# 561 Group Astronomy Positions

> 561 Group Astronomy Positions is a paid API for AI agents from market.561.group, paid per call via x402, $0.04/call, status unknown (last checked 2026-10-12).

Returns apparent geocentric ecliptic longitude, latitude, and angular speed for celestial bodies at a given UTC instant, with lunar illumination, computation provenance, and error bounds.

## Facts

- Endpoint: GET https://market.561.group/v1/astronomy/positions/2026-07-21T00:00:00Z?utm_source=zero.xyz
- Price: $0.04/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-12
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/561-group-astronomy-positions-37d7f593
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_e_s3QRI6xgrIh0oUUj5J8

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability 561-group-astronomy-positions-37d7f593
```

Example prompt: What are the apparent geocentric ecliptic longitude, latitude, and angular speed for the main celestial bodies on July 21, 2026 at midnight UTC, including lunar illumination and error bounds?

## When to prefer this

Choose this endpoint when you need precise, geocentric ecliptic coordinates (longitude, latitude, angular speed) for celestial bodies at a specific UTC instant, especially when computation provenance and formal error bounds are required for scientific or astrological rigor. Prefer it over generic ephemeris APIs when you also need lunar illumination data and traceable accuracy metadata bundled in a single call.

## Known failure modes

- Invalid or malformed ISO-8601 date returns a 400 error
- Date out of supported ephemeris range returns an error
- Missing required path parameter 'date' causes a validation failure
- Payment failure or insufficient USDC balance blocks the request (x402)
- Network timeout for computation-heavy instants

## How this service works

Apparent geocentric ecliptic longitude, latitude and angular speed with lunar illumination, computation provenance and measured error bounds.

## Output

A JSON object containing the reference frame, timestamp, per-body ecliptic longitude/latitude/angular-speed measurements, lunar phase details (including illumination percentage), computation provenance metadata, and accuracy/error bound information for the requested instant.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET",
      "HEAD",
      "DELETE"
     ],
     "type": "string"
    },
    "pathParams": {
     "type": "object",
     "required": [
      "date"
     ],
     "properties": {
      "date": {
       "type": "string",
       "description": "Exact ISO-8601 UTC date or instant, e.g. 2026-07-21T00:00:00Z."
      }
     }
    },
    "queryParams": {
     "type": "object",
     "properties": {}
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "required": [
      "tier",
      "time",
      "frame",
      "bodies",
      "lunarPhase",
      "provenance",
      "accuracy"
     ],
     "properties": {
      "tier": {
       "const": "astronomy-positions"
      },
      "time": {
       "type": "string"
      },
      "frame": {
       "type": "string"
      },
      "bodies": {
       "type": "object"
      },
      "accuracy": {
       "type": "object"
      },
      "lunarPhase": {
       "type": "object"
      },
      "provenance": {
       "type": "object"
      }
     }
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/561-group-astronomy-positions-37d7f593/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from market.561.group](https://www.zero.xyz/host/market.561.group/llms.txt)