AgentCalendar

Headless MCP CalDAV calendar server for AI agents. Sibling to AgentMail: same credential boundary, same stdio-only architecture, no web UI.

What it does

• Mirrors CalDAV calendars and events into local SQLite for fast event_search / event_read.

• Resolves CalDAV credentials only through SecretFabric short-lived leases (caldav-sync purpose).

• Gates every real write behind event_preview → event_approval_create → event_write with a payload-bound, five-minute approval.

Related MCP server: iCloud Calendar MCP

Safety model

• No secrets in MCP tools — account passwords never appear in tool arguments or JSON results.

• Active-account allowlist — only accounts registered via calendar_account_register (with an opaque secretRef) are synced or written.

• Human in the loop — creating or updating calendar events requires an explicit approval matching the exact iCal body.

Runtime configuration (required)

Local development

export AGENTCAL_DB_PATH=/tmp/agentcalendar.db
export AGENTCAL_SYNC_INTERVAL_SECONDS=300
export AGENTCAL_LOG_LEVEL=info
export AGENTCAL_TRANSPORT=stdio
export SECRET_FABRIC_URL=http://127.0.0.1:3000
export SECRET_FABRIC_API_TOKEN=your-token

yarn install
yarn check
yarn start

Docker

export SECRET_FABRIC_URL=http://127.0.0.1:3000
export SECRET_FABRIC_API_TOKEN=your-token
docker compose build
docker compose up -d

network_mode: host lets the container reach SecretFabric on the host loopback.

Hermes MCP example

hermes mcp add agentcalendar -- docker compose -f /path/to/agentcalendar/compose.yaml run --rm -T agentcalendar

(Adjust paths and ensure SECRET_FABRIC_* are set in the environment passed to Compose.)

MCP tools (summary)

• Accounts: calendar_account_list, calendar_account_status, calendar_account_register, calendar_account_deactivate

• Sync: calendar_list, calendar_sync, calendar_sync_all

• Read: event_search, event_read

• Write (approval-gated): event_preview, event_approval_create, event_write

License

Apache-2.0