golang-samber-ro
samber/cc-skills-golang
Reactive streams and event-driven programming in Go with 150+ type-safe operators, subjects, and plugins.
What is golang-samber-ro?
samber/ro is a ReactiveX implementation for Go that enables declarative, composable pipelines for asynchronous and infinite data streams. Use it when building event-driven architectures, real-time data processing, or complex async workflows where manual goroutine/channel wiring becomes unwieldy.
- 150+ type-safe operators (Map, Filter, FlatMap, Merge, Zip, CombineLatest, Retry, Timeout, etc.) chainable via Pipe
- 5 subject types (Publish, Behavior, Replay, Async, Unicast) for hot observables and pub/sub patterns
- Cold and hot observables with Share, ShareReplay, and Connectable for controlling subscription behavior
- Automatic backpressure, error propagation, and Go context integration throughout pipelines
- 40+ plugins (HTTP, cron, fsnotify, JSON, logging) for common async sources and sinks
- Lazy evaluation and time-aware operators (Delay, Throttle, Interval, Timeout, Buffer)
How to install golang-samber-ro
npx skills add https://github.com/samber/cc-skills-golang --skill golang-samber-ro- Go installed (go command available)
- github.com/samber/ro imported in your project (go get github.com/samber/ro)
How to use golang-samber-ro
- 1.Identify your data source (channel, ticker, API, file watcher) and wrap it in an observable using From*, Range, Interval, or a Subject
- 2.Chain operators via Pipe2–Pipe25 (typed) or Pipe (untyped) to transform, filter, combine, or handle errors
- 3.Decide if you need a cold observable (default, safe) or hot observable (Share, ShareReplay, Subject) based on subscriber count and source cost
- 4.Subscribe with an Observer (onNext, onError, onComplete callbacks) or use terminal operators like Collect, ToSlice, or ToChannel
- 5.Call .Wait() to block until completion or .Unsubscribe() to cancel early; use context integration for graceful shutdown
Use cases
- Build WebSocket or file-watcher pipelines with declarative operators instead of manual select loops
- Combine multiple async data sources (APIs, database polls, event streams) with CombineLatest or Zip
- Implement retry logic, timeouts, and error recovery across complex async workflows
- Create pub/sub systems where multiple subscribers share a single expensive source via hot observables
- Transform infinite event streams in real-time with backpressure-aware operators
- Go engineers building asynchronous or event-driven systems
- Teams adopting reactive programming patterns to replace manual goroutine/channel wiring
- Developers working with infinite or long-lived data streams (WebSockets, sensors, event buses)
- Projects requiring composable, declarative async pipelines with built-in error handling
golang-samber-ro FAQ
Use samber/ro for infinite or long-lived async streams (WebSockets, tickers, event buses). Use samber/lo for finite slice transforms. Use plain goroutines or errgroup only for simple, bounded concurrency without complex operator composition.
Cold observables (default) execute independently for each subscriber — safe and predictable. Hot observables (Share, Subjects) share a single execution across subscribers — use when the source is expensive or subscribers must see the same events.
Use Merge (all values from all sources), Zip (tuples when all emit), CombineLatest (latest from each), or Race (first to emit). Choose based on whether you want all events, synchronized tuples, or latest values.
Errors propagate through the pipeline and trigger the onError callback. Use Catch, OnErrorReturn, OnErrorResumeNextWith, or Retry operators to recover and continue the stream.
Subjects are hot observables you control directly: call .Send() to emit, .Error() to propagate errors, .Complete() to finish. Use PublishSubject for simple pub/sub, BehaviorSubject to replay the last value, or ReplaySubject to buffer N past values.
Full instructions (SKILL.md)
Source of truth, from samber/cc-skills-golang.
name: golang-samber-ro
description: "Reactive streams and event-driven programming in Golang using samber/ro — ReactiveX implementation with 150+ type-safe operators, cold/hot observables, 5 subject types (Publish, Behavior, Replay, Async, Unicast), declarative pipelines via Pipe, 40+ plugins (HTTP, cron, fsnotify, JSON, logging), automatic backpressure, error propagation, and Go context integration. Apply when using or adopting samber/ro, when the codebase imports github.com/samber/ro, or when building asynchronous event-driven pipelines, real-time data processing, streams, or reactive architectures in Go. Not for finite slice transforms (→ See samber/cc-skills-golang@golang-samber-lo skill)."
user-invocable: true
license: MIT
compatibility: Designed for Claude Code, Codex or similar harness, and for projects using Golang.
metadata:
author: samber
version: "1.2.2"
openclaw:
emoji: "👁"
homepage: https://github.com/samber/cc-skills-golang
requires:
bins:
- go
install: []
skill-library-version: "0.3.0"
allowed-tools: Read Edit Write Glob Grep Bash(go:) Bash(golangci-lint:) Bash(git:) Agent mcp__context7__resolve-library-id mcp__context7__query-docs AskUserQuestion Bash(godig:) Bash(gopls:) LSP mcp__gopls__
paths:
- "**/*.go"
Persona: You are a Go engineer who reaches for reactive streams when data flows asynchronously or infinitely. You use samber/ro to build declarative pipelines instead of manual goroutine/channel wiring, but you know when a simple slice + samber/lo is enough.
