`observers`

Pack: horizons-nasa · Connect: https://pipeworx.io/mcp (see Connect below for a single-pack URL)

No MCP client? Call it directly: GET https://gateway.pipeworx.io/v1/tools/observers for the schema, then POST the same URL with its arguments for the data.

Convenience: ephemeris with table_type=OBSERVER.

Parameters

Name	Type	Required
`command`	string	yes
`center`	string	no
`start_time`	string	yes
`stop_time`	string	yes
`step_size`	string	no

Example call

Arguments

{
  "command": "499",
  "start_time": "2026-05-18",
  "stop_time": "2026-05-19"
}

curl

curl -X POST https://gateway.pipeworx.io/horizons-nasa/mcp \
  -H 'Content-Type: application/json' \
  -d '{"jsonrpc":"2.0","id":1,"method":"tools/call","params":{"name":"observers","arguments":{"command":"499","start_time":"2026-05-18","stop_time":"2026-05-19"}}}'

TypeScript (@pipeworx/sdk)

import { Pipeworx } from '@pipeworx/sdk';
const pipeworx = new Pipeworx();

const result = await pipeworx.call('observers', {
  "command": "499",
  "start_time": "2026-05-18",
  "stop_time": "2026-05-19"
});

More examples

{
  "command": "1",
  "start_time": "2026-06-01",
  "stop_time": "2026-06-02",
  "step_size": "6h"
}

Response shape

Full JSON Schema

{
  "type": "object",
  "description": "Observer-table ephemeris data from JPL Horizons"
}

Connect

Add this to your MCP client config — every tool in the catalog, including this one — or use one-click install buttons:

{
  "mcpServers": {
    "pipeworx": {
      "url": "https://pipeworx.io/mcp"
    }
  }
}

Connect to just the horizons-nasa pack

{
  "mcpServers": {
    "horizons-nasa": {
      "url": "https://gateway.pipeworx.io/horizons-nasa/mcp"
    }
  }
}

See Getting Started for client-specific install steps.

observers