Standard Library

Import modules with from "std/<name>" import { symbols }.

Most utilities are namespaced: call a static on the namespace (Path.join, Json.parse, Math.sqrt) or a method on the value (s.trim(), dt.format()).

I/O & Filesystem

Module	What it provides
std/io	readStdin, writeStdout, File.openRead/.openWrite/.openAppend, f.readAll(), f.writeAll(), RAII file handles
std/fs	readFile, readLines, readDir, fileInfo, isDir/isFile, pathExists, writeFile
std/path	Path.join, Path.basename, Path.dirname, Path.ext, Path.stem
std/env	Env.get, Env.getOr

Networking

Module	What it provides
std/net	TCP, DNS
std/fetch	HTTP client: fetch, fetchWith, redirects, and the TLS client socket TlsStream
std/tls	TLS server transport: TlsListener.bind, accept
std/https	HTTPS server: serveTls, serveRouterTls
std/ws	WebSocket client and server: wsAccept, wsConnect, WsConn
std/wsframe	WebSocket wire format, no IO: computeAcceptKey, encodeWsFrame, parseWsFrame
std/chunked	HTTP/1.1 chunked transfer coding, no IO: ChunkScan, decodeChunked
std/unix	Unix-domain sockets: UnixListener, UnixStream
std/http	HTTP server with Hono-style router, context, middleware
std/httpmw	Optional HTTP middleware: gzip, verifyBearer
std/webpush	Web Push: payload encryption (RFC 8291) and VAPID headers (RFC 8292): WebPush.encrypt, WebPush.vapid, VapidKeys
std/html	HTML escaping — Html.escapeText, Html.escapeAttr, Html.isSafeUrl
std/mime	Media types by extension — Mime.fromPath, Mime.contentType
std/multipart	multipart/form-data parsing — Multipart.parse, Part.safeFilename

Data

Module	What it provides
std/json	Zero-copy JSON parser: Json.parse, keyed accessors (.str(), .i64(), .f64(), .bool()). Serializing a struct is the built-in jsonStringify, no import
std/arena	Generational arena for cyclic/graph data with safe Handle<T>; the how-to is Patterns
std/set	HashSet<T> — s.add, s.contains, s.remove
std/collections	BinaryHeap, Deque, SortedMap (B-tree), OrderedMap, Counter, bisectLeft/insertSorted
std/cache	LruCache and TtlCache (per-entry expiry, optional LRU capacity)

CLI & System

Module	What it provides
std/argparse	CLI argument parsing with typed getters and --help generation
std/args	Raw CLI arguments — args(), getFlag, hasFlag
std/process	Command execution, Process.spawn/.wait()/.signal(), run, capture
std/signal	POSIX signal handling — onSignal, ignoreSignal
std/term	Terminal raw mode and size: enableRawMode, terminalSize
std/keys	Decode terminal input bytes into keys: decodeKey, KeyCode
std/ansi	Cursor, screen and 256/24-bit color escapes: Ansi.cursorTo, Ansi.fg256
std/pty	Pseudoterminals: Pty.open, openAndSpawn
std/sysinfo	Host and process info: hostname, cpuCount, totalMem, cwd
std/environ	The whole environment: envVars
std/os	Typed libc bindings the rest of std is built on
std/dl	Load shared libraries at run time: dlOpen, Lib.sym

Data Formats

Module	What it provides
std/csv	CSV parsing with header support — Csv.parse, Csv.stringify
std/xml	Strict XML 1.0: a pull parser (XmlReader) and an owned tree (Xml.parse, XmlNode)
std/base64	Base64 encode/decode — Base64.encode, Base64.decode
std/hex	Hex encode/decode — Hex.encode, Hex.decode
std/binary	Fixed-width int/float codecs — Bytes.readU32Le, Bytes.writeI16Be, both byte orders
std/png	PNG encode/decode: Png.encode, Png.decode
std/jpeg	JPEG encode/decode, baseline and progressive: Jpeg.decode, Jpeg.encode, Jpeg.orientation
std/image	The Image type both codecs share, with crop, resize, rotate90, oriented

Date, Time & IDs

Module	What it provides
std/time	Wall clock, elapsed time, Duration arithmetic/parse/format, sleep
std/timer	Timer, Ticker, recvTimeout, waitReadable/waitWritable
std/datetime	Date/time — DateTime.now/.fromEpoch, then dt.format(), weekdayName
std/uuid	UUIDs — Uuid.v4, Uuid.v7, Uuid.parse

