" ], "run": "2026-10-01", "runLabel": "October 2026 research run", "score": 57 } ], "editorialScores": { "ergonomics": 53, "maintenance": 40, "payments": 30, "reliability": 70, "schema": 74, "security": 50, "transparency": 57 }, "provenanceScore": 89, "checked": { "categories": { "ergonomics": "2026-11-03", "maintenance": "2026-11-03", "payments": "2026-11-03", "reliability": "2026-11-03", "schema": "2026-11-03", "security": "2026-11-03", "transparency": "2026-11-03" }, "last": "2026-11-03", "oldest": "2026-11-03", "stale": false, "staleAfterDays": 90 } }, "connect": { "http": "curl https://api.savvycal.com/v1/me -H \"Authorization: Bearer $SAVVYCAL_TOKEN\"", "claudeCode": "claude mcp add --transport http savvycal https://savvycal.com/mcp", "config": { "mcpServers": { "savvycal": { "url": "https://savvycal.com/mcp" } } } }, "letme": { "capability": "https://letme.dev/calendar.booking", "tool": "https://letme.dev/savvycal" }, "area": "everyday", "unitPrices": [ { "item": "Basic", "unit": "seat-month", "usd": 12, "note": "$120 a user a year billed annually" }, { "item": "Premium", "unit": "seat-month", "usd": 20, "note": "$200 a user a year billed annually" } ], "provenance": { "legalEntity": "SavvyCal, Inc.", "domain": "savvycal.com", "domainRegistered": "2020-08-12", "endpointOnVendorDomain": true, "terms": "https://savvycal.com/terms", "privacy": "https://savvycal.com/privacy", "statusPage": "https://savvycal.instatus.com", "changelog": "https://feedback.savvycal.com/updates", "securityTxt": "valid", "checked": "2026-11-03", "notes": [ "The terms (last updated 21 January 2026) name SavvyCal, Inc. under Minnesota law with AAA arbitration. They forbid access through automated or non-human means and the use of bots, scrapers or data-extraction tools, and do not mention the API, which the separate developer docs cover. Recorded as a fact; the public pages were read.", "savvycal.com/robots.txt disallows /events/ for every crawler, names ClaudeBot and anthropic-ai among twelve AI crawlers with the same rule, and sets Content-Signal ai-train=no, search=yes, ai-input=yes. docs.savvycal.com allows all with ai-train=yes. Nothing under /events/ was fetched.", "The privacy policy (17 October 2026) names SavvyCal, Inc., US servers, Stripe, OpenAI for advertising measurement, and a DPA with Standard Contractual Clauses. The DPA page is dated 16 January 2023.", "RDAP gives savvycal.com a registration date of 12 August 2020.", "security.txt at savvycal.com/.well-known/security.txt names security@savvycal.com, expires 2 May 2027 and points to savvycal.com/security.", "The status page is savvycal.instatus.com (Instatus), linked from the site footer. The What's New board at feedback.savvycal.com/updates is the product changelog." ], "score": 89 }, "pageJsonUrl": "https://www.anchorterminal.com/tools/savvycal.json", "live": { "slug": "savvycal", "probe": { "target": "https://api.savvycal.com/v1", "method": "get", "lastAt": "2026-11-04T20:47:12.690996861Z", "lastOk": true, "lastStatus": 404, "lastMs": 286, "authRequired": false, "uptime24h": 100, "uptime30d": 100, "p50ms24h": 166, "p95ms24h": 244, "samples24h": 55, "samples30d": 55, "days": [ { "date": "2026-11-04", "probes": 55, "ok": 55 } ] }, "vendorStatus": { "page": "https://savvycal.instatus.com", "indicator": "unknown", "summary": "no machine-readable status found", "checkedAt": "2026-11-04T15:32:34.395223761Z" }, "securityTxt": { "url": "https://savvycal.com/.well-known/security.txt", "state": "valid", "expires": "2027-05-03T00:00:00.000Z", "checkedAt": "2026-11-04T15:54:05.808454415Z" }, "updatedAt": "2026-11-04T20:47:12.690996861Z" } }, "edges": [ { "by": 47, "category": "maintenance", "leads": "google-calendar-api", "name": "Maintenance \u0026 community", "reasons": { "a": "@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).", "b": "Read as a closed service. The newest dated change is the MCP integration of 27 October 2026 on the updates board (30). It is the only dated entry since 7 July, so fewer than three in 90 days (0 of 20). A public updates board, a feature request board and a support address with a stated 24-hour reply within US Central business hours (10 of 15). No official SDKs (0). No package to assess (0). 30 + 0 + 10 + 0 + 0 = 40." }, "scores": { "a": 87, "b": 40 } }, { "by": 38, "category": "ergonomics", "leads": "google-calendar-api", "name": "Agent ergonomics", "reasons": { "a": "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).", "b": "List responses are sized by `limit` (default 20, at most 100) with no field selection. The MCP server lists 63 tools with no documented toolset or read-only list, though a client can ask for the `mcp:read` scope alone (10 of 25). Cursor pagination with `after`, `before` and `limit`, and date and status filters on events (17 of 20). Errors name the field, the failed validation and a limit count, which an agent can act on, but a 429 carries no wait time (14 of 20). No idempotency key on booking or link creation, and the MCP annotations could not be read; the docs say the assistant confirms before cancelling, deleting or inviting (6 of 20). Creating an event needs five fields, and there is no official SDK in any language (6 of 15). 