log2fast-fastapi

🚀 Advanced logging module for FastAPI with file rotation, colored output, and environment-based auto-configuration

📖 Conventions reference: this package follows the 2fast-handbook for ecosystem conventions (structure, versioning, README, commits, release).

Features

• 🎨 Multiple Output Formats: JSON (production), Colored (development), Structured (debugging), Simple (testing)
• 🌍 Environment-Based Configuration: Automatic setup for dev, test, prod, and debug
• 📦 Module-Based Loggers: Each module gets its own logger instance
• 🔄 File Rotation: Automatic log file rotation with configurable size
• 🔄 Environment-Specific Logging: Control which logs appear in which environments (prevent sensitive data leaks)
• 🚀 FastAPI Integration: Middleware for automatic request/response logging with unique request IDs
• 📊 Structured Logging: Add context data to any log message
• 📊 Context Injection: Support for request_id, user_id, and custom context data
• 🎯 Zero Configuration: Works out of the box with sensible defaults

📚 Documentation

• Usage Guide - Comprehensive usage guide with examples
• File Management - Complete guide on log rotation and storage (English)
• Gestión de Archivos - Guía completa de rotación y almacenamiento (Español)
• Logger Best Practices - Best practices for creating and naming loggers

Installation

From PyPI (Recommended)

pip install log2fast-fastapi

From Source

# Clone the repository
git clone https://github.com/AngelDanielSanchezCastillo/log2fast-fastapi.git
cd log2fast-fastapi

# Install in development mode
pip install -e .

# Or install with dev dependencies
pip install -e ".[dev]"

Quick Start

Basic Usage

from log2fast_fastapi import get_logger

logger = get_logger(__name__)

logger.info("Application started")
logger.warning("This is a warning")
logger.error("An error occurred")

FastAPI Integration

from fastapi import FastAPI
from log2fast_fastapi import RequestLoggingMiddleware, get_logger

app = FastAPI()
app.add_middleware(RequestLoggingMiddleware)

logger = get_logger(__name__)

@app.get("/")
async def root():
    logger.info("Root endpoint accessed")
    return {"message": "Hello World"}

Logging with Context

from log2fast_fastapi import get_logger

logger = get_logger(__name__)

logger.info(
    "User logged in",
    extra_data={
        "user_id": "12345",
        "ip_address": "192.168.1.1"
    }
)

Environment-Specific Logging (Prevent Sensitive Data Leaks!)

# Logs ONLY in development/debug (NOT in production)
logger.debug(
    "Sensitive debug info",
    extra_data={"password_hash": "...", "token": "..."},
    only_in=["development", "debug"]
)

# Logs ONLY in production
logger.info(
    "Performance metrics",
    extra_data={"response_time": 120},
    only_in=["production"]
)

Configuration

Simple: Just set the environment in .env

# That's it! Format and level auto-configure
LOG_ENVIRONMENT=production

Auto-configuration by environment:

Environment	Auto Level	Auto Format
development	INFO	colored
production	WARNING	json
testing	INFO	simple
debug	DEBUG	colored

Optional: Override defaults

# Optional: Override auto-configuration
LOG_LEVEL=DEBUG
LOG_FORMAT=json
LOG_FILE_SETTINGS__ENABLED=true

Environment Presets

Development

• Format: Colored console output
• Level: INFO
• Perfect for local development

Production

• Format: JSON (structured)
• Level: WARNING
• Optimized for log aggregation tools

Testing

• Format: Simple
• Level: INFO
• Minimal output for tests

Debug

• Format: Colored
• Level: DEBUG
• Maximum verbosity

Documentation

See docs/usage.md for complete documentation including:

• Advanced configuration
• Custom formatters
• Best practices
• Integration examples

Example

Run the example application:

python log2fast_fastapi/example.py

Then visit:

• http://localhost:8000/ - Root endpoint
• http://localhost:8000/users/123 - User endpoint
• http://localhost:8000/docs - API documentation

Testing

Run the test suite:

python log2fast_fastapi/tests/test_logging.py

Module Structure

log2fast-fastapi/
├── pyproject.toml       # Package configuration
├── MANIFEST.in          # Additional files to include
├── README.md            # This file
├── LICENSE              # License file
├── src/
│   └── log2fast_fastapi/
│       ├── __init__.py          # Main exports
│       ├── __version__.py       # Version information
│       ├── base.py              # Core FastLogger class
│       ├── settings.py          # Configuration with Pydantic
│       ├── formatters.py        # Custom log formatters
│       └── middleware.py        # FastAPI middleware
├── docs/
│   ├── usage.md                 # Complete documentation
│   ├── file_management.md       # File rotation guide (EN)
│   ├── file_management_es.md    # File rotation guide (ES)
│   ├── logger_best_practices.md # Best practices
│   └── publishing.md            # PyPI publishing guide
├── examples/
│   ├── example.py               # Basic example
│   ├── demo_features.py         # Feature demonstrations
│   └── demo_rotation.py         # Rotