API & MCP server for AI agents

Every CalcBright calculator is available to apps and AI assistants – free, no API key, same engine as the website.

1. MCP server (Claude, ChatGPT, Cursor, VS Code…)

Connect any MCP-compatible assistant to https://calcbright.com/mcp (Streamable HTTP, no authentication). It exposes all 100 tools with typed inputs.

{
  "mcpServers": {
    "calcbright": {
      "type": "http",
      "url": "https://calcbright.com/mcp"
    }
  }
}

• Claude: Settings → Connectors → Add custom connector → URL https://calcbright.com/mcp.
• ChatGPT: Settings → Connectors (developer mode) → add an MCP server with the same URL.
• Cursor / VS Code / Claude Code: add the JSON above to your MCP configuration.

2. JSON API

GET https://calcbright.com/api/calc/<tool>?param=value – unspecified parameters use the calculator's defaults.

curl "https://calcbright.com/api/calc/mortgage-calculator?price=350000&down=10&rate=6.5&years=30"
curl "https://calcbright.com/api/calc/tip-calculator?bill=84&tip=18&people=3"
curl "https://calcbright.com/api/calc/unit-converter?value=5&from=feet&to=meters"

Responses contain summary (plain-text answer), result (structured data), inputs, and a url to the full calculation. The complete list of tools and parameters is in the OpenAPI 3.1 spec (works with GPT Actions, LangChain and most agent frameworks).

3. For crawlers and LLMs

• /llms.txt – site map for language models; /llms-full.txt – every tool with its formula and quick answer.
• /sitemap.xml – all pages. AI crawlers are welcome (see robots.txt).

Fair use

The API is free for personal, educational and commercial use. Please link to the result url when you show results to people, cache where you can, and keep traffic reasonable. Results are estimates, not financial, tax or medical advice. Questions: [email protected].