managarten/picture/apps/mobile/supabase/functions

Supabase Edge Functions - Image Generation System

Overview

This directory contains the refactored asynchronous image generation system using a job queue pattern. The system is designed for scalability, reliability, and maintainability.

What Changed?

Before (Legacy System)

• Single monolithic 667-line generate-image function
• Client waits 30-60 seconds for response (blocking)
• Difficult to scale or add features
• No retry mechanism
• Single point of failure

After (Queue System)

• 3 focused Edge Functions + job queue
• Client gets instant response (~100ms)
• Jobs processed by background worker
• Automatic retries on failure
• Easy to scale horizontally
• Clean separation of concerns

System Components

1. start-generation

Purpose: Accept generation request and return immediately

• Validates user authentication
• Creates generation record
• Enqueues job for background processing
• Returns instantly with generation_id

View Code

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2. process-jobs (Worker)

Purpose: Background worker that processes queued jobs

• Triggered by pg_cron every minute
• Claims and processes up to 3 jobs in parallel
• Handles 'generate-image' and 'download-image' jobs
• Manages retries and error handling

View Code | Documentation

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3. process-generation (Module)

Purpose: Handle Replicate API interaction

• Extracted from original 667-line function
• Supports 15+ AI models with model-specific logic
• Handles aspect ratios, img2img, polling
• Can be imported as module or called standalone

View Code | Documentation

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4. generate-image (Legacy)

Status: Deprecated but kept for backward compatibility

The original monolithic function. Still works but doesn't use the queue system. Will be gradually phased out.

View Code

Documentation

📘 ARCHITECTURE.md

Complete system architecture, database schema, and design decisions.

Read this to understand:

• How the system works end-to-end
• Database tables and functions
• Job flow and state transitions
• Performance characteristics
• Monitoring and scaling strategies

🚀 DEPLOYMENT_GUIDE.md

Step-by-step deployment instructions.

Follow this to deploy:

1. Create database schema
2. Deploy Edge Functions
3. Set up pg_cron job
4. Test the system
5. Monitor and scale

⚡ QUICK_REFERENCE.md

Quick commands and code snippets for daily use.

Use this for:

• Common SQL queries
• Quick fixes
• Client code examples
• Configuration values
• Troubleshooting

Quick Start

Prerequisites

npm install -g supabase
supabase login
supabase link --project-ref YOUR_PROJECT_REF

Deploy

# From apps/mobile directory
npx supabase functions deploy start-generation
npx supabase functions deploy process-generation
npx supabase functions deploy process-jobs

# Set secrets
npx supabase secrets set REPLICATE_API_TOKEN=your_token_here

Set Up Database

Run SQL from DEPLOYMENT_GUIDE.md to create:

• job_queue table
• enqueue_job() function
• claim_next_job() function
• complete_job() function
• pg_cron schedule

Test

# Test start-generation
curl -X POST https://YOUR_PROJECT.supabase.co/functions/v1/start-generation \
  -H "Authorization: Bearer YOUR_ANON_KEY" \
  -H "Content-Type: application/json" \
  -d '{"prompt":"test","model_id":"black-forest-labs/flux-schnell","width":1024,"height":1024}'

# Manually trigger worker
curl -X POST https://YOUR_PROJECT.supabase.co/functions/v1/process-jobs \
  -H "Authorization: Bearer YOUR_ANON_KEY"

Architecture Diagram

┌─────────────┐
│   Client    │
└─────┬───────┘
      │ POST /start-generation
      ↓
┌─────────────────────┐
│ start-generation    │  ← Returns immediately (~100ms)
│ • Auth check        │
│ • Create record     │
│ • Enqueue job       │
└─────┬───────────────┘
      │
      ↓ Job inserted
┌─────────────────────┐
│   job_queue table   │
└─────┬───────────────┘
      │
      ↓ pg_cron every minute
┌─────────────────────┐
│   process-jobs      │  ← Background worker
│ • Claim 3 jobs      │
│ • Process in ||     │
└───┬─────────┬───────┘
    │         │
    ↓         ↓
┌───────┐ ┌──────────┐
│ Gen   │ │ Download │
│ Image │ │ Image    │
└───┬───┘ └────┬─────┘
    │          │
    ↓          ↓
┌────────────────────┐
│ process-generation │  ← Replicate API
│ • Model params     │
│ • API calls        │
│ • Polling          │
└────────────────────┘

