@chronary/mcp

MCP server for Chronary — calendar tools for AI assistants.

Drops 65 calendar tools (manage agents, calendars, and events, request human Google/Microsoft setup, find meeting times, run scheduling proposals, configure availability rules, manage webhooks, iCal subscriptions, scoped keys, audit log, usage, and billing status with ask-your-human upgrade requests) into any MCP-compatible client: Claude Desktop, Cursor, VS Code Copilot, Claude Code, Windsurf.

One-click install via Smithery: npx -y @smithery/cli mcp add chronary/agent-calendar --client claude (swap --client for cursor, vscode, claude-code, windsurf, …).

Prerequisites

1. A Chronary account — sign up at chronary.ai.
2. An API key from the console (starts with chr_sk_).
3. Node.js ≥ 18 on the machine where the MCP client runs.

Client configurations

All examples use npx -y @chronary/mcp, which downloads and runs the latest version on demand. No install step required.

Claude Desktop

Edit ~/Library/Application Support/Claude/claude_desktop_config.json (macOS) or %APPDATA%\Claude\claude_desktop_config.json (Windows):

macOS / Linux:

{
  "mcpServers": {
    "chronary": {
      "command": "npx",
      "args": ["-y", "@chronary/mcp"],
      "env": {
        "CHRONARY_API_KEY": "chr_sk_..."
      }
    }
  }
}

Windows (uses cmd /c because spawn can't resolve npx.cmd directly):

{
  "mcpServers": {
    "chronary": {
      "command": "cmd",
      "args": ["/c", "npx", "-y", "@chronary/mcp"],
      "env": {
        "CHRONARY_API_KEY": "chr_sk_..."
      }
    }
  }
}

Restart Claude Desktop after saving.

Cursor

Edit .cursor/mcp.json (project-level) or ~/.cursor/mcp.json (user-level):

macOS / Linux:

{
  "mcpServers": {
    "chronary": {
      "command": "npx",
      "args": ["-y", "@chronary/mcp"],
      "env": { "CHRONARY_API_KEY": "chr_sk_..." }
    }
  }
}

Windows:

{
  "mcpServers": {
    "chronary": {
      "command": "cmd",
      "args": ["/c", "npx", "-y", "@chronary/mcp"],
      "env": { "CHRONARY_API_KEY": "chr_sk_..." }
    }
  }
}

VS Code Copilot

Edit .vscode/mcp.json (workspace) or run the MCP: Open User Configuration command for a user-level config. VS Code uses a different top-level key (servers) and requires an explicit type:

macOS / Linux:

{
  "servers": {
    "chronary": {
      "type": "stdio",
      "command": "npx",
      "args": ["-y", "@chronary/mcp"],
      "env": { "CHRONARY_API_KEY": "chr_sk_..." }
    }
  }
}

Windows:

{
  "servers": {
    "chronary": {
      "type": "stdio",
      "command": "cmd",
      "args": ["/c", "npx", "-y", "@chronary/mcp"],
      "env": { "CHRONARY_API_KEY": "chr_sk_..." }
    }
  }
}

Claude Code

Edit .mcp.json at the project root, or ~/.claude.json for user-level:

macOS / Linux:

{
  "mcpServers": {
    "chronary": {
      "command": "npx",
      "args": ["-y", "@chronary/mcp"],
      "env": { "CHRONARY_API_KEY": "chr_sk_..." }
    }
  }
}

Windows:

{
  "mcpServers": {
    "chronary": {
      "command": "cmd",
      "args": ["/c", "npx", "-y", "@chronary/mcp"],
      "env": { "CHRONARY_API_KEY": "chr_sk_..." }
    }
  }
}

Windsurf

Edit ~/.codeium/windsurf/mcp_config.json (%USERPROFILE%\.codeium\windsurf\mcp_config.json on Windows):

macOS / Linux:

{
  "mcpServers": {
    "chronary": {
      "command": "npx",
      "args": ["-y", "@chronary/mcp"],
      "env": { "CHRONARY_API_KEY": "chr_sk_..." }
    }
  }
}

Windows:

{
  "mcpServers": {
    "chronary": {
      "command": "cmd",
      "args": ["/c", "npx", "-y", "@chronary/mcp"],
      "env": { "CHRONARY_API_KEY": "chr_sk_..." }
    }
  }
}

Windsurf limit: Cascade enforces a hard cap of 100 total tools across all MCP servers and 20 tool calls per prompt. Chronary exposes 65; consider --tools filtering if you stack multiple servers.