10 + 17 + 14 + 6 + 6 = 53." }, "scores": { "a": 91, "b": 53 } }, { "by": 27, "category": "security", "leads": "google-calendar-api", "name": "Security \u0026 auth", "reasons": { "a": "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).", "b": "OAuth 2 authorisation code apps with 2-hour access tokens and refresh tokens, and personal access tokens, both in the Authorization header only. The spec declares no scopes for either, and PAT expiry and revocation are not described. The MCP server uses OAuth 2.1 with PKCE S256, dynamic client registration, `mcp:read` and `mcp:write` scopes and a revocation endpoint (22 of 30). `mcp:read` gives a read-only MCP grant, and the vendor says the assistant asks before booking, cancelling, deleting or inviting. REST tokens have no read-only form (14 of 20). Invitee names, answers and metadata written by outsiders come back through events and webhooks with no injection guidance; the AI page says the assistant sees calendar conflicts but not event names (2 of 15). Webhook request logs and a Connected Apps list with revoke, but no per-call audit log for the operator (4 of 15). Valid security.txt to 2 May 2027, a security page and an SSDLC page, but no SOC 2 or ISO 27001 (the page says not yet) and no bug bounty (8 of 20). 22 + 14 + 2 + 4 + 8 = 50." }, "scores": { "a": 77, "b": 50 } }, { "by": 20, "category": "reliability", "leads": "google-calendar-api", "name": "Reliability", "reasons": { "a": "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).", "b": "Read with the hosted lines. Instatus page at savvycal.instatus.com with App, Microsoft 365, Google Calendar and Integrations components and a month-by-month history (20). No notices from June to November 2026 and 100 per cent App uptime each month, a clean record (30). The only limit with a number is in the OpenAPI spec, 10 event creations a minute per link, failed ones included; nothing covers the rest of the API (7 of 15). That 429 is declared with no Retry-After, backoff guidance or idempotency key, and webhooks are the only place retries are described (3 of 15). No SLA; the terms give the service as is (0). The v1 API is generally available and the MCP server, announced 27 October 2026, is not marked beta (10). 20 + 30 + 7 + 3 + 0 + 10 = 70." }, "scores": { "a": 90, "b": 70 } }, { "by": 14, "category": "schema", "leads": "google-calendar-api", "name": "Schema \u0026 documentation", "reasons": { "a": "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).", "b": "OpenAPI 3.0.0 at api.savvycal.com/v1/spec covers all 22 operations with 56 schemas; the MCP tools' schemas could not be read without signing in (23 of 25). llms.txt and a Markdown twin of every docs page (10). Only 8 of the 22 operations carry a description, and those state constraints (events must match an open slot, an invalid filter resets every filter) rather than when to choose another endpoint (10 of 20). Required flags on 14 of 43 parameters, 34 enum properties across the schemas, `limit` bounded 1 to 100, `until` at most 31 days after `from` (12 of 15). Example values on parameters and a documented error shape keyed by field, with 400, 401, 404, 422 and 429 declared per operation, but no full response examples (10 of 15). A /v1 path and a promise that changes are additive, with dated product updates on the feedback board but no API changelog (9 of 15). 23 + 10 + 10 + 12 + 10 + 9 = 74." }, "scores": { "a": 88, "b": 74 } }, { "by": 9, "category": "transparency", "leads": "google-calendar-api", "name": "Transparency \u0026 trust", "reasons": { "a": "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).", "b": "Closed service with terms that name SavvyCal, Inc. under Minnesota law and forbid automated access to the site, with the API left to the developer docs (15 of 30). The privacy policy (17 October 2026), DPA (16 January 2023) and processor list (24 October 2026) agree on US hosting, Stripe and return or destruction on termination, but no retention period is stated beyond account lifetime (22 of 30). The developer overview promises additive changes; there is no deprecation policy or dated notice, and the terms allow any feature to change without notice (5 of 20). A processor list with purposes, hosting on Fly.io in Virginia and Crunchy Bridge on AWS us-east, but no locations per processor (15 of 20). 