# Google Calendar API vs Truto Unified Calendar API (slim)

> Google Calendar scores 79.7 (A) to Truto Unified Calendar's 60.4 (C) for calendar access. Prices, MCP, x402, uptime and agent notes side by side.

- Full: https://www.anchorterminal.com/compare/google-calendar-api-vs-truto-calendar.md (~4,950 tokens) · this version ~2,880 tokens · JSON https://www.anchorterminal.com/compare/google-calendar-api-vs-truto-calendar.json · canonical https://www.anchorterminal.com/compare/google-calendar-api-vs-truto-calendar
- Index: https://www.anchorterminal.com/llms.txt · API: https://www.anchorterminal.com/api/v1/index.json · MCP: https://www.anchorterminal.com/mcp · Updated: 2026-11-07
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Google Calendar API scores 79.7 (A) on agent readiness against Truto Unified Calendar API's 60.4 (C), and leads in every scored category. Both do calendar access.

- Google Calendar API: A 79.7, rank #16 of 1510 · https://www.anchorterminal.com/tools/google-calendar-api.min.md
- Truto Unified Calendar API: C 60.4, rank #655 of 1510 · https://www.anchorterminal.com/tools/truto-calendar.min.md
- Google Calendar API, good 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 77; Schema & documentation, 88 against 75; Agent ergonomics, 91 against 71; Security & auth, 77 against 52; Payments & pricing, 35 against 20; Maintenance & community, 87 against 50; Transparency & trust, 82 against 61. Also Agent-ready, a grade of BB or better; A hosted endpoint, with nothing to install.
- Truto Unified Calendar API, good for Software companies that need their product's agent to read and book across customers' Google, Outlook, Cal.com and Calendly accounts.

| Category | Google Calendar API | Truto Unified Calendar API |
| --- | --- | --- |
| Reliability (16%) | 90 | 77 |
| Performance (10%) | pending | pending |
| Schema & documentation (13%) | 88 | 75 |
| Agent ergonomics (13%) | 91 | 71 |
| Security & auth (14%) | 77 | 52 |
| Payments & pricing (10%) | 35 | 20 |
| Task success (10%) | pending | pending |
| Maintenance & community (7%) | 87 | 50 |
| Transparency & trust (7%) | 82 | 61 |

| Fact (where they differ) | Google Calendar API | Truto Unified Calendar API |
| --- | --- | --- |
| Vendor | Google | Yin Yang Inc. |
| Hosted endpoint | `https://www.googleapis.com/calendar/v3` | no (local only) |
| Transports | HTTP, Streamable HTTP |  |
| Auth | OAuth | API key |
| Pricing | Free | Paid |
| Licence | Apache-2.0 (client libraries) | none |
| Tools exposed | 9 | none |
| Read-only variant documented | yes | no |
| llms.txt | no | yes |
| Last release | 2026-10-03 | 2026-10-26 |
| Terms last updated | 2021-11-09 | no date given |
| Privacy policy last updated | 2026-10-01 | 2024-10-19 |
| Customer content may train models | yes | not found in the text |
| Terms restrict automated access | yes | not found in the text |
| Arbitration or class-action waiver | not found in the text | yes |
| Popularity | 12k stars, 1M npm/wk | none |
| Agent reviews | 4/5 (8) | none |

Why the edge:
- Maintenance & community, Google Calendar API +37: 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).); Truto Unified Calendar API 50 (No API changelog, so the last API change can't be dated; the official @truto/truto-link-sdk was published as 1.3.5 on 26 October 2026, which we take as the latest dated release (20 of 30, since it is the connection widget, not the calendar API). Six Link SDK versions since 8 August (10 of 20, for the same reason). Support through Slack on paid plans, with no public tracker (5 of 15). A CLI and the Link SDK are official, with no API client (10 of 15). Package health not checked (5 of 10). 20 + 10 + 5 + 10 + 5 = 50.)
- Security & auth, Google Calendar API +25: 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).); Truto Unified Calendar API 52 (API tokens are per environment and sent as Bearer headers; no scopes or expiry for them were found (20 of 30). Per-account MCP servers can be limited to read methods or tags and set to expire, and the customer's connection form can restrict access to specific resources, but the REST token reaches every integrated account in its environment (14 of 20). Event titles, descriptions and attendee text from outside parties pass through, and no prompt-injection guidance was found (0). Plans keep request logs 30 or 90 days (10 of 15). SOC 2 is stated in a 2023 blog post, with no trust page, security.txt or disclosure policy found (8 of 20). 20 + 14 + 0 + 10 + 8 = 52.)
- Transparency & trust, Google Calendar API +21: 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).); Truto Unified Calendar API 61 (Closed service under terms naming Yin Yang Inc. (15 of 30). Truto says it stores no customer data and calls vendors live, logs are kept 30 or 90 days by plan, data is kept 15 days after termination, and a DPA is public (25 of 30). Deprecated admin endpoints are marked with no policy or dates (6 of 20). Enterprise customers can choose a data region and tokens can be stored regionally; no subprocessor list was found (8 of 20). 15 + 25 + 6 + 8 = 54.)
- Agent ergonomics, Google Calendar API +20: 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).); Truto Unified Calendar API 71 (`truto_exclude_fields`, `truto_ignore_remote_data`, `truto_key_by` and response formats (`unified`, `raw`, `normalized`) size the reply (22 of 25). Query operators such as `[gt]` and `[in]`, `sort_by`, `limit` and cursors, with a meta endpoint that says which filters each vendor supports (18 of 20). Errors name the HTTP status and say whether Truto or the provider failed, with the provider's message extracted (18 of 20). No idempotency key found for creates (5 of 20). Every call needs only the token and `integrated_account_id`; a CLI and the Link SDK exist, with no general API SDK found (8 of 15). 22 + 18 + 18 + 5 + 8 = 71.)
- Payments & pricing, Google Calendar API +15: Google Calendar API 35 (No x402, MPP or L402 (0). Free within published quotas, but the price for use above 1,000,000 requests a day, planned for later in 2026, isn't published on the quota page or the standardised-model page on 4 October (15). No charge for standard use and no card needed to enable the API (20). A person creates a Cloud project, an OAuth consent screen and, for sensitive or restricted scopes, goes through app verification (0).); Truto Unified Calendar API 20 (No x402, MPP or L402 (0). Plan prices per connector a year are public, with unlimited calls (10). A free 30-day sandbox is given after a work-email request reviewed within a business day (10 of 20). A person requests access or books a demo (0). 0 + 10 + 10 + 0 = 20.)
- Reliability, Google Calendar API +13: 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).); Truto Unified Calendar API 77 (Graded as a hosted service on the Unified Calendar API. Better Stack status page with components for api.truto.one health, ping and link-token endpoints and the static IP proxy, with incident history (20). The feed lists "APIs and Dashboard are down" on 29 October 2026 and delayed sync jobs and webhooks on 1 November, which counts as one major outage (10). Truto's own limit is 50 requests every 10 seconds per integrated account, in front of each vendor's (15). A vendor 429 comes back with Retry-After and normalised `ratelimit-limit`, `-remaining` and `-reset` headers, with no idempotency guidance for creates (12 of 15). The Enterprise plan lists an SLA guarantee (10). Generally available (10). 20 + 10 + 15 + 12 + 10 + 10 = 77.)