Concurrency

Module	What it provides
std/runtime	Task.spawn, Promise / Promise.blocking, green scheduler
std/event	kqueue/epoll/IOCP readiness polling — the layer std/runtime drives
std/sync	Channel, WaitGroup, AtomicI64, AtomicBool — all method-based
std/select	Wait on the first ready channel, fd or timeout: Select
std/shard	parallelMap, parallelScanStr — divide a buffer's ownership across cores, no copy, nothing shared

Database & Network

Module	What it provides
std/sqlite	SQLite3 bindings — dbOpen, dbQuery, dbExec, prepared statements; compile-time checked dbPrepare/dbRun/dbScalar
std/browser	Headless Chrome over DevTools — navigate, viewport, color scheme, evaluate, PNG screenshots
std/migrate	Versioned SQLite migrations — Migration, dbMigrate, adopting a pre-migration database, dbBackup
std/url	URL parsing — Url.parse, then u.queryGet, u.toString

Strings & Formatting

Module	What it provides
std/string	String methods — s.contains, s.split, s.replace, s.trim, case conversion
std/seal	Sealed — freeze a string so stored Spans can never be invalidated
std/fmt	Template formatting (fmt1–fmt4), padLeft/padRight, join
std/strconv	parseInt, parseFloat, parseBool, radix conversions, formatFloat, quoteString/unquoteString
std/unicode	UTF-8 decoding, code points, display width: codepoints, displayWidth

Math & Random

Module	What it provides
std/math	Math.abs, Math.min, Math.max, Math.pow, Math.sqrt, Math.log, trig
std/random	Random.int, Random.float, Random.range, Random.shuffleI64
std/rng	Seedable, reproducible generator: Rng.new(seed)

Utilities

Module	What it provides
std/color	SGR text styling — Color.red, Color.green, Color.bold, etc.
std/re	JavaScript-syntax regex in pure Milo (lookaround, backreferences, step budget): Re.new, .test, .find, .replaceAll, .split
std/regex	Regular expression matching — Regex.compile, .isMatch, .find
std/sort	Sorting for Vec — sortI32, sortI64, sortStrings
std/testing	assert, assertEqual, assertStrEqual
std/replay	The record/replay engine behind MILO_RECORD / MILO_REPLAY: replayOff, replayRet, replayBlob
std/log	Leveled structured logging — Log, Logger, LogLevel, LogFormat
std/mem	mmapAnon, mmapFile, Bump bump allocator
std/pool	Fixed-size block pool allocator: Pool
std/foreign	Borrow and adopt foreign memory: withRaw, adopt
std/cstr	NUL-terminated C string view: CStr.wrap
std/smt	The QF_LIA decision procedure behind milo prove
std/prelude	Auto-imported: Error, Unit, ErrorContext

Cryptography

OpenSSL-backed hashing plus pure-Milo hashing, MAC, and token modules (no C codec dependency; constant-time and WCET-analyzable).

Module	What it provides
std/crypto	Crypto.sha256, Crypto.sha1, Crypto.md5, and Crypto.aesGcmEncrypt/.aesGcmDecrypt (128/256-bit AES-GCM)
std/sha256	Pure-Milo SHA-256 — Sha256.hash, Sha256.bytes
std/sha512	Pure-Milo SHA-512 / SHA-384 — Sha512.hash, Sha384.bytes
std/sha1	Pure-Milo SHA-1 — Sha1.hash, Sha1.bytes
std/hmac	HMAC-SHA256 / 384 / 512 / SHA-1 — Hmac.sha256, Hmac.sha512Bytes
std/subtle	Constant-time comparison — constantTimeEq
std/hkdf	HKDF extract-and-expand (RFC 5869) — Hkdf.sha256
std/pbkdf2	Password-based KDF (RFC 8018) — Pbkdf2.sha256
std/jwt	JWT sign/verify (HS256/384/512) with claim validation — Jwt.signHS256, Jwt.verifyHS256, JwtVerifier
std/totp	RFC 6238 TOTP / RFC 4226 HOTP one-time passwords — Totp.generate, Totp.hotp
std/base32	Base32 encode/decode (RFC 4648) — Base32.encode, Base32.decode

Compression

Pure-Milo DEFLATE (RFC 1951) and the gzip / zlib / zip containers built on it.

Module	What it provides
std/deflate	Compress — Deflate.raw, Deflate.gzip, Deflate.zlib
std/inflate	Decompress — Inflate.raw, Inflate.gzip, Inflate.zlib
std/zip	Read ZIP archives — Zip.read (.zip/.jar/.epub/.docx)
std/zstd	Zstandard: Zstd.compress, Zstd.decompress
std/checksum	CRC-32 and Adler-32: Checksum.crc32
std/xxhash	XXH64: Xxhash.hash64