Astronomy

Light-Year and Astronomical Unit Converter

Convert between light-years (ly), parsecs (pc), astronomical units (AU), kilometers and meters using IAU-defined constants, with a parallax-angle → distance helper.

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Quick start

Call this tool from your code in three languages.

cURL

curl -X POST 'https://api.elysiatools.com/en/api/tools/light-year-and-astronomical-unit-converter' \
  -H 'Content-Type: application/json' \
  -d '{"value":1,"fromUnit":"ly","decimals":6,"scientific":false,"parallax":"e.g. 0.7685 (Proxima Centauri)"}'

API reference

Send a POST request with your inputs as JSON. File parameters require a separate upload first.

Endpoint

HTTP

POST https://api.elysiatools.com/en/api/tools/light-year-and-astronomical-unit-converter

Parameters

Name	Type	Required	Description
value	number	Yes	The distance value to convert.
fromUnit	select	No	The unit of the value you entered.
decimals	number	No	Number of digits after the decimal point in the result.
scientific	checkbox	No	Display results in scientific (exponential) notation.
parallax	text	No

MCP integration

Add this tool to your Model Context Protocol server so AI agents can list and call it.

Server configuration

Add this block to your MCP client configuration:

mcp.json

{
  "mcpServers": {
    "elysiatools-light-year-and-astronomical-unit-converter": {
      "name": "light-year-and-astronomical-unit-converter",
      "description": "Convert between light-years (ly), parsecs (pc), astronomical units (AU), kilometers and meters using IAU-defined constants, with a parallax-angle → distance helper.",
      "baseUrl": "https://api.elysiatools.com/mcp/sse?toolId=light-year-and-astronomical-unit-converter",
      "command": "",
      "args": [],
      "env": {},
      "isActive": true,
      "type": "sse"
    }
  }
}

List available tools

After connecting to the SSE endpoint, list the exposed tools:

tools/list

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/list"
}

Call this tool

Invoke the tool by its id, passing arguments built from its parameters:

tools/call

{
  "jsonrpc": "2.0",
  "id": 2,
  "method": "tools/call",
  "params": {
    "name": "light-year-and-astronomical-unit-converter",
    "arguments": {
  "value": 1,
  "fromUnit": "ly",
  "decimals": 6,
  "scientific": false,
  "parallax": "e.g. 0.7685 (Proxima Centauri)"
}
  }
}

Chain multiple tools in one session with a comma-separated toolId list, e.g. /mcp/sse?toolId=png-to-webp,jpg-to-webp,gif-to-webp (max 20).

Questions or issues? Contact [email protected]

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