Moon phase API: illumination, age and next new and full moon
Moon phase name, illuminated percentage and age in days for any date, plus the next new and full moon (UTC, to the minute). Computed locally from the Moon's and Sun's orbital terms; the times agree with published almanacs within about a minute. Use for calendars and night-sky planning.
When to use it
- Calendars and night-sky planning
- Get the phase name, illuminated percentage and age in days for any date
$0.001 per call with prepaid credits: $1 by card pays for 1,000 calls, with no account and no subscription.
Inputs
| Name | Type | Description |
|---|---|---|
date | string | Date or ISO time (default now) |
Request
Over HTTP, with a card key from /credits:
curl -H "Authorization: Bearer adt_…" "https://glyphcall.com/moon?date=2026-10-18"Or one of your 3 free calls, no key:
curl "https://glyphcall.com/moon?date=2026-10-18&trial=1"Without a key, the same URL answers 402 Payment Required with x402 and MPP terms, so an agent with a wallet pays per call in USDC (Base, Polygon, Arbitrum or Solana over x402; Base or Tempo over MPP) and retries.
Live result
The real answer to the request above, read 2026-11-15 18:46 UTC and refreshed every 15 minutes.
{
"date": "2026-10-18",
"phase": "First Quarter",
"illuminationPercent": 50.8,
"ageDays": 7.8,
"nextNewMoon": "2026-11-09T07:02:00.000Z",
"nextFullMoon": "2026-10-26T04:12:00.000Z"
}From an AI agent (MCP)
Add the MCP server to Claude, Cursor or any MCP client. This tool is moon, and the first 25 successful calls are free:
https://glyphcall.com/mcpQuestions
Is it computed or looked up?
Computed locally from the mean synodic month.
How do I pay?
Each successful call costs $0.01; failed calls are not charged. The first 3 calls are free (25 through an MCP client). Then pay with card credits (from $1; the key goes in an Authorization header or, for clients that can only fetch a URL, as api_key= in the URL) or per call in USDC over x402 or MPP. No account is needed.