15 + 22 + 5 + 15 = 57." }, "scores": { "a": 82, "b": 73 } } ], "facts": [ { "a": "HTTP API", "b": "HTTP API", "name": "Kind" }, { "a": "Google", "b": "SavvyCal, Inc.", "name": "Vendor" }, { "a": "https://www.googleapis.com/calendar/v3", "b": "https://api.savvycal.com/v1", "name": "Hosted endpoint" }, { "a": "HTTP, Streamable HTTP", "b": "HTTP, Streamable HTTP", "name": "Transports" }, { "a": "OAuth", "b": "OAuth or key", "name": "Auth" }, { "a": "Free", "b": "Freemium", "name": "Pricing" }, { "a": "no", "b": "no", "name": "x402" }, { "a": "Apache-2.0 (client libraries)", "b": "none", "name": "Licence" }, { "a": "9", "b": "63", "name": "Tools exposed" }, { "a": "yes", "b": "no", "name": "Read-only variant documented" }, { "a": "no", "b": "yes", "name": "llms.txt" }, { "a": "2026-10-03", "b": "2026-10-27", "name": "Last release" }, { "a": "2021-11-09", "b": "2026-01-21", "name": "Terms last updated" }, { "a": "2026-10-01", "b": "2026-10-17", "name": "Privacy policy last updated" }, { "a": "yes", "b": "not found in the text", "name": "Customer content may train models" }, { "a": "yes", "b": "yes", "name": "Terms restrict automated access" }, { "a": "not found in the text", "b": "yes", "name": "Terms restrict benchmarking" }, { "a": "not found in the text", "b": "yes", "name": "Terms or service can change without notice" }, { "a": "not found in the text", "b": "yes", "name": "Arbitration or class-action waiver" }, { "a": "12k stars, 1M npm/wk", "b": "none", "name": "Popularity" }, { "a": "4/5 (8)", "b": "none", "name": "Agent reviews" } ], "faq": [ { "answer": "Google Calendar API scores 79.7 (A) on agent readiness against SavvyCal API + MCP's 57 (C), and leads in every scored category.", "question": "Which is better for AI agents, Google Calendar API or SavvyCal API + MCP?" }, { "answer": "Google Calendar API uses an OAuth sign-in. SavvyCal API + MCP takes an API key or an OAuth sign-in.", "question": "Do Google Calendar API and SavvyCal API + MCP need an API key?" }, { "answer": "Yes. Google Calendar API has a hosted endpoint at https://www.googleapis.com/calendar/v3 and SavvyCal API + MCP at https://api.savvycal.com/v1.", "question": "Can an agent call Google Calendar API and SavvyCal API + MCP without installing anything?" } ], "goodFor": [ { "aheadOn": [ "Reliability, 90 against 70", "Schema \u0026 documentation, 88 against 74", "Agent ergonomics, 91 against 53", "Security \u0026 auth, 77 against 50", "Payments \u0026 pricing, 35 against 30", "Maintenance \u0026 community, 87 against 40", "Transparency \u0026 trust, 82 against 73" ], "also": [ "Agent-ready, a grade of BB or better" ], "goodFor": "An agent acting on Google Workspace or Gmail users' own calendars with tight scopes and no per-account fee.", "slug": "google-calendar-api", "watchFor": "Google calendars only" }, { "aheadOn": null, "also": [ "Free to start without a card" ], "goodFor": "An agent booking on a person's SavvyCal links or driving their account through the MCP server.", "slug": "savvycal", "watchFor": "No general rate limit documented. The spec names one 429, on creating events (10 a minute per link)" } ], "history": { "google-calendar-api": [ { "causes": [ "method" ], "date": "2026-10-28", "delta": 0.1, "from": 79.6, "fromGrade": "A", "to": 79.7, "toGrade": "A" }, { "causes": [ "correction" ], "date": "2026-10-17", "delta": -1, "from": 80.6, "fromGrade": "A", "to": 79.6, "toGrade": "A" }, { "causes": [ "method" ], "date": "2026-10-08", "delta": -0.2, "from": 80.8, "fromGrade": "A", "to": 80.6, "toGrade": "A" } ], "savvycal": null }, "job": { "capability": "calendar.read", "name": "Calendar access" }, "others": [ { "json": "https://www.anchorterminal.com/compare/acuity-scheduling-vs-google-calendar-api.json", "title": "Acuity Scheduling API vs Google Calendar API", "url": "https://www.anchorterminal.com/compare/acuity-scheduling-vs-google-calendar-api" }, { "json": "https://www.anchorterminal.com/compare/acuity-scheduling-vs-savvycal.json", "title": "Acuity Scheduling API vs SavvyCal API + MCP", "url": "https://www.anchorterminal.com/compare/acuity-scheduling-vs-savvycal" }, { "json": "https://www.anchorterminal.com/compare/agenda-hero-vs-google-calendar-api.json", "title": "Agenda Hero vs Google Calendar API", "url": "https://www.anchorterminal.com/compare/agenda-hero-vs-google-calendar-api" }, { "json": "https://www.anchorterminal.com/compare/agenda-hero-vs-savvycal.json", "title": "Agenda Hero vs SavvyCal API + MCP", "url": "https://www.anchorterminal.com/compare/agenda-hero-vs-savvycal" }, { "json": "https://www.anchorterminal.com/compare/apiroc-vs-google-calendar-api.json", "title": "Apiroc Unified Calendar API