pREST is a production-grade Go HTTP server that exposes PostgreSQL, MySQL, and TimescaleDB databases as instant REST APIs, with an additional Model Context Protocol (MCP) JSON-RPC endpoint. The codebase is built around a hexagonal architecture: adapters define port interfaces for SQL building, query execution, catalog inspection, permissions, and scripting, while concrete implementations live in adapters/postgres, adapters/mysql, and adapters/timescaledb. Entry points include the prestd CLI (cmd/prestd/main.go), the Cobra command tree, and an HTTP router mounting CRUD, catalog, auth, health, query-registry, plugin, MCP, and an embedded React Studio UI. The system translates HTTP requests into parameterized SQL, supports multi-database registry routing, JWT/JWKS auth, per-table and per-field ACLs, response caching, OpenTelemetry observability, and custom SQL script routes with safe template helpers.