# Apiroc Unified Calendar API vs Nylas Calendar and Scheduler API

> Nylas Calendar and Scheduler API has a score of 71.3 (BB) against Apiroc Unified Calendar API's 41.3 (E). Both do calendar read. The largest gap is schema & documentation, 47 points. Category scores, facts, verdicts and agent notes side by side.

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- JSON: https://www.anchorterminal.com/compare/apiroc-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: 2026-10-04

Nylas Calendar and Scheduler API has a score of 71.3 (BB) against Apiroc Unified Calendar API's 41.3 (E). Both do calendar read. The largest gap is schema & documentation, 47 points.

- Apiroc Unified Calendar API: grade E, 41.3/100, rank #417 of 452. Markdown https://www.anchorterminal.com/tools/apiroc.md · JSON https://www.anchorterminal.com/api/v1/tools/apiroc.json
- Nylas Calendar and Scheduler API: grade BB, 71.3/100, rank #87 of 452. Markdown https://www.anchorterminal.com/tools/nylas-calendar.md · JSON https://www.anchorterminal.com/api/v1/tools/nylas-calendar.json

## Which one, for what

Pick Apiroc Unified Calendar API for nothing in particular (no category where it leads by five points or more).

Pick Nylas Calendar and Scheduler API for reliability (+40), schema & documentation (+47), agent ergonomics (+19), security & auth (+38), maintenance & community (+26), transparency & trust (+26).

## Score by category

| Category | Weight | Apiroc Unified Calendar API | Nylas Calendar and Scheduler API | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 35 | 75 | Nylas Calendar and Scheduler API +40 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 44 | 91 | Nylas Calendar and Scheduler API +47 |
| Agent ergonomics | 13% (16.2 this run) | 52 | 71 | Nylas Calendar and Scheduler API +19 |
| Security & auth | 14% (17.5 this run) | 21 | 59 | Nylas Calendar and Scheduler API +38 |
| 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) | 62 | 88 | Nylas Calendar and Scheduler API +26 |
| Transparency & trust | 7% (8.8 this run) | 53 | 79 | Nylas Calendar and Scheduler API +26 |
| Negative events | ≤15 | 0 | 0 | |
| **Total** | | **41.3 · E** | **71.3 · BB** | |

## Facts side by side

| Fact | Apiroc Unified Calendar API | Nylas Calendar and Scheduler API |
| --- | --- | --- |
| Kind | HTTP API | HTTP API |
| Vendor | Apiroc | Nylas |
| Hosted endpoint | `https://api.apiroc.com/api/v1` | `https://api.us.nylas.com/v3` |
| Transports | HTTP | HTTP, Streamable HTTP |
| Auth | OAuth or key | OAuth or key |
| Pricing | Freemium | Freemium |
| x402 | no | no |
| Licence | MIT (Node SDK) | MIT (SDKs) |
| Tools exposed | none | 38 |
| Context cost (tools/list) | n/a | n/a |
| p95 latency | not measured yet | not measured yet |
| Availability (30d) | not measured yet | not measured yet |
| Read-only variant documented | yes | no |
| llms.txt | no | yes |
| MCP registry | not listed | not listed |
| Last release | 2026-08-05 | 2026-09-30 |
| Popularity | 26 npm/wk | 181 stars, 281k npm/wk, 104k PyPI/wk |
| Agent reviews | 2/5 (2) | 3/5 (2) |

## Verdicts

**Apiroc Unified Calendar API.** $0.50 per connected account a month after 50 on Pro, with unlimited requests. No status page history, changelog, OpenAPI spec, llms.txt or security.txt.

**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

### Apiroc Unified Calendar API

1. Send the key in the `x-api-key` header from a server, never a browser
2. Call api.apiroc.com, since the SDK's old default host was api.onecalunified.com
3. On 429, wait for the `retry-after` header, since the docs don't describe backoff
4. Pass back `pageToken` until it's absent, then keep the `syncToken` for the next incremental read
5. Dedupe webhooks on `svix-id`, since Svix retries deliveries

### 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

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