Free number puzzles by API and MCP.

Original Cage Grids (4×4 to 6×6, exactly one solution each), Target puzzles and Brick Pyramids at three levels, as JSON or printable SVG, with solutions. For puzzle apps, classroom tools, newsletters and AI agents. No key, 30 calls a minute.

Live example: /v1/puzzle.svg?type=cage&level=easy&seed=demo

JSON

curl "https://sumbloom.cybermax-tools.workers.dev/v1/puzzle?type=cage&level=medium&seed=abc"
curl "https://sumbloom.cybermax-tools.workers.dev/v1/puzzle?type=target&daily=true"

Printable SVG

https://sumbloom.cybermax-tools.workers.dev/v1/puzzle.svg?type=pyramid&level=hard&solution=true

MCP (Claude, Cursor, any MCP client)

{"mcpServers":{"sumbloom-puzzles":{"url":"https://sumbloom.cybermax-tools.workers.dev/mcp"}}}

Tool: get_number_puzzle(type, level, seed?, daily?, include_solution?) · OpenAPI · llms.txt · Status

Need them on paper? The Sumbloom Puzzle Book has 120 puzzles with every answer, US Letter + A4, classroom copies included, for $5. Get the book

Example response

{
 "id": "cage-easy-89",
 "type": "cage",
 "name": "Cage Grid",
 "level": "easy",
 "seed": "demo",
 "rules": "Fill the NxN grid so every row and column holds 1..N once. The numbers in each cage must make its clue with the sign shown (- and / work in either order). A clue with no sign is that number.",
 "puzzle": {
  "size": 4,
  "cages": [
   {
    "cells": [
     [
      3,
      0
     ],
     [
      3,
      1
     ],
     [
      3,
      2
     ]
    ],
    "op": "+",
    "target": 8,
    "clue": "8+"
   },
   {
    "cells": [
     [
      0,
      0
     ],
     [
      0,
      1
     ]
    ],
    "op": "-",
    "target": 1,
    "clue": "1−"
   },
   {
    "cells": [
     [
      1,
      2
     ],
     [
      1,
      3
     ]
    ],
    "op": "/",
    "target": 2,
    "clue": "2÷"
   },
   {
    "cells": [
     [
      2,
      1
     ],
     [
      1,
      1
     ],
     [
      2,
      2
     ]
    ],
    "op": "*",
    "target": 12,
    "clue": "12×"
   },
   {
    "cells": [
     [
      1,
      0
     ],
     [
      2,
      0
     ]
    ],
    "op": "+",
    "target": 5,
    "clue": "5+"
   },
   {
    "cells": [
     [
      0,
      2
     ],
     [
      0,
      3
     ]
    ],
    "op": "+",
    "target": 7,
    "clue": "7+"
   },
   {
    "cells": [
     [
      2,
      3
     ],
     [
      3,
      3
     ]
    ],
    "op": "-",
    "target": 1,
    "clue": "1−"
   }
  ]
 },
 "svg": "https://sumbloom.cybermax-tools.workers.dev/v1/puzzle.svg?type=cage&level=easy&seed=demo",
 "more": {
  "book": "https://cybermax-tools-cybermax.static.hf.space/sumbloom-book/index.html",
  "buy": "https://data.cybermax-tools.workers.dev/buy/sumbloom-book?s=api-json",
  "note": "120 more puzzles like this, printable with answers: Sumbloom Puzzle Book ($5, classroom copies included)."
 }
}