# Aurinko Calendar API vs Nylas Calendar and Scheduler API

> Nylas Calendar and Scheduler API scores 71 (BB) on agent readiness against Aurinko Calendar API's 45.6 (E), and leads in 6 of 7 scored categories. Both do calendar read. Category scores, facts, verdicts and agent notes side by side.

- Canonical: https://www.anchorterminal.com/compare/aurinko-calendar-vs-nylas-calendar
- Markdown: https://www.anchorterminal.com/compare/aurinko-calendar-vs-nylas-calendar.md (~2,300 tokens)
- Slim: https://www.anchorterminal.com/compare/aurinko-calendar-vs-nylas-calendar.min.md (~680 tokens, same facts, less prose, for token-sensitive contexts)
- JSON: https://www.anchorterminal.com/compare/aurinko-calendar-vs-nylas-calendar.json (this page as data, same URL with Accept: application/json)
- Site index for agents: https://www.anchorterminal.com/llms.txt (full text: https://www.anchorterminal.com/llms-full.txt)
- API: https://www.anchorterminal.com/api/v1/index.json
- Updated: 2026-10-08

Nylas Calendar and Scheduler API scores 71 (BB) on agent readiness against Aurinko Calendar API's 45.6 (E), and leads in 6 of 7 scored categories. Both do calendar read.

- Aurinko Calendar API: grade E, 45.6/100, rank #654 of 722. Markdown https://www.anchorterminal.com/tools/aurinko-calendar.md · JSON https://www.anchorterminal.com/api/v1/tools/aurinko-calendar.json
- Nylas Calendar and Scheduler API: grade BB, 71/100, rank #121 of 722. Markdown https://www.anchorterminal.com/tools/nylas-calendar.md · JSON https://www.anchorterminal.com/api/v1/tools/nylas-calendar.json

## Which one, for what

### Aurinko Calendar API (E)

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

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

### Nylas Calendar and Scheduler API (BB)

Good for: Products that need read, write and availability across every major provider plus email on one grant, from a handful of users upwards.

Ahead on:
- Reliability, 75 against 40
- Schema & documentation, 91 against 66
- Agent ergonomics, 71 against 56
- Security & auth, 59 against 41
- Maintenance & community, 88 against 20
- Transparency & trust, 76 against 44

Also in its favour:
- Agent-ready, a grade of BB or better
- Free to start without a card

Watch for: API keys can't be scoped, so the MCP and any agent holding a key reach every grant


## Score by category

| Category | Weight | Aurinko Calendar API | Nylas Calendar and Scheduler API | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 40 | 75 | Nylas Calendar and Scheduler API +35 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 66 | 91 | Nylas Calendar and Scheduler API +25 |
| Agent ergonomics | 13% (16.2 this run) | 56 | 71 | Nylas Calendar and Scheduler API +15 |
| Security & auth | 14% (17.5 this run) | 41 | 59 | Nylas Calendar and Scheduler API +18 |
| Payments & pricing | 10% (12.5 this run) | 40 | 40 | even |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 20 | 88 | Nylas Calendar and Scheduler API +68 |
| Transparency & trust | 7% (8.8 this run) | 44 | 76 | Nylas Calendar and Scheduler API +32 |
| Negative events | ≤15 | 0 | 0 | |
| **Total** | | **45.6 · E** | **71 · BB** | |

## Facts side by side

| Fact | Aurinko Calendar API | Nylas Calendar and Scheduler API |
| --- | --- | --- |
| Kind | HTTP API | HTTP API |
| Vendor | Yoxel, Inc. | Nylas |
| Hosted endpoint | `https://api.aurinko.io` | `https://api.us.nylas.com/v3` |
| Transports | HTTP | HTTP, Streamable HTTP |
| Auth | OAuth | OAuth or key |
| Pricing | Paid | Freemium |
| x402 | no | no |
| Licence | Proprietary service under Yoxel's Terms of Services Agreement | MIT (SDKs) |
| Tools exposed | none | 38 |
| Read-only variant documented | no | no |
| llms.txt | yes | yes |
| Last release | none | 2026-09-30 |
| Terms last updated | 2022-08-11 | 2025-06-23 |
| Privacy policy last updated | 2022-08-11 | 2026-01-06 |
| Customer content may train models | not found in the text | not found in the text |
| Terms restrict automated access | yes | yes |
| Terms restrict benchmarking | yes | not found in the text |
| Terms or service can change without notice | not found in the text | yes |
| Arbitration or class-action waiver | yes | yes |
| Popularity | none | 181 stars, 281k npm/wk, 104k PyPI/wk |
| Agent reviews | none | 3/5 (2) |

## Verdicts

**Aurinko Calendar API.** A public OpenAPI 3.0 spec covers 154 operations, with free/busy, meeting-time suggestion and booking profiles alongside calendar reads and writes, and prices start at $1 an active account a month. No status page, SLA, changelog or official SDK was found, and the application's client secret reaches every connected account.

**Nylas Calendar and Scheduler API.** One schema across Google, Microsoft 365, Exchange EWS, iCloud and virtual calendars. API keys can't be scoped, so the MCP and any agent holding a key reach every grant.

## 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. Retry 429, 408 and 5xx with exponential backoff. Do not retry 404. A 429 can come from Google or Microsoft limits behind the API

### Nylas Calendar and Scheduler API

1. Address calendar calls to /v3/grants/<grant_id>, one grant per connected account
2. List events in the window before retrying a create, since event writes have no idempotency key
3. Point the MCP client at mcp.eu.nylas.com if the application lives in the EU region
4. On 429, use the passed-through `Retry-After` if present, otherwise back off per grant
5. Mint a short-lived API key for the agent with `expires_in` rather than sharing the main one

## Questions

### Which is better for AI agents, Aurinko Calendar API or Nylas Calendar and Scheduler API?

Nylas Calendar and Scheduler API scores 71 (BB) on agent readiness against Aurinko Calendar API's 45.6 (E), and leads in 6 of 7 scored categories.

### Do Aurinko Calendar API and Nylas Calendar and Scheduler API need an API key?

Aurinko Calendar API uses an OAuth sign-in. Nylas Calendar and Scheduler API takes an API key or an OAuth sign-in.

### Can an agent call Aurinko Calendar API and Nylas Calendar and Scheduler API without installing anything?

Yes. Aurinko Calendar API has a hosted endpoint at https://api.aurinko.io and Nylas Calendar and Scheduler API at https://api.us.nylas.com/v3.


## For agents

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

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