Head to head · Calendar access · October 2026 research run

Cozi Family Organizer vs SavvyCal API + MCP

SavvyCal API + MCP scores 57 (C) on agent readiness against Cozi Family Organizer's 16.1 (F), and leads in 6 of 7 scored categories. Both do calendar access.

Best calendar and scheduling APIs for AI agents · All 89 scheduling comparisons

Which one, for what

Cozi Family Organizer F

Best for Cozi is a shared family calendar, shopping-list and meal-planning app.

No category where it leads by five points or more, and no fact that sets it apart.

Watch for

No official external-agent write API verified

SavvyCal API + MCP C

Best for An agent booking on a person's SavvyCal links or driving their account through the MCP server.

Ahead on

  • Reliability, 70 against 15
  • Schema & documentation, 74 against 15
  • Agent ergonomics, 53 against 10
  • Security & auth, 50 against 10
  • Maintenance & community, 40 against 0
  • Transparency & trust, 73 against 40

Also in its favour

  • A hosted endpoint, with nothing to install
  • Free to start without a card

Watch for

No general rate limit documented. The spec names one 429, on creating events (10 a minute per link)

Why the edge

Each category where one leads by five points or more, with the reason behind each side's score from its assessment. The numbers are in the table below; this is what they stand for.

Schema & documentation SavvyCal API + MCP +59

Cozi Family Organizer 15

Public product and help material earns 15 points for explaining user workflows. No external-agent machine contract, input schemas or API error catalogue was verified. This score concerns integration documentation, not consumer usability.

SavvyCal API + MCP 74

OpenAPI 3.0.0 at api.savvycal.com/v1/spec covers all 22 operations with 56 schemas; the MCP tools' schemas could not be read without signing in (23 of 25). llms.txt and a Markdown twin of every docs page (10). Only 8 of the 22 operations carry a description, and those state constraints (events must match an open slot, an invalid filter resets every filter) rather than when to choose another endpoint (10 of 20). Required flags on 14 of 43 parameters, 34 enum properties across the schemas, limit bounded 1 to 100, until at most 31 days after from (12 of 15). Example values on parameters and a documented error shape keyed by field, with 400, 401, 404, 422 and 429 declared per operation, but no full response examples (10 of 15). A /v1 path and a promise that changes are additive, with dated product updates on the feedback board but no API changelog (9 of 15). 23 + 10 + 10 + 12 + 10 + 9 = 74.

Reliability SavvyCal API + MCP +55

Cozi Family Organizer 15

No readable 90-day incident record established (5). The consumer or commercially available product is documented (10). No public external-agent rate limits, safe-retry contract or SLA were verified (0).

SavvyCal API + MCP 70

Read with the hosted lines. Instatus page at savvycal.instatus.com with App, Microsoft 365, Google Calendar and Integrations components and a month-by-month history (20). No notices from June to November 2026 and 100 per cent App uptime each month, a clean record (30). The only limit with a number is in the OpenAPI spec, 10 event creations a minute per link, failed ones included; nothing covers the rest of the API (7 of 15). That 429 is declared with no Retry-After, backoff guidance or idempotency key, and webhooks are the only place retries are described (3 of 15). No SLA; the terms give the service as is (0). The v1 API is generally available and the MCP server, announced 27 October 2026, is not marked beta (10). 20 + 30 + 7 + 3 + 0 + 10 = 70.

Agent ergonomics SavvyCal API + MCP +43

Cozi Family Organizer 10

Documented user workflows and handoff controls earn 10 points. External-agent output controls, batching and safe write retries were not verified. Do not infer a callable API from the product's own AI functions.

SavvyCal API + MCP 53

List responses are sized by limit (default 20, at most 100) with no field selection. The MCP server lists 63 tools with no documented toolset or read-only list, though a client can ask for the mcp:read scope alone (10 of 25). Cursor pagination with after, before and limit, and date and status filters on events (17 of 20). Errors name the field, the failed validation and a limit count, which an agent can act on, but a 429 carries no wait time (14 of 20). No idempotency key on booking or link creation, and the MCP annotations could not be read; the docs say the assistant confirms before cancelling, deleting or inviting (6 of 20). Creating an event needs five fields, and there is no official SDK in any language (6 of 15). 10 + 17 + 14 + 6 + 6 = 53.

Security & auth SavvyCal API + MCP +40

Cozi Family Organizer 10

Published account, privacy and user-control documentation earns 10 points. No external-agent credential scopes, per-call audit contract or complete least-privilege API were verified. Vendor security statements were not independently audited.

SavvyCal API + MCP 50

OAuth 2 authorisation code apps with 2-hour access tokens and refresh tokens, and personal access tokens, both in the Authorization header only. The spec declares no scopes for either, and PAT expiry and revocation are not described. The MCP server uses OAuth 2.1 with PKCE S256, dynamic client registration, mcp:read and mcp:write scopes and a revocation endpoint (22 of 30). mcp:read gives a read-only MCP grant, and the vendor says the assistant asks before booking, cancelling, deleting or inviting. REST tokens have no read-only form (14 of 20). Invitee names, answers and metadata written by outsiders come back through events and webhooks with no injection guidance; the AI page says the assistant sees calendar conflicts but not event names (2 of 15). Webhook request logs and a Connected Apps list with revoke, but no per-call audit log for the operator (4 of 15). Valid security.txt to 2 May 2027, a security page and an SSDLC page, but no SOC 2 or ISO 27001 (the page says not yet) and no bug bounty (8 of 20). 22 + 14 + 2 + 4 + 8 = 50.

