API & MCP

Everything a person can do on Fun & games, a program or AI agent can do with the same inputs and get the identical result.

HTTP API

• GET https://fun.usefulweb.site/api/v1/tools – catalog
• GET https://fun.usefulweb.site/api/v1/tools/{id} – inputs, output schema, examples
• POST https://fun.usefulweb.site/api/v1/tools/{id}/calculate – run a tool
• GET https://fun.usefulweb.site/api/v1/workflows · POST https://fun.usefulweb.site/api/v1/workflows/{id}/run
• OpenAPI 3.1: /openapi.json · /openapi.yaml
• Errors: application/problem+json; 422 includes per-field errors.

Every result contains

inputs (normalised, defaults applied), summary, result (validated against the published schema), units, assumptions, sources, warnings, computedAt and links.

MCP (Model Context Protocol)

• Streamable HTTP endpoint: https://fun.usefulweb.site/mcp – protocol revisions 2026-07-28 (stateless) and 2025-11-25 / 2025-06-18 / 2025-03-26 (initialize handshake).
• Tools: chore_roulette, elo_glicko_rating_lab, emoji_cipher_playground, equation_art_studio, keyboard_heatmap_visualizer, runtime_marathon_planner, movie_night_consensus_picker, padel_pickleball_scheduler, password_entropy_race, regex_golf_arena, sports_what_if_simulator, tournament_bracket_maker
• Local stdio connector: node src/mcp-stdio.ts

{
  "mcpServers": {
    "usefulweb": { "type": "http", "url": "https://fun.usefulweb.site/mcp" }
  }
}