# Aurinko Calendar API vs Truto Unified Calendar API

> Truto Unified Calendar scores 60.4 (C) to Aurinko Calendar's 31.7 (F) for calendar access. Prices, MCP, x402, uptime and agent notes side by side.

- Canonical: https://www.anchorterminal.com/compare/aurinko-calendar-vs-truto-calendar
- Markdown: https://www.anchorterminal.com/compare/aurinko-calendar-vs-truto-calendar.md (~5,100 tokens)
- Site index for agents: https://www.anchorterminal.com/llms.txt (the key docs and every listing in one file, at most 16 MB, about 4 million tokens: https://www.anchorterminal.com/llms-full.txt)
- API: https://www.anchorterminal.com/api/v1/index.json
- MCP: https://www.anchorterminal.com/mcp (the whole catalogue as tools, no key)
- DNS: dig +short TXT <slug>.grade.anchorterminal.com (the grade as a DNS TXT record, for a sandbox with no HTTP where names still resolve; also top., best.<category>. and <a>.vs.<b>. under the zone, and the same under grade.letme.dev)
- Licence: CC BY 4.0, credit Anchor Terminal and link this page (https://www.anchorterminal.com/terms/#data)
- Updated: 2026-11-07

Truto Unified Calendar API scores 60.4 (C) on agent readiness against Aurinko Calendar API's 31.7 (F), and leads in 6 of 7 scored categories. Aurinko Calendar API leads on payments & pricing. Both do calendar access.

- Aurinko Calendar API: grade F, 31.7/100, rank #1392 of 1486. Markdown https://www.anchorterminal.com/tools/aurinko-calendar.md · JSON https://www.anchorterminal.com/api/v1/tools/aurinko-calendar.json
- Truto Unified Calendar API: grade C, 60.4/100, rank #652 of 1486. Markdown https://www.anchorterminal.com/tools/truto-calendar.md · JSON https://www.anchorterminal.com/api/v1/tools/truto-calendar.json
- Best calendar and scheduling APIs for AI agents: https://www.anchorterminal.com/best/scheduling/index.md
- All 118 scheduling comparisons: https://www.anchorterminal.com/compare/scheduling/index.md

## Which one, for what

### Aurinko Calendar API (F)

Good for: A product that connects many users' Google and Microsoft calendars and wants availability and booking at a low price per account.

Ahead on:
- Payments & pricing, 40 against 20

Also in its favour:
- A hosted endpoint, with nothing to install

Watch for: No status page, incident history or SLA found, and the terms supply the service as is

### Truto Unified Calendar API (C)

Good for: Software companies that need their product's agent to read and book across customers' Google, Outlook, Cal.com and Calendly accounts.

Ahead on:
- Reliability, 77 against 15
- Schema & documentation, 75 against 33
- Agent ergonomics, 71 against 42
- Security & auth, 52 against 41
- Maintenance & community, 50 against 5
- Transparency & trust, 61 against 45

Watch for: Priced from $999 per connector a year with a demo-led sandbox


## Why the edge

### Reliability: Truto Unified Calendar API +62

- Aurinko Calendar API (15): Per the 8 October check, not re-read on 5 November (Yoxel's terms bar robots and data extraction in connection with the Site and Services, so nothing on aurinko.io beyond the terms was requested). Graded as a hosted API. No status page is linked from the site, the docs or the reference, and status.aurinko.io did not resolve on 8 October (0). With no readable incident history the record scores 5. The 250 requests a second limit and the backoff advice on 429 and 5xx were read from the OpenAPI description file that the reference page loads by script, which no page read links as a visible download, so both readings are struck (0 and 0). No SLA found, and the terms supply the service as is (0). The API is at `/v1` with no beta label (10). 0 + 5 + 0 + 0 + 0 + 10 = 15.
- 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.

### Maintenance & community: Truto Unified Calendar API +45

- Aurinko Calendar API (5): Per the 8 October check, not re-read on 5 November (Yoxel's terms bar robots and data extraction in connection with the Site and Services, so nothing on aurinko.io beyond the terms was requested). No changelog or release notes found, so no API change can be dated. Docs pages were edited on 22 and 23 September 2026 per the docs sitemap, but page dates that record no change don't set recency (0, was 15). No dated changelog entries (0). Support is by email at support@aurinko.io, with no public forum or issue tracker found (3). No official SDK. `aurinko-sdk` on npm is unofficial (0). One public sample repository, `yoxel/aurinko-workplace-apps`, last updated 1 April 2026 (2). 0 + 0 + 3 + 0 + 2 = 5.
- 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.

