Multiplication Chart Printable

Site: https://multiplicationchartprintable.app/
Primary tool: https://multiplicationchartprintable.app/
API documentation: https://multiplicationchartprintable.app/api/

Summary
- Multiplication Chart Printable is a static chart generator for classroom-ready multiplication tables.
- It generates printable reference charts, blank charts, and practice worksheets.
- The production site currently exposes a stable URL parameter contract for chart configuration.
- Direct JSON and server-side PDF endpoints described below are a proposed v1 contract for future Agent/API support.

Available today: URL configuration contract
- Base URL: /
- Method: GET
- Output: interactive HTML page with live preview and browser-side PDF download.

Supported query parameters
- size: integer. Allowed presets: 5, 10, 12, 15, 20, 25, 30, 50, 100.
- start: integer. Inclusive start value. Valid range: 0 to size - 1.
- orient: portrait | landscape.
- mode: reference | blank | practice.
- missing: integer. Practice mode blank percentage. Valid range: 10 to 90, step 5.
- focus: comma-separated integers. Optional focus numbers for practice mode.
- theme: bw | rows | squares | rainbow | contrast.
- font: standard | nunito | dyslexic.
- rpp: integer. Rows per page. Allowed values: 0, 10, 12, 15, 20, 25, 50. 0 means all rows on one page.
- cpp: integer. Columns per page. Allowed values: 0, 10, 12, 15, 20, 25, 50. 0 means all columns on one page.
- title: string. Optional chart title.
- subtitle: string. Optional subtitle or student name/date line.

Normalization rules
- Unknown parameters should be ignored.
- Invalid enum values should fall back to defaults.
- Invalid numeric values should clamp to the nearest allowed value or default.
- If start >= size, start should be normalized to size - 1.
- If mode is not practice, missing and focus should be accepted but have no effect on rendered holes.

Examples
- https://multiplicationchartprintable.app/?size=12&start=1&orient=portrait&mode=reference&theme=bw&font=standard
- https://multiplicationchartprintable.app/?size=20&start=1&orient=landscape&mode=blank&rpp=10&cpp=10
- https://multiplicationchartprintable.app/?size=30&start=11&orient=landscape&mode=practice&missing=40&focus=7,8,9&theme=rows&rpp=10&cpp=10

Recommended Agent workflow today
1. Build a canonical share URL using the supported query parameters.
2. Open the URL in a browser context if visual verification is needed.
3. Use the on-page Download PDF action for final export.
4. Prefer landscape for larger charts and use rpp/cpp for multi-page output.

Planned v1 Agent/API contract
- Status: proposed, not yet live as a production HTTP API.
- Goal: allow Agents to generate config metadata, preview data, and PDF files without browser clicking.

Proposed endpoints
- GET /api/v1/config
- GET /api/v1/preview
- GET /api/v1/pdf

Common request parameters for proposed endpoints
- size, start, orient, mode, missing, focus, theme, font, rpp, cpp, title, subtitle
- Semantics should match the URL configuration contract above.

Proposed JSON response: /api/v1/config
```json
{
  "version": "1.0",
  "requestId": "req_01hxyz...",
  "normalized": {
    "size": 20,
    "start": 1,
    "orient": "landscape",
    "mode": "reference",
    "missing": 50,
    "focus": [],
    "theme": "bw",
    "font": "standard",
    "rpp": 10,
    "cpp": 10,
    "title": "Multiplication Chart",
    "subtitle": "Name: _________________________  Date: _______________"
  },
  "derived": {
    "rowCount": 20,
    "columnCount": 20,
    "pageCount": 4,
    "tiles": [
      { "page": 1, "rStart": 1, "rEnd": 10, "cStart": 1, "cEnd": 10 },
      { "page": 2, "rStart": 1, "rEnd": 10, "cStart": 11, "cEnd": 20 },
      { "page": 3, "rStart": 11, "rEnd": 20, "cStart": 1, "cEnd": 10 },
      { "page": 4, "rStart": 11, "rEnd": 20, "cStart": 11, "cEnd": 20 }
    ],
    "filename": "multiplication-chart-landscape-1-20-r10-c10.pdf"
  },
  "links": {
    "share": "https://multiplicationchartprintable.app/?size=20&start=1&orient=landscape&mode=reference&theme=bw&font=standard&rpp=10&cpp=10",
    "preview": "https://multiplicationchartprintable.app/api/v1/preview?size=20&start=1&orient=landscape&mode=reference&theme=bw&font=standard&rpp=10&cpp=10",
    "pdf": "https://multiplicationchartprintable.app/api/v1/pdf?size=20&start=1&orient=landscape&mode=reference&theme=bw&font=standard&rpp=10&cpp=10"
  },
  "warnings": []
}
```

Proposed JSON response: /api/v1/preview
- Returns normalized config plus lightweight page metadata for Agent inspection.
- May optionally return SVG or HTML fragments per page in a future version.

Proposed binary response: /api/v1/pdf
- Content-Type: application/pdf
- Content-Disposition: attachment; filename="multiplication-chart-landscape-1-20-r10-c10.pdf"

Proposed error model
- Error format: application/json
- Fields: error.code, error.message, error.details, requestId
- Recommended codes:
  - invalid_parameter
  - invalid_enum
  - out_of_range
  - unsupported_combination
  - rate_limited
  - export_failed
  - internal_error

Agent guidance
- Prefer /api/v1/config for validation before requesting PDF output.
- Treat share URLs as the canonical, portable representation of a chart request.
- If an endpoint is unavailable, fall back to building the share URL and using the browser UI.
- Keep title and subtitle concise for best print results.

Human support
- Product documentation: https://multiplicationchartprintable.app/api/