Same PRD, four stacks, zero LLM calls — and EU AI Act Annex IV from the same spec

#specdriven #fastapi #flask #euaiact

Last month I published spec-driven development across NestJS, Go, Spring Boot, Laravel, and Rust. This follow-up narrows to the four stable web stacks and adds the compliance angle teams are asking about before August 2, 2026.

The problem with prompt-driven codegen

Re-prompt the same PRD in Cursor or Copilot and you get different schemas, auth bugs, and divergent APIs. For demos that's fine. For production and regulatory documentation, it's a liability.

Spec-to-application treats the PRD as a formal model and compiles it — same input, same output, no LLM in the generation step.

Try it in 90 seconds

git clone https://github.com/Anioko/spec-driven-development.git
cd spec-driven-development
chmod +x demo.sh
./demo.sh           # FastAPI (default)
./demo.sh flask
./demo.sh django
./demo.sh nestjs    # requires Node 18+

Each command runs the same examples/sample-prd.md through a deterministic pipeline:

PRD → manifest → genome → stack-native app → directory/ZIP

No API key. No "it depends on the model."

Where this sits vs GitHub Spec Kit

Tier	What it does
Agent workflow (Spec Kit, Kiro)	Spec files guide an LLM to edit your repo
Spec compiler (archiet-microcodegen)	Spec compiles into a new bootable application

Full comparison: archiet.com/vs/spec-kit and the SDD guide on GitHub.

EU AI Act: same genome, code + Annex IV

If you're building high-risk AI for the EU market, Annex IV technical documentation is the bottleneck — not the framework choice.

Free risk classifier — https://archiet.com/tools/eu-ai-act-risk-classifier

Same blueprint that emits Flask/NestJS/etc. also emits compliance/eu_ai_act/article_11_technical_documentation.md
Traceability — Annex IV §2 rows link to routes, entities, tests (Flask example)
Stack boilerplate pages: Flask · FastAPI · Django · NestJS

Open source vs platform

Open source (archiet-microcodegen)	Platform (archiet.com)
Deterministic PRD → one stack	15 stacks + frontend + mobile
Bootable API scaffold	Delivery gates, compliance overlays
demo.sh	Professional+ Annex IV bundle