golang-contextlisted

> **Community default.** A company skill that explicitly supersedes `samber/cc-skills-golang@golang-context` skill takes precedence. # Go context.Context Best Practices `context.Context` is Go's mechanism for propagating cancellation signals, deadlines, and request-scoped values across API boundaries and between goroutines. Think of it as the "session" of a request — it ties together every operation that belongs to the same unit of work. ## Best Practices Summary 1. Propagate the same context through the entire request lifecycle: HTTP handler → service → DB → external APIs — any link that starts a fresh context keeps working after the client is gone. 2. Take `ctx` as the first parameter, named `ctx context.Context` — the fixed position is what makes context-aware APIs recognizable at a glance and what linters check. 3. Pass context through function parameters instead of storing it in a struct — the struct outlives the request that filled it, so later calls reuse a context that is already cancelled or belongs to someone else. 4. Pass `context.TODO()` rather than a `nil` context — `nil` panics on the first `Done()` or `Value()` call, far from the caller that passed it. 5. Call `cancel()` on all control-flow paths for `WithCancel`/`WithTimeout`/`WithDeadline`, unless ownership of the context and cancel function is explicitly returned or transferred — an uncalled `cancel()` keeps the child attached to its parent and leaks its timer until the parent finishes. 6. Create `contex