lcore 0.0.4

A fast, lightweight, single-file Python WSGI framework with zero dependencies.

Lcore

A fast, lightweight, single-file Python WSGI framework with zero dependencies.
Inspired by the simplicity of Bottle.

Documentation • Getting Started • API Reference

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Installation

uv add lcore          # uv (recommended)
pip install lcore     # pip

Quick Start

from lcore import Lcore

app = Lcore()

@app.route('/hello/<name>')
def hello(name):
    return {'message': f'Hello, {name}!'}

app.run()

Key Features

• Single file, zero dependencies drop lcore.py into any project
• Full WSGI compliance works with Gunicorn, uWSGI, Waitress, and 17+ server adapters
• 7 built-in middleware CORS, CSRF, security headers, compression, body limits, request ID, logging
• Security primitives PBKDF2 password hashing, HMAC-SHA256 signed cookies, rate limiting
• Dependency injection singleton, scoped, and transient lifetimes
• Plugin system JSON serialization, template rendering, and custom plugins
• Request validation JSON body and query parameter validation with type checking
• Built-in test client unit test routes without starting a server
• 12 lifecycle hooks request start, auth, handler enter/exit, response build/send, and more
• Module mounting compose sub-applications with isolated routes and middleware

Full documentation at lcore.lusansapkota.com.np.

Performance

Benchmarked with 100,000 iterations × 3 runs per framework (best run recorded), single process, no I/O, measuring pure framework overhead:

Framework	JSON (req/s)	Plaintext (req/s)
Lcore	91,917	116,794
Flask 3.1.3	22,757	25,497
Bottle 0.13.4	138,299	187,334

Lcore processes 2.2x – 4.6x more requests per second than Flask across 7 test scenarios (plaintext, JSON, route params, middleware stack, 404 miss, multi-route dispatch, POST JSON). See the full benchmarks for details.

Run the benchmarks yourself:

pip install flask bottle
cd benchmarks && python benchmark.py --full

When NOT to Use Lcore

Situation	Better choice
You need WebSockets or real-time async I/O	FastAPI, Starlette, Quart
You need true async concurrency (async DB drivers, hundreds of concurrent outbound HTTP calls)	FastAPI, Starlette
You need automatic OpenAPI / Swagger generation	FastAPI
You need ASGI and Uvicorn / Daphne	FastAPI, Starlette
You need a full MVC framework with ORM, admin panel, and migrations	Django
Your team is already on Flask and migration cost outweighs the benefit	Stay on Flask

If your workload is primarily synchronous REST APIs, internal services, microservices with sync DB drivers Lcore is a strong fit.

License

MIT see LICENSE for details.

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Built by Lusan Sapkota • Inspired by Bottle