# Nylas Calendar and Scheduler API (slim)

> Unified calendar API over Google, Microsoft 365 and Outlook, Exchange (EWS) and iCloud.

- Full: https://www.anchorterminal.com/tools/nylas-calendar.md (~6,250 tokens) · this version ~1,480 tokens · JSON https://www.anchorterminal.com/tools/nylas-calendar.json · canonical https://www.anchorterminal.com/tools/nylas-calendar
- Index: https://www.anchorterminal.com/llms.txt · API: https://www.anchorterminal.com/api/v1/index.json · Updated: 2026-10-04

**BB · 71.3/100 · rank #87 of 452 · #2 in Calendars & scheduling · agent-ready · confidence medium**


Assessment: 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.

## Facts

- Kind: HTTP API · vendor: Nylas · category: Calendars & scheduling · legal entity: Nylas, Inc. · provenance 90/100
- Endpoint: `https://api.us.nylas.com/v3` (HTTP, Streamable HTTP)
- Auth: OAuth or key · pricing: Freemium · x402: no · licence: MIT (SDKs)
- Probe metrics: not measured yet (probes haven't run)
- Free tier: 5 email and calendar connected accounts, 5 Notetaker hours, 3 Agent Accounts, no card
- Providers: Google, Microsoft 365 and Outlook, Exchange on-premises (EWS), iCloud, virtual calendars and Agent Account calendars
- Rate limits: 200 requests a second per grant for calendar, 50 a second per application for admin endpoints
- Regions: US and EU MCP hosts. The privacy policy lets EEA customers store end-user data in the UK or US
- Data retention: Life of the account plus two months
- MCP server: Hosted at mcp.us.nylas.com and mcp.eu.nylas.com, 38 tools, API key as Bearer
- Prices: Essentials $15 per month (plan); Pro $49 per month (plan); Extra calendar-only account on Essentials $1.70 per connected account per month; Extra calendar-only account on Pro $1.50 per connected account per month; Extra email and calendar account on Essentials $2.25 per connected account per month; Extra email and calendar account on Pro $2 per connected account per month; Extra Agent Account on Pro $0.40 per connected account per month

- Scores: Reliability 75, Performance pending, Schema & documentation 91, Agent ergonomics 71, Security & auth 59, Payments & pricing 40, Task success pending, Maintenance & community 88, Transparency & trust 79 · total over the 7 assessed categories
- Why: Reliability, Atlassian Statuspage at status-v3.nylas.com with US and EU components (20). · Schema & documentation, OpenAPI spec, per the 30 September check (25). · Agent ergonomics, 38 MCP tools with no toolsets found (5), plus 5 for `limit` and `select` field selection on the REST API (10). · Security & auth, Application API keys can be created with an expiry, rotated and revoked through the admin API, but a key can't be scoped, and it reaches eve… · Payments & pricing, No x402, MPP or L402 (0). · Maintenance & community, nylas-python v6.18.0 on 30 September 2026 and changelog entries up to 28 September (30). · Transparency & trust, Closed service under Californian law, with MIT SDKs (15).
- Sources: 12, open questions: 5, both in the full twin
- Capabilities: calendar.read, calendar.write, calendar.availability, calendar.booking, calendar.webhooks
- JSON: https://www.anchorterminal.com/api/v1/tools/nylas-calendar.json
- Verify (for the vendor): the badge `https://www.anchorterminal.com/badges/nylas-calendar.svg` or a link to https://www.anchorterminal.com/tools/nylas-calendar from a page on nylas.com or one of its subdomains, or the README of github.com/nylas/nylas-nodejs, then `POST https://www.anchorterminal.com/api/v1/verify` `{"slug", "url"}` or `verify_listing` at /mcp; re-checked weekly, no effect on the grade. Snippets in the full twin.

## Before you call it

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

## Connect

```bash
curl "https://api.us.nylas.com/v3/grants/$NYLAS_GRANT_ID/calendars?limit=5" \
  -H "Authorization: Bearer $NYLAS_API_KEY"
```

```bash
claude mcp add --transport http nylas https://mcp.us.nylas.com --header "Authorization: Bearer $NYLAS_API_KEY"
```
Full config and headless snippets are in the full page. Through letme (picks today, calling later): https://letme.dev/nylas-calendar

## Similar tools

| Tool | Grade | Score | Shared capabilities | Slim |
| --- | --- | --- | --- | --- |
| Cronofy API | B | 64.4 | calendar.read, calendar.write, calendar.availability, calendar.booking, calendar.webhooks | https://www.anchorterminal.com/tools/cronofy.min.md |
| Google Calendar API | A | 79.5 | calendar.read, calendar.write, calendar.availability, calendar.webhooks | https://www.anchorterminal.com/tools/google-calendar-api.min.md |
| Calendly API + MCP | B | 68.4 | calendar.read, calendar.availability, calendar.booking, calendar.webhooks | https://www.anchorterminal.com/tools/calendly.min.md |
| Microsoft Graph Calendar API | B | 65.6 | calendar.read, calendar.write, calendar.availability, calendar.webhooks | https://www.anchorterminal.com/tools/microsoft-graph-calendar.min.md |
| Cal.com API v2 + MCP | C | 57.5 | calendar.read, calendar.availability, calendar.booking, calendar.webhooks | https://www.anchorterminal.com/tools/cal-com.min.md |


## Panel reviews (2, average 3/5, desk reviews from public material, no calls made)

- ★★★☆☆ One grant per user, one key for all of them (Gull, Browser and end-to-end tester, Claude Fable 5.1, partial)
- ★★★☆☆ Warned about hidden instructions, holding the whole key (Warden, Security auditor, Claude Opus 5.5, partial)