What is a calendar for AI agents?

A calendar for AI agents is a calendar system an agent controls programmatically instead of through a human UI. Chronary gives every agent its own calendars, events, and availability over a REST API and MCP server — no Google OAuth and no iCal parsing required.

How do AI agents create and manage calendar events?

Agents call the Chronary REST API or invoke MCP tools to create calendars, schedule events, query availability, and subscribe to webhook notifications. Human calendar apps can subscribe to the generated iCal feeds.

Is there a calendar API for AI agents?

Yes. Chronary is a calendar API for AI agents with both REST and MCP interfaces. It works as a drop-in AI agent calendar and scheduling API, with SDKs for TypeScript, Python, and Go and adapters for the Vercel AI SDK, OpenAI SDK, LangChain, and Mastra.

How is an AI agent calendar different from Google Calendar?

Chronary is built for programmatic, multi-agent scheduling rather than a single human user. Every agent gets its own first-class calendar, identity, and rate limits, plus agent-native primitives like temporal holds, cross-agent availability, and scheduling proposals — without wiring up Google OAuth.

Is there a calendar MCP server?

Yes. Chronary ships a calendar MCP server — run `npx @chronary/mcp` to register its calendar and scheduling tools with Claude, Cursor, VS Code, Windsurf, or any MCP-compatible host over stdio or HTTP. The same tools are also available as a hosted MCP endpoint.

Early access · Full features

Calendar infrastructure for AI agents

Chronary is a calendar for AI agents: create calendars, manage events, query availability, and sync with human calendar apps, all through a simple REST API and MCP server.

Get early access Read the Docs

Free Pro tier until our public launch. No credit card.

cURL TypeScript Python

# 1. Create an event on an agent's calendar
curl -X POST https://api.chronary.ai/v1/calendars/cal_a1b2c3d4/events \
  -H "Authorization: Bearer chr_sk_..." \
  -d '{"title": "Standup", "start_time": "2026-04-10T09:00:00Z"}'
# → 201 Created. iCal feed updated, webhook fan-out fires.

# 2. Find a 30-minute slot across three agents
curl "https://api.chronary.ai/v1/availability?duration=30\
&agent_ids=agt_alice,agt_bob,agt_carol" \
  -H "Authorization: Bearer chr_sk_..."
# → [{"start":"2026-04-10T14:00:00Z","end":"2026-04-10T14:30:00Z"},
#    {"start":"2026-04-10T16:30:00Z","end":"2026-04-10T17:00:00Z"}]

import { Chronary } from '@chronary/sdk';
const chronary = new Chronary({ apiKey: 'chr_sk_...' });

// 1. Create an event on an agent's calendar
const event = await chronary.events.create('cal_a1b2c3d4', {
  title: 'Standup',
  start_time: '2026-04-10T09:00:00Z',
  end_time:   '2026-04-10T09:30:00Z',
});
// → { id: 'evt_...', ... }  iCal feed + webhooks fire.

// 2. Find a 30-minute slot across three agents
const { slots } = await chronary.availability.check({
  agents: ['agt_alice', 'agt_bob', 'agt_carol'],
  start: '2026-04-10T00:00:00Z',
  end:   '2026-04-11T00:00:00Z',
  slot_duration: { minutes: 30 },
});
// → [{ start: '2026-04-10T14:00:00Z', end: '...' }, ...]

from chronary import Chronary
chronary = Chronary(api_key="chr_sk_...")

# 1. Create an event on an agent's calendar
event = chronary.events.create(
    "cal_a1b2c3d4",
    title="Standup",
    start_time="2026-04-10T09:00:00Z",
    end_time="2026-04-10T09:30:00Z",
)
# → Event(id="evt_...", ...) iCal feed + webhooks fire.

# 2. Find a 30-minute slot across three agents
result = chronary.availability.check(
    agents=["agt_alice", "agt_bob", "agt_carol"],
    start="2026-04-10T00:00:00Z",
    end="2026-04-11T00:00:00Z",
    slot_duration={"minutes": 30},
)
# → [{"start": "2026-04-10T14:00:00Z", ...}, ...]

Built for the agent ecosystem

LangChain CrewAI AutoGen OpenAI Agents MCP

Works with any LLM framework. No SDK lock-in.

Features

Everything your agents need to manage time

A complete AI agent calendar and scheduling API — drive it over REST, the native SDKs, or the Chronary calendar MCP server. No human UI, no Google OAuth.

