MCP server

Endpoint

https://fatcalendar.com/mcp - MCP Streamable HTTP, stateless, no authentication. Server card: /.well-known/mcp/server-card.json.

Tools

All tools are read-only (readOnlyHint: true), idempotent and closed-world.

• get_month - Get a month calendar. Arguments: tradition, lang, digits, variant, lat, lon, tz, place, year, month.
• get_week - Get a week calendar. Arguments: tradition, lang, digits, variant, lat, lon, tz, place, date.
• get_year - Get a year calendar. Arguments: tradition, lang, digits, variant, lat, lon, tz, place, year.
• get_day - Get a full day (panchang) view. Arguments: tradition, lang, digits, variant, lat, lon, tz, place, date.
• get_panchang - Get the raw normalised panchang. Arguments: lat, lon, tz, place, date.
• list_festivals - List festivals of a year. Arguments: tradition, lang, digits, variant, lat, lon, tz, place, year.
• search_places - Search places (geocoder). Arguments: q.
• list_traditions - List calendar traditions. Arguments: none.
• list_languages - List display languages. Arguments: none.

Results are returned as JSON text plus structuredContent.

Resources and prompts

• Resources: fatcalendar://traditions, fatcalendar://languages.
• Prompt: explain_day (arguments: date, tradition, place) - asks the model to explain a day's panchang in plain language.

Configure a client

Claude Code

claude mcp add --transport http fatcalendar https://fatcalendar.com/mcp

Claude Desktop (via mcp-remote)

{
  "mcpServers": {
    "fatcalendar": {
      "command": "npx",
      "args": ["-y", "mcp-remote", "https://fatcalendar.com/mcp"]
    }
  }
}

Claude.ai and ChatGPT connectors

Add a custom connector with URL https://fatcalendar.com/mcp and no authentication.

Cursor (~/.cursor/mcp.json)

{
  "mcpServers": {
    "fatcalendar": { "url": "https://fatcalendar.com/mcp" }
  }
}

Raw JSON-RPC example

curl -s https://fatcalendar.com/mcp \
  -H 'content-type: application/json' -H 'accept: application/json, text/event-stream' \
  -d '{"jsonrpc":"2.0","id":1,"method":"tools/call","params":{"name":"get_day","arguments":{"tradition":"telugu","place":"Hyderabad","date":"2026-11-08"}}}'

Example prompts

• "What is today's tithi and Rahu Kalam in Chennai?"
• "List Sikh gurpurabs in 2026 using the Nanakshahi calendar."
• "When does Ramadan start in 2027 according to the Indian moon-sighting estimate?"

Limits

Same quota as the REST API: 120 requests per 60 seconds per client.