Traits
This skill should be used when the user asks about "Effect Equal", "Effect Hash", "Equivalence", "Order", "structural equality", "custom equality", "comparing objects", "sorting", "Equal.equals", "Hash.hash", "Equivalence.make", "Order.lessThan", "comparable types", or needs to understand how Effect handles equality, hashing, and ordering of values.
Resources
This skill should be used when the user asks about "Effect resources", "acquireRelease", "Scope", "finalizers", "resource cleanup", "Effect.addFinalizer", "Effect.ensuring", "scoped effects", "resource lifecycle", "bracket pattern", "safe resource handling", "database connections", "file handles", or needs to understand how Effect guarantees resource cleanup.
Observability
This skill should be used when the user asks about "Effect logging", "Effect.log", "Effect metrics", "Effect tracing", "spans", "telemetry", "Metric.counter", "Metric.gauge", "Metric.histogram", "OpenTelemetry", "structured logging", "log levels", "Effect.logDebug", "Effect.logInfo", "Effect.logWarning", "Effect.logError", or needs to understand how Effect handles logging, metrics, and distribute…
Code Style
This skill should be used EVERY TIME you're writing TypeScript with Effect, especially when the user asks about "Effect best practices", "Effect code style", "idiomatic Effect", "functional programming", "no loops", "no for loops", "avoid imperative", "Effect Array", "Effect Record", "Effect Struct", "Effect Tuple", "Effect Predicate", "Schema-first", "Match-first", "when to use Schema", "when to…
Streams
This skill should be used when the user asks about "Effect Stream", "Stream.from", "Stream.map", "Stream.filter", "Stream.run", "streaming data", "async iteration", "Sink", "Channel", "Stream.concat", "Stream.merge", "backpressure", "Stream.fromIterable", "chunked processing", "real-time data", or needs to understand how Effect handles streaming data processing.
Api Doc Lookup
This skill should be used when the user asks to "look up Effect API", "check the Effect docs", "find Effect function signature", "what does Effect.X do", "how to use Effect.X", "Effect API reference", "fetch Effect documentation", or needs to look up specific function signatures, parameters, or usage examples from the official Effect-TS API documentation.
Platform
This skill should be used when the user asks about "@effect/platform", "Effect HTTP client", "Effect HTTP server", "FileSystem", "KeyValueStore", "Terminal", "platform services", "HttpClient", "HttpServer", "Effect file operations", "Effect networking", or needs to understand Effect's platform-agnostic I/O capabilities.
Error Management
This skill should be used when the user asks about "Effect errors", "typed errors", "error handling", "Effect.catchAll", "Effect.catchTag", "Effect.mapError", "Effect.orElse", "error accumulation", "defects vs errors", "expected errors", "unexpected errors", "sandboxing", "retrying", "timeout", "Effect.cause", "TaggedError", "Schema.TaggedError", or needs to understand how Effect handles failures…
Verifying Assumptions
MANDATORY verification before/after code changes. Triggers on: modifying files, calling APIs, assuming file locations, checking dependencies, first time in codebase. ALWAYS write script to file, execute, then proceed. Never inline verification.
Batching Caching
This skill should be used when the user asks about "Effect batching", "request batching", "Effect caching", "Cache", "Request", "RequestResolver", "Effect.cached", "Effect.cachedWithTTL", "automatic batching", "N+1 problem", "data loader pattern", "deduplication", or needs to understand how Effect optimizes API calls through batching and caching.
Effect Core
This skill should be used ANY TIME you're writing TypeScript with Effect, especially when the user asks about "Effect type", "creating effects", "running effects", "Effect.gen", "Effect.succeed", "Effect.fail", "Effect.sync", "Effect.promise", "Effect.tryPromise", "Effect.runPromise", "Effect.runSync", "pipe", "andThen", "flatMap", "map", "Effect basics", or needs to understand the fundamental Ef…
Sinks
This skill should be used when the user asks about "Effect Sink", "Sink.collectAll", "Sink.sum", "Sink.fold", "stream consumers", "Sink.forEach", "creating sinks", "sink operations", "sink leftovers", "sink concurrency", "Stream.run with Sink", or needs to understand how Effect Sinks consume stream data.
