fastapi-profiler-lite 0.3.3

Lightweight performance profiler for FastAPI applications

FastAPI Profiler Lite

A lightweight, zero-configuration performance profiler for FastAPI applications. Monitor your API performance in real-time without external dependencies.

Why FastAPI Profiler?

Monitoring API performance shouldn't require complex setups or external services. FastAPI Profiler gives you instant visibility into your application's performance with just one line of code.

• Instant insights - See which endpoints are slow without complex instrumentation
• Zero configuration - Works out of the box with sensible defaults
• Rust-powered statistics - High-performance stats calculation using Rust
• Developer-friendly - Designed for both development and lightweight production use

Installation

pip install fastapi-profiler-lite

For more installation options, see the Installation Guide.

Quick Start

from fastapi import FastAPI
from fastapi_profiler import Profiler

app = FastAPI()

# Add the profiler with just one line
Profiler(app)

@app.get("/")
async def read_root():
    return {"Hello": "World"}

That's it! Visit /profiler to see the performance dashboard.

Features

• One-line integration - Add to any FastAPI app with minimal code
• Real-time dashboard - Live updates with automatic refresh
• Response time tracking - Measure execution time of each request
• Endpoint analysis - Identify your slowest and most used endpoints
• Request filtering - Search and sort through captured requests
• Visual metrics - Charts for response times and request distribution
• Database monitoring - Tracking of SQLAlchemy queries
• Minimal overhead - Designed to have low performance impact

Technical Details

• Rust Core: Statistics calculations are powered by a Rust extension using PyO3 for improved performance. Benchmarks comparing to NumPy will be published soon. Pre-built wheels are provided for all major platforms, but if you encounter any issues, please open a GitHub issue.

• UI Framework: The dashboard uses Tabler.io, a premium and open-source admin dashboard template, providing a clean and modern interface.

• Database Instrumentation: Track database queries with SQLAlchemy integration. Manually instrument your SQLAlchemy engines to see detailed query performance data.

Running Examples

The repository includes several examples to demonstrate different features:

# Basic example with simple endpoints
python example.py

# Example with SQLAlchemy database instrumentation
python examples/sqlalchemy_demo.py

# Example with multiple database engines
python examples/multi_db_demo.py

# Real-time continuous monitoring demo
python examples/realtime_demo.py

# Stress test with high load
python examples/stress_test.py

Database Instrumentation Example

To manually instrument database engines:

from fastapi import FastAPI
from sqlalchemy import create_engine
from fastapi_profiler import Profiler
from fastapi_profiler.instrumentations import SQLAlchemyInstrumentation

app = FastAPI()

# Create SQLAlchemy engines
primary_db = create_engine("sqlite:///./primary.db")
analytics_db = create_engine("sqlite:///./analytics.db")

# Initialize profiler
profiler = Profiler(app)

# Manually instrument each database engine
SQLAlchemyInstrumentation.instrument(primary_db)
SQLAlchemyInstrumentation.instrument(analytics_db)

Visit /profiler to see the dashboard with database query performance data.

Documentation

• Installation
• Configuration
• Contributing
• Extending

License

This project is licensed under the MIT License - see the LICENSE file for details.