android-localisation 1.0.5

Zero-dependency Android strings.xml translation and verification using LLMs (Gemini, OpenAI, Anthropic, Ollama).

android-localisation

PyPI: android-localisation · CLI: android-localise · Repo: android-llm-localization

Translate your Android strings.xml into multiple languages using AI — Gemini, OpenAI, Anthropic, or a local model via Ollama. No paid translation service, no CSV exports, no copy-paste.

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The problem

Localizing an Android app the usual way means exporting strings, running them through Google Translate or some dashboard, cleaning up the output, and re-importing — for every language, every update. It's slow, error-prone, and the translations often feel robotic.

This tool does it differently. It reads your strings.xml, sends it to an LLM with context about your app, and writes the translated files directly into your project. The model understands UI language, keeps format specifiers intact, and produces natural-sounding output rather than word-for-word translations.

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Installation

pip install android-localisation

Requires Python 3.8+. No other dependencies.

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Quick start

# Step 1 — translate
android-localise translate --api-key YOUR_GEMINI_KEY

# Step 2 — fix any formatting issues the LLM may have introduced
android-localise fix

# Step 3 — verify nothing will crash at runtime
android-localise verify

That's the full workflow. Run these three commands after every time you update your English strings.

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What happens when you run translate

When you run android-localise translate --api-key YOUR_KEY, here's exactly what it does:

1. Looks for app/src/main/res/values/strings.xml — this is your English source
2. If --languages is provided, creates any missing values-<lang>/ folders automatically. Otherwise scans the res/ directory for existing values-* folders
3. For each locale, if strings.xml doesn't exist it creates the file first, then sends your full English XML to the LLM with a prompt that instructs it to translate naturally, preserve all XML structure, and never touch format specifiers like %1$s or %d
4. Writes the translated strings.xml directly into each locale folder
5. Waits 5 seconds between each language request to avoid hitting API rate limits

Defaults used when you don't specify anything:

What	Default
Provider	Gemini
Model	gemini-3.5-flash
Source directory	app/src/main/res
Delay between requests	5 seconds
App context	none (generic prompt)

Nothing is modified unless the translation comes back with valid XML. If a request fails, that language is skipped and logged — other languages continue.

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Setup

The only requirement is that app/src/main/res/values/strings.xml exists — your English source file.

For target languages, you have two options:

Option A — let the tool create everything:

android-localise translate --api-key YOUR_KEY --languages hi,es,fr,de

This creates values-hi/, values-es/, values-fr/, values-de/ folders and their strings.xml files automatically, then translates into each one.

Option B — pre-create folders yourself:

app/src/main/res/
├── values/               ← your English source (must exist)
│   └── strings.xml
├── values-hi/            ← empty folder is fine
├── values-es/
└── values-fr/

Run android-localise translate --api-key YOUR_KEY and it picks up any values-* folder it finds, creating strings.xml inside each one if it doesn't exist yet.

Get a free API key: Google Gemini AI Studio → Get API Key. The free tier handles most apps without hitting limits.

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Commands

translate

android-localise translate --api-key YOUR_KEY

Add --app-context with a one-line description of your app. This meaningfully improves translation quality — the model knows whether "record" means a music track, a health log, or a database entry:

android-localise translate \
  --api-key YOUR_KEY \
  --app-context "a workout tracking app for gym beginners"

All flags:

Flag	What it does	Default
--api-key	Your API key	reads from env var
--provider	Which AI to use: gemini openai anthropic custom	gemini
--model	Specific model to use	see Providers
--languages	Comma-separated language codes — creates folders and files automatically	—
--app-context	One-line description of your app	—
--res-dir	Path to your res/ folder	app/src/main/res
--base-url	API endpoint for local/custom providers	—
--sleep	Seconds to wait between language requests	5.0
--timeout	Seconds to wait for each API response (retries up to 3 times on timeout)	180

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fix

android-localise fix
android-localise fix --res-dir path/to/res

LLMs occasionally produce output that looks correct but breaks the Android build — curly apostrophes (') instead of escaped ones (\'), unescaped double quotes, or mangled % signs. This command scans every translated strings.xml and corrects these silently.

Strings marked formatted="false" are skipped — their % signs are literal, not format specifiers.

Always run this before verify and before building.

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verify

android-localise verify
android-localise verify --res-dir path/to/res

Takes every translated string that contains a format specifier (%1$s, %d, %1$f, etc.) and calls String.format() on it using Java's actual runtime. If a translated string would throw UnknownFormatConversionException or MissingFormatArgumentException in your app, this catches it before your users do.

Strings marked formatted="false" are skipped. Requires javac in your PATH. If you don't have it system-wide, run this from the Terminal tab inside Android Studio — it ships with a JDK.

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models

android-localise models                  # all providers
android-localise models --provider openai  # one provider

Lists every available model and fallback for each provider.

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Providers

By default the tool uses Gemini with gemini-3.5-flash. You can switch providers with --provider and optionally pin a specific model with --model.

Provider	Default model	Fallbacks	API key env var
gemini (default)	gemini-3.5-flash	gemini-3.1-flash-lite → gemini-2.5-flash → gemini-2.5-flash-lite	GEMINI_API_KEY
openai	gpt-5.4-mini	gpt-5-mini → gpt-4o-mini	OPENAI_API_KEY
anthropic	claude-haiku-4-5	claude-sonnet-4-6 → claude-opus-4-8	ANTHROPIC_API_KEY
custom	set with --model	none	OPENAI_API_KEY (optional)

If the default model returns a "model not found" error (e.g. it was deprecated), the tool automatically retries with the next fallback. If you pin a model with --model, no fallback is used.

