I've been working on https://flux1kontext.io – an AI image editor that uses Black Forest Labs' FLUX.1 Kontext models for context-aware image editing.

*What it does:* Upload an image, describe what you want to change, and it modifies just that part while keeping everything else intact. Think "add sunglasses to this person" or "make the cat open its eyes" – it understands context instead of regenerating the whole image.

*Tech stack:* Next.js 19, TypeScript, Supabase, FAL.AI for model hosting, Stripe for payments, Cloudflare R2 for storage. Pretty standard SaaS setup.

*Why I built this:* Most AI image tools either generate from scratch or do crude inpainting. FLUX.1 Kontext actually understands what you're asking for and preserves the original image's composition, lighting, and style while making targeted edits.

*Current state:* - Two model tiers (Pro/Max) with different quality/speed tradeoffs - Credit-based pricing (8 credits for Pro, 16 for Max) - Works with common image formats, handles up to 10MB files - About 15-60 seconds processing time depending on complexity

*Challenges:* - Model costs are high (~$0.10-0.20 per generation), so had to implement careful credit management - FAL.AI API can be inconsistent during peak times - Balancing quality vs speed is tricky – users want both

The tech is genuinely impressive when it works. The model was trained by the same team that created Stable Diffusion, so the quality is solid. Still working on reliability and cost optimization.

Would love feedback from anyone who's worked with similar AI APIs or has thoughts on the UX. The demo works without signup if you want to try it.

Built this mostly as a learning project but it's getting decent usage (~2.5M images generated so far). Happy to answer questions about the implementation or business side.