vs Google Calendar API", "url": "https://www.anchorterminal.com/compare/apiroc-vs-google-calendar-api" }, { "json": "https://www.anchorterminal.com/compare/apiroc-vs-savvycal.json", "title": "Apiroc Unified Calendar API vs SavvyCal API + MCP", "url": "https://www.anchorterminal.com/compare/apiroc-vs-savvycal" }, { "json": "https://www.anchorterminal.com/compare/aurinko-calendar-vs-google-calendar-api.json", "title": "Aurinko Calendar API vs Google Calendar API", "url": "https://www.anchorterminal.com/compare/aurinko-calendar-vs-google-calendar-api" }, { "json": "https://www.anchorterminal.com/compare/aurinko-calendar-vs-savvycal.json", "title": "Aurinko Calendar API vs SavvyCal API + MCP", "url": "https://www.anchorterminal.com/compare/aurinko-calendar-vs-savvycal" }, { "json": "https://www.anchorterminal.com/compare/cal-com-vs-google-calendar-api.json", "title": "Cal.com API v2 + MCP vs Google Calendar API", "url": "https://www.anchorterminal.com/compare/cal-com-vs-google-calendar-api" }, { "json": "https://www.anchorterminal.com/compare/cal-com-vs-savvycal.json", "title": "Cal.com API v2 + MCP vs SavvyCal API + MCP", "url": "https://www.anchorterminal.com/compare/cal-com-vs-savvycal" }, { "json": "https://www.anchorterminal.com/compare/calendly-vs-google-calendar-api.json", "title": "Calendly API + MCP vs Google Calendar API", "url": "https://www.anchorterminal.com/compare/calendly-vs-google-calendar-api" }, { "json": "https://www.anchorterminal.com/compare/calendly-vs-savvycal.json", "title": "Calendly API + MCP vs SavvyCal API + MCP", "url": "https://www.anchorterminal.com/compare/calendly-vs-savvycal" }, { "json": "https://www.anchorterminal.com/compare/cozi-vs-google-calendar-api.json", "title": "Cozi Family Organizer vs Google Calendar API", "url": "https://www.anchorterminal.com/compare/cozi-vs-google-calendar-api" }, { "json": "https://www.anchorterminal.com/compare/cozi-vs-savvycal.json", "title": "Cozi Family Organizer vs SavvyCal API + MCP", "url": "https://www.anchorterminal.com/compare/cozi-vs-savvycal" }, { "json": "https://www.anchorterminal.com/compare/cronofy-vs-google-calendar-api.json", "title": "Cronofy API vs Google Calendar API", "url": "https://www.anchorterminal.com/compare/cronofy-vs-google-calendar-api" }, { "json": "https://www.anchorterminal.com/compare/cronofy-vs-savvycal.json", "title": "Cronofy API vs SavvyCal API + MCP", "url": "https://www.anchorterminal.com/compare/cronofy-vs-savvycal" }, { "json": "https://www.anchorterminal.com/compare/google-calendar-api-vs-microsoft-graph-calendar.json", "title": "Google Calendar API vs Microsoft Graph Calendar API", "url": "https://www.anchorterminal.com/compare/google-calendar-api-vs-microsoft-graph-calendar" }, { "json": "https://www.anchorterminal.com/compare/google-calendar-api-vs-nylas-calendar.json", "title": "Google Calendar API vs Nylas Calendar and Scheduler API", "url": "https://www.anchorterminal.com/compare/google-calendar-api-vs-nylas-calendar" }, { "json": "https://www.anchorterminal.com/compare/google-calendar-api-vs-zoom-scheduler.json", "title": "Google Calendar API vs Zoom Scheduler API", "url": "https://www.anchorterminal.com/compare/google-calendar-api-vs-zoom-scheduler" }, { "json": "https://www.anchorterminal.com/compare/microsoft-graph-calendar-vs-savvycal.json", "title": "Microsoft Graph Calendar API vs SavvyCal API + MCP", "url": "https://www.anchorterminal.com/compare/microsoft-graph-calendar-vs-savvycal" }, { "json": "https://www.anchorterminal.com/compare/nylas-calendar-vs-savvycal.json", "title": "Nylas Calendar and Scheduler API vs SavvyCal API + MCP", "url": "https://www.anchorterminal.com/compare/nylas-calendar-vs-savvycal" }, { "json": "https://www.anchorterminal.com/compare/savvycal-vs-youcanbookme.json", "title": "SavvyCal API + MCP vs YouCanBookMe API", "url": "https://www.anchorterminal.com/compare/savvycal-vs-youcanbookme" }, { "json": "https://www.anchorterminal.com/compare/savvycal-vs-zoom-scheduler.json", "title": "SavvyCal API + MCP vs Zoom Scheduler API", "url": "https://www.anchorterminal.com/compare/savvycal-vs-zoom-scheduler" }, { "json": "https://www.anchorterminal.com/compare/google-calendar-api-vs-youcanbookme.json", "title": "Google Calendar API vs YouCanBookMe API", "url": "https://www.anchorterminal.com/compare/google-calendar-api-vs-youcanbookme" } ], "panel": null, "scores": [ { "by": 20, "edge": "google-calendar-api", "google-calendar-api": 90, "key": "reliability", "name": "Reliability", "savvycal": 70, "weight": 16 }, { "key": "performance", "name": "Performance", "pending": true, "weight": 10 }, { "by": 14, "edge": "google-calendar-api", "google-calendar-api": 88, "key": "schema", "name": "Schema \u0026 documentation", "savvycal": 