Pro

Scheduling Proposals

Negotiate meetings between multiple agents. Each agent responds with availability; the proposal resolves into events on every calendar.

POST /v1/scheduling/proposals
→ each agent responds → resolves into N events

Pro

Temporal Holds

Reserve a slot, then confirm or release within a window. Built for the 'agent A is checking 3 calendars before committing' pattern.

PUT /v1/events/:id/confirm
PUT /v1/events/:id/release

Pro

Cross-Agent Availability

Find when N agents are free at once. Intersection algorithm across any number of calendars.

GET /v1/availability
  ?agent_ids=agt_a,agt_b,agt_c

Calendar & Event API

Full CRUD with arbitrary JSON metadata. Each calendar gets an iCal feed URL. Subscribe to external Google, Apple, or Outlook calendars too.

POST /v1/calendars/:id/events
{ "title": "Standup", "start_time": "..." }

Webhook Events

18 event types covering agent, event, hold, proposal, and webhook lifecycle. HMAC-SHA256 signed.

x-chronary-signature: t=...,v1=...
{ "type": "event.created", "data": {...} }

First-Class Agents

Agents are entities, not service accounts. Per-agent IDs, audit trails, and rate limits. Pro: dedicated API key per agent so each customer integration uses its own credential. Leaked keys revoke a single tenant, not the whole org.

POST /v1/agents
→ agt_xxx (with audit trail + per-agent key)

MCP Server

23 tools for Claude, GPT, and any MCP-compatible agent. stdio + HTTP transports.

npx @chronary/mcp
→ 23 tools registered with the host

Framework Adapters

Drop Chronary tools into the framework you already use: Vercel AI SDK, OpenAI SDK, LangChain, or Mastra. One package, same tool surface across all of them.

import { ChronaryToolkit } from '@chronary/toolkit/ai-sdk'
generateText({ tools: toolkit.getTools(), ... })

Native SDKs

TypeScript, Python, and Go SDKs plus a CLI. Versioned packages with typed responses and full surface coverage.

npm i @chronary/sdk
pip install chronary
go get github.com/chronary/go-sdk

Simple integration

Create an event in 5 lines

cURL TypeScript SDK Python SDK

curl -X POST https://api.chronary.ai/v1/calendars/cal_a1b2c3d4/events \
  -H "Authorization: Bearer chr_sk_..." \
  -H "Content-Type: application/json" \
  -d '{
    "title": "Code review with Agent B",
    "start_time": "2026-04-10T14:00:00Z",
    "end_time": "2026-04-10T14:30:00Z",
    "metadata": { "priority": "high", "workflow_id": "wf_review_42" }
  }'

import { Chronary } from '@chronary/sdk';

const chronary = new Chronary({ apiKey: process.env.CHRONARY_API_KEY! });

const event = await chronary.events.create('cal_a1b2c3d4', {
  title: 'Code review with Agent B',
  start_time: '2026-04-10T14:00:00Z',
  end_time: '2026-04-10T14:30:00Z',
  metadata: { priority: 'high', workflow_id: 'wf_review_42' },
});

console.log(event.id); // "evt_x9y8z7w6"

import os
from chronary import Chronary

chronary = Chronary(api_key=os.environ["CHRONARY_API_KEY"])

event = chronary.events.create(
    calendar_id="cal_a1b2c3d4",
    title="Code review with Agent B",
    start_time="2026-04-10T14:00:00Z",
    end_time="2026-04-10T14:30:00Z",
    metadata={"priority": "high", "workflow_id": "wf_review_42"},
)

print(event.id)  # "evt_x9y8z7w6"

Getting started

How it works

1 Key

Sign up & get your API key

No credit card. API keys generated instantly.

2 POST

Create a calendar and add events

One POST request. Full CRUD, metadata, timezone-aware.

3 iCal

See it on your phone

Every calendar gets an iCal feed URL. Subscribe in Google, Apple, or Outlook.

For agents

Or have your agent sign itself up

No console, no human in the loop. An agent provisions its own org, verifies an email OTP, and runs on the same Free tier as any developer signup.

1 POST

Agent posts to /v1/agent/sign-up

Email + agent name + accepted ToS version. Returns an API key on the sandbox tier; a 6-digit OTP is sent to the email.

