Source: https://seerepo.com/r/leon-ai/leon/built
Markdown source: https://seerepo.com/r/leon-ai/leon/built.md
Description: leon is a TypeScript repo built with React, @tanstack/react-router, Vite, and Fastify. It stores its data in SQLite and signs people in with jose.

# What is leon built with?

leon is a TypeScript repo built with React, @tanstack/react-router, Vite, and Fastify. It stores its data in SQLite, signs people in with jose, uses AI through ai-sdk, transformers, node-llama-cpp, ai, faster-whisper, and 2 more, makes its content with beautifulsoup4, yaml, and shiki, validates its data with @sinclair/typebox, Ajv, and ajv-formats, is tested with Vitest, @playwright/test, and playwright-chromium, and uses Hugging Face. It has 225,418 written lines, with 182 test files.

Read on November 6, 2026, at commit f5795bd.

Repository: https://github.com/leon-ai/leon

## Frontend (/)

### The base

- **[React](https://seerepo.com/uses/react)**: 84 files · [in package.json](https://github.com/leon-ai/leon/blob/f5795bd79ef946933603b4b47b27225912278df6/package.json)
- **@tanstack/react-router**: 15 files
- **[Vite](https://seerepo.com/uses/vite)**: 1 file · [in package.json](https://github.com/leon-ai/leon/blob/f5795bd79ef946933603b4b47b27225912278df6/package.json)

### Styles

- **@fontsource/jetbrains-mono**: 2 files

### Interface

- **@ark-ui/react**: 11 files
- **[@tanstack/react-virtual](https://seerepo.com/uses/tanstack-react-virtual)**: 7 files
- **@pierre/highlights**: 2 files
- **cli-spinner**: 1 file

### Icons

- **remixicon**: 1 file

## Backend (/)

### Data

- **[SQLite](https://seerepo.com/uses/sqlite)**: 5 files · [server/src/core/experience-manager.ts, line 9](https://github.com/leon-ai/leon/blob/f5795bd79ef946933603b4b47b27225912278df6/server/src/core/experience-manager.ts#L9)

### Sign-in

- **[jose](https://seerepo.com/uses/jose)**: 1 file

### AI

- **[ai-sdk](https://seerepo.com/uses/ai-sdk)**: 4 files
- **[transformers](https://seerepo.com/uses/transformers)**: 4 files
- **node-llama-cpp**: 3 files
- **[ai](https://seerepo.com/uses/ai)**: 1 file
- **faster-whisper**: 1 file
- **g2p-en**: 1 file
- **[OpenRouter](https://seerepo.com/uses/openrouter)**: 1 file

### Services

- **[Hugging Face](https://seerepo.com/uses/hugging-face)**: 1 file · [server/src/core/llm-manager/media-generation/media-generation-providers.ts, line 5](https://github.com/leon-ai/leon/blob/f5795bd79ef946933603b4b47b27225912278df6/server/src/core/llm-manager/media-generation/media-generation-providers.ts#L5)

## Support (/)

### The base

- **[Fastify](https://seerepo.com/uses/fastify)**: 38 files

### Content

- **[beautifulsoup4](https://seerepo.com/uses/beautifulsoup4)**
- **[yaml](https://seerepo.com/uses/yaml)**: 3 files
- **[shiki](https://seerepo.com/uses/shiki)**: 1 file

### Validation

- **@sinclair/typebox**: 18 files
- **[Ajv](https://seerepo.com/uses/ajv)**: 1 file
- **[ajv-formats](https://seerepo.com/uses/ajv-formats)**: 1 file

### Testing

- **Vitest**: 81 files
- **@playwright/test**: 5 files
- **playwright-chromium**: 1 file

### Tools

- **tree-kill**: 3 files
- **@ffprobe-installer/ffprobe**: 1 file
- **Numba**: 1 file