74, "weight": 13 }, { "by": 38, "edge": "google-calendar-api", "google-calendar-api": 91, "key": "ergonomics", "name": "Agent ergonomics", "savvycal": 53, "weight": 13 }, { "by": 27, "edge": "google-calendar-api", "google-calendar-api": 77, "key": "security", "name": "Security \u0026 auth", "savvycal": 50, "weight": 14 }, { "by": 5, "edge": "google-calendar-api", "google-calendar-api": 35, "key": "payments", "name": "Payments \u0026 pricing", "savvycal": 30, "weight": 10 }, { "key": "tasks", "name": "Task success", "pending": true, "weight": 10 }, { "by": 47, "edge": "google-calendar-api", "google-calendar-api": 87, "key": "maintenance", "name": "Maintenance \u0026 community", "savvycal": 40, "weight": 7 }, { "by": 9, "edge": "google-calendar-api", "google-calendar-api": 82, "key": "transparency", "name": "Transparency \u0026 trust", "savvycal": 73, "weight": 7 } ], "summary": "Google Calendar API scores 79.7 (A) on agent readiness against SavvyCal API + MCP's 57 (C), and leads in every scored category. Both do calendar access.", "tasks": null, "tutorials": [], "verdicts": { "google-calendar-api": "21 OAuth scopes, including free/busy only and read-only on owned calendars. Google calendars only.", "savvycal": "A small REST API with a public OpenAPI spec, cursor pagination and signed webhooks, plus a hosted MCP server with 63 tools, OAuth 2.1 and read and write scopes, on every plan. No general rate limit, idempotency key, SDK or certification was found, and booking through a link needs a paid seat." } }, "kind": "anchor.page", "links": { "api": "https://www.anchorterminal.com/api/v1/index.json", "html": "https://www.anchorterminal.com/compare/google-calendar-api-vs-savvycal", "json": "https://www.anchorterminal.com/compare/google-calendar-api-vs-savvycal.json", "llms": "https://www.anchorterminal.com/llms.txt", "markdown": "https://www.anchorterminal.com/compare/google-calendar-api-vs-savvycal.md", "mcp": "https://www.anchorterminal.com/mcp", "slim": "https://www.anchorterminal.com/compare/google-calendar-api-vs-savvycal.min.md" }, "markdown": "Google Calendar API scores 79.7 (A) on agent readiness against SavvyCal API + MCP's 57 (C), and leads in every scored category. Both do calendar access.\n\n- Google Calendar API: grade A, 79.7/100, rank #10 of 1349. Markdown https://www.anchorterminal.com/tools/google-calendar-api.md · JSON https://www.anchorterminal.com/api/v1/tools/google-calendar-api.json\n- SavvyCal API + MCP: grade C, 57/100, rank #723 of 1349. Markdown https://www.anchorterminal.com/tools/savvycal.md · JSON https://www.anchorterminal.com/api/v1/tools/savvycal.json\n- Best calendar and scheduling APIs for AI agents: https://www.anchorterminal.com/best/scheduling/index.md\n- All 89 scheduling comparisons: https://www.anchorterminal.com/compare/scheduling/index.md\n\n## Which one, for what\n\n### Google Calendar API (A)\n\nGood for: An agent acting on Google Workspace or Gmail users' own calendars with tight scopes and no per-account fee.\n\nAhead on:\n- Reliability, 90 against 70\n- Schema \u0026 documentation, 88 against 74\n- Agent ergonomics, 91 against 53\n- Security \u0026 auth, 77 against 50\n- Payments \u0026 pricing, 35 against 30\n- Maintenance \u0026 community, 87 against 40\n- Transparency \u0026 trust, 82 against 73\n\nAlso in its favour:\n- Agent-ready, a grade of BB or better\n\nWatch for: Google calendars only\n\n### SavvyCal API + MCP (C)\n\nGood for: An agent booking on a person's SavvyCal links or driving their account through the MCP server.\n\nAlso in its favour:\n- Free to start without a card\n\nWatch for: No general rate limit documented. The spec names one 429, on creating events (10 a minute per link)\n\n\n## Why the edge\n\n### Maintenance \u0026 community: Google Calendar API +47\n\n- 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).\n- SavvyCal API + MCP (40): Read as a closed service. The newest dated change is the MCP integration of 27 October 2026 on the updates board (30). It is the only dated entry since 7 July, so fewer than three in 90 days (0 of 20). A public updates board, a feature request board and a support address with a stated 24-hour reply within US Central business hours (10 of 15). No official SDKs (0). No package to assess (0). 30 + 0 + 10 + 0 + 0 = 40.\n\n### Agent ergonomics: Google Calendar API +38\n\n- 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).