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42cal in ChatGPT

Ask ChatGPT about a race and it answers from 42cal: dates, entry prices, elevation, weather and crowds, with a link to the race page. The 42cal calculators work there too.

The 42cal card in ChatGPT for the New York City Marathon: Sunday, November 1, 2026, 52°F, 807 ft of elevation gain, 55K participants, crowd rating 10 out of 10, entry from $295.

Things to ask

  • “Half marathons in the US this November”
  • “Tell me about the New York City Marathon”
  • “Find me a fast marathon in North America in 3–6 months, under $1,200 for entry and hotel”
  • “I ran a 1:45 half. What could I run in a marathon?”

Add it to ChatGPT

  1. 1. On chatgpt.com, open Plugins and choose Add → Create MCP App. This needs ChatGPT Plus or Pro.
  2. 2. Name it 42cal and paste this address as the server URL:
    https://www.42cal.com/api/mcp
  3. 3. Set authentication to No authentication, confirm, and create it.
  4. 4. In a new chat, type @42cal before your question.

No account or sign-in. 42cal sees only the question ChatGPT passes to it, never your chat history. What the plugin receives