Reducing context with --tools

Exposing all 65 tools uses LLM tokens on every request. For focused workflows, whitelist only what you need:

{
  "mcpServers": {
    "chronary": {
      "command": "npx",
      "args": [
        "-y", "@chronary/mcp",
        "--tools", "list_events,find_meeting_time,create_event"
      ],
      "env": { "CHRONARY_API_KEY": "chr_sk_..." }
    }
  }
}

Pointing at a non-production API

For self-hosted Chronary instances or development against a local API. The URL must use https://; plain http:// is accepted only for localhost, 127.0.0.1 and [::1], because your API key travels in the Authorization header:

{
  "args": ["-y", "@chronary/mcp", "--base-url", "http://localhost:8787"]
}

Tools exposed

Tool	Read-only	Destructive
list_calendars, get_calendar	✓
create_calendar, update_calendar
delete_calendar		✓
list_events, list_org_events, get_event	✓
create_event, update_event, confirm_event
cancel_event, release_event		✓
list_agents, get_agent	✓
create_agent, update_agent
delete_agent		✓
get_availability, find_meeting_time	✓
get_calendar_context	✓
list_proposals, get_proposal	✓
create_proposal, respond_to_proposal, resolve_proposal
cancel_proposal		✓
get_availability_rules	✓
set_availability_rules
clear_availability_rules		✓
list_webhooks, get_webhook, list_webhook_deliveries, get_webhook_delivery	✓
create_webhook, send_test_webhook, replay_webhook_delivery
update_webhook		✓
delete_webhook		✓
list_ical_subscriptions, get_ical_subscription	✓
subscribe_ical, update_ical_subscription, sync_ical_subscription, pause_ical_subscription, resume_ical_subscription
delete_ical_subscription		✓
list_scoped_keys	✓
create_scoped_key
revoke_scoped_key		✓
get_audit_log	✓
accept_terms
get_usage	✓
get_usage_history	✓

Tool annotations (readOnlyHint, destructiveHint, idempotentHint, openWorldHint) are surfaced to MCP clients so hosts can decide whether to require user confirmation. They are identical on the hosted server (https://api.chronary.ai/mcp). Tools that make Chronary contact a URL you supply (webhooks, iCal feeds, setup links) set openWorldHint: true.

Third-party text

Some event and webhook text is written by people outside your organization: a booking-page booker chooses the name and notes that become a booking's title, description and metadata, and a webhook receiver writes a delivery's response_body. The server instructions tell the model to treat that text as data, never as instructions, and the results of the event and webhook-delivery tools start with an untrusted_fields key naming those fields (for example ["title", "description", "metadata"]).

Troubleshooting

"spawn npx ENOENT" on Windows — use the cmd /c npx ... form shown above.

"CHRONARY_API_KEY is required" — the env block must be nested under the server entry, not at the top of the config file.

Tools aren't showing up — restart the MCP client after editing the config. Most clients only read the config on startup.

Verify the binary runs locally:

CHRONARY_API_KEY=test npx -y @chronary/mcp --help

Links

• Chronary docs
• MCP spec
• Report an issue

Security and support

Report vulnerabilities to security@chronary.ai or through private vulnerability reporting on this package's GitHub repository. Please don't open a public issue. Read the full security policy.

Version 1.x is supported with security fixes until at least June 2031. Fixes ship in a new 1.x release, so keep up with the latest one. Supported versions and end dates for every Chronary package are listed in the security policy.

License

Apache-2.0