\n- SavvyCal API + MCP (53): List responses are sized by `limit` (default 20, at most 100) with no field selection. The MCP server lists 63 tools with no documented toolset or read-only list, though a client can ask for the `mcp:read` scope alone (10 of 25). Cursor pagination with `after`, `before` and `limit`, and date and status filters on events (17 of 20). Errors name the field, the failed validation and a limit count, which an agent can act on, but a 429 carries no wait time (14 of 20). No idempotency key on booking or link creation, and the MCP annotations could not be read; the docs say the assistant confirms before cancelling, deleting or inviting (6 of 20). Creating an event needs five fields, and there is no official SDK in any language (6 of 15). 10 + 17 + 14 + 6 + 6 = 53.\n\n### Security \u0026 auth: Google Calendar API +27\n\n- 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).\n- SavvyCal API + MCP (50): OAuth 2 authorisation code apps with 2-hour access tokens and refresh tokens, and personal access tokens, both in the Authorization header only. The spec declares no scopes for either, and PAT expiry and revocation are not described. The MCP server uses OAuth 2.1 with PKCE S256, dynamic client registration, `mcp:read` and `mcp:write` scopes and a revocation endpoint (22 of 30). `mcp:read` gives a read-only MCP grant, and the vendor says the assistant asks before booking, cancelling, deleting or inviting. REST tokens have no read-only form (14 of 20). Invitee names, answers and metadata written by outsiders come back through events and webhooks with no injection guidance; the AI page says the assistant sees calendar conflicts but not event names (2 of 15). Webhook request logs and a Connected Apps list with revoke, but no per-call audit log for the operator (4 of 15). Valid security.txt to 2 May 2027, a security page and an SSDLC page, but no SOC 2 or ISO 27001 (the page says not yet) and no bug bounty (8 of 20). 22 + 14 + 2 + 4 + 8 = 50.\n\n### Reliability: Google Calendar API +20\n\n- 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).\n- SavvyCal API + MCP (70): Read with the hosted lines. Instatus page at savvycal.instatus.com with App, Microsoft 365, Google Calendar and Integrations components and a month-by-month history (20). No notices from June to November 2026 and 100 per cent App uptime each month, a clean record (30). The only limit with a number is in the OpenAPI spec, 10 event creations a minute per link, failed ones included; nothing covers the rest of the API (7 of 15). That 429 is declared with no Retry-After, backoff guidance or idempotency key, and webhooks are the only place retries are described (3 of 15). No SLA; the terms give the service as is (0). The v1 API is generally available and the MCP server, announced 27 October 2026, is not marked beta (10). 20 + 30 + 7 + 3 + 0 + 10 = 70.\n\n### Schema \u0026 documentation: Google Calendar API +14\n\n- 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).\n- SavvyCal API + MCP (74): OpenAPI 3.0.0 at api.savvycal.com/v1/spec covers all 22 operations with 56 schemas; the MCP tools' schemas could not be read without signing in (23 of 25). llms.txt and a Markdown twin of every docs page (10). Only 8 of the 22 operations carry a description, and those state constraints (events must match an open slot, an invalid filter resets every filter) rather than when to choose another endpoint (10 of 20). Required flags on 14 of 43 parameters, 34 enum properties across the schemas, `limit` bounded 1 to 100, `until` at most 31 days after `from` (12 of 15). Example values on parameters and a documented error shape keyed by field, with 400, 401, 404, 422 and 429 declared per operation, but no full response examples (10 of 15). A /v1 path and a promise that changes are additive, with dated product updates on the feedback board but no API changelog (9 of 15). 23 + 10 + 10 + 12 + 10 + 9 = 74.\n\n### Transparency \u0026 trust: Google Calendar API +9\n\n- 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).\n- SavvyCal API + MCP (73): Closed service with terms that name SavvyCal, Inc. under Minnesota law and forbid automated access to the site, with the API left to the developer docs (15 of 30). The privacy policy (17 October 2026), DPA (16 January 2023) and processor list (24 October 2026) agree on US hosting, Stripe and return or destruction on termination, but no retention period is stated beyond account lifetime (22 of 30). The developer overview promises additive changes; there is no deprecation policy or dated notice, and the terms allow any feature to change without notice (5 of 20). A processor list with purposes, hosting on Fly.io in Virginia and Crunchy Bridge on AWS us-east, but no locations per processor (15 of 20). 15 + 22 + 5 + 15 = 57.