Common Technology Platform

The Common Technology Platform spec records the shared substrate every Constellation module sits on — the Next.js framework decision, the unified technology stack, the shared @constellation-platform/* package architecture, and the repository strategy that keeps modules consistent without coupling them.

Status: v1.0 — Most of this document's content has since been distilled into the active engineering pages on this site (see "Where to read what" below). The full spec is preserved on GitHub for reference.

What's in the document

• §1. Purpose — why this spec exists and how it differs from the per-module specs.
• §2. Technology Stack Summary — the canonical stack (Next.js 16, Postgres 16, Prisma, Zod, Vitest, etc.).
• §3. Framework Decision: Next.js 16 — why Next.js + App Router, alternatives considered.
• §4. Unified Technology Decisions — auth, persistence, events, jobs, tracing, testing — one decision per concern.
• §5. Shared Package Architecture — the @constellation-platform/* package taxonomy and what each owns.
• §6. Repository Strategy — Turborepo monorepo layout, app-vs-package boundaries.
• §7. The @constellation-platform/ai Package — when to extract, how ai-core / ai-embeddings / ai-rag compose.
• §8. Catalog Module Feature Roadmap — historical record of the Stella merger.
• §9. Decision Summary — the table of canonical decisions.
• §10. Open Questions — any outstanding items at the time of writing.

Where to read what

Most of the load-bearing detail has been distilled into the active engineering pages on this site. Reach for those first:

If you want	Read this
The canonical decision table	Architecture overview — "Canonical Architecture Decisions"
The shared-package surface and when to use what	Shared packages
The platform invariants every layer enforces	Rules & invariants
The runtime sequence one request takes	Request lifecycle

If you want the document as it was originally written, the full source is in the monorepo at docs/constellation/specs/common-technology-platform.md.