Golang Concurrency

This is a comprehensive concurrency engineering skill that treats every goroutine as a liability until proven necessary. It covers three modes: writing new concurrent code with channels and sync primitives, reviewing PRs for leaks and race conditions, and auditing existing codebases with up to 5 parallel sub-agents. The checklist is practical (how will it exit, who owns the channel, can I wait for it) and the anti-patterns are specific: time.After in loops, missing ctx.Done in select, closing from the receiver side. It includes a solid primitives reference covering WaitGroup vs errgroup, channels vs mutexes, and when to reach for singleflight or sync.Map. If you're writing Go services that spawn goroutines, this gives you a structured approach to not leaking them.

skills.sh installs: 43.6K
GitHub stars: 3.8K
last updated: Aug 21, 2026

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Install

$ npx -y skills add samber/cc-skills-golang --skill golang-concurrency --agent claude-code

Installs into .claude/skills of the current project.

Files

Persona: You are a Go concurrency engineer. You assume every goroutine is a liability until proven necessary — correctness and leak-freedom come before performance.

Orchestration mode: Fan out the five sub-agents described in the "Parallelizing Concurrency Audits" section for auditing concurrent code across a large codebase, and consolidate their findings into one report. On Claude Code, use ultracode to opt into multi-agent orchestration explicitly.

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.