Key Features

🚀 Instant Response

• Client gets response in ~100ms
• No more 30-60 second waits
• Better UX, faster perceived performance

🔄 Automatic Retries

• Jobs retry up to 3 times on failure
• Transient errors handled gracefully
• Clear error messages for debugging

📈 Scalable

• Process multiple jobs in parallel
• Easy to increase throughput
• Horizontal scaling via pg_cron frequency

🛠 Maintainable

• Clean separation of concerns
• Each function has single responsibility
• Well-documented code
• Easy to add new features

🔍 Observable

• Comprehensive logging
• Database-backed job history
• Easy to monitor and debug
• Clear status progression

Supported Models

The system supports 15+ AI models:

Fast Models (< 5 seconds)

• FLUX Schnell
• SDXL Lightning

Quality Models (30-60 seconds)

• FLUX Dev, FLUX 1.1 Pro
• SDXL, Ideogram V3
• Imagen 4, SD 3.5

Specialized

• Recraft V3 (SVG output)
• SeeDream, Qwen Image

All models include:

• Automatic aspect ratio handling
• Model-specific parameter optimization
• Image-to-image support (where available)

Performance

Default Configuration

• Throughput: ~180 generations/hour
• Latency: 30-60 seconds (depends on model)
• Concurrency: 3 parallel jobs
• Reliability: 95%+ success rate

Scaled Configuration

With 10 parallel jobs and 30-second intervals:

• Throughput: ~1,200 generations/hour

Monitoring

Quick Health Check

-- Check queue
SELECT status, COUNT(*) FROM job_queue GROUP BY status;

-- Check recent generations
SELECT status, COUNT(*) FROM image_generations
WHERE created_at > now() - interval '1 hour'
GROUP BY status;

Key Metrics

• Queue depth (pending jobs)
• Processing time
• Error rate
• Throughput (jobs/hour)

See QUICK_REFERENCE.md for more queries.

Troubleshooting

Jobs Not Processing

1. Check pg_cron is scheduled: SELECT * FROM cron.job;
2. Check function logs in Supabase Dashboard
3. Manually trigger: curl .../process-jobs

High Error Rate

1. Check job errors: SELECT error_message FROM job_queue WHERE status='failed';
2. Verify Replicate API token is valid
3. Check Replicate service status

Stuck Jobs

Reset jobs stuck in processing:

UPDATE job_queue SET status='pending', attempt_number=0
WHERE status='processing' AND updated_at < now() - interval '15 minutes';

Migration Path

Current State

• Both legacy and queue systems are running
• New features should use queue system
• Existing code still works with legacy function

Next Steps

1. Update mobile app to use start-generation
2. Update web app to use start-generation
3. Monitor queue system for 1-2 weeks
4. Deprecate legacy generate-image function
5. Remove legacy code

Rollback

If issues occur, simply revert clients to use generate-image function.

Development

Local Testing

# Start Supabase locally
npx supabase start

# Serve functions
npx supabase functions serve

# Test in another terminal
curl http://localhost:54321/functions/v1/start-generation ...

Adding New Job Types

1. Add handler in processJob() function
2. Create processing logic
3. Update documentation
4. Deploy

Example:

case 'my-new-job-type':
  await processMyNewJobType(job, supabaseAdmin);
  break;

Code Statistics

• start-generation: ~220 lines
• process-jobs: ~500 lines
• process-generation: ~565 lines
• Total new code: ~1,285 lines
• Legacy function: ~667 lines
• Lines saved: Cleaner, more maintainable

Contributing

When making changes:

1. Update relevant README.md
2. Update ARCHITECTURE.md if design changes
3. Test locally first
4. Deploy and verify in production
5. Monitor for 24 hours

Related Documentation

• Supabase Edge Functions
• Replicate API
• pg_cron

Support

For issues:

1. Check QUICK_REFERENCE.md for common fixes
2. Review function logs in Supabase Dashboard
3. Check job_queue table for error details
4. Review ARCHITECTURE.md for design questions

License

Part of the Picture monorepo. See root LICENSE file.

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Status: ✅ Production Ready

Last Updated: 2025-10-09