Borrowing it
Nothing to install: this file belongs to braswelljr/rmx. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/braswelljr/rmx/main/.agents/skills/golang-concurrency/SKILL.mdgit clone --depth 1 https://github.com/braswelljr/rmxWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/braswelljr/rmx/golang-concurrency)<a href="https://agentmods.dev/skills/braswelljr/rmx/golang-concurrency"><img src="https://agentmods.dev/badge/skills/braswelljr/rmx/golang-concurrency/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/braswelljr/rmx/golang-concurrency"><img src="https://agentmods.dev/badge/skills/braswelljr/rmx/golang-concurrency.svg" alt="Reviewed on agentmods" width="80" height="20"></a>What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00074 | $0.02130 |
| Opus 5 | $0.00037 | $0.01065 |
| Sonnet 5 | $0.00015 | $0.00426 |
| Haiku 4.5 | $0.00007 | $0.00213 |
Grade A, and why
golang-concurrency scanned grade A with 1 finding against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 11d ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Makes network callslowCapability
Not a fault in itself. Listed so you know the mod talks to something, and to what.
curl http://localhost:6060/debug/pprof/goroutineleak?debug=2 This is a copy
91% identical to golang-concurrency — 30 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.
How it starts
The opening of the file, as written. The whole thing — 153 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Persona: You are a Go concurrency engineer. You assume every goroutine is a liability until proven necessary — correctness and leak-freedom come before performance.
Modes:
- Write mode — implement concurrent code (goroutines, channels, sync primitives, worker pools, pipelines). Follow the sequential instructions below.
- Review mode — reviewing a PR's concurrent code changes. Focus on the diff: check for goroutine leaks, missing context propagation, ownership violations, and unprotected shared state. Sequential.
- Audit mode — auditing existing concurrent code across a codebase. Use up to 5 parallel sub-agents as described in the "Parallelizing Concurrency Audits" section.
Community default. A company skill that explicitly supersedes
samber/cc-skills-golang@golang-concurrencyskill takes precedence.
Go Concurrency Best Practices
Go's concurrency model is built on goroutines and channels. Goroutines are cheap but not free — every goroutine you spawn is a resource you must manage. The goal is structured concurrency: every goroutine has a clear owner, a predictable exit, and proper error propagation.
Core Principles
- Every goroutine must have a clear exit — without a shutdown mechanism (context, done channel, WaitGroup), they leak and accumulate until the process crashes
- Share memory by communicating — channels transfer ownership explicitly; mutexes protect shared state but make ownership implicit
- Send copies, not pointers on channels — sending pointers creates invisible shared memory, defeating the purpose of channels
- Only the sender closes a channel — closing from the receiver side panics if the sender writes after close
- Specify channel direction (
chan<-,<-chan) — the compiler prevents misuse at build time - Default to unbuffered channels — larger buffers mask backpressure; use them only with measured justification
- Always include
ctx.Done()in select — without it, goroutines leak after caller cancellation - Avoid repeated
time.Afterin hot loops — each call allocates a timer and creates unnecessary churn; usetime.NewTimer+Resetfor long-running loops - Track goroutine leaks in tests with
go.uber.org/goleak
What ships with it
4 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 11d ago First seen · 153 lines · 74 tokens per session scan A 8e68d3f89da8
golang-concurrency is a skill published in the GitHub repository braswelljr/rmx (5 stars, last pushed 22d ago), licensed MIT. It adds 74 tokens to every session and 2,130 once invoked, about $0.0004 per session on Opus 5. A static security scan graded it A with 1 finding (makes network calls). It is 91% identical to golang-concurrency, differing in 30 lines, and is treated as a copy.
Other skills, from other repositories
golang-graphql
Implements GraphQL APIs in Golang using gqlgen or graphql-go. Apply when building GraphQL servers, designing schemas, writing resolvers, handling subscriptions, or integrating GraphQL with existing Go HTTP services. Also apply when the codebase imports github.com/99designs/gqlgen or github.com/graph-gophers/graphql-go.
golang-pro
Implements concurrent Go patterns using goroutines and channels, designs and builds microservices with gRPC or REST, optimizes Go application performance with pprof, and enforces idiomatic Go with generics, interfaces, and robust error handling. Use when building Go applications requiring concurrent programming…
golang-grpc
Provides gRPC usage guidelines, protobuf organization, and production-ready patterns for Golang microservices. Use when implementing, reviewing, or debugging gRPC servers/clients, writing proto files, setting up interceptors, handling gRPC errors with status codes, configuring TLS/mTLS, testing with bufconn, or…
golang-swagger
Golang OpenAPI/Swagger documentation with swaggo/swag — annotation comments (@Summary, @Param, @Success, @Router, @Security), swag init code generation, framework integrations (gin, echo, fiber, chi, net/http), security definitions (Bearer/JWT, OAuth2, API key), and struct tags (swaggertype, enums, example…
layered-architecture-types
Enforce primitive-at-edges / strong-types-in-Business layering and the toBus/fromBusResponse/toDB converter pattern. Use when writing, editing, or auditing Go files under app/, business/domain/, or .../stores/db.
printing-press
Set up a new integration, connector, or CLI binding for any API. Wrap or generate a ship-ready Go CLI from an OpenAPI, HAR, or Postman spec via the lean research -> generate -> build -> shipcheck loop. Use when the user says build a CLI, wrap this API, set up a new integration, add a connector, integrate with a…