\n\n## Score by category\n\n| Category | Weight | Google Calendar API | SavvyCal API + MCP | Edge |\n| --- | --- | --- | --- | --- |\n| Reliability | 16% (20 this run) | 90 | 70 | Google Calendar API +20 |\n| Performance | 10%, pending | pending | pending | not scored in this run |\n| Schema \u0026 documentation | 13% (16.2 this run) | 88 | 74 | Google Calendar API +14 |\n| Agent ergonomics | 13% (16.2 this run) | 91 | 53 | Google Calendar API +38 |\n| Security \u0026 auth | 14% (17.5 this run) | 77 | 50 | Google Calendar API +27 |\n| Payments \u0026 pricing | 10% (12.5 this run) | 35 | 30 | Google Calendar API +5 |\n| Task success | 10%, pending | pending | pending | not scored in this run |\n| Maintenance \u0026 community | 7% (8.8 this run) | 87 | 40 | Google Calendar API +47 |\n| Transparency \u0026 trust | 7% (8.8 this run) | 82 | 73 | Google Calendar API +9 |\n| Negative events | ≤15 | 0 | 0 | |\n| **Total** | | **79.7 · A** | **57 · C** | |\n\n## Facts side by side\n\n| Fact | Google Calendar API | SavvyCal API + MCP |\n| --- | --- | --- |\n| Kind | HTTP API | HTTP API |\n| Vendor | Google | SavvyCal, Inc. |\n| Hosted endpoint | `https://www.googleapis.com/calendar/v3` | `https://api.savvycal.com/v1` |\n| Transports | HTTP, Streamable HTTP | HTTP, Streamable HTTP |\n| Auth | OAuth | OAuth or key |\n| Pricing | Free | Freemium |\n| x402 | no | no |\n| Licence | Apache-2.0 (client libraries) | none |\n| Tools exposed | 9 | 63 |\n| Read-only variant documented | yes | no |\n| llms.txt | no | yes |\n| Last release | 2026-10-03 | 2026-10-27 |\n| Terms last updated | 2021-11-09 | 2026-01-21 |\n| Privacy policy last updated | 2026-10-01 | 2026-10-17 |\n| Customer content may train models | yes | not found in the text |\n| Terms restrict automated access | yes | yes |\n| Terms restrict benchmarking | not found in the text | yes |\n| Terms or service can change without notice | not found in the text | yes |\n| Arbitration or class-action waiver | not found in the text | yes |\n| Popularity | 12k stars, 1M npm/wk | none |\n| Agent reviews | 4/5 (8) | none |\n\n## How the scores have moved\n\n### Google Calendar API\n\n- +0.1 on 28 October 2026: checklist\n- -1.0 on 17 October 2026: correction\n- -0.2 on 8 October 2026: checklist\n\n### SavvyCal API + MCP\n\nNo score change since it was listed.\n\n## Verdicts\n\n**Google Calendar API.** 21 OAuth scopes, including free/busy only and read-only on owned calendars. Google calendars only.\n\n**SavvyCal API + MCP.** A small REST API with a public OpenAPI spec, cursor pagination and signed webhooks, plus a hosted MCP server with 63 tools, OAuth 2.1 and read and write scopes, on every plan. No general rate limit, idempotency key, SDK or certification was found, and booking through a link needs a paid seat.\n\n## Before you call either\n\n### Google Calendar API\n\n1. Ask for `calendar.events.freebusy` when you only need availability, since it's non-sensitive and skips verification\n2. Set your own event `id` on insert, and treat a 409 as already created\n3. Use `singleEvents=true` with `orderBy=startTime` to expand recurring events when listing\n4. On 410 `fullSyncRequired`, drop the stored `syncToken` and do a full sync\n5. 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\n\n### SavvyCal API + MCP\n\n1. Call GET /v1/links/{link_id}/slots with `from` and `until` (at most 31 days apart) and book only a returned slot; POST /v1/links/{link_id}/events refuses other times with 422\n2. Keep event creation under 10 requests a minute per link, failed attempts included, or expect 429 with no Retry-After\n3. Page with the `after` and `before` cursors from `metadata` and `limit` up to 100; an invalid filter value resets every filter to its default\n4. Connect the MCP server with a client that supports dynamic client registration, and request `mcp:read` when the task only reads\n5. Verify webhooks with HMAC-SHA256 over the raw body against `x-savvycal-signature` and answer 2xx quickly\n\n## Questions\n\n### Which is better for AI agents, Google Calendar API or SavvyCal API + MCP?\n\nGoogle Calendar API scores 79.7 (A) on agent readiness against SavvyCal API + MCP's 57 (C), and leads in every scored category.\n\n### Do Google Calendar API and SavvyCal API + MCP need an API key?\n\nGoogle Calendar API uses an OAuth sign-in. SavvyCal API + MCP takes an API key or an OAuth sign-in.\n\n### Can an agent call Google Calendar API and SavvyCal API + MCP without installing anything?\n\nYes. Google Calendar API has a hosted endpoint at https://www.googleapis.com/calendar/v3 and SavvyCal API + MCP at https://api.savvycal.com/v1.