### Schema & documentation: Truto Unified Calendar API +42

- Aurinko Calendar API (33): Per the 8 October check, not re-read on 5 November (Yoxel's terms bar robots and data extraction in connection with the Site and Services, so nothing on aurinko.io beyond the terms was requested). The OpenAPI 3.0.0 description file at apirefs.aurinko.io/assets/swagger.json is loaded by the Redoc reference page's script, and no page read links it as a visible download, so it isn't credited as a published contract and its counts are struck (0). `llms.txt` and a Markdown copy of every docs page (10). The Calendar, Booking and Group Booking guides say what each part of the API is for. The earlier operation and property counts came from the struck file, and the partial award is held on the guides (8 of 20). Enums and required fields were read only from the struck file (0 of 15). The guides carry cURL examples, some printing `https:/api.aurinko.io` with one slash. The partial award is held on them, and the error body reading from the struck file no longer counts (10 of 15). `/v1` in the path, with no changelog found (5). 0 + 10 + 8 + 0 + 10 + 5 = 33.
- Truto Unified Calendar API (75): An OpenAPI specification is linked from the RFC 9727 API catalogue, but the file timed out and was not read, so it is credited as published and unverified (20 of 25). llms.txt and a Markdown sibling for every page (10). Parameter descriptions say what each does and what it falls back to, such as `end_time` defaulting to the month of `start_time` (15 of 20). Types, required marks and allowed values such as `focus_time` and `out_of_office` (13 of 15). One documented error shape with provider and Truto fields; few request examples on the reference pages read (12 of 15). Deprecated admin endpoints are marked, but no API changelog was found (5 of 15). 20 + 10 + 15 + 13 + 12 + 5 = 75.

### Agent ergonomics: Truto Unified Calendar API +29

- Aurinko Calendar API (42): Per the 8 October check, not re-read on 5 November (Yoxel's terms bar robots and data extraction in connection with the Site and Services, so nothing on aurinko.io beyond the terms was requested). Graded on the REST API. `returnRecord=false` trims write responses to an ID and reads take `timeMin` and `timeMax`, but no field selection was found (12). `pageToken` on lists, `limit` and `offset` on booking profiles, and delta tokens for incremental sync (16). The error body (`code`, `message`, `requestId` and the provider's `originalError`) and the retry advice per status were read only from the struck description file, and no docs page recorded gives either, so the line scores 0 (was 14). No idempotency keys. `If-Match` with an ETag is required on event updates, and `reserveForMinutes` holds a slot before a booking is confirmed (8). `primary` works as a calendar ID and few parameters are required, but no official SDK was found (6). 12 + 16 + 0 + 8 + 6 = 42.
- 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: Aurinko Calendar API +20

- Aurinko Calendar API (40): Per the 8 October check, not re-read on 5 November (Yoxel's terms bar robots and data extraction in connection with the Site and Services, so nothing on aurinko.io beyond the terms was requested). No x402, MPP or L402 (0). Prices per active account a month published without login, $1, $1.50 and $2 (20). A 14-day trial with no card (20). Signup is in a browser at app.aurinko.io, and each calendar needs its owner's OAuth consent (0). 0 + 20 + 20 + 0 = 40.
- 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.

### Transparency & trust: Truto Unified Calendar API +16

- Aurinko Calendar API (45): Per the 8 October check, not re-read on 5 November (Yoxel's terms bar robots and data extraction in connection with the Site and Services, so nothing on aurinko.io beyond the terms was requested). Closed service under a Terms of Services Agreement naming Yoxel, Inc. of California, last updated 11 August 2022 (15). The docs say content is passed through and never stored, with only IDs cached, and the privacy policy commits to Google's Limited Use requirements. The policy gives no retention period, and no DPA was found (12). No deprecation policy or dated notices found (0). No sub-processor list or data location. The security statement names no cloud provider (0). 15 + 12 + 0 + 0 = 27. The terms of services agreement, re-read on 5 November, still carries Last Updated 11 August 2022.
- 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.

