🔍 LogLens — Real-time Log Viewer for Developers

Real-time log viewer for developers who don't have time to tail files.

Stream, filter, search, and export application logs with a terminal-style UI — no backend setup, no auth, no database. Just logs.

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✨ Features

• Real-time streaming — logs arrive via SSE without page refresh
• Multiple log sources — switch between app, error, system, and access log streams
• Keyword search — type and matching lines highlight instantly across all fields
• Level filtering — toggle INFO / WARN / ERROR / DEBUG with color-coded badges
• Pause & resume — freeze the stream without losing buffered lines
• Clear logs — one click wipes the buffer
• Auto-scroll — snaps to bottom as new logs arrive; disable to inspect history
• Line count — live count of visible lines after filters are applied
• Relative timestamps — every line shows "2s ago", "14m ago" on hover
• Copy on click — click any line to copy the full formatted entry to clipboard
• Export as .txt — download all currently visible lines in a structured format
• Dark terminal UI — monospace font, ANSI-style color coding, zero chrome

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🛠 Tech Stack

Layer	Technology
Framework	Next.js 14 App Router
Language	TypeScript (strict)
API	tRPC v11 with superjson
Validation	Zod
Styling	Tailwind CSS
Streaming	Server-Sent Events (SSE)
State	React hooks (no external store)

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Screenshots

⚡ Live Streaming	🔍 Keyword Search
🎯 Log Level Filter	📤 Export Logs

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🏗 Architecture

Data flow for streaming:

1. useLogStream opens an EventSource to /api/stream?source=<source>
2. The route handler calls generateLogLine() every ~800ms and pushes JSON via SSE
3. Incoming events are buffered in a ref and flushed to React state every 200ms (batched)
4. useLogFilter and useLogSearch derive the visible set from the buffered logs
5. useAutoScroll scrolls the container whenever the visible list grows

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🚀 Getting Started

# 1. Clone
git clone https://github.com/mdryaan/loglens.git
cd loglens

# 2. Install
npm install

# 3. Configure (optional — works out of the box with defaults)
cp .env.example .env.local

# 4. Run
npm run dev

Open http://localhost:3000.

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🔑 Environment Variables

Variable	Default	Description
NEXT_PUBLIC_APP_URL	http://localhost:3000	Used by the tRPC server client for SSR requests

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🤝 Contributing

See CONTRIBUTING.md for how to add log sources, tRPC routes, and PR guidelines.

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📄 License

MIT © 2026 mdryaan