# Go Guidelines > Go best practices for performance, modern syntax, generics, patterns, testing, error handling, and concurrency. Use when writing or reviewing Go code. Use when this capability is needed. - Skill: `tomevault-io/go-guidelines` (Agent Skill, multi-file: 2 files) - Install (CLI): `npx skillmds@latest add tomevault-io/go-guidelines` - Raw SKILL.md: https://api.skillmd.com/api/skills/tomevault-io/go-guidelines/raw - Safety review: pending (external: skill-scanner PASS, skillspector PASS) - Works with: Claude Code, Claude.ai, OpenAI Codex - Category: Coding & Dev Tools - Author: tomevault-io (https://skillmd.com/u/tomevault-io) - Updated: 2026-09-17 - Page: https://skillmd.com/skills/tomevault-io/go-guidelines --- # Go Guidelines ## Detected Go Version !`grep -rh "^go " --include="go.mod" . 2>/dev/null | cut -d' ' -f2 | sort | uniq -c | sort -nr | head -1 | xargs | cut -d' ' -f2 | grep . || echo unknown` ## How to Use DO NOT search for go.mod files or try to detect the version yourself. Use ONLY the version shown above. **If version detected (not "unknown"):** - Say: "This project is using Go X.XX, so I'll follow Go best practices and modern syntax up to and including this version. If you'd prefer a different target version, just let me know." - Do NOT list features, do NOT ask for confirmation **If version is "unknown":** - Say: "Could not detect Go version in this repository" - Use AskUserQuestion: "Which Go version should I target?" with options ... / [1.20] / [1.21] / [1.22] / [1.23] / [1.24] / [1.25] / [1.26] / ... ## Reference Loading **Read ONLY the reference file(s) relevant to your current task. Do NOT load all files at once.** When reading reference files, **stop at the detected Go version boundary** — ignore features from newer versions. | When you are... | Read this reference | |---|---| | Using version-specific Go syntax or idioms | [references/modern-syntax.md](references/modern-syntax.md) | | Optimizing performance, struct layout, escape analysis | [references/performance.md](references/performance.md) | | Working with goroutines, channels, sync, select, false sharing | [references/concurrency.md](references/concurrency.md) | | Writing HTTP servers, shutdown, health checks, middleware, interfaces, io.Reader | [references/patterns.md](references/patterns.md) | | Writing tests, mocks, benchmarks, fuzz tests | [references/testing.md](references/testing.md) | | Handling errors, wrapping, custom error types | [references/error-handling.md](references/error-handling.md) | | Working with slices, maps, append, memory leaks | [references/slices-and-maps.md](references/slices-and-maps.md) | | Using context.Context, values, cancellation, timeouts | [references/context-patterns.md](references/context-patterns.md) | | Using generics, type parameters, constraints | [references/generics.md](references/generics.md) | | Debugging subtle bugs, nil traps, shadowing, sync copying, defer, time | [references/pitfalls.md](references/pitfalls.md) | **Multiple topics may apply.** For example, writing a concurrent function with tests: load `modern-syntax.md` + `concurrency.md` + `testing.md`. --- ## After Making Changes After making Go code changes, run static analysis and tests on the changed packages: ```bash which golangci-lint >/dev/null 2>&1 && golangci-lint run ./path/to/changed/package/... || go vet ./path/to/changed/package/... go test ./path/to/changed/package/... -race ``` - Prefer `golangci-lint` when available, fall back to `go vet` - Always run tests with the race detector - Fix all reported issues in the changed code before finishing - Do not fix pre-existing issues in unrelated code - If neither linter is available, skip silently and continue --- > Source: [mhmtszr/go-guidelines](https://github.com/mhmtszr/go-guidelines) — distributed by [TomeVault](https://tomevault.io).