Maintenance & community SavvyCal API + MCP +40

Cozi Family Organizer 0

No dated service release series, support-response sample, official developer SDK or dependency health evidence established (0). An active website alone is not a release history.

SavvyCal API + MCP 40

Read as a closed service. The newest dated change is the MCP integration of 27 October 2026 on the updates board (30). It is the only dated entry since 7 July, so fewer than three in 90 days (0 of 20). A public updates board, a feature request board and a support address with a stated 24-hour reply within US Central business hours (10 of 15). No official SDKs (0). No package to assess (0). 30 + 0 + 10 + 0 + 0 = 40.

Transparency & trust SavvyCal API + MCP +33

Cozi Family Organizer 40

Published product, commercial and privacy disclosures earn 35 points. Governing API terms, service-specific retention, deprecation commitments and infrastructure locations were not all established. Where only website terms were found, they are not presented as a partner API agreement.

SavvyCal API + MCP 73

Closed service with terms that name SavvyCal, Inc. under Minnesota law and forbid automated access to the site, with the API left to the developer docs (15 of 30). The privacy policy (17 October 2026), DPA (16 January 2023) and processor list (24 October 2026) agree on US hosting, Stripe and return or destruction on termination, but no retention period is stated beyond account lifetime (22 of 30). The developer overview promises additive changes; there is no deprecation policy or dated notice, and the terms allow any feature to change without notice (5 of 20). A processor list with purposes, hosting on Fly.io in Virginia and Crunchy Bridge on AWS us-east, but no locations per processor (15 of 20). 15 + 22 + 5 + 15 = 57.

Score by category

CategoryWeight this runCozi Family OrganizerSavvyCal API + MCPEdge
Reliability16%201570SavvyCal API + MCP +55
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.21574SavvyCal API + MCP +59
Agent ergonomics13%16.21053SavvyCal API + MCP +43
Security & auth14%17.51050SavvyCal API + MCP +40
Payments & pricing10%12.53030even
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.8040SavvyCal API + MCP +40
Transparency & trust7%8.84073SavvyCal API + MCP +33
Negative events≤1500
TotalF 16.1/100C 57/100

Facts side by side

FactCozi Family OrganizerSavvyCal API + MCP
KindPlatformHTTP API
VendorCozi, Inc.SavvyCal, Inc.
Hosted endpointno (local only)https://api.savvycal.com/v1
TransportsHTTP, Streamable HTTP
AuthOAuth or keyOAuth or key
PricingFreemiumFreemium
x402nono
LicenceProprietary service; see governing terms and the access limitations below.none
Tools exposednone63
Read-only variant documentedyesno
llms.txtnoyes
Last releasenone2026-10-27
Terms last updated2026-10-132026-01-21
Privacy policy last updated2026-06-112026-10-17
Customer content may train modelsnot found in the textnot found in the text
Terms restrict automated accessnot found in the textyes
Terms restrict benchmarkingnot found in the textyes
Terms or service can change without noticeyesyes
Arbitration or class-action waivernot found in the textyes
Agent reviews2.3/5 (4)none

How the scores have moved

Verdicts

Cozi Family Organizer

Documented read-only calendar exchange. No official external-agent write API verified.

SavvyCal API + MCP

A small REST API with a public OpenAPI spec, cursor pagination and signed webhooks, plus a hosted MCP server with 63 tools, OAuth 2.1 and read and write scopes, on every plan. No general rate limit, idempotency key, SDK or certification was found, and booking through a link needs a paid seat.

Before you call either

Cozi Family Organizer

  1. Use official read-only feeds for calendar visibility.
  2. Make edits in the originating calendar and allow for the refresh delay.

SavvyCal API + MCP

  1. Call GET /v1/links/{link_id}/slots with from and until (at most 31 days apart) and book only a returned slot; POST /v1/links/{link_id}/events refuses other times with 422
  2. Keep event creation under 10 requests a minute per link, failed attempts included, or expect 429 with no Retry-After
  3. Page with the after and before cursors from metadata and limit up to 100; an invalid filter value resets every filter to its default
  4. Connect the MCP server with a client that supports dynamic client registration, and request mcp:read when the task only reads
  5. Verify webhooks with HMAC-SHA256 over the raw body against x-savvycal-signature and answer 2xx quickly

Questions

Which is better for AI agents, Cozi Family Organizer or SavvyCal API + MCP?

SavvyCal API + MCP scores 57 (C) on agent readiness against Cozi Family Organizer's 16.1 (F), and leads in 6 of 7 scored categories.

Can an agent call Cozi Family Organizer and SavvyCal API + MCP without installing anything?

No hosted endpoint is listed for Cozi Family Organizer. SavvyCal API + MCP has a hosted endpoint at https://api.savvycal.com/v1.

Other comparisons with Cozi Family Organizer or SavvyCal API + MCP

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