API & MCP

Everything a person can do on Skyfold Printable Moon Calendar, a program or AI agent can do with the same inputs and get the identical result.

HTTP API

POST https://skyfoldmooncalendar.usefulweb.app/api/v1/calculate – run Skyfold Printable Moon Calendar
GET https://skyfoldmooncalendar.usefulweb.app/api/v1/tool – inputs, output schema, examples
OpenAPI 3.1: /openapi.json · /openapi.yaml
Errors: application/problem+json; 422 includes per-field errors.

Skyfold Printable Moon Calendar

Draws the Moon of every day of a month or year for your place, with the illuminated fraction, moonrise and moonset in local time, the four principal phases, perigee and apogee with distances and the supermoons, as a print-ready PDF, SVG and PNG in 17 languages.

Inputs of Skyfold Printable Moon Calendar
Field	Type	Default	Description
`location`	text	"52.52, 13.405"	Location (latitude, longitude). Decimal degrees such as 52.09, 5.12 (north and east positive), or DMS, UTM, MGRS, Maidenhead or a plus code.
`elevation`	number	0	Elevation above sea level
`timeZone`	text	"Europe/Berlin"	Time zone. IANA name such as Europe/Berlin or America/New_York, or a fixed offset such as UTC+2.
`year`	integer	2027	Year
`month`	select (0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)	"0"	Month
`layout`	select (month, year)	"month"	Layout
`lang`	select (en, de, fr, es, it, pt, nl, pl, tr, ru, uk, ar, hi, zh, ja, ko, id)	"en"	Language of the calendar
`paper`	select (a4, a3, letter, tabloid)	"a4"	Paper size
`orientation`	select (portrait, landscape)	"portrait"	Orientation
`weekStart`	select (auto, mon, sun, sat)	"auto"	Week starts on
`placeLabel`	text	"Berlin"	Place line

Example request

Berlin, January 2027, German

curl -X POST https://skyfoldmooncalendar.usefulweb.app/api/v1/calculate -H 'content-type: application/json' -d '{"location":"52.52, 13.405","timeZone":"Europe/Berlin","year":2027,"month":"1","layout":"month","lang":"de","paper":"a4","orientation":"portrait","weekStart":"auto","placeLabel":"Berlin"}'

Every result contains

inputs (normalised, defaults applied), summary, result (validated against the published schema), units, assumptions, sources, warnings, computedAt and links.

MCP (Model Context Protocol)

Streamable HTTP endpoint: https://skyfoldmooncalendar.usefulweb.app/mcp – protocol revisions 2026-07-28 (stateless) and 2025-11-25 / 2025-06-18 / 2025-03-26 (initialize handshake).
Tools: skyfold_moon_calendar
Local stdio connector: node src/mcp-stdio.ts --tool=skyfold-moon-calendar

{
  "mcpServers": {
    "skyfold-moon-calendar": { "type": "http", "url": "https://skyfoldmooncalendar.usefulweb.app/mcp" }
  }
}