db — Architecture

The @mnemose/db package is the data-access layer for Mnemose. It owns the Drizzle ORM schema for every Postgres table (event store + read models), the migrations directory, the createDb() client factory, and re-exports commonly used Drizzle query operators.

Responsibilities

• Define the Drizzle schema for all tenant-scoped tables (kernels, sessions, sandbox, KMS, IAM, SEO, etc.) and the append-only domain_events event store
• Provide createDb(connectionString) returning a typed DbClient (Drizzle + Postgres)
• Ship migrations under src/migrations/ (applied by jobs/db-migrate)
• Re-export eq, and, desc, sql, … so resolvers and handlers import query operators from a single package

Key Components

File / Dir	Role
src/client.ts	createDb() factory + DbClient type (Drizzle + Postgres connection)
src/schema/index.ts	Re-exports every table schema
src/schema/*.ts	Per-aggregate Drizzle table definitions (agent-kernels, domain-events, seo, …)
src/migrations/	Versioned SQL migrations applied by the db-migrate Cloud Run Job

Dependencies

• drizzle-orm + postgres driver
• @mnemose/domain — identifier + enum types used in column definitions

Data Flow

gateway resolver / command handler / agent
  ↓ createDb(DATABASE_URL) → DbClient
  ↓ db.select(...).from(table).where(eq(tenant_id, ...))    (read model)
  ↓ db.insert(domainEvents).values(event)                   (event store — append only)

The domain_events table is the authoritative audit trail — no UPDATE / DELETE paths exist in the application layer. Tenant isolation is enforced at the application layer (with RLS as a DB-level backstop per Stripe G).