# Travelthepath My Claude Codex Go Playbook

> Go Playbook (1.21-1.26)

- Skill: `tomevault-io/travelthepath-my-claude-codex-go-playbook` (Agent Skill, multi-file: 2 files)
- Install (CLI): `npx skillmds@latest add tomevault-io/travelthepath-my-claude-codex-go-playbook`
- Raw SKILL.md: https://api.skillmd.com/api/skills/tomevault-io/travelthepath-my-claude-codex-go-playbook/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/travelthepath-my-claude-codex-go-playbook

---


# Go Playbook (1.21-1.26)

Idiomatic Go patterns and production-ready recipes. Load only the reference file(s) needed for the current task.

## When to Use

- Writing, reviewing, or refactoring Go code where the right idiom or API choice is not obvious
- Touching error paths, wrapping, classification, logging, or transport mapping
- Creating helpers/utilities or choosing between repo code, stdlib, dependencies, and custom code
- Designing packages, structs, or dependency injection
- Optimizing performance (PGO, GC tuning, allocations)
- Writing tests (table-driven, fuzz, integration, benchmarks)
- Working with gRPC/Protobuf, databases, or structured logging

**Not for:** Non-Go languages, generic algorithms unrelated to Go idioms, trivial syntax questions, or mechanical edits with no Go design, error, testing, API, performance, or tooling judgment.

## Version Gate

Before using version-specific APIs, check the repo's `go.mod` `go` directive. If the module targets an older Go version, use the fallback pattern already shown nearby or the older equivalent in the reference.

## Quick Reference

| Idiom | Min Go | Pattern | Section |
|-------|--------|---------|---------|
| Error matching | 1.26 | `errors.AsType[*T](err)` | `references/errors.md` |
| Error wrapping | Any | `fmt.Errorf("context: %w", err)` | `references/errors.md` |
| Error ownership | Any | Trace source -> wrap -> classify -> log -> transport map | `references/errors.md` |
| New helper gate | Any | Existing repo -> stdlib -> compiler-backed stdlib -> go.mod deps -> custom | `references/design.md` |
| Goroutine launch | 1.25 | `wg.Go(func() { ... })` | `references/concurrency.md` |
| Bounded parallelism | Dependency | `conc/pool` with `WithMaxGoroutines` | `references/concurrency.md` |
| Iterators | 1.23 | `iter.Seq[V]`, `iter.Seq2[K,V]` | `references/version-notes.md` |
| HTTP routing | 1.22 | `mux.HandleFunc("GET /users/{id}", h)` | `references/version-notes.md` |
| Test concurrency | 1.25 | `testing/synctest` virtual time | `references/testing.md` |
| Benchmarks | 1.24 | `b.Loop()` | `references/testing.md` |
| Logging fan-out | 1.26 | `slog.NewMultiHandler` | `references/logging.md` |
| Container perf | 1.25 | Auto GOMAXPROCS from cgroup | `references/performance.md` |
| GC | 1.26 | Green Tea GC default | `references/performance.md` |
| Lint | 1.24 | `golangci-lint v2` with `go tool` | `references/tooling.md` |

## Reference Routing

Read only the file(s) that match the current work:

- `references/errors.md` — wrapping, sentinels, custom types, `errors.AsType[T]`, error ownership, duplicate logging
- `references/concurrency.md` — `WaitGroup.Go`, conc, `errgroup`, context, goroutine leaks, graceful shutdown
- `references/version-notes.md` — Go 1.22-1.26 APIs: iterators, ServeMux, tool directives, `omitzero`, flight recorder, release highlights
- `references/design.md` — stdlib-first helper decisions, interfaces, packages, dependency injection, structs, method receivers, zero values
- `references/testing.md` — table-driven tests, `testing/synctest`, mockery v3, fuzzing, testcontainers, artifacts
- `references/logging.md` — slog setup, child loggers, groups, `NewMultiHandler`, redaction
- `references/performance.md` — PGO, GOMAXPROCS, Green Tea GC, memory limits, `sync.Pool`, allocation analysis
- `references/grpc-protobuf.md` — buf, gRPC status errors, rich errors, interceptors, health checks
- `references/database.md` — Ent, `database/sql` pools, transactions
- `references/tooling.md` — golangci-lint v2, formatting, essential commands, anti-patterns

---
> Source: [TravelThePath/my-claude-codex](https://github.com/TravelThePath/my-claude-codex) — distributed by [TomeVault](https://tomevault.io).
<!-- tomevault:4.0:skill_md:2026-05-22 -->