Runtime Platform APIs & Tooling
5 topics in this chapter
CLI Flags
How Node.js consumes startup flags, NODE_OPTIONS, preloads, V8 options, source maps, conditions, warnings, diagnostics, memory flags, node --run, and experimental config files.
.env Files
How Node.js loads .env files with --env-file, parses DotEnv syntax, resolves precedence, handles NODE_OPTIONS, uses process.loadEnvFile() and util.parseEnv(), and turns raw strings into validated config.
Web Platform APIs
How Node.js exposes web-compatible globals including fetch, Request, Response, Web Streams, Blob, File, FormData, URL, and structuredClone.
TypeScript & Compile Cache
How Node.js v24.15 runs TypeScript through type stripping, handles .ts module formats, rejects unsupported syntax, and stores compile cache data.
REPL, Inspector, Watch & SEA
How Node.js REPL, inspector sessions, watch mode, and single executable applications evaluate code, expose debugging state, restart, and package apps.