What each tool does
GitHub Spec Kit structures how AI coding agents work inside your repository. Slash commands (/speckit.specify, /speckit.plan, /speckit.tasks, /speckit.implement) produce markdown artifacts that agents follow. It supports 30+ agents (Copilot, Claude Code, Gemini CLI). The spec lives in .speckit/; the agent edits your existing codebase.
Archiet (and open-source archiet-microcodegen) starts from a PRD or blueprint and emits a new application — backend, frontend, mobile, migrations, Docker, ADRs, compliance docs — as a downloadable ZIP. The spec is an Architectural Genome (formal IR). Code generation in the lowering path is deterministic, not agent-driven.
Comparison table
| Dimension | GitHub Spec Kit | archiet-microcodegen | Archiet platform | |-----------|-----------------|----------------------|------------------| | Primary output | Agent-edited repo files | Bootable app directory / ZIP | Multi-stack ZIP + handoff pack | | LLM in codegen | Yes (agent) | No | LLM only in PRD parsing | | Reproducibility | Agent-dependent | Same spec → same output | Gated deterministic pipeline | | IDE / agent required | Yes | No — CLI | Web UI | | Brownfield | Yes | No (greenfield regen) | Greenfield-first | | Stacks | Your existing stack | 10 CLIs | 15+ backend + Next.js + Expo | | Compliance docs | DIY / agent-drafted | ARCHITECTURE.md | SOC 2, GDPR, HIPAA, traceability | | Cost | Free (MIT) | Free (MIT) | Free tier + paid plans |
SDD maturity levels
| Level | Examples | LLM writes code? | |-------|----------|------------------| | 2 Spec-Anchored | Spec Kit, Kiro, BMad | Yes | | 4 Spec-to-Application | archiet-microcodegen | No |
See the full framework: SDD maturity levels on GitHub.
When to use Spec Kit
- Existing codebase; incremental features
- Team already on Cursor, Copilot, or Claude Code
- You accept agent variance for flexibility
When to use Archiet
- Greenfield product from PRD or architecture spec
- Reproducible output for audit / regulated environments
- Multi-stack from one spec (Flask, NestJS, Go, Java, …)
- Compliance artifacts generated alongside code
Complementary workflow
- Archiet — compile greenfield scaffold from PRD
- Spec Kit — iterate features with agents in that repo
- Archiet regen — when genome-level architecture changes
Spec Kit does not replace a compiler. A compiler does not replace agent-assisted iteration.
Try archiet-microcodegen (no account)
pip install archiet-microcodegen
git clone https://github.com/Anioko/spec-driven-development.git
cd spec-driven-development && ./demo.sh
CTA
Full platform: archiet.com/spec-driven-development.
Open guide: GitHub SDD repo.
FAQ
Is Archiet a Spec Kit alternative?
Different layer. Spec Kit = agent workflow. Archiet = spec compiler + platform. Many teams use both.
Does Archiet support /speckit commands?
No. Archiet uses genome editing and stack selection in the web UI, or CLI for microcodegen.
Which is better for Show HN / side projects?
Spec Kit if you live in an IDE. archiet-microcodegen if you want docker compose up from a PRD file in 90 seconds.