Emmett is a TypeScript monorepo providing an opinionated event sourcing and CQRS framework for Node.js applications. It implements the decider pattern for business logic, with pluggable event store backends (PostgreSQL, SQLite, MongoDB, EventStoreDB, in-memory) and web framework integrations (Express, Hono, Fastify). The framework includes built-in projections (single/multi-stream, raw SQL, document-oriented via Pongo), consumer/processor pipelines with checkpointing and locking, workflow orchestration, and comprehensive observability via OpenTelemetry (tracing, metrics, logging). The codebase is modular with separate packages per database and web framework, extensive test coverage (unit, integration, e2e), and a CLI for schema migrations. It is actively maintained with a large community (539 stars, 53 forks) and zero dependabot alerts. The architecture demonstrates high craftsmanship with reusable patterns for middleware composition, streaming transformations, and BDD-style testing specifications.