Using OpenAI:

android-localise translate --provider openai --api-key YOUR_KEY
android-localise translate --provider openai --model gpt-5.4-mini --api-key YOUR_KEY

Using Anthropic:

android-localise translate --provider anthropic --api-key YOUR_KEY

Using a local model (no API key needed):

# Ollama
android-localise translate \
  --provider custom \
  --base-url http://localhost:11434/v1/chat/completions \
  --model llama3

# LM Studio
android-localise translate \
  --provider custom \
  --base-url http://localhost:1234/v1/chat/completions \
  --model mistral

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Environment variables

Set your API key as an env variable so you don't have to pass it every time:

# macOS / Linux
export GEMINI_API_KEY=your_key

# Windows PowerShell
$env:GEMINI_API_KEY = "your_key"

# Windows CMD
set GEMINI_API_KEY=your_key

Then just run:

android-localise translate

Variable	Used by
GEMINI_API_KEY	--provider gemini
OPENAI_API_KEY	--provider openai and --provider custom
ANTHROPIC_API_KEY	--provider anthropic
API_KEY	fallback for any provider if the provider-specific var is not set

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Full workflow example

# First time setup — create locale folders (macOS / Linux)
mkdir -p app/src/main/res/values-hi
mkdir -p app/src/main/res/values-es
mkdir -p app/src/main/res/values-de

# Windows PowerShell
New-Item -ItemType Directory -Force app/src/main/res/values-hi
New-Item -ItemType Directory -Force app/src/main/res/values-es
New-Item -ItemType Directory -Force app/src/main/res/values-de

# Set your key once
export GEMINI_API_KEY=your_key   # or $env:GEMINI_API_KEY on Windows

# Translate, fix, verify
android-localise translate --app-context "a habit tracking app"
android-localise fix
android-localise verify

# Build your app as usual
./gradlew assembleDebug

After this, whenever you add or change strings in your English strings.xml, run the same three commands again. Existing translated strings will be overwritten with fresh translations.

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Platform support

This project is developed and manually tested on Windows only at the moment. It is written in pure Python (stdlib only) and should run on macOS and Linux, but those platforms have not been verified by the maintainer yet.

We especially need help testing on:

• macOS — translate, fix, verify (including javac / Android Studio terminal)
• Linux — same workflow, plus common CI environments

If you use another OS, please try the quick start workflow and report what you find:

• Works? — open a GitHub issue titled e.g. Confirmed working on macOS 14 with your OS, Python version, and provider used
• Broken? — open a bug report with the full error output
• Want to help more? — see Contributing and CONTRIBUTING.md

Cross-platform fixes and test notes in pull requests are very welcome.

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Limitations

Topic	Detail
Platform testing	Maintainer-tested on Windows only — macOS and Linux need community verification (see Platform support)
Scope	Translates values/strings.xml only — not plurals.xml, arrays.xml, or other resource files
Overwrite	Each run replaces the entire strings.xml in each locale folder with a fresh LLM translation
Folder scan	Without --languages, every values-* folder is treated as a locale. Qualifier-only folders like values-night or values-sw600dp may be picked up incorrectly — prefer --languages or keep only locale folders in res/
Network	translate requires internet access to reach the LLM API (except local custom providers)
JDK	verify requires javac on your PATH

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Troubleshooting

Problem	What to try
Could not find English strings.xml	Check --res-dir points to your res/ folder and values/strings.xml exists
No locale directories found	Add --languages hi,es,fr or create values-<lang>/ folders manually
API auth errors	Confirm your key env var or --api-key matches the --provider
javac not found	Install a JDK or run verify from Android Studio's terminal
Build fails on apostrophes	Run android-localise fix before building
% crashes at runtime	Run android-localise verify — it catches bad format specifiers before release
Wrong folder translated	Use --languages to target exact locale codes instead of folder scan

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Roadmap

• iOS support — translate Localizable.strings and Localizable.xcstrings for iOS/macOS apps. The LLM prompt and provider logic is already in place — it mainly needs a parser for Apple's strings format and the right folder structure (<lang>.lproj/). Good first contribution if you're familiar with iOS projects.
• Smarter locale folder detection — skip non-locale values-* qualifiers (night, sw600dp, v21, etc.) when scanning without --languages
• Automated test suite — unit tests for fix, XML parsing, and format-specifier edge cases
• Cross-platform verification — confirm translate, fix, and verify on macOS and Linux (Windows is maintainer-tested today)

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Contributing

Bug reports, pull requests, and cross-platform testing are all welcome. For larger changes, open an issue first.

No code required — if you are on macOS or Linux, running the tool and filing an issue (pass or fail) is a real contribution. See Platform support.

See CONTRIBUTING.md for the full development workflow, branch strategy, and release process.

git clone https://github.com/BharathKmalviya/android-llm-localization
cd android-llm-localization
git checkout dev
pip install -e .

Day-to-day work happens on the dev branch. Releases are merged to master via pull request, which triggers automated PyPI publishing.

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Security

To report a security vulnerability, see SECURITY.md. Please do not open public issues for security-sensitive reports.

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License

MIT