2 TRY

Try it on the sandbox tier

Create up to 10 events, register 1 webhook, subscribe via iCal. Real responses, real fan-out, enough to evaluate the API end-to-end before verifying.

3 OTP

Verify to unlock the Free tier

POST the OTP to /v1/agent/verify with the same key. Caps jump 50-250x, 2,500 events/mo, 50K API calls, 5K webhook deliveries.

cURL TypeScript SDK Python SDK

# Step 1: Agent self-signup (unauthenticated)
curl -X POST https://api.chronary.ai/v1/agent/sign-up \
  -H "Content-Type: application/json" \
  -d '{
    "email": "[email protected]",
    "agent_name": "Alice Bot",
    "tos_version": "2026-04-17"
  }'

# → 200 OK
# {
#   "org_id":   "org_abc123",
#   "agent_id": "agt_abc123",
#   "api_key":  "chr_sk_restricted_...",
#   "message":  "Verification code sent to email"
# }

# Step 2: Verify the OTP with the restricted key
curl -X POST https://api.chronary.ai/v1/agent/verify \
  -H "Authorization: Bearer chr_sk_restricted_..." \
  -H "Content-Type: application/json" \
  -d '{"otp": "123456"}'

# → 200 OK { "verified": true }   # same key, full Free-tier access

import { Chronary, isAgentSignUpNewOrg } from '@chronary/sdk';

// Step 1: unauthenticated sign-up
const bootstrap = new Chronary();
const signup = await bootstrap.agentAuth.signUp({
  email: '[email protected]',
  agent_name: 'Alice Bot',
  tos_version: '2026-04-17',
});

if (isAgentSignUpNewOrg(signup)) {
  // Step 2: verify with the restricted key from the response
  const client = new Chronary({ apiKey: signup.api_key });
  await client.agentAuth.verify({ otp: await readOtpFromInbox() });

  // Step 3: same client now has full Free-tier access
  await client.calendars.create({ name: 'Alice ops' });
}

from chronary import Chronary

# Step 1: unauthenticated sign-up
bootstrap = Chronary(api_key=None)
signup = bootstrap.agent_auth.sign_up(
    email="[email protected]",
    agent_name="Alice Bot",
    tos_version="2026-04-17",
)

if signup.is_new_org:
    # Step 2: verify with the restricted key from the response
    client = Chronary(api_key=signup.api_key)
    client.agent_auth.verify(otp=read_otp_from_inbox())

    # Step 3: same client now has full Free-tier access
    client.calendars.create(name="Alice ops")

Sandbox tier, pre-verification

Real calls, small budget

Enough to wire the API end-to-end and watch a webhook fire, not enough to run production. Once you hit a cap, verify your email to unlock the Free tier.

Calendars: 1
Events: 10/mo
Webhook endpoints: 1
Webhook deliveries: 25/mo
iCal subscriptions: 1
Availability queries: 50/mo
API calls: 1,000/mo

After OTP verification

Free tier, identical to developer signup

The same key gains full write access. Every cap below is the same number we enforce on a Free-tier developer signup, no discount, no penalty for self-signing-up.

Calendars: 10
Events: 2,500/mo
Webhook endpoints: 3
Webhook deliveries: 5,000/mo
iCal subscriptions: 5
Availability queries: 10,000/mo
API calls: 50,000/mo

Full contract: docs.chronary.ai/api-reference/agent

For agents · zero context

Three one-liners to bootstrap an agent

Discovery primitives at the root domain let a cold AI coding agent find Chronary, install skills, point an MCP client at the hosted server, and provision its own API key, without human hand-holding.

1 · Install skills

IDE skill packs

# Install Chronary skill packs into your IDE
#   targets: claude-code | cursor | windsurf | vscode | codex | all
curl -sSfL https://chronary.ai/skills.sh | bash

2 · Wire MCP

MCP client config

# Claude Desktop / Cursor / Windsurf, claude_desktop_config.json
{
  "mcpServers": {
    "chronary": {
      "command": "npx",
      "args": ["-y", "@chronary/mcp@latest"],
      "env": { "CHRONARY_API_KEY": "chr_sk_..." }
    }
  }
}

3 · Bootstrap key

agent-init

# One-liner that signs up an agent, captures the OTP, verifies,
# and creates a smoke calendar, exits with $CHRONARY_API_KEY set.
npx @chronary/agent-init@latest

# Or shell fallback (no Node required):
curl -sSfL https://chronary.ai/agent-init.sh | sh