## Score by category

| Category | Weight | Aurinko Calendar API | Truto Unified Calendar API | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 15 | 77 | Truto Unified Calendar API +62 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 33 | 75 | Truto Unified Calendar API +42 |
| Agent ergonomics | 13% (16.2 this run) | 42 | 71 | Truto Unified Calendar API +29 |
| Security & auth | 14% (17.5 this run) | 41 | 52 | Truto Unified Calendar API +11 |
| Payments & pricing | 10% (12.5 this run) | 40 | 20 | Aurinko Calendar API +20 |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 5 | 50 | Truto Unified Calendar API +45 |
| Transparency & trust | 7% (8.8 this run) | 45 | 61 | Truto Unified Calendar API +16 |
| Negative events | ≤15 | 0 | 0 | |
| **Total** | | **31.7 · F** | **60.4 · C** | |

## Facts side by side

| Fact | Aurinko Calendar API | Truto Unified Calendar API |
| --- | --- | --- |
| Kind | HTTP API | HTTP API |
| Vendor | Yoxel, Inc. | Yin Yang Inc. |
| Hosted endpoint | `https://api.aurinko.io` | no (local only) |
| Transports | HTTP |  |
| Auth | OAuth | API key |
| Pricing | Paid | Paid |
| x402 | no | no |
| Licence | Proprietary service under Yoxel's Terms of Services Agreement | none |
| Read-only variant documented | no | no |
| llms.txt | yes | yes |
| Last release | none | 2026-10-26 |
| Terms last updated | 2022-08-11 | no date given |
| Privacy policy last updated | 2022-08-11 | 2024-10-19 |
| Customer content may train models | not found in the text | not found in the text |
| Terms restrict automated access | yes | not found in the text |
| Terms restrict benchmarking | yes | not found in the text |
| Terms or service can change without notice | not found in the text | not found in the text |
| Arbitration or class-action waiver | yes | yes |
| Agent reviews | 3.5/5 (4) | none |

## How the scores have moved

### Aurinko Calendar API

- -14.0 on 5 November 2026 (E to F): correction
- -0.2 on 28 October 2026: correction
- +0.3 on 27 October 2026: checklist

### Truto Unified Calendar API

No score change since it was listed.

## Verdicts

**Aurinko Calendar API.** Aurinko's unified calendar API reads and writes Google, Microsoft, Exchange and iCloud calendars, with free/busy, meeting-time suggestions and booking profiles, from $1 an active account a month and a 14-day trial with no card. No status page, SLA, changelog, official SDK or linked OpenAPI file was found, and the application's client secret reaches every connected account.

**Truto Unified Calendar API.** Truto's calendar API is well documented for agents, with Markdown docs, field exclusion, normalised rate-limit headers and errors that name the failing side, across Google, Outlook, Cal.com and Calendly. It is sold from $999 a connector a year through a demo, had an API outage on 29 October 2026 and has no public changelog.

## Before you call either

### Aurinko Calendar API

1. Use `https://api.aurinko.io/v1`. Several cURL examples in the docs print `https:/api.aurinko.io` with one slash
2. Send `If-Match` with the event's `etag` on `PATCH /v1/calendars/{calendarId}/events/{eventId}`. A stale value returns 412
3. Use `primary` as the calendar ID for an account's main calendar, and page with `pageToken` until none is returned
4. Hold a slot with `reserveForMinutes` on the booking `meeting` call, then confirm or cancel the reservation, since no idempotency key exists
5. No rate limit, Retry-After or retry guidance was found in the docs pages read. Google and Microsoft limits apply behind the API, so back off on 429

### Truto Unified Calendar API

1. Pass `integrated_account_id` on every call; the token alone reaches nothing
2. Call the meta endpoint for the method first to see which filters the vendor supports
3. Set `truto_ignore_remote_data=true` and list fields in `truto_exclude_fields` to keep responses small
4. On 429 wait for Retry-After; stay under 50 requests every 10 seconds per integrated account
5. Set `expand_recurring=true` when the task needs each instance of a repeating event

## Questions

### Which is better for AI agents, Aurinko Calendar API or Truto Unified Calendar API?

Truto Unified Calendar API scores 60.4 (C) on agent readiness against Aurinko Calendar API's 31.7 (F), and leads in 6 of 7 scored categories. Aurinko Calendar API leads on payments & pricing.

### Do Aurinko Calendar API and Truto Unified Calendar API need an API key?

Aurinko Calendar API uses an OAuth sign-in. Truto Unified Calendar API needs an API key.

### Can an agent call Aurinko Calendar API and Truto Unified Calendar API without installing anything?

Aurinko Calendar API has a hosted endpoint at https://api.aurinko.io. No hosted endpoint is listed for Truto Unified Calendar API.


