One document per public stdlib class: purpose, the @EntryPoint-tagged methods, and the full public method surface, verified against runtime/src/cajeta/. The guide is the linear tutorial; it links here for API detail. Docs link the tour demo that exercises each class, where one exists.

cajeta.lang

Class
String	Immutable UTF-8 text, the single string type
StringBuilder	Growable byte buffer for building a String in amortized O(N)
Optional	Value-typed sum: present or empty
Pair	Two-field generic value type
Math	Numeric utilities + device math intrinsics
Guid	128-bit UUID backed by a single `uint128`
Slice	Zero-copy array window, the `arr[a:b]` result type

cajeta.lang.stream

Class
Stream	The pull-protocol base for stdlib iteration
ArrayStream	A `Stream` over a contiguous `T[]` range

cajeta.collection

Class
ArrayList	Growable index-addressable sequence; the workhorse list
LinkedList	Doubly-linked list
HashMap	SwissTable-backed hash map over a dense entry array
HashSet	Hash-based set of unique values
ImmutableList	Immutable array-backed list
ImmutableMap	Frozen hash-indexed map snapshot
ImmutableSet	Frozen hash-indexed set
Heap	Array-backed binary heap / priority queue
RedBlackTree	Ordered map, CLRS red-black tree
BPlusTree	In-memory ordered map, B+ tree leaves in a linked chain
Cache	Bounded cache with LRU eviction and optional TTL
Collectors	Standard `Collector` factories for stream terminal ops
Sort	General-purpose host sorting + shared comparison protocol

cajeta.collection.ltm

Class
LtmBPlusTree	Disk-backed larger-than-memory ordered map

cajeta.concurrent

Class
Mutex	Fused mutual exclusion + protected data
RwLock	Reader-writer lock for read-heavy shared state
Lock	No-data RAII gate
Semaphore	Counting permit pool
Channel	Bounded MPMC queue
AtomicInt32	Lock-free atomic `int32` cell
AtomicInt64	Lock-free atomic `int64` cell
FiberLocal	Ambient per-request state
Tasks	Task utilities

cajeta.time

Class
Clock	The static “what time is it” surface
Instant	A moment on the UTC timeline, nanosecond precision
Duration	Signed time-based amount, nanosecond precision
Period	Calendar-based amount: years, months, days
LocalDate	Calendar date, no time-of-day or zone
LocalTime	Time-of-day, no date or zone
LocalDateTime	Date paired with time, no zone
ZonedDateTime	Date-time with a fixed UTC offset
ZoneId	Region time-zone identifier
ZoneOffset	Fixed offset from UTC
DateTimeFormatter	Temporal value ⇄ text formatting

cajeta.io

Class
Buffer	Byte buffer with typed, reinterpreting access

cajeta.io.file

Class
File	Filesystem access: whole-file statics + handle instance
FileInfo	One-`stat` snapshot: size, timestamps, type, permissions
FileReader	Streaming byte reader
FileWriter	Streaming byte writer
Path	Immutable filesystem path
Watcher	Filesystem-change notifier

cajeta.io.net

Class
IpAddress	Immutable IPv4/IPv6 address
SocketAddress	IP address + port
TcpStream	Connected blocking TCP stream
TcpListener	Passive TCP listening socket
UdpSocket	UDP datagram socket
Server	TCP server core: bind, listen, accept loop
ServerBuilder	Model-selection builder for `Server`

cajeta.io.net.dns

Class
Dns	Blocking hostname resolution

cajeta.io.net.uri

Class
Uri	Immutable parsed URI (RFC 3986)
UriBuilder	Builder for `Uri`

HTTP/1.1 and WebSocket are not stdlib — they are application-layer protocols and live in the external dev.cajeta.http library.

cajeta.io.net.tls

Class
TlsConnection	One TLS connection’s engine state
TlsListener	Server-side TLS termination over `TcpListener`

cajeta.hash

Class
Hash	Hash utility namespace
DefaultHasher	Process-seeded XXH3-64 behind synthesized `hash()`
XXHash3	Fast 64-bit non-cryptographic hash
SipHash	DoS-resistant keyed 64-bit hash
Blake3	Fast modern cryptographic hash (and XOF)
Sha256	SHA-256 digest
Sha1	SHA-1 digest
MD5	MD5 checksum / identifier

cajeta.math

Class
Tensor	The keystone n-dimensional array
DType	Runtime numeric dtype descriptor
Rotation	Quaternion construction ergonomics
Transform	TRS rigid+scale transform
Camera	Projection and view matrix builders
Ray	Half-line query primitive for picking and culling
Color	RGBA color, sRGB ⇄ linear

cajeta.math.* (numerics)

Class
Fft	Discrete Fourier transform surface
LinAlg	Linear-algebra factorizations
Generator	Random numbers over Philox4x32-10
Stats	Descriptive statistics: histogram, bincount, digitize
Poly	Polynomial operations
Npy	NumPy `.npy` binary array I/O

cajeta.codec

Class
Base64	Base64 (RFC 4648) byte ⇄ text codec
Csv	Typed CSV: bind rows to a declared type
Json	Top-level JSON parse/serialize entry points

cajeta.wire

Class
Encoder	Bidirectional wire codec: `T` ⇄ bytes
Schema	The schema a `SchemaEncoder` decodes against
SchemaEncoder	Schema-carrying wire codec
Compressor	Block-compress stage
Decompressor	Block-decompress stage

cajeta.search

Class
Distance	String edit-distance functions
Index	N-gram inverted index for fuzzy candidates
Matcher	Typo-tolerant key→value lookup

cajeta.process

Class
Command	Subprocess command: program, args, env, capture
Process	A spawned, still-running child

cajeta.error

Class
Throwable	Root of the exception hierarchy: message, diagnostic code, stack trace, JSON
Exception	Base of the catchable exception hierarchy
RecoverableException	Errors a caller might handle and proceed past
NoOptionalValueException	Unwrap of an empty `Optional` — catchable, not panic
UnrecoverableException	Fatal conditions: invariant violations, OOM

cajeta.reflect

Class
Class	Runtime class representation; the reflection entry point

cajeta.xpu

Class
Device	The active XPU device and host-side queries
KernelBuffer	Unified handle to device memory
KernelStream	Ordered queue of XPU work
MeshSimplifier	Garland–Heckbert edge-collapse mesh simplifier

cajeta.nucleo

The ML spine: compile-time function transforms and the runtime eager tape.

Class
Transforms	The `Grad`/`Vmap`/`Jit` compile-time transform intrinsics + `@Grad`/`@Vmap`/`@Jit` sugar
GradResult	The typed `{value, grads}` return bag of a differentiated function
Tape	Define-by-run autograd: records ops eagerly, replays gradients in reverse
Var	Handle to one tape node (value + gradient readback)
Table	The lazy, record-typed dataframe: relational plan, gradual typing, pushdown + index interface, Arrow/Parquet boundaries
Column	The Arrow-laid-out columnar substrate: `Column<T>` / `NullableColumn<T>` / `StringColumn`, tensor-bit-identical, the frozen Arrow C ABI seam

cajeta.gfx

Class
Texture2D	Read-only 2-D float32 texture, sampled in kernels
Sampler	Filtering + addressing configuration for `Texture2D`

cajeta.ifx

Class
BackendRegistry	UI backend registry, probe, and dispatcher
Window	The portable window contract

Coverage is checked: scripts/check-stdlib-coverage.sh fails if any class with an @EntryPoint-tagged member lacks a document here.