日本語 | English
AI-powered coding practice generator for VS Code
Generate exercises, run code, auto-judge, and track your progress — all inside your editor.
Most coding practice platforms run in a browser. CodePractice brings the entire experience inside VS Code — where you already write code. No context switching, no browser tabs. Generate a problem, solve it in the editor, get instant feedback with auto-judging, and track your progress in the same workflow.
Key highlights:
- Works 100% offline with 138 built-in exercises, localized offline practice text, and verified offline bug-fix variants
- Supports 8 AI providers (free tiers available) for unlimited unique exercises
- Built-in code runners — no external setup for Java, TypeScript, or SQL
- Multi-test validation with detailed pass/fail feedback per test case when the practice includes multiple test inputs
- Review scheduling to help you revisit practice topics over time
| Feature | Description |
|---|---|
| 3 Languages | Java, TypeScript, SQL — each with built-in runner |
| Adaptive Difficulty | 5 levels, auto-adjusted based on your performance |
| AI-Generated | Unique problems every time via free AI providers |
| 138 Offline Practices | Full built-in exercise bank that works without internet |
| Custom Practice | Describe what you want to practice, AI generates it in AI mode |
| Bug Fix Mode | AI mode uses real GitHub code; offline mode generates verified local bug-fix variants |
| Feature | Description |
|---|---|
| Built-in Runners | Run Java, TypeScript, SQL directly — no terminal needed |
| Multi-Test Cases | Each exercise validated against multiple inputs |
| Auto Judge | Output comparison with intelligent normalization |
| Partial Pass Feedback | See exactly which test cases failed and why |
| SQL Schema View | In-memory SQLite with visual schema browser |
| Feature | Description |
|---|---|
| AI Feedback | Line-by-line code review on wrong solutions |
| Progressive Hints | Hints inserted as comments in your code |
| Quick Solve | AI solves and explains the approach |
| Teach Me | Step-by-step teaching with examples |
| Ghost Text | Inline code suggestions while you type |
| Alternative Solutions | 2-3 different approaches to the same problem |
| Cross-Language | Open translated solution files with per-line notes; offline only shows targets authored for that practice |
| Localized Practice Text | Offline titles, tasks, hints, judge feedback, alternative-method notes, and cross-language notes follow the selected UI language |
| Feature | Description |
|---|---|
| XP System | Earn XP for each completed exercise |
| Level Progression | Difficulty scales as you improve |
| Topic Mastery | Per-language, per-topic retention tracking |
| Daily Goals | Track daily practice targets |
| Weekly Trends | 7-day practice history with pass rates |
| Review Scheduling | Helps surface practice topics again over time |
- UI languages: English, Japanese, Turkish
- Offline practice prose is localized for Japanese and Turkish while runnable code stays in English
- Bug-fix explanations, custom-panel AI-required messages, and cross-language annotations follow the selected UI language
Click "Open in GitHub Codespaces" above → wait for setup → click the CodePractice icon in the sidebar. Everything is pre-configured: Node.js, JDK 21, and the extension auto-installed.
git clone https://github.com/barankul/codepractice.git
cd codepractice
npm install
npm run compilePress F5 in VS Code to launch the extension, then click the CodePractice icon in the sidebar.
npm install && npm run package
npx @vscode/vsce package --no-dependencies -o codepractice.vsix
code --install-extension codepractice.vsix| Language | Requirement | Auto-install? |
|---|---|---|
| SQL | Nothing — built-in SQLite (WASM) | N/A |
| TypeScript | Node.js | Comes with VS Code |
| Java | JDK 21+ | Yes — click "Install JDK Now" when prompted |
Java auto-install uses
winget(Windows),brew(macOS), orapt/dnf(Linux). If none are available, it downloads directly from Adoptium.