Thinking mode: Reason as thoroughly as possible when designing advanced reactive pipelines or choosing between cold/hot observables, subjects, and combining operators — wrong architecture leads to resource leaks or missed events. On Claude Code, use ultrathink to trigger extended thinking explicitly.
samber/ro — Reactive Streams for Go
Go implementation of ReactiveX. Generics-first, type-safe, composable pipelines for asynchronous data streams with automatic backpressure, error propagation, context integration, and resource cleanup. 150+ operators, 5 subject types, 40+ plugins.
Official Resources:
This skill is not exhaustive — refer to library documentation and code examples for more information:
- For Go package docs, symbols, versions, importers, and known vulnerabilities, → See
samber/cc-skills-golang@golang-pkg-go-devskill (godig), preferred over Context7 for Go package facts. - To navigate this library's usage in your own code (definitions, call sites, diagnostics), → See
samber/cc-skills-golang@golang-goplsskill (gopls). - Context7 remains a fallback for docs not indexed on pkg.go.dev.
Why samber/ro (Streams vs Slices)
Go channels + goroutines become unwieldy for complex async pipelines: manual channel closures, verbose goroutine lifecycle, error propagation across nested selects, and no composable operators. samber/ro solves this with declarative, chainable stream operators.
When to use which tool:
| Scenario | Tool | Why |
|---|---|---|
| Transform a slice (map, filter, reduce) | samber/lo | Finite, synchronous, eager — no stream overhead needed |
| Simple goroutine fan-out with error handling | errgroup | Standard lib, lightweight, sufficient for bounded concurrency |
| Infinite event stream (WebSocket, tickers, file watcher) | samber/ro | Declarative pipeline with backpressure, retry, timeout, combine |
| Real-time data enrichment from multiple async sources | samber/ro | CombineLatest/Zip compose dependent streams without manual select |
| Pub/sub with multiple consumers sharing one source | samber/ro | Hot observables (Share/Subjects) handle multicast natively |
Key differences: lo vs ro
| Aspect | samber/lo | samber/ro |
|---|---|---|
| Data | Finite slices | Infinite streams |
| Execution | Synchronous, blocking | Asynchronous, non-blocking |
| Evaluation | Eager (allocates intermediate slices) | Lazy (processes items as they arrive) |
| Timing | Immediate | Time-aware (delay, throttle, interval, timeout) |
| Error model | Return (T, error) per call | Error channel propagates through pipeline |
| Use case | Collection transforms | Event-driven, real-time, async pipelines |
Installation
go get github.com/samber/ro
Core Concepts
Four building blocks:
- Observable — a data source that emits values over time. Cold by default: each subscriber triggers independent execution from scratch
- Observer — a consumer with three callbacks:
onNext(T),onError(error),onComplete() - Operator — a function that transforms an observable into another observable, chained via
Pipe - Subscription — the connection between observable and observer. Call
.Wait()to block or.Unsubscribe()to cancel
observable := ro.Pipe2(
ro.RangeWithInterval(0, 5, 1*time.Second),
ro.Filter(func(x int) bool { return x%2 == 0 }),
ro.Map(func(x int) string { return fmt.Sprintf("even-%d", x) }),
)
observable.Subscribe(ro.NewObserver(
func(s string) { fmt.Println(s) }, // onNext
func(err error) { log.Println(err) }, // onError
func() { fmt.Println("Done!") }, // onComplete
))
// Output: "even-0", "even-2", "even-4", "Done!"
// Or collect synchronously:
values, err := ro.Collect(observable)
Cold vs Hot Observables
Cold (default): each .Subscribe() starts a new independent execution. Safe and predictable — use by default.
Hot: multiple subscribers share a single execution. Use when the source is expensive (WebSocket, DB poll) or subscribers must see the same events.
| Convert with | Behavior |
|---|---|
Share() | Cold → hot with reference counting. Last unsubscribe tears down |
ShareReplay(n) | Same as Share + buffers last N values for late subscribers |
Connectable() | Cold → hot, but waits for explicit .Connect() call |
| Subjects | Natively hot — call .Send(), .Error(), .Complete() directly |
| Subject | Constructor | Replay behavior |
|---|---|---|
PublishSubject | NewPublishSubject[T]() | None — late subscribers miss past events |
BehaviorSubject | NewBehaviorSubject[T](initial) | Replays last value to new subscribers |
ReplaySubject | NewReplaySubject[T](bufferSize) | Replays last N values |
AsyncSubject | NewAsyncSubject[T]() | Emits only last value, only on complete |
UnicastSubject | NewUnicastSubject[T](bufferSize) | Single subscriber only |
For subject details and hot observable patterns, see Subjects Guide.
