Standard library

Familiar, conventional APIs — the names you already know (fs.readFileSync, path.join, process.cwd) — but statically typed and compiled to native code. Every member is type- and arity-checked before it lowers.

Available now

console

API	Type
`console.log(x)`	any → void
`console.error(x)`	any → void

Math

API	Type
`Math.abs(n)`	number → number
`Math.max(a, b)` · `Math.min(a, b)`	(number, number) → number
`Math.sign(n)`	number → int
`Math.clamp(n, lo, hi)`	(number, number, number) → number
`Math.sqrt(n)`	number → number

String

API	Type
`s.length` · `s + t`	int · concatenation
`String.isEmpty(s)`	string → bool
`String.contains(s, sub)`	(string, string) → bool
`String.startsWith(s, prefix)`	(string, string) → bool

Array

API	Type
`a[i]` · `a.length`	element access · int
`Array.isEmpty(a)`	T[] → bool

Errors

API	Notes
`Error("message")` · `throw e`	throw an error value
`try { … } catch (e) { … } finally { … }`	`e.message` holds the message

fs · process

API	Type	Notes
`fs.readFileSync(path, encoding?)`	(string, string?) → string	UTF-8 text; "" if unreadable
`argsCount()` · `arg(i)`	→ int · int → string	process arguments

Planned

The surface grows in explicit, conformance-backed slices. These modules use the same conventional names; some depend on upcoming language features (noted below).

fs

API	Notes
`fs.writeFileSync(path, data)`
`fs.appendFileSync(path, data)`
`fs.existsSync(path)`	→ bool
`fs.mkdirSync(path, recursive?)`
`fs.rmSync(path)` · `fs.unlinkSync(path)`
`fs.renameSync(a, b)` · `fs.copyFileSync(a, b)`
`fs.statSync(path)` → `{ size, isFile, isDirectory }`	record return
`fs.readdirSync(path)` → `string[]`	needs growable arrays

path

API	Notes
`path.join(a, b, …)` · `path.resolve(…)`
`path.basename(p)` · `path.dirname(p)` · `path.extname(p)`
`path.isAbsolute(p)` · `path.sep`

process

API	Notes
`process.cwd()`	→ string
`process.exit(code)`
`process.env(key)`	→ string \| null
`process.platform` · `process.arch`	compile-time constants
`process.argv` → `string[]`	needs growable arrays

os

API	Notes
`os.platform()` · `os.arch()`
`os.tmpdir()` · `os.homedir()`
`os.cpus()` · `os.hostname()`

Math · String · Array (more)

API	Notes
`Math.floor/ceil/round/trunc/pow/log/sin/cos` · `Math.PI`
`s.toUpperCase/toLowerCase/trim/replace/indexOf/slice`
`s.split(sep)` → `string[]`	needs growable arrays
`a.map/filter/reduce/forEach(fn)`	uses closures
`a.push/pop/sort`	needs growable arrays

time · crypto · http

API	Notes
`time.now()` · `time.monotonic()`	milliseconds
`crypto.sha256(data)` · `crypto.sha1(data)`	→ hex string
`http.get(url)` → `{ status, body }`	record return
async `fs` / `http` / timers	needs the async runtime

Lumen is statically typed and has no dynamic JSON value — JSON.parse<T> and generic containers (Map, Set) arrive with generics. This is not a package manager; the library is a fixed, contracted surface.