Moon Phase Skill

Overview

A moon phase and lunar phase API that returns the phases of the moon as JSON, with an emoji icon for each phase you can drop straight into a weather or calendar UI. Moon Phases works by calculating the moon phase based on the date provided. Every response names the next principal phase, and paid plans add when it arrives plus the next and last new moon, the next first and last quarters, and the next and last full moon, all from the mean lunar month, so they are approximate to within about a day.

Live Test Moon Phase Skill Skill →

The tool

Once your client is connected to the VerveKit server, this appears in its tool list as MoonPhaseSkill. It is read-only and open-world — it fetches and never mutates anything on your side — so most clients call it without asking you to confirm.

{
  "name": "MoonPhaseSkill",
  "arguments": {}
}

Connecting

One server URL covers every skill in the catalog, including this one. Authorization is OAuth: the client opens a browser once, and there is no key to paste into a config file.

{
  "mcpServers": {
    "vervekit": {
      "url": "https://api.vervekit.com/v1/mcp"
    }
  }
}

https://api.vervekit.com/v1/mcp

Per-client setup — Claude, Cursor, VS Code, ChatGPT — is on the MCP setup page.

Arguments

These are the properties on the tool's inputSchema, so a well-behaved client validates them before the call is made. Premium arguments are accepted on every plan but only take effect on plans that include them.

What the model gets back

The result carries a structuredContent object matching the tool's declared outputSchema, so a client reads fields without parsing prose. status is "ok" and error is null on success; a null field means the value was not available for that input, not that the call failed.

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{
  "status": "ok",
  "error": null,
  "data": {
    "date": "2026-10-27",
    "phase": "Full",
    "phaseEmoji": "🌕",
    "illumination": 98.8,
    "waxing": false,
    "waning": true,
    "lunarAge": 15.775469393347242,
    "lunarAgePercent": 0.534207769602574,
    "lunationNumber": 1285,
    "lunarDistance": 57.48396905317442,
    "nextFullMoon": "2026-11-24T17:29:23.611Z",
    "lastFullMoon": "2026-10-26T04:45:20.833Z",
    "daysToFullMoon": 29,
    "daysSinceFullMoon": 1,
    "lunarDistanceKm": 366230,
    "nextPhase": "Last Quarter",
    "nextPhaseDate": "2026-11-02T13:56:21.527Z",
    "daysToNextPhase": 6,
    "nextNewMoon": "2026-11-09T23:07:22.222Z",
    "lastNewMoon": "2026-10-11T10:23:19.444Z",
    "daysToNewMoon": 14,
    "daysSinceNewMoon": 16,
    "nextFirstQuarter": "2026-11-17T08:18:22.916Z",
    "nextLastQuarter": "2026-11-02T13:56:21.527Z"
  }
}

Response fields

Paths are relative to data. Premium fields are absent rather than zeroed on plans that do not include them, so check for presence instead of comparing to 0.

Failure modes

Errors come back as tool errors carrying a sentence the model can act on, not a bare status code. Error handling covers the full list.

A call costs 2 credits each time the tool actually runs; a model that reasons about the tool without calling it costs nothing.

Use cases

Night Sky Photography

Astrophotographers check lunar illumination and waxing status to schedule dark-sky Milky Way shoots around the new moon.

Biodynamic Planting Calendars

Gardening software aligns root and above-ground crop sowing schedules using lunar cycle progression and current lunar age.

Stargazing Event Planning

When planning evening telescope sessions, observatory guides inspect illumination percentages to schedule viewing nights under pitch-black skies.

Fishing Forecast Dashboards

Forecast peak feeding activity by pairing lunation numbers and waxing indicators with local marine tables in fishing apps.

Other ways to use Moon Phase Skill

Set up Moon Phase Skill on VerveKit, or reach the same source a different way. Your VerveKit account and credits work on all of them — one key, one balance.

Related

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