Operator Quick Reference
| Category | Key operators | Purpose |
|---|---|---|
| Creation | Just, FromSlice, FromChannel, Range, Interval, Defer, Future | Create observables from various sources |
| Transform | Map, MapErr, FlatMap, Scan, Reduce, GroupBy | Transform or accumulate stream values |
| Filter | Filter, Take, TakeLast, Skip, Distinct, Find, First, Last | Selectively emit values |
| Combine | Merge, Concat, Zip2–Zip6, CombineLatest2–CombineLatest5, Race | Merge multiple observables |
| Error | Catch, OnErrorReturn, OnErrorResumeNextWith, Retry, RetryWithConfig | Recover from errors |
| Timing | Delay, DelayEach, Timeout, ThrottleTime, SampleTime, BufferWithTime | Control emission timing |
| Side effect | Tap/Do, TapOnNext, TapOnError, TapOnComplete | Observe without altering stream |
| Terminal | Collect, ToSlice, ToChannel, ToMap | Consume stream into Go types |
Use typed Pipe2, Pipe3 ... Pipe25 for compile-time type safety across operator chains. The untyped Pipe uses any and loses type checking.
For the complete operator catalog (150+ operators with signatures), see Operators Guide.
Common Mistakes
| Mistake | Why it fails | Fix |
|---|---|---|
Using ro.OnNext() without error handler | Errors are silently dropped — bugs hide in production | Use ro.NewObserver(onNext, onError, onComplete) with all 3 callbacks |
Using untyped Pipe() instead of Pipe2/Pipe3 | Loses compile-time type safety, errors surface at runtime | Use Pipe2, Pipe3...Pipe25 for typed operator chains |
Forgetting .Unsubscribe() on infinite streams | Goroutine leak — the observable runs forever | Use TakeUntil(signal), context cancellation, or explicit Unsubscribe() |
Using Share() when cold is sufficient | Unnecessary complexity, harder to reason about lifecycle | Use hot observables only when multiple consumers need the same stream |
Using samber/ro for finite slice transforms | Stream overhead (goroutines, subscriptions) for a synchronous operation | Use samber/lo — it's simpler, faster, and purpose-built for slices |
| Not propagating context for cancellation | Streams ignore shutdown signals, causing resource leaks on termination | Chain ContextWithTimeout or ThrowOnContextCancel in the pipeline |
Best Practices
- Always handle all three events — use
NewObserver(onNext, onError, onComplete), not justOnNext. Unhandled errors cause silent data loss - Use
Collect()for synchronous consumption — when the stream is finite and you need[]T,Collectblocks until complete and returns the slice + error - Prefer typed Pipe functions —
Pipe2,Pipe3...Pipe25catch type mismatches at compile time. Reserve untypedPipefor dynamic operator chains - Bound infinite streams — use
Take(n),TakeUntil(signal),Timeout(d), or context cancellation. Unbounded streams leak goroutines - Use
Tap/Dofor observability — log, trace, or meter emissions without altering the stream. ChainTapOnErrorfor error monitoring - Prefer
samber/lofor simple transforms — if the data is a finite slice and you need Map/Filter/Reduce, uselo. Reach forrowhen data arrives over time, from multiple sources, or needs retry/timeout/backpressure
Plugin Ecosystem
40+ plugins extend ro with domain-specific operators:
| Category | Plugins | Import path prefix |
|---|---|---|
| Encoding | JSON, CSV, Base64, Gob | plugins/encoding/... |
| Network | HTTP, I/O, FSNotify | plugins/http, plugins/io, plugins/fsnotify |
| Scheduling | Cron, ICS | plugins/cron, plugins/ics |
| Observability | Zap, Slog, Zerolog, Logrus, Sentry, Oops | plugins/observability/..., plugins/samber/oops |
| Rate limiting | Native, Ulule | plugins/ratelimit/... |
| Data | Bytes, Strings, Sort, Strconv, Regexp, Template | plugins/bytes, plugins/strings, etc. |
| System | Process, Signal | plugins/proc, plugins/signal |
For the full plugin catalog with import paths and usage examples, see Plugin Ecosystem.
For real-world reactive patterns (retry+timeout, WebSocket fan-out, graceful shutdown, stream combination), see Patterns.
If you encounter a bug or unexpected behavior in samber/ro, open an issue at github.com/samber/ro/issues.
Cross-References
- → See
samber/cc-skills-golang@golang-samber-loskill for finite slice transforms (Map, Filter, Reduce, GroupBy) — use lo when data is already in a slice - → See
samber/cc-skills-golang@golang-samber-moskill for monadic types (Option, Result, Either) that compose with ro pipelines - → See
samber/cc-skills-golang@golang-samber-hotskill for in-memory caching (also available as an ro plugin) - → See
samber/cc-skills-golang@golang-concurrencyskill for goroutine/channel patterns when reactive streams are overkill - → See
samber/cc-skills-golang@golang-observabilityskill for monitoring reactive pipelines in production
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