red/.planning/phases/13-ai-field-placement-and-pre-fill/13-01-SUMMARY.md

phase, plan, subsystem, tags, requires, provides, affects, tech-stack, key-files, key-decisions, patterns-established, requirements-completed, duration, completed

phase	plan	subsystem	tags	requires	provides	affects	tech-stack	key-files	key-decisions	patterns-established	requirements-completed	duration	completed
13-ai-field-placement-and-pre-fill	01	ai	openai pdfjs-dist coordinate-conversion tdd gpt-4o-mini structured-output	phase provides 12.1-per-field-text-editing-and-quick-fill textFillData keyed by field UUID, DocumentPageClient state architecture phase provides 10-expanded-field-types-end-to-end SignatureFieldType union, SignatureFieldData interface	extractPdfText(filePath) — pdfjs-dist server-side text extraction returning PageText[] aiCoordsToPagePdfSpace() — AI top-left pct to PDF bottom-left points with Y-axis flip classifyFieldsWithAI() — GPT-4o-mini structured output call returning SignatureFieldData[] + textFillData AiFieldCoords interface Unit test for coordinate conversion (3 cases, US Letter dimensions)	13-02-ai-route 13-03-ui-button 13-04-integration-test	added patterns openai@6.32.0 pdfjs-dist legacy build with GlobalWorkerOptions.workerSrc='' for Node.js server-side use Manual json_schema response_format with strict=true (NOT zodResponseFormat — broken with Zod v4) Standard field sizes override AI dimensions (checkbox=24x24pt, others=144x36pt) textFillData keyed by crypto.randomUUID() field ID (not label)	created modified teressa-copeland-homes/src/lib/ai/extract-text.ts teressa-copeland-homes/src/lib/ai/field-placement.ts teressa-copeland-homes/src/lib/pdf/__tests__/ai-coords.test.ts teressa-copeland-homes/package.json (openai dependency added) teressa-copeland-homes/package-lock.json	openai 6.32.0 installed as production dependency (not devDependency) GlobalWorkerOptions.workerSrc = '' required for Node.js server-side pdfjs-dist — do NOT share with browser components Manual json_schema response_format confirmed required — zodResponseFormat broken with Zod v4 (issues #1540 #1602 #1709) Standard field sizes (checkbox=24x24, others=144x36pt) override AI widthPct/heightPct for consistency textFillData keyed by UUID assigned in route handler — not by label — matches Phase 12.1 design	Pattern: lib/ai/* files carry // server-only guard comment — never imported from client components Pattern: aiCoordsToPagePdfSpace is the single named utility for AI-to-PDF coord conversion — replicated from FieldPlacer.tsx formula	AI-01 AI-02	2min	2026-03-21

Phase 13 Plan 01: AI Field Placement Foundation Summary

openai SDK installed, pdfjs-dist server-side text extraction module, and GPT-4o-mini structured output field classifier with Y-axis-flip coordinate conversion verified by TDD unit tests

Performance

• Duration: 2 min
• Started: 2026-03-21T22:58:46Z
• Completed: 2026-03-21T23:01:00Z
• Tasks: 2 (TDD: RED then GREEN)
• Files modified: 5

Accomplishments

• TDD RED phase: wrote 3 failing unit tests for aiCoordsToPagePdfSpace with US Letter (612x792pt) dimensions
• TDD GREEN phase: implemented extract-text.ts and field-placement.ts passing all 3 tests
• openai 6.32.0 installed as production dependency
• TypeScript compiles without errors (npx tsc --noEmit passes)

Task Commits

Each task was committed atomically:

1. Task 1: Write failing unit test for aiCoordsToPagePdfSpace - f7d74c0 (test)
2. Task 2: Implement extract-text.ts and field-placement.ts (GREEN) - c1e1e5e (feat)

Files Created/Modified

• teressa-copeland-homes/src/lib/ai/extract-text.ts - extractPdfText() using pdfjs-dist legacy build; GlobalWorkerOptions.workerSrc='' for Node.js; PageText interface; text capped at 2000 chars/page
• teressa-copeland-homes/src/lib/ai/field-placement.ts - AiFieldCoords interface; aiCoordsToPagePdfSpace() with Y-axis flip; classifyFieldsWithAI() calling GPT-4o-mini with manual json_schema; standard field sizes; textFillData keyed by UUID
• teressa-copeland-homes/src/lib/pdf/__tests__/ai-coords.test.ts - 3 unit tests: text field near top, checkbox near bottom-right, client-sig at center
• teressa-copeland-homes/package.json - openai 6.32.0 added to dependencies

Decisions Made

• Manual json_schema response_format confirmed (NOT zodResponseFormat) — broken with Zod v4.3.6 per issues #1540, #1602, #1709; this is a locked decision from STATE.md research phase
• Standard field sizes override AI-returned widthPct/heightPct: checkbox=24x24pt, all others=144x36pt — consistent with FieldPlacer defaults, prevents poorly-sized AI fields
• textFillData built with UUID keys assigned in route handler — matches Phase 12.1 design where DocumentPageClient uses field.id as the key
• GlobalWorkerOptions.workerSrc='' set at module level in extract-text.ts — this is the Node.js fake-worker pattern; client components (PdfViewer, PreviewModal) set their own workerSrc independently

Deviations from Plan

None - plan executed exactly as written.

Issues Encountered

None.

User Setup Required

OPENAI_API_KEY must be set in .env.local before the AI auto-place feature works. The classifyFieldsWithAI() function throws 'OPENAI_API_KEY not configured' if the key is absent — this is a clear error that surfaces to the agent in the browser. No silent failures.

No other external service configuration required for this plan.

Next Phase Readiness

• Both AI utility modules exist and are importable from the server-only route handler (Plan 02)
• Coordinate conversion is unit-tested and correct for US Letter dimensions
• openai SDK ready for use in /api/documents/[id]/ai-prepare route (Plan 02)
• FieldPlacer + DocumentPageClient unchanged — Plan 03 will add the UI button and state wiring
• Blocker from STATE.md still active: AI coordinate accuracy on real Utah forms is untested — Plan 04 integration test required before Phase 13 ships to production

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Phase: 13-ai-field-placement-and-pre-fill Completed: 2026-03-21