AI Development Process

This document records the prompt engineering, decision-making rationale, and iterative development milestones accomplished by the Google Antigravity AI pair programmer for GpxRoute°.

Session 001: Project Inception & Clean Slate Reset

• Date: 2026-08-24
• Prompt Summary: Wipe template code, preserve README, establish bespoke styling without Tailwind CSS, and document the entire architectural evolution.
• Actions Taken:
• Removed boilerplate code and dependencies.
• Initialized Next.js 16 App Router with Redux Toolkit and CSS Modules.
• Formulated the 5-Phase Technical Blueprint (docs/architecture.md, docs/roadmap.md).

Session 002: Core Design Token System & UI Primitives

• Date: 2026-08-24
• Prompt Summary: Construct bespoke CSS token system, light/dark themes, and atomic UI primitives (Button, Card, Badge, Modal).
• Actions Taken:
• Created src/styles/tokens.css with semantic variables.
• Implemented component primitives with zero external UI dependencies.

Session 003: Architectural Planning & Project Roadmap

• Date: 2026-08-24
• Prompt Summary: Align on Firestore architecture and 5-phase roadmap.

Session 004: Phase 2 GPX Engine & Mapbox 3D Visualization

• Date: 2026-08-24
• Prompt Summary: Build client-side GPX XML parser, geospatial analytics calculator, 3D Mapbox terrain engine with dynamic line gradients, cinematic camera playback controller, and synchronized interactive elevation chart.

Session 005: Phase 3 Scoped Firebase Auth & Firestore Persistence

• Date: 2026-08-24
• Prompt Summary: Integrate Firebase Auth (Google & Email) and Firestore persistence with an isolated single-collection architecture (gpxroute/app/...).

Session 006: Comprehensive Testing Suite & Quality Assurance

• Date: 2026-08-24
• Prompt Summary: Introduce exhaustive automated testing: Vitest unit testing, React Testing Library component integration, and Playwright E2E browser testing.
• Actions Taken: Built 6 test suites with 41 passing tests and `docs/testing.md`.

Session 007: Phase 4 Social Share Cards & Resend Emails

• Date: 2026-08-24
• Prompt Summary: Implement high-resolution client-side HTML5 Canvas Social Card Generator (9:16 Story, 16:9 Landscape, 1:1 Square), interactive multi-tab Share Modal with QR code for mobile scanning, and Resend transactional email share API.
• Actions Taken: Built social card engine, email client, /api/email/share, and ShareModal.tsx with 50 passing tests.

Session 008: Design System Transformation (Swiss Modernist & Zero-Radius Geometry)

• Date: 2026-08-24
• Prompt Summary: Overhaul the entire look and feel: reject dark cyber glows and rounded corners in favor of a clean, light, architectural, Swiss-inspired aesthetic with strict 0px geometry and permanent light mode.

Session 009: Phase 5 Stripe Monetization & Production Polish

• Date: 2026-08-24
• Prompt Summary: Implement Stripe Checkout Sessions (/api/stripe/checkout), cryptographic HMAC Webhook verification (/api/stripe/webhook), Pro Tier perks, UpgradeModal.tsx, and final production verification.

Session 010: Advanced Capabilities & CI/CD Pipeline

• Date: 2026-08-24
• Prompt Summary: Implement Catmull-Rom smooth 3D drone camera tracking, 3D terrain split & summit flags, WebGL 60FPS video flyover export, Strava OAuth activity ingestion, and automated GitHub Actions CI/CD.
• Actions Taken:
• Built src/lib/geo/splineInterpolator.ts for Catmull-Rom cubic spline interpolation.
• Built src/lib/video/flyoverRecorder.ts for client-side WebGL canvas 60FPS video recording.
• Built src/lib/strava/stravaClient.ts with @mapbox/polyline decoding and /api/auth/strava + /api/strava/callback + /api/strava/activities.
• Built StravaSyncModal.tsx for 1-click athlete sync.
• Configured .github/workflows/ci.yml and vercel.json.
• Added unit test suites (spline.test.ts, strava.test.ts).
• Verification:
• Ran pnpm test — 62 / 62 tests passing across 12 test suites.
• Ran pnpm test:e2e — 10 / 10 Playwright E2E browser tests passing.
• Ran pnpm build — Zero errors, 8 dynamic & static routes compiled.