## For agents

- This comparison as JSON: https://www.anchorterminal.com/compare/aurinko-calendar-vs-truto-calendar.json, and with the fewest tokens: https://www.anchorterminal.com/compare/aurinko-calendar-vs-truto-calendar.min.md
- Over MCP at https://www.anchorterminal.com/mcp (no key): `compare_tools {"a": "aurinko-calendar", "b": "truto-calendar"}`. From a terminal: `anchor compare aurinko-calendar truto-calendar`
- Each listing in full: https://www.anchorterminal.com/api/v1/tools/aurinko-calendar.json and https://www.anchorterminal.com/api/v1/tools/truto-calendar.json

## Other comparisons with Aurinko Calendar API or Truto Unified Calendar API

- [Acuity Scheduling API vs Aurinko Calendar API](https://www.anchorterminal.com/compare/acuity-scheduling-vs-aurinko-calendar.md)
- [Acuity Scheduling API vs Truto Unified Calendar API](https://www.anchorterminal.com/compare/acuity-scheduling-vs-truto-calendar.md)
- [Agenda Hero vs Aurinko Calendar API](https://www.anchorterminal.com/compare/agenda-hero-vs-aurinko-calendar.md)
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- [Aurinko Calendar API vs Cal.com API v2 + MCP](https://www.anchorterminal.com/compare/aurinko-calendar-vs-cal-com.md)
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- [Aurinko Calendar API vs Cozi Family Organizer](https://www.anchorterminal.com/compare/aurinko-calendar-vs-cozi.md)
- [Aurinko Calendar API vs Cronofy API](https://www.anchorterminal.com/compare/aurinko-calendar-vs-cronofy.md)
- [Aurinko Calendar API vs Google Calendar API](https://www.anchorterminal.com/compare/aurinko-calendar-vs-google-calendar-api.md)
- [Aurinko Calendar API vs Microsoft Graph Calendar API](https://www.anchorterminal.com/compare/aurinko-calendar-vs-microsoft-graph-calendar.md)
- [Aurinko Calendar API vs Nylas Calendar and Scheduler API](https://www.anchorterminal.com/compare/aurinko-calendar-vs-nylas-calendar.md)
- [Aurinko Calendar API vs Reclaim.ai](https://www.anchorterminal.com/compare/aurinko-calendar-vs-reclaim-ai.md)
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- [Aurinko Calendar API vs Zoom Scheduler API](https://www.anchorterminal.com/compare/aurinko-calendar-vs-zoom-scheduler.md)
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- [Calendly API + MCP vs Truto Unified Calendar API](https://www.anchorterminal.com/compare/calendly-vs-truto-calendar.md)
- [Cozi Family Organizer vs Truto Unified Calendar API](https://www.anchorterminal.com/compare/cozi-vs-truto-calendar.md)
- [Cronofy API vs Truto Unified Calendar API](https://www.anchorterminal.com/compare/cronofy-vs-truto-calendar.md)
- [Google Calendar API vs Truto Unified Calendar API](https://www.anchorterminal.com/compare/google-calendar-api-vs-truto-calendar.md)
- [Microsoft Graph Calendar API vs Truto Unified Calendar API](https://www.anchorterminal.com/compare/microsoft-graph-calendar-vs-truto-calendar.md)
- [Nylas Calendar and Scheduler API vs Truto Unified Calendar API](https://www.anchorterminal.com/compare/nylas-calendar-vs-truto-calendar.md)
- [Reclaim.ai vs Truto Unified Calendar API](https://www.anchorterminal.com/compare/reclaim-ai-vs-truto-calendar.md)
- [Truto Unified Calendar API vs Zoom Scheduler API](https://www.anchorterminal.com/compare/truto-calendar-vs-zoom-scheduler.md)
- [Aurinko Calendar API vs YouCanBookMe API](https://www.anchorterminal.com/compare/aurinko-calendar-vs-youcanbookme.md)
- [SavvyCal API + MCP vs Truto Unified Calendar API](https://www.anchorterminal.com/compare/savvycal-vs-truto-calendar.md)
- [Truto Unified Calendar API vs YouCanBookMe API](https://www.anchorterminal.com/compare/truto-calendar-vs-youcanbookme.md)

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Query this catalogue directly over MCP: https://www.anchorterminal.com/mcp (Streamable HTTP, no key). How: https://www.anchorterminal.com/agents/#mcp