name: go-i18n description: Use when defining or updating Go CLI i18n rules in this repo, especially around locale files, env-based language selection, and key naming.

Go CLI i18n

Overview

This skill documents the Go CLI i18n rules used in this repo, including language detection, locale files, and key naming conventions.

When to Use

• You add or edit any user-facing CLI string in cmd/skills-x
• You need to add a new skill description for list output
• You are troubleshooting mixed language output or missing translations

Architecture Snapshot

• i18n runtime: cmd/skills-x/i18n/i18n.go
• Locale files: cmd/skills-x/i18n/locales/zh.yaml, cmd/skills-x/i18n/locales/en.yaml
• Embed: //go:embed locales/*.yaml (locales are embedded at build time)

Language Selection

Priority order in detectLanguage():

1. SKILLS_LANG
2. LANG
3. LC_ALL
4. Default: zh

Normalization uses prefix matching:

• zh, zh_CN, zh_TW → zh
• en, en_US → en
• Unsupported → zh

Using i18n in Go

Initialize once (early in main):

import "github.com/castle-x/skills-x/cmd/skills-x/i18n"

i18n.MustInit()

Translate strings:

title := i18n.T("list_header")
msg := i18n.Tf("init_success", skillName)

Missing keys return the key itself (useful for spotting gaps).

Key Naming Conventions

Use lowercase + underscores with category prefixes:

• app_ app metadata
• cmd_ command descriptions/flags
• list_ list output
• init_ init output
• err_ error messages
• cat_ category names
• skill_ skill descriptions
• meta_ meta warnings

Rule: Never mix Chinese and English in the same string. Use two locale keys instead.

Adding New Strings

1. Add the same key to both locale files:
   • cmd/skills-x/i18n/locales/zh.yaml
   • cmd/skills-x/i18n/locales/en.yaml
2. Use i18n.T / i18n.Tf in Go code.
3. Rebuild (make build) to embed the updated YAML.
4. Test:
   • SKILLS_LANG=zh ./bin/skills-x list
   • SKILLS_LANG=en ./bin/skills-x list

New Skill Description

Add a skill_<skill-name> key to both locale files. The list view reads descriptions from i18n, not from the skill file.

Example

# locales/en.yaml
init_success: "Installed: %s"

# locales/zh.yaml
init_success: "安装成功: %s"

fmt.Println(i18n.Tf("init_success", skillName))

Quick Reference

Common Mistakes

• Only adding a key in one locale file
• Hardcoding mixed-language strings
• Forgetting to rebuild after YAML changes
• Formatting with fmt.Sprintf before calling i18n.Tf