Node.js Compatibility

Pure implements the most common Node.js built-in modules. The goal is drop-in compatibility for the vast majority of npm packages. This page lists what is available, what is partial, and what is absent.

Module support summary

Module	Status	Notes
`node:fs` / `fs`	✅ Full	Sync and async, streams, watchers
`node:path`	✅ Full
`node:os`	✅ Full
`node:crypto`	✅ Full	Including `crypto.subtle`
`node:buffer`	✅ Full	`Buffer.from`, `Buffer.alloc`, etc.
`node:stream`	✅ Full	Readable, Writable, Transform, PassThrough, pipeline
`node:stream/promises`	✅ Full
`node:events`	✅ Full	`EventEmitter`
`node:net`	✅ Full	TCP sockets, server, `createConnection`
`node:http`	✅ Full	`http.createServer`, `http.request`, `http.get`
`node:https`	✅ Full
`node:http2`	⚠️ Partial	Client support only; server push not implemented
`node:url`	✅ Full
`node:querystring`	✅ Full
`node:zlib`	✅ Full	gzip, deflate, brotli
`node:util`	✅ Full	`promisify`, `inspect`, `format`, `inherits`, etc.
`node:assert`	✅ Full
`node:child_process`	✅ Full	`spawn`, `exec`, `execFile`, `spawnSync`, `execSync`
`node:process`	✅ Full	`env`, `argv`, `exit`, `cwd`, `pid`, signals, `stdin`/`stdout`/`stderr`
`node:worker_threads`	✅ Full	`Worker`, `workerData`, `parentPort`, `MessageChannel`
`node:timers`	✅ Full
`node:timers/promises`	✅ Full
`node:readline`	✅ Full
`node:string_decoder`	✅ Full
`node:perf_hooks`	✅ Full	`performance.now()`, `PerformanceObserver`
`node:diagnostics_channel`	✅ Full
`node:async_hooks`	⚠️ Partial	`AsyncLocalStorage` supported; `AsyncResource` partial
`node:inspector`	❌ Not supported
`node:vm`	❌ Not supported	See Not supported
`node:repl`	❌ Not supported
`node:v8`	⚠️ Partial	`serialize`/`deserialize` supported; heap profiling not available
`node:wasi`	❌ Not supported
`node:sqlite`	❌ Not supported	Use `better-sqlite3` or `@electric-sql/pglite`
`node:domain`	❌ Not supported	Deprecated upstream

Notable caveats

`fs.watch` and `fs.watchFile`

File watchers work on Linux and macOS. On macOS, fs.watch uses FSEvents. Watch events on paths inside a VFS directory are not supported (VFS is read-only and does not change at runtime).

`child_process`

fork() is not supported. Use spawn or exec. The shell: true option on spawn is supported.

`node:http` and `node:https`

The HTTP server is fully functional. The Agent class (keep-alive connection pooling) is supported. http.globalAgent and custom agents work as expected.

`node:async_hooks` / `AsyncLocalStorage`

AsyncLocalStorage is the recommended API and is fully supported. AsyncResource is partially supported — runInAsyncScope works, but manual trigger tracking via AsyncResource.bind has edge cases with some callback patterns.

`process.stdin` in non-TTY mode

process.stdin works as a readable stream when piped. Interactive TTY mode (raw mode) is supported via readline.

`process.execPath`

Returns the path to the compiled binary, not a node or bun executable. Code that does child_process.spawn(process.execPath, ...) to start a sub-process works as expected — it spawns another instance of the same binary.

Bun compatibility

See the Bun-specific notes in Not supported for Bun APIs that do not apply to Pure binaries.

Node.js Compatibility

Module support summary

Notable caveats

fs.watch and fs.watchFile

child_process

node:http and node:https

node:async_hooks / AsyncLocalStorage

process.stdin in non-TTY mode