CodePractice supports the 8 provider options currently exposed in Settings. Models are configurable; the table below reflects the current built-in selections shown in the settings UI.
| Provider | Pricing | Current selectable models |
|---|---|---|
| Groq | Free tier available | GPT-OSS 120B, GPT-OSS 20B, Llama 3.3 70B, Llama 3.1 8B |
| Cerebras | Free tier available | Qwen 3 235B, GPT-OSS 120B, Llama 3.1 8B |
| Together AI | Free credit on signup | Llama 3.3 70B Turbo, Llama 3.1 8B Turbo |
| OpenRouter | Free tier available | Nemotron 3 Super 120B, Qwen3 Coder 480B, GPT-OSS 120B, Hunter Alpha 1T, Llama 3.3 70B, Gemini 2.0 Flash, Qwen 3 235B |
| Google Gemini | Free tier available (region dependent) | Gemini 2.5 Flash, Gemini 2.5 Pro, Gemini 2.0 Flash |
| OpenAI | Pay-as-you-go | GPT-4.1 Mini, GPT-4.1 Nano, GPT-4.1, o4-mini, o3 |
| Claude | Pay-as-you-go | Sonnet 4.6, Sonnet 4, Haiku 4.5, Opus 4.6 |
| Local | Free (self-hosted) | LM Studio, Ollama, or any OpenAI-compatible endpoint |
Setup: Open sidebar → gear icon → select provider → enter API key → Save.
No API key? CodePractice includes 138 built-in exercises that work completely offline with judging, localized hints and feedback, offline bug-fix mode, progress tracking, and authored cross-language comparisons where available.
Works without any API key or internet connection. Toggle between AI and Offline mode from the main screen.
- 138 practices across Java, TypeScript, and SQL
- All difficulty levels (1-5)
- Offline bug-fix mode for the built-in catalog
- Multi-test validation when the selected practice includes multiple test cases
- Full judging with feedback
- Hints, judge feedback, alternative methods, and cross-language notes localized to English, Japanese, or Turkish
- Cross-language comparison for authored offline targets only; unsupported targets are hidden
- Progress tracking and XP
- Randomized values — different numbers/names each time
Offline limitations:
- Custom Practice, AI Chat, Teach Me, and other provider-backed features still require AI mode
- SQL offline practices do not expose cross-language targets
- In bug-fix mode, the sidebar focuses on the buggy file and hides "Other Ways" / "Other Languages"
Topics covered:
| Java | TypeScript | SQL |
|---|---|---|
| Array, ArrayList | Arrays, Objects | SELECT, WHERE |
| HashMap, HashSet | Functions, Types | JOIN, GROUP BY |
| String, Methods | Union Types, Async | ORDER BY, INSERT/UPDATE |
| Shortcut | Action |
|---|---|
Ctrl+Enter |
Run SQL file |
Ctrl+Shift+E |
Explain selected code |
src/
extension.ts Entry point & command registration
appView.ts Webview provider (sidebar UI host)
webviewHtml.ts Frontend UI (HTML/CSS/JS)
aiHelpers.ts AI provider routing & configuration
aiGenerators.ts Prompt engineering for all AI features
javaRunner.ts Java compilation & execution
sqlRunner.ts SQL execution via sql.js (WASM)
multiTestRunner.ts Multi-test harness generation
outputChecker.ts Output normalization & comparison
parsers.ts AI response parsing & error patterns
progressTracker.ts XP, levels, and review scheduling
practiceRandomizer.ts Offline practice value randomization
demoData.ts Offline mode detection, selection, and localization hookup
offlineBugFix.ts Verified offline bug-fix mutation generation
offlinePracticeLocalization.ts
Offline prose / feedback localization (en/ja/tr)
offlinePracticeAudit.ts Offline catalog integrity + localization coverage checks
offlineSmokeAudit.ts Full offline runtime smoke matrix
offlineSmokeCli.ts CLI entry for offline smoke reports
smokeTest.ts Automated AI quality audit
i18n.ts Internationalization (en/ja/tr)
offlinePractices/ 138 built-in exercises
handlers/
generateHandler.ts Practice generation flow
executionHandler.ts Code execution & judging pipeline
aiFeatureHandler.ts AI features (hints, teach, solve, ghost text)
settingsHandler.ts Settings & progress management
core-java/src/
CoreMain.java Practice generator (Java subprocess)
Ai.java AI client for Java-side generation
DebugMain.java Bug fix practice generator
Tech stack: TypeScript × esbuild × VS Code Webview API × sql.js (WASM)
For extension-side AI audits:
npm testFor the offline catalog smoke matrix:
npm run offline:smokeThe offline smoke command writes reports to:
.codepractice/offline-smoke/report.txt.codepractice/offline-smoke/report.json
It verifies topic coverage, runtime health, offline bug-fix generation, and Japanese localization coverage across the built-in catalog.
MIT