Runtime Localization Middleware for UI Systems

Production-safe localization middleware for UI systems. Prevents broken interfaces, preserves UX integrity, and integrates into CI/CD pipelines.

---

What This Actor Does

Runtime Localization Middleware for UI Systems is not a generic translation tool. It's a localization middleware specifically engineered for UI string safety.

A mistranslated UI error can break onboarding, compliance, or conversions — this Actor prevents that.

Core Capabilities

Feature	What It Means
UX Integrity Lock	Error messages remain errors. Warnings stay warnings. Confirmation prompts stay cautious. No tone softening that breaks UX.
Placeholder Preservation	Variables like {{name}}, {count}, %s are never mistranslated or corrupted
Structured Localization	Handles JSON/YAML i18n bundles, not just raw text
Tone Enforcement	Apply friendly, formal, or neutral tones consistently across all languages
Batch Processing	Translate entire locale files into 10+ languages in a single run

---

Why This Exists

This Actor is intentionally not designed for documentation, blogs, or long-form text.

It solves a specific, high-stakes problem:

UI text is code. A broken translation = a broken app.

Generic translators don't understand:

• That {{username}} must stay exactly as {{username}}
• That "Cancel" in a destructive action context must remain cautious
• That error messages need severity preservation

This Actor does.

---

Built for Automation

Designed to run inside CI/CD pipelines, MCP servers, and agent workflows.

Integration Examples

# CI/CD Pipeline (GitHub Actions)
- name: Localize UI strings
  run: |
    apify call your-username/runtime-ui-text-translator \
      -i '{"uiStrings": ${{ steps.extract.outputs.strings }}, "targetLanguages": ["fr","de","ja"]}'

// MCP Server Integration
const localizedStrings = await apifyClient.call('runtime-ui-text-translator', {
    uiStrings: appStrings,
    targetLanguages: ['es', 'pt', 'zh'],
    tone: 'professional'
});

---

Input Configuration

Field	Type	Required	Description
uiStrings	Object	Yes	Key-value pairs of UI strings to localize
targetLanguages	Array	Yes	ISO 639-1 codes (e.g., ["fr", "de", "ja"])
lingoApiKey	String	Yes	Your Lingo.dev API key (stored securely)
sourceLanguage	String	No	Source language code (default: en)
tone	String	No	friendly
placeholders	Array	No	Patterns to preserve (e.g., ["{{name}}", "{count}"])

Example Input

{
  "uiStrings": {
    "auth.login.title": "Welcome back",
    "auth.login.button": "Sign in",
    "auth.login.error": "Invalid email or password",
    "profile.greeting": "Hello, {{username}}",
    "checkout.confirm": "Are you sure you want to proceed?"
  },
  "sourceLanguage": "en",
  "targetLanguages": ["fr", "de", "es"],
  "tone": "professional",
  "placeholders": ["{{username}}"],
  "lingoApiKey": "YOUR_LINGO_API_KEY"
}

---

Output

Localized strings are returned in the same structure as input, grouped by language:

{
  "fr": {
    "auth.login.title": "Bon retour",
    "auth.login.button": "Se connecter",
    "auth.login.error": "Adresse e-mail ou mot de passe incorrect",
    "profile.greeting": "Bonjour, {{username}}",
    "checkout.confirm": "Êtes-vous sûr de vouloir continuer ?"
  },
  "de": {
    "auth.login.title": "Willkommen zurück",
    "auth.login.button": "Anmelden",
    "auth.login.error": "Ungültige E-Mail-Adresse oder Passwort",
    "profile.greeting": "Hallo, {{username}}",
    "checkout.confirm": "Sind Sie sicher, dass Sie fortfahren möchten?"
  }
}

Output Locations

• Key-Value Store: OUTPUT record contains the full localized JSON
• Dataset: Translation status summary for each language

---

Architecture

+-------------------------------------------------------------+
|                    YOUR CI/CD / MCP / AGENT                 |
+-------------------------------------------------------------+
                              |
                              v
+-------------------------------------------------------------+
|           Runtime Localization Middleware for UI Systems    |
|  +--------------+  +--------------+  +-------------------+  |
|  |    Input     |--|   Lingo.dev  |--|  UX Integrity     |  |
|  |   Validator  |  |    Engine    |  |  Lock (Tone +     |  |
|  |              |  |              |  |  Severity)        |  |
|  +--------------+  +--------------+  +-------------------+  |
+-------------------------------------------------------------+
                              |
                              v
+-------------------------------------------------------------+
|              PRODUCTION-READY LOCALE FILES                  |
|         (fr.json, de.json, ja.json, es.json, ...)           |
+-------------------------------------------------------------+

---

FAQ

Is this for translating documentation or READMEs?

No. This Actor is strictly for UI strings — short, context-heavy labels, buttons, error messages, and prompts. For long-form content, use a different tool.

How is this different from a generic translator?

Generic translators treat text as text. This Actor treats UI text as code — preserving placeholders, maintaining severity context, and enforcing tone consistency.

Can I use this in my CI/CD pipeline?

Yes. This is the primary use case. Run it on every build to generate fresh locale files automatically.

Is my API key safe?

Yes. The lingoApiKey field is marked as isSecret and is never exposed in logs or dataset output.

What happens if translation fails for a language?

The Actor logs the error and continues with other languages. The dataset output includes status for each language so you can handle failures gracefully.

---

Resources

• Lingo.dev Documentation
• Apify Platform
• i18next — Compatible i18n library
• react-intl — Compatible i18n library

---

Support

For Actor issues, use the Issues tab on Apify. For translation quality or Lingo.dev questions, refer to Lingo.dev Documentation.