### Other

- **clsx**: 53 files
- **Axios**: 18 files
- **[TanStack](https://seerepo.com/uses/tanstack)**: 16 files
- **NumPy**: 7 files
- **execa**: 6 files
- **.ENV**: 4 files
- **dayjs**: 3 files
- **inflect**: 2 files
- **socket.io-client**: 2 files
- **@pierre/diffs**: 1 file
- **confbox**: 1 file
- **ffmpeg-static**: 1 file
- **node-pty**: 1 file
- **os-name**: 1 file
- **ps-list**: 1 file
- **python-dotenv**: 1 file
- **requests**: 1 file
- **SemVer**: 1 file
- **Socket.io**: 1 file
- **soundfile**: 1 file
- **tqdm**: 1 file
- **ws**: 1 file

## Support (bridges/nodejs)

### Tools

- **tree-kill**: 1 file

### Other

- **Axios**: 2 files
- **fflate**: 1 file
- **Lodash**: 1 file

## Other repos with a similar stack

- [CherryHQ/cherry-studio](https://seerepo.com/r/CherryHQ/cherry-studio/built): React, Vite, SQLite, @tanstack/react-virtual, @pierre/highlights, ai-sdk, ai, OpenRouter, yaml · [Compare](https://seerepo.com/compare/CherryHQ/cherry-studio/vs/leon-ai/leon)
- [langgenius/dify](https://seerepo.com/r/langgenius/dify/built): React, Vite, SQLite, @tanstack/react-virtual, @pierre/highlights, yaml, Ajv · [Compare](https://seerepo.com/compare/langgenius/dify/vs/leon-ai/leon)
- [ruvnet/ruflo](https://seerepo.com/r/ruvnet/ruflo/built): React, Vite, SQLite, Hugging Face, jose, yaml, Ajv · [Compare](https://seerepo.com/compare/leon-ai/leon/vs/ruvnet/ruflo)
- [cline/cline](https://seerepo.com/r/cline/cline/built): React, Vite, SQLite, ai-sdk, ai, yaml, shiki · [Compare](https://seerepo.com/compare/cline/cline/vs/leon-ai/leon)
- [mudler/LocalAI](https://seerepo.com/r/mudler/LocalAI/built): React, Vite, SQLite, Hugging Face, transformers, faster-whisper, yaml · [Compare](https://seerepo.com/compare/leon-ai/leon/vs/mudler/LocalAI)
- [janhq/jan](https://seerepo.com/r/janhq/jan/built): React, Vite, SQLite, @tanstack/react-virtual, ai-sdk, ai, shiki · [Compare](https://seerepo.com/compare/janhq/jan/vs/leon-ai/leon)

## Frequently asked questions

### What language is leon written in?

leon is written in TypeScript, with 225,418 written lines.

### What framework does leon use?

leon is built with React, @tanstack/react-router, Vite, and Fastify.

The proof: [in package.json](https://github.com/leon-ai/leon/blob/f5795bd79ef946933603b4b47b27225912278df6/package.json)

### What database does leon use?

leon stores its data in SQLite.

The proof: [server/src/core/experience-manager.ts, line 9](https://github.com/leon-ai/leon/blob/f5795bd79ef946933603b4b47b27225912278df6/server/src/core/experience-manager.ts#L9)

### What does leon sign people in with?

leon signs people in with jose.

### Does leon use AI?

Yes. leon uses AI through ai-sdk, transformers, node-llama-cpp, ai, faster-whisper, g2p-en, and OpenRouter.

### What services does leon use?

leon uses Hugging Face.

The proof: [server/src/core/llm-manager/media-generation/media-generation-providers.ts, line 5](https://github.com/leon-ai/leon/blob/f5795bd79ef946933603b4b47b27225912278df6/server/src/core/llm-manager/media-generation/media-generation-providers.ts#L5)

### Does leon have tests?

Yes. leon has 182 test files and is tested with Vitest, @playwright/test, and playwright-chromium.

### Which repos have a stack like leon's?

The ones that share most of its stack: CherryHQ/cherry-studio, langgenius/dify, and ruvnet/ruflo.

## What is your repo built with?

Any public repo, with no account: https://seerepo.com/r/owner/repo/built, with the owner and name it has on GitHub.