Testing
This skill should be used when the user asks about "Effect testing", "@effect/vitest", "it.effect", "it.live", "it.scoped", "it.layer", "it.prop", "Schema Arbitrary", "property-based testing", "fast-check", "TestClock", "testing effects", "mocking services", "test layers", "TestContext", "Effect.provide test", "time testing", "Effect test utilities", "unit testing Effect", "generating test data",…
Requirements
This skill should be used when the user asks about "Effect services", "dependency injection", "Effect.Tag", "Context.Tag", "Layer", "Effect.provide", "Effect.provideService", "service implementation", "managing dependencies", "Layer.succeed", "Layer.effect", "Layer.scoped", "composing layers", "Layer.merge", "Layer.provide", "default services", "layer memoization", "testability", "test layers", "…
Scheduling
This skill should be used when the user asks about "Effect Schedule", "retry schedules", "repetition", "Schedule.exponential", "Schedule.spaced", "Schedule.recurs", "cron scheduling", "backoff strategy", "schedule combinators", "Effect.repeat", "Effect.retry", "polling", or needs to understand how Effect handles scheduled operations and retry policies.
State
This skill should be used when the user asks about "Effect Ref", "mutable state", "Ref.make", "Ref.get", "Ref.set", "Ref.update", "SubscriptionRef", "SynchronizedRef", "reactive state", "state updates", "concurrent state", "shared mutable state", or needs to understand how Effect handles mutable state in a functional way.
Runtime
This skill should be used when the user asks about "Effect Runtime", "ManagedRuntime", "Effect.Tag", "custom runtime", "runtime layers", "running effects", "runtime configuration", "runtime context", "Effect.runPromise", "Effect.runSync", "runtime scope", or needs to understand how Effect's runtime system executes effects.
Effect Ai
This skill should be used when the user asks about "Effect AI", "@effect/ai", "LLM integration", "AI tool use", "AI execution planning", "building AI agents", "AI providers", "structured AI output", "AI completions", "Effect OpenAI", "Effect Anthropic", or needs to understand how Effect integrates with AI/LLM services.
Data Types
This skill should be used when the user asks about "Effect Option", "Effect Either", "Option.some", "Option.none", "Either.left", "Either.right", "Cause", "Exit", "Chunk", "Data", "Data.TaggedEnum", "Data.Class", "Duration", "DateTime", "HashMap", "HashSet", "Redacted", or needs to understand Effect's built-in data types and functional data structures.
Pattern Matching
This skill should be used when the user asks about "Effect Match", "pattern matching", "Match.type", "Match.tag", "Match.when", "Schema.is()", "Schema.is with Match", "exhaustive matching", "discriminated unions", "Match.value", "converting switch to Match", "converting if/else to Match", "TaggedClass with Match", or needs to understand how Effect provides type-safe exhaustive pattern matching.
Configuration
This skill should be used when the user asks about "Effect Config", "environment variables", "configuration management", "Config.string", "Config.number", "ConfigProvider", "Config.nested", "Config.withDefault", "Config.redacted", "sensitive values", "config validation", "loading config from JSON", "config schema", or needs to understand how Effect handles application configuration.
Schema
This skill should be used when the user asks about "Effect Schema", "Schema.Struct", "Schema.decodeUnknown", "data validation", "parsing", "Schema.transform", "Schema filters", "Schema annotations", "JSON Schema", "Schema.Class", "Schema branded types", "encoding", "decoding", "Schema.parseJson", or needs to understand how Effect handles data validation and transformation.
Concurrency
This skill should be used when the user asks about "Effect concurrency", "fibers", "Fiber", "forking", "Effect.fork", "Effect.forkDaemon", "parallel execution", "Effect.all concurrency", "Deferred", "Queue", "PubSub", "Semaphore", "Latch", "fiber interruption", "Effect.race", "Effect.raceAll", "concurrent effects", or needs to understand how Effect handles parallel and concurrent execution.