LingFlow AI

AI-powered translation, text correction, and prompt engineering — right in your browser.

Install · Features · Usage · Build from source · Privacy

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LingFlow AI is an open-source, Manifest V3 browser extension that combines AI translation, text correction, OCR, text-to-speech, and prompt engineering (graphics, video & code) in a single workspace. Work from the popup, side panel, or directly on any page.

v2.0 UI languages: English and Polish (_locales/en, _locales/pl). Translation targets still include 26 languages in the language picker.

How it works

LingFlow AI supports two tiers:

Tier	What you get	Requirements
Chrome AI (Free)	Translation via Chrome's built-in Translator API; correction and prompts via Prompt API (limited to supported languages)	Chromium 138+ with Built-in AI. First use downloads the on-device model (~1 GB). No API key. Text stays on-device.
BYOK (Bring Your Own Key)	Full translation, correction, tone rewriting, prompt engineering, and OCR via OpenAI or Google Gemini	Your own API key. Text sent to the provider over HTTPS.

Chrome AI does not send your content to external servers. The browser may need internet on first use to download the on-device model.

Installation

Chrome Web Store

1. Visit the LingFlow AI listing (link coming soon).
2. Click Add to Chrome.
3. Pin the extension for quick access.

From a release ZIP

1. Download lingflow-ai-v2.0.0-rc.2.zip from GitHub Releases.
2. Unzip to a folder.
3. Open chrome://extensions → Developer mode → Load unpacked → select the folder.

From source

See Build from source.

First-time setup

1. Open the extension → Settings.
2. Pick your AI engine:
   • Chrome AI (Free) — on-device, no key. Model download progress is shown on first use.
   • OpenAI or Google Gemini — paste your API key for OCR and full language/tone support.
3. Set default target language and save.

API keys: OpenAI · Google Gemini

Features

Translation

• 26 target languages with auto-detect and swap.
• Tone & register (BYOK only): Auto, Formal, Casual, Business, Friendly.
• Chrome AI uses the native Translator API; unsupported pairs fall back to Prompt API.
• BYOK providers support all pairs with tone control.

Text correction

• Same source and target language → grammar and style correction.
• Chrome AI: Prompt API (languages: en, ja, es, de, fr).
• BYOK: full model capabilities with tone.

Prompt engineering

• Category Pills: Quick switching between Graphics, Video, and Code prompt domains.
• Graphics (Nano Banana & Diffusion models):
  • Photo: Structured formula (Subject, Style, Composition, Lighting, Camera, Constraints).
  • Graphic design: Vector, 3D icons, minimal, editorial, and branding visual prompts.
  • Enhance / Expand: Turn rough text or tag-lists into full descriptive prompts.
  • Web UI Mockup: Clean Dribbble/Behance-level UI mockups (strictly no hands/stock lifestyle clutter).
  • Mobile App UI: Flat and isometric mobile screen presentations with touch ergonomics.
  • 4-Screen UI Collage: Panoramic 16:9 4-screen app showcase (Onboarding, Dashboard, Detail, Profile).
• Video (Sora, Runway, Kling, Luma, Veo):
  • Cinematic: Dynamic camera angles, volumetric fog, fluid dynamics, and 60fps lighting cues.
  • Image-to-Video (I2V): Static frame animation with subject consistency.
  • 3D Product Commercial: Macro studio lighting and luxury industrial design reveal.
  • Social Media: High-energy hooks for TikTok, Reels, and Shorts.
  • Seamless Loop: Ambient backgrounds, lofi animations, and wallpaper motion.
• Code (AI Assistants & Design Directives):
  • AI Coding Agent: Concise, actionable task prompts with signatures, logic, and edge cases.
  • UI Aesthetic Spec: Avant-garde design direction, spatial rhythm, and kinetic styling specifications.
• Inline Controls: Direct inline aspect ratio selector (16:9, 9:16, 1:1, 4:5, 21:9) and camera motion selector (zoom-in/out, pan, tracking, orbit, fpv, static).

OCR & screenshot translation (BYOK only)

• Region capture on any page.
• OpenAI or Gemini vision models.
• Transcription + translation with copy and TTS.

On-page translation

• Floating button on selection, tooltip UI, in-place replace.

History & TTS

• Persistent history (max 100 items), search, filter, pin.
• Web Speech API or Chrome TTS.

Usage

Task	How
Translate	Translate tab → languages → text → action button
Fix text	Same source/target language → Translate
Generate prompt	Prompt tab → Category (Graphics/Video/Code) → Type & Parameters → Generate
OCR	Camera icon → drag region (BYOK)
On-page	Select text → floating button
Side panel	Ctrl+Shift+Y / Cmd+Shift+Y

Tech stack

• Vanilla ES6+, Tailwind CSS 3.x, Manifest V3
• Chrome Built-in AI, @google/genai, OpenAI Chat Completions
• webpack, Vitest, Playwright

Models and defaults: popup/modules/constants.js

Build from source

Prerequisites: Node.js 20+ (see .nvmrc), Chromium browser.

git clone https://github.com/dilitS/LinkFlowAI.git
cd LinkFlowAI
npm install
npm run verify          # lint + test + build + manifest checks
npm run package         # creates releases/lingflow-ai-v<version>.zip

Load unpacked: chrome://extensions → Developer mode → project root folder.

popup/output.css is committed; re-run npm run build:css after Tailwind class changes.

Manual QA: see SMOKE-TEST.md.

Privacy

• Chrome AI: on-device processing; model download may use network once.
• BYOK: HTTPS to OpenAI or Google. Keys in chrome.storage.local (trusted contexts only).
• No telemetry by LingFlow AI.

Full policy: PRIVACY.md · Contact: privacy@lingflow.ai

Known limitations

• OCR requires BYOK (no on-device vision in v2.0).
• Chrome AI depends on hardware, OS, and browser version.
• Chrome AI Prompt API languages: en, ja, es, de, fr.
• UI localized to English and Polish only in v2.0.
• Provider rate limits apply to BYOK.

Roadmap

See ROADMAP.md and PLAN-AKTUALIZACJI-V2.md.

Contributing

See CONTRIBUTING.md. Run npm run verify before opening a PR.

License

MIT License