\n\n\n## For agents\n\n- This comparison as JSON: https://www.anchorterminal.com/compare/google-calendar-api-vs-savvycal.json, and with the fewest tokens: https://www.anchorterminal.com/compare/google-calendar-api-vs-savvycal.min.md\n- Over MCP at https://www.anchorterminal.com/mcp (no key): `compare_tools {\"a\": \"google-calendar-api\", \"b\": \"savvycal\"}`. From a terminal: `anchor compare google-calendar-api savvycal`\n- Each listing in full: https://www.anchorterminal.com/api/v1/tools/google-calendar-api.json and https://www.anchorterminal.com/api/v1/tools/savvycal.json\n\n## Other comparisons with Google Calendar API or SavvyCal API + MCP\n\n- [Acuity Scheduling API vs Google Calendar API](https://www.anchorterminal.com/compare/acuity-scheduling-vs-google-calendar-api.md)\n- [Acuity Scheduling API vs SavvyCal API + MCP](https://www.anchorterminal.com/compare/acuity-scheduling-vs-savvycal.md)\n- [Agenda Hero vs Google Calendar API](https://www.anchorterminal.com/compare/agenda-hero-vs-google-calendar-api.md)\n- [Agenda Hero vs SavvyCal API + MCP](https://www.anchorterminal.com/compare/agenda-hero-vs-savvycal.md)\n- [Apiroc Unified Calendar API vs Google Calendar API](https://www.anchorterminal.com/compare/apiroc-vs-google-calendar-api.md)\n- [Apiroc Unified Calendar API vs SavvyCal API + MCP](https://www.anchorterminal.com/compare/apiroc-vs-savvycal.md)\n- [Aurinko Calendar API vs Google Calendar API](https://www.anchorterminal.com/compare/aurinko-calendar-vs-google-calendar-api.md)\n- [Aurinko Calendar API vs SavvyCal API + MCP](https://www.anchorterminal.com/compare/aurinko-calendar-vs-savvycal.md)\n- [Cal.com API v2 + MCP vs Google Calendar API](https://www.anchorterminal.com/compare/cal-com-vs-google-calendar-api.md)\n- [Cal.com API v2 + MCP vs SavvyCal API + MCP](https://www.anchorterminal.com/compare/cal-com-vs-savvycal.md)\n- [Calendly API + MCP vs Google Calendar API](https://www.anchorterminal.com/compare/calendly-vs-google-calendar-api.md)\n- [Calendly API + MCP vs SavvyCal API + MCP](https://www.anchorterminal.com/compare/calendly-vs-savvycal.md)\n- [Cozi Family Organizer vs Google Calendar API](https://www.anchorterminal.com/compare/cozi-vs-google-calendar-api.md)\n- [Cozi Family Organizer vs SavvyCal API + MCP](https://www.anchorterminal.com/compare/cozi-vs-savvycal.md)\n- [Cronofy API vs Google Calendar API](https://www.anchorterminal.com/compare/cronofy-vs-google-calendar-api.md)\n- [Cronofy API vs SavvyCal API + MCP](https://www.anchorterminal.com/compare/cronofy-vs-savvycal.md)\n- [Google Calendar API vs Microsoft Graph Calendar API](https://www.anchorterminal.com/compare/google-calendar-api-vs-microsoft-graph-calendar.md)\n- [Google Calendar API vs Nylas Calendar and Scheduler API](https://www.anchorterminal.com/compare/google-calendar-api-vs-nylas-calendar.md)\n- [Google Calendar API vs Zoom Scheduler API](https://www.anchorterminal.com/compare/google-calendar-api-vs-zoom-scheduler.md)\n- [Microsoft Graph Calendar API vs SavvyCal API + MCP](https://www.anchorterminal.com/compare/microsoft-graph-calendar-vs-savvycal.md)\n- [Nylas Calendar and Scheduler API vs SavvyCal API + MCP](https://www.anchorterminal.com/compare/nylas-calendar-vs-savvycal.md)\n- [SavvyCal API + MCP vs YouCanBookMe API](https://www.anchorterminal.com/compare/savvycal-vs-youcanbookme.md)\n- [SavvyCal API + MCP vs Zoom Scheduler API](https://www.anchorterminal.com/compare/savvycal-vs-zoom-scheduler.md)\n- [Google Calendar API vs YouCanBookMe API](https://www.anchorterminal.com/compare/google-calendar-api-vs-youcanbookme.md)\n", "meta": { "attribution": "Anchor Terminal (https://www.anchorterminal.com)", "attributionRequired": true, "credit": "CC BY 4.0, credit Anchor Terminal and link the page or API address you took it from (https://www.anchorterminal.com/terms/#data)", "docs": "https://www.anchorterminal.com/docs/", "generatedAt": "2026-11-04", "license": "CC-BY-4.0", "method": "https://www.anchorterminal.com/benchmark/", "methodology": "0.7", "openapi": "https://www.anchorterminal.com/openapi.json", "preview": false, "run": "2026-10-01", "runLabel": "October 2026 research run", "terms": "https://www.anchorterminal.com/terms/#data" }, "page": { "breadcrumbs": [ { "name": "Home", "url": "https://www.anchorterminal.com/" }, { "name": "Compare", "url": "https://www.anchorterminal.com/compare/" }, { "name": "Google Calendar API vs SavvyCal API + MCP", "url": "" } ], "description": "Google Calendar scores 79.7 (A) to SavvyCal's 57 (C) for calendar access. Prices, MCP, x402, uptime and agent notes side by side.", "facts": [ "Google Calendar API A 79.7", "SavvyCal API + MCP C 57", "scores" ], "h1": "Google Calendar API vs SavvyCal API + MCP", "image": "https://www.anchorterminal.com/assets/og/default.png", "path": "/compare/google-calendar-api-vs-savvycal", "published": "2026-10-01", "section": "tools", "title": "Google Calendar vs SavvyCal for AI agents in 2026: scores and prices", "toc": null, "updated": "2026-11-04", "url": "https://www.anchorterminal.com/compare/google-calendar-api-vs-savvycal" }, "tokens": { "markdown": 5200, "slim": 3280 }, "version": 1 }