Getting it into your agent
This one installs as part of its plugin. Adding the marketplace and installing the plugin brings it with everything else the plugin ships.
/plugin marketplace add int2t05/engineering-skills/plugin install engineering-skillsWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/int2t05/engineering-skills/i18n)<a href="https://agentmods.dev/skills/int2t05/engineering-skills/i18n"><img src="https://agentmods.dev/badge/skills/int2t05/engineering-skills/i18n.svg" alt="Measured on agentmods" height="20"></a>What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00068 | $0.01785 |
| Opus 5 | $0.00034 | $0.00892 |
| Sonnet 5 | $0.00014 | $0.00357 |
| Haiku 4.5 | $0.00007 | $0.00178 |
Grade A, and why
i18n scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 8d ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
How it starts
The opening of the file, as written. The whole thing — 140 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Internationalization (i18n)
Internationalization is not translation — it is the engineering discipline of making an application locale-aware so translation is a content change, not a code change. Hardcoded strings, locale-blind formatting, and LTR-only layouts all become bugs the moment a second locale is needed. Build the scaffolding before the second locale arrives, not after.
When to use
- Preparing an application for multiple locales (message extraction, locale routing, formatting)
- Adding RTL support or locale-specific pluralization/gender rules
- Auditing an existing app for hardcoded strings or locale-blind formatting
- Triggers on "i18n", "localization", "l10n", "RTL", "国际化", "本地化", "多语言"
Not for: frontend visual design (use frontend-design); API contract design (use api-design).
i18n is a cross-cutting implementation discipline touching frontend, backend, and build tooling.
Steps
1. Audit the locale surface
Before writing code, find every locale-sensitive surface in the application:
- Hardcoded user-facing strings (UI labels, error messages, email templates, push notifications)
- Formatted values: dates, times, numbers, currencies, percentages, units
- Pluralization and gender-dependent phrasing
- Layout assumptions: LTR-only CSS, fixed-width containers, text concatenation
- Locale-affecting config: timezone handling, first-day-of-week, calendar system
Verify: the audit produces a list of locale-sensitive surfaces grouped by type, not a vague "needs translation."
2. Extract messages
Replace every hardcoded string with a message ID resolved through an i18n library. Messages live in locale files keyed by ID, not inline:
- Use the framework's i18n library (react-intl, i18next, FormatJS, vue-i18n, or equivalent)
- Message IDs are descriptive (
user.profile.edit_button), not positional (btn_3) - Leave source-locale strings as the fallback; never leave a missing-key hole in production
- Extract programmatically (CLI extractors) where the framework supports it — manual extraction drifts
What ships with it
3 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 8d ago First seen · 140 lines · 68 tokens per session scan A d97c26f8d853
i18n is a skill published in the GitHub repository int2t05/engineering-skills (3 stars, last pushed 7d ago), licensed MIT. It adds 68 tokens to every session and 1,785 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.
Other skills, from other repositories
pr-workflow
Crear pull requests completas con descripcion, labels y reviewers.
review-all
Multi-agent code review for diffs (project-agnostic). Covers standards, bugs, security, DRY, smells, perf, tests, API contracts, a11y/i18n. Verifies each finding to eliminate false positives. Use for /review-all, pre-PR/pre-commit review, or auditing uncommitted/staged changes.
fec-drawio-studio
An editable workflow for making technical diagrams in draw.io (also called diagrams.net), with the original .drawio file saved alongside exported images or documents. It covers architecture, database, UML, sequence, flow, machine-learning, and code-structure diagrams.
fec-nextjs-project-standard
A development guide for Next.js 14 and newer projects using App Router, Next.js’s file-based routing system. It covers server-rendered pages, layouts, data loading, middleware, metadata, and server actions.
fec-monorepo-project-standard
A guide for organising a monorepo, which is one code repository containing several applications and shared packages. It covers workspace dependencies, folder structure, build tasks, testing, caching, and package releases.
fec-route-protection
A guide for protecting front-end routes, meaning the pages and URLs of a web application, based on whether someone is signed in and what permissions they have. It covers login checks, role-based access, expired sessions, and redirects.