Make printable cross sum puzzles for puzzle fans, teachers and students as a PDF with an answer key.
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Use this when the user wants printable cross-sum puzzles (cross sums, number crossword puzzles with sums, addition logic puzzles) as a PDF with an answer key, or wants to solve one on screen. Each grid from 6 x 6 to 12 x 12 (counting the clue row and column) has white squares for the digits 1 to 9 and clue squares with sums; each run of white squares adds up to its clue with no repeated digit. Put one object per puzzle in puzzles[] when they differ (size, difficulty, seed); for a set of the same kind, set count with size and difficulty. A solver checks each puzzle for one solution. The PDF has 1, 2 or 4 puzzles per page on Letter or A4, an optional title and name line, and answer pages; the card lets the user fill in digits and check them. Defaults: 1 medium 8 x 8 puzzle, Letter, 1 per page, name line and answer key on. Does not solve a puzzle from a photo or make grids larger than 12 x 12.
Starting seed; puzzle N uses seed + N - 1. Reuse it to reprint the same puzzles. Example: 2026
Grid size for all puzzles, 6 to 12 (default 8), counting the clue row and column. Example: 10
How many puzzles when they are all the same kind (1 to 12, default 1). Example: 4
letter (default, US 8.5 x 11 in) or a4. Example: a4
Title printed at the top of each page. Example: Weekend Cross Sums
One object per puzzle when the puzzles differ, e.g. [{"size":6,"difficulty":"easy"},{"size":10,"difficulty":"hard"}]. Leave out and use count for a set of the same kind. Up to 12.
Puzzles per printed page: 1 (default), 2 or 4. Example: 2
Print a Name and Date line on the puzzle pages (default true). Example: false
Add answer pages with the solved grids (default true). Example: true
Difficulty for all puzzles: easy, medium (default) or hard. Example: easy
Pick your client. Values in capitals, like YOUR_TOKEN, are yours to fill in.
Run in a terminal
claude mcp add --transport http cross-sums https://cross-sums.zovo.one/mcp
Use this when the user wants printable cross-sum puzzles (cross sums, number crossword puzzles with sums, addition logic puzzles) as a PDF with an answer key, or wants to solve one on screen. Each grid from 6 x 6 to 12 x 12 (counting the clue row and column) has white squares for the digits 1 to 9 and clue squares with sums; each run of white squares adds up to its clue with no repeated digit. Put one object per puzzle in puzzles[] when they differ (size, difficulty, seed); for a set of the same kind, set count with size and difficulty. A solver checks each puzzle for one solution. The PDF has 1, 2 or 4 puzzles per page on Letter or A4, an optional title and name line, and answer pages; the card lets the user fill in digits and check them. Defaults: 1 medium 8 x 8 puzzle, Letter, 1 per page, name line and answer key on. Does not solve a puzzle from a photo or make grids larger than 12 x 12.
| Argument | Type | Description |
|---|---|---|
| seed | number | string | null | Starting seed; puzzle N uses seed + N - 1. Reuse it to reprint the same puzzles. Example: 2026 |
| size | number | string | null | Grid size for all puzzles, 6 to 12 (default 8), counting the clue row and column. Example: 10 |
| count | number | string | null | How many puzzles when they are all the same kind (1 to 12, default 1). Example: 4 |
| paper | any | letter (default, US 8.5 x 11 in) or a4. Example: a4 |
| title | any | Title printed at the top of each page. Example: Weekend Cross Sums |
| puzzles | any | One object per puzzle when the puzzles differ, e.g. [{"size":6,"difficulty":"easy"},{"size":10,"difficulty":"hard"}]. Leave out and use count for a set of the same kind. Up to 12. |
| per_page | number | string | null | Puzzles per printed page: 1 (default), 2 or 4. Example: 2 |
| name_line | boolean | string | number | null | Print a Name and Date line on the puzzle pages (default true). Example: false |
| answer_key | boolean | string | number | null | Add answer pages with the solved grids (default true). Example: true |
| difficulty | any | Difficulty for all puzzles: easy, medium (default) or hard. Example: easy |
{
"type": "object",
"$schema": "http://json-schema.org/draft-07/schema#",
"properties": {
"seed": {
"type": [
"number",
"string",
"null"
],
"description": "Starting seed; puzzle N uses seed + N - 1. Reuse it to reprint the same puzzles. Example: 2026"
},
"size": {
"type": [
"number",
"string",
"null"
],
"description": "Grid size for all puzzles, 6 to 12 (default 8), counting the clue row and column. Example: 10"
},
"count": {
"type": [
"number",
"string",
"null"
],
"description": "How many puzzles when they are all the same kind (1 to 12, default 1). Example: 4"
},
"paper": {
"anyOf": [
{
"type": "string",
"maxLength": 30
},
{
"type": "null"
}
],
"description": "letter (default, US 8.5 x 11 in) or a4. Example: a4"
},
"title": {
"anyOf": [
{
"type": "string",
"maxLength": 200
},
{
"type": "null"
}
],
"description": "Title printed at the top of each page. Example: Weekend Cross Sums"
},
"puzzles": {
"anyOf": [
{
"type": "array",
"items": {
"type": "object",
"properties": {
"seed": {
"type": [
"number",
"string",
"null"
],
"description": "Seed for this puzzle (same seed and settings give the same puzzle). Example: 4821"
},
"size": {
"type": [
"number",
"string",
"null"
],
"description": "Grid size from 6 to 12, counting the clue row and column (8 means an 8 x 8 grid). Example: 8"
},
"difficulty": {
"anyOf": [
{
"type": "string",
"maxLength": 40
},
{
"type": "null"
}
],
"description": "easy, medium (default) or hard. Harder puzzles have longer runs and fewer clue squares. Example: hard"
}
},
"additionalProperties": {}
},
"maxItems": 12
},
{
"type": "null"
}
],
"description": "One object per puzzle when the puzzles differ, e.g. [{\"size\":6,\"difficulty\":\"easy\"},{\"size\":10,\"difficulty\":\"hard\"}]. Leave out and use count for a set of the same kind. Up to 12."
},
"per_page": {
"type": [
"number",
"string",
"null"
],
"description": "Puzzles per printed page: 1 (default), 2 or 4. Example: 2"
},
"name_line": {
"type": [
"boolean",
"string",
"number",
"null"
],
"description": "Print a Name and Date line on the puzzle pages (default true). Example: false"
},
"answer_key": {
"type": [
"boolean",
"string",
"number",
"null"
],
"description": "Add answer pages with the solved grids (default true). Example: true"
},
"difficulty": {
"anyOf": [
{
"type": "string",
"maxLength": 40
},
{
"type": "null"
}
],
"description": "Difficulty for all puzzles: easy, medium (default) or hard. Example: easy"
}
}
}We read every tool's name, description and inputs the way the model will, looking for instructions hidden from you. A clean result means no warning signs, not a guarantee. Scanned Nov 8, 2026.