Effect.TS in a cast
Below is an alphabetised glossary of every public construct that ships with the Effect
ecosystem (v 3.19, December 2025).
For legibility it is grouped by package → module → symbol.
Internal helpers, deprecated aliases, benchmark stubs and re-export barrels are omitted.
Use it as an index: every identifier shown here can be imported exactly as written.
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1 Core package effect
1.1 Types & Type-Level Helpers
Cause Clock Context Data Duration Effect<A,E,R> Either Equal
Exit Fiber FiberId FiberRef Hash Layer Option Predicate
ReadonlyArray utilities (Chunk, NonEmptyArray, …) Schema TaggedError
These Time Tuple Types HKT utilities Variance 
1.2 Constructors / Creators
succeed fail sync syncThrowable tryPromise async acquireRelease
gen fromEither fromOption fromNullable fromFiber fromCallback
schedule constructors (fixed, exponential, cron)
Ref.make Deferred.make Queue.make Hub.make Semaphore.make 
1.3 Combinators & Operators
map flatMap tap zip zipWith zipRight/Left race timeout
all/allPar/allWith reduce foreach partition retry repeat
uninterruptible interruptible onInterrupt onError
provide / provideLayer / provideService
withSpan withLogLevel withContext
bind bindAll do notation helpers 
1.4 Executors (Runtimes)
runPromise runCallback runSync runFork (returns RuntimeFiber)
Runtime.defaultRuntime
Runtime.run (with custom PlatformLogger) 
1.5 Concurrency & Coordination
Deferred Queue (unbounded, bounded, dropping, sliding) Hub Mailbox
Semaphore Scope Supervisor Request RequestResolver
STM (TRef, TSemaphore, TArray, TQueue)
Stream Sink Channel Subscribable utilities (map, mapEffect) 
1.6 Diagnostics
log logDebug logInfo logError traced
Metric Span Annotation Tracer (OpenTelemetry bridge)
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2 @effect/platform (+ runtimes)
2.1 Stable modules 
Command FileSystem KeyValueStore Path PlatformLogger Runtime Terminal
2.2 Unstable / experimental modules
HttpApi HttpClient (Client, Request, Response) HttpServer
Socket Worker Micro (5 kB subset)
2.3 Runtime layers
platform-node platform-browser platform-bun provide concrete services.
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3 Official add-on packages
Package Notable APIs
@effect/ai AI facade, provider-specific layers (ai-openai, ai-anthropic, ai-bedrock, ai-google)
@effect/cli CliApp, Command, Option, Argument, HelpDoc
@effect/opentelemetry Tracer, Span, runtime exporter layers
@effect/printer Doc, Printer, syntax-highlight helpers
@effect/rpc RpcClient, RpcServer, RpcCodec
@effect/testing TestClock, TestRandom, Layer.mock, assert*
@effect/language-service TypeScript LSP plugin for diagnostics and refactors
@effect/cluster Cluster, Shard, Workflow (alpha)
Community highlights: effect-http (OpenAPI → client / server), sqlfx (SQL toolkit) 
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4 Data-Structures & Helpers (effect/Data)
Array, Chunk, HashMap, HashSet, List, Vector, SortedMap, SortedSet,
algebraic types Option, Either, These, Validation, plus:
Pattern matching via Match.value, Match.type 
Tagging helpers Data.struct, Data.tuple, TaggedClass, TaggedError 
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5 Resource Management (Layer, Scope)
• Layer.succeed Layer.sync Layer.scoped Layer.effect
• Combinators: merge, zip, andThen, using, catchAll, memoize
• Scope helpers: use, extend, fork, close, onExit
• Advanced: LayerMap for dynamic resource lookup 
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6 Scheduling
Schedule.fixed Schedule.exponential Schedule.recurs Schedule.windowed
Schedule.cron, Schedule.fibonacci, Schedule.delayed – all combinable with
and, or, jittered, whileOutput, whileInput, intersect.
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7 Generator / Do-notation utilities
Effect.gen (generator DSL)
Effect.Do (with bind, bindAll, let)
Effect.asyncGen for back-pressured async streams. 
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8 Glossary quick-index (A-Z)
Below is a one-liner catalogue of all importable symbols across all official
packages (core + add-ons). Paste-search any name in your IDE to jump to docs.
acquireRelease all Annotation AsyncInput Brand
Cause Channel Chunk Clock Command Config Console Context
CronField Data Deferred Doc Do Duration
Either Effect Exit Fiber FiberId FiberRef FileSystem
Gen GenKind Hash HashMap HashSet Hub HttpApi HttpClient
HttpServer KeyValueStore Layer LayerMap List LogLevel Mailbox
Match Metric Micro NonEmptyArray Option Path PlatformLogger
Predicate Printer Queue Random Ref Request RequestResolver
RetryPolicy RpcClient RpcServer Schedule Scope Semaphore
Sink Span Stream Supervisor TaggedClass TaggedError Terminal
These Tracer Tuple Validation Worker
(α-stage modules like Cluster, Workflow, Socket, Worker, Micro are
flagged experimental; names may change in minor releases.)