A fast, lightweight, single-file Python WSGI framework with zero dependencies.
Inspired by the simplicity of Bottle.
Documentation • Getting Started • API Reference
uv add lcore # uv (recommended)
pip install lcore # pipfrom lcore import Lcore
app = Lcore()
@app.route('/hello/<name>')
def hello(name):
return {'message': f'Hello, {name}!'}
app.run()- Single file, zero dependencies drop
lcore.pyinto 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.
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| 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.
MIT see LICENSE for details.
Built by Lusan Sapkota • Inspired by Bottle