StackAlchemist

Write what you want in plain English. StackAlchemist hands back a compilable .NET + Next.js + Postgres SaaS — schema, API, frontend, the lot — and proves it builds before it ships.

What it is

StackAlchemist is a code-generation engine for full-stack SaaS applications. The user writes (or wizards) a brief; StackAlchemist orchestrates a .NET 10 Web API generator, a Next.js 15 App Router frontend generator, a PostgreSQL schema generator, and an infrastructure layer — all driven by the same opinionated template system and validated by an in-process compile worker.

The result is downloadable as a single zip. Unpack it, run dotnet build and npm run dev, ship it.

What it does well

Guarantees compilable output. Every generation runs dotnet build in a temp directory. If it fails, the error context goes back into the LLM for repair, up to three retries. Broken builds don't reach customers.

The Swiss Cheese Method. Static Handlebars templates carry the predictable scaffolding — Program.cs, route handlers, EF configuration, Tailwind config, Docker Compose, GitHub Actions. The LLM only fills the holes — business logic, controllers, schemas, prompts. Less surface for the model to hallucinate; more reliability for the user.

Real engineering substrate. Generated apps come with PostgreSQL Row-Level Security, Supabase auth wiring, Cloudflare R2 object storage scaffolding, Stripe Checkout + webhook handling, Testcontainers integration test scaffolding, and CI workflows. Not just a CRUD demo — a project a real team would extend.

Live progress. The frontend listens over Supabase Realtime to a generation row in Postgres. The user watches the engine cycle — extracting schema → rendering templates → calling LLM → building → repairing → packaging → uploading — in real time. Generated zips land at a presigned R2 URL valid for 168 hours.

Two entry modes. Simple Mode lets the LLM extract a JSON schema from your prompt directly. Advanced Mode opens a canvas-style schema builder (via @xyflow/react) where you wire entities and relations by hand. Both feed the same engine.

Who it's for

Founders prototyping who need a real .NET + Next.js + Postgres scaffold in an hour instead of a week.

Agencies and consultancies that ship five similar client SaaS apps a year and want the boilerplate factory to be deterministic.

Engineers exploring what the limits of LLM-generated code actually look like when the loop is closed by a real compiler.

Buyers of the Infrastructure tier who want not just code but the AWS CDK, Terraform, and Helm charts to run it.

What it looks like in practice

A solo founder describes a B2B SaaS for tracking veterinary appointments. StackAlchemist extracts entities (Practice, Vet, Patient, Appointment, Owner), generates a PostgreSQL schema with RLS scoped to practice_id, scaffolds the .NET Web API with controllers and Supabase auth, builds out the Next.js console with auth-protected routes, and validates the whole thing compiles. Twenty minutes after the brief, the founder downloads practice-tracker.zip and starts customizing.

A consultancy uses StackAlchemist as the floor of every client engagement. Generation produces the boilerplate; engineers spend their billable hours on the parts that matter.

What it's not

It's not no-code. The output is a real codebase. You still need an engineer to take it the last mile.

It's not a forever home for the codebase. Once generated, it's yours — fork, extend, deploy, regenerate as you like.

It's not a substitute for product thinking. Garbage brief in, garbage scaffold out. StackAlchemist accelerates execution; it doesn't decide what to build.

Pricing

| Tier | Price | What you get | |---|---|---| | Spark | Free | Schema capture, prompt planning — evaluation use | | Blueprint | $299 | Schema JSON, OpenAPI spec, SQL migrations, Markdown docs | | Boilerplate | $599 | Everything in Blueprint plus the full compilable codebase (zip) | | Infrastructure | $999 | Everything in Boilerplate plus AWS CDK, Terraform, Helm Charts, deployment runbook |

Status

Shipping. Live at stackalchemist.app. Powered by Claude Sonnet 4.6 and Cloudflare R2.