Extension Plan: Canva Interop (Import MVP Projects into Canva)

CI-0. Interop requirements lock

CI-0.1 Define “Canva-compatible export” modes
- CI-0.1.1 Mode A (manual): user downloads .pptx / .pdf and uploads to Canva
- CI-0.1.2 Mode B (direct): “Send to Canva” via Canva Connect Design Import API (canva.dev)
CI-0.2 Set primary export target
- CI-0.2.1 Primary: PPTX
- CI-0.2.2 Secondary: PDF
CI-0.3 Define supported MVP element set for “editable-in-Canva” guarantee
- CI-0.3.1 Text (single box, no path text)
- CI-0.3.2 Shapes (rect/roundrect/ellipse/line)
- CI-0.3.3 Images (placed + cropped)
- CI-0.3.4 Groups (flatten to children for export unless grouping supported)
- CI-0.3.5 Background (solid color or image)
CI-0.4 Define “flattening policy” (auto-rasterize unsupported features)
- CI-0.4.1 Effects: blur, complex shadows, blend modes → rasterize element
- CI-0.4.2 Gradients/pattern fills → rasterize element (unless verified editable)
- CI-0.4.3 Masks/frames → rasterize masked result
CI-0.5 Create a fixed “Canva Import Compatibility Test Pack” document
- CI-0.5.1 1 page: text styling matrix
- CI-0.5.2 1 page: shapes matrix
- CI-0.5.3 1 page: images + crop matrix
- CI-0.5.4 1 page: layering + transparency matrix
- CI-0.5.5 1 page: mixed stress test (50+ objects)

CI-1.1 Add Export entry point
- CI-1.1.1 Top bar: Export → Export for Canva
- CI-1.1.2 Options: PPTX (recommended), PDF
CI-1.2 Add export settings panel
- CI-1.2.1 Pages: current page / all pages
- CI-1.2.2 Scale: 1x / 2x
- CI-1.2.3 Text handling: “Keep text editable” (default on)
- CI-1.2.4 Fallback: “Rasterize text” (toggle)
- CI-1.2.5 Flattening: “Auto-flatten unsupported features” (default on)
- CI-1.2.6 Font substitution policy: “Use Canva-safe fonts” (toggle)
CI-1.3 Implement export preflight scanner (runs before file generation)
- CI-1.3.1 Traverse document model and collect unsupported features, fonts, images, counts
- CI-1.3.2 Preflight report: editable list, flattened list (ids), layout warnings
- CI-1.3.3 Controls: Continue / Cancel / “Export with more flattening”
CI-1.4 Export delivery options
- CI-1.4.1 Download file
- CI-1.4.2 (Optional, if CI-5 enabled) Send to Canva

CI-2.1 Package packages/export-pptx
- exportPptx(doc, options) -> Uint8Array
- preflightPptx(doc) -> Report
- mapFonts(fonts) -> FontMap
CI-2.2 Geometry/units
- Choose DPI (e.g., 96); helpers pxToIn/pxToPt/pxToEmu
- Slide sizing: presets → layout; custom sizes supported
- Rotation around center; bbox matches selection
CI-2.3 Element mapping
- Background: solid or image as base layer
- Shapes: rect/roundrect/ellipse/line; stroke/fill; opacity else flatten
- Text: textbox, map font/size/color/align/lineHeight; warn letterSpacing; rotation ok
- Images: embed bytes; native crop if supported else bake; opacity else bake
- Groups: flatten to children with composed transforms
- Z-order: ascending z; background first
CI-2.4 Font strategy
- Canva-safe font list; fallback map; warn missing fonts; option to rasterize all text
CI-2.5 QA
- Unit tests: conversions, transforms, z-order
- Golden exports from CI-0.5 pack (property assertions)
- Manual Canva import checklist; target ≥95% editable (excluding intentional flatten)

CI-3.1 Package packages/export-pdf
- exportPdf(doc, options) -> Uint8Array
- preflightPdf(doc) -> Report
CI-3.2 Rendering strategies (flagged)
- Vector-first: draw shapes/text/images directly
- Browser-rendered: headless print of HTML/SVG/canvas
CI-3.3 Multi-page sizing: per-page PDFs, exact dims, optional bleed/trim
CI-3.4 Canva editability checklist: keep text vector, flatten risky constructs, warn
CI-3.5 QA: run CI-0.5 pack; verify editability on Canva import

CI-4.1 Document-level “Canva Compatibility Mode”
- Disable/flag unsupported effects; enforce safe fonts/solid fills; auto-flatten
CI-4.2 Element-level rules (must have tests)
- Text: single-style runs; letter spacing/shadows flatten or warn
- Shapes: solid fills; normalize unsupported strokes; gradients flatten
- Images: native crop or bake; masks flatten
- Transforms: rotation ok; skew flatten
- Blending: per-element opacity if supported; blend modes flatten
CI-4.3 Import fidelity score
- Score from preflight (% editable, % flattened, font subs); gate releases on threshold

CI-5.1 Canva app + OAuth (scope design:content:write)
CI-5.2 Backend endpoints: POST /canva/import/start, GET /canva/import/status
CI-5.3 Call Canva Design Import API (POST /rest/v1/imports, job polling)
CI-5.4 Frontend flow: Export modal “Send to Canva”, progress states, “Open in Canva”, persist doc↔design id

Docs: best-practices + supported vs flattened list
Regression: CI-0.5 pack exports on every release; invariants checked
Telemetry: export success/fail by format, preflight warnings, (if CI-5) import job latency/success