managarten/apps/picture/CLAUDE.md

Picture App - CLAUDE.md

AI image generation app using Replicate API with freemium credit system.

Project Structure

apps/picture/
├── apps/
│   ├── backend/     # NestJS API (port 3006)
│   ├── mobile/      # Expo React Native app
│   ├── web/         # SvelteKit web app
│   └── landing/     # Astro marketing page
└── packages/        # Shared code

Quick Start

# From monorepo root
pnpm dev:picture:full    # Start backend + web + auto DB setup

# Individual apps
pnpm --filter @picture/backend dev    # Backend only (port 3006)
pnpm --filter @picture/web dev        # Web only
pnpm --filter @picture/mobile dev     # Mobile only

Backend Architecture

Key Services

Service	Purpose
GenerateService	AI image generation with freemium/credit logic
ReplicateService	Replicate API integration
StorageService	MinIO/S3 storage via @manacore/shared-storage
CreditClientService	Credit system via @mana-core/nestjs-integration

Freemium Model

• Free tier: 3 free generations per user
• Paid tier: 10 credits per generation
• Enforcement: Only in staging (NODE_ENV=staging)
• Development: Fail-open (no credit enforcement)

Environment Variables

Variable	Description	Required
REPLICATE_API_TOKEN	Replicate API key	Yes
DATABASE_URL	PostgreSQL connection	Yes
S3_ENDPOINT	MinIO/S3 endpoint	Yes
MANA_CORE_AUTH_URL	Auth service URL	Yes
MANA_CORE_SERVICE_KEY	Service key for credits	Staging only
APP_ID	App identifier	Yes

---

TODO List

Testing Required

• Test freemium flow with new user

  • Create new user ID and verify 3 free generations work
  • Verify freeGenerationsRemaining decrements correctly (3 → 2 → 1 → 0)
  • Verify 4th generation still works in development (fail-open)

• Test staging credit enforcement

  • Set NODE_ENV=staging and test credit check
  • Verify HTTP 402 returned when credits insufficient
  • Test with valid MANA_CORE_SERVICE_KEY

• Test async generation (webhook mode)

  • Test generation without waitForResult: true
  • Verify webhook receives completion callback
  • Verify credits consumed on webhook success

• Test error handling

  • Test with invalid model ID
  • Test with invalid Replicate API token
  • Test storage upload failures

• Integration tests

  • Write Jest tests for GenerateService
  • Mock CreditClientService calls
  • Test all generation paths (free/paid, sync/async)

Features to Implement

• Add credit balance endpoint

  • GET /api/v1/credits/balance - Return user's credit balance
  • Use CreditClientService.getBalance()

• Add generation history endpoint

  • GET /api/v1/generate/history - User's generation history
  • Include credits used per generation

• Improve error messages

  • Add proper error codes for credit failures
  • Return helpful messages for insufficient credits

• Rate limiting

  • Add rate limits for generation endpoints
  • Prevent abuse of free tier

Web App Tasks

• Show free generations remaining

  • Display counter in UI
  • Show warning when approaching limit

• Credit purchase flow

  • Integrate with mana-core credit purchase
  • Show credit balance in header

• Generation queue UI

  • Show pending generations
  • Poll for status updates

Mobile App Tasks

• Implement generation screen

  • Model selection
  • Prompt input with suggestions
  • Generation progress indicator

• Gallery view

  • Grid view of user's generated images
  • Favorites functionality

DevOps Tasks

• Staging deployment

  • Deploy backend to staging server
  • Configure MANA_CORE_SERVICE_KEY in staging
  • Test credit system end-to-end

• Monitoring

  • Add logging for credit operations
  • Track generation success/failure rates
  • Monitor Replicate API usage

---

API Endpoints

Generate

# Generate image (sync)
POST /api/v1/generate
{
  "prompt": "A beautiful sunset",
  "modelId": "uuid",
  "waitForResult": true
}

# Check status
GET /api/v1/generate/:id/status

# Cancel generation
DELETE /api/v1/generate/:id

# Webhook (internal)
POST /api/v1/generate/webhook

Models

GET /api/v1/models         # List all models
GET /api/v1/models/:id     # Get model details

Images

GET /api/v1/images         # List user's images
GET /api/v1/images/:id     # Get image details
DELETE /api/v1/images/:id  # Delete image

---

Recent Changes

2025-12-10: Credit System Integration

• Added @mana-core/nestjs-integration for credit system
• Implemented freemium model (3 free, then 10 credits)
• Credit enforcement only in staging environment
• Updated GenerateService with checkGenerationAccess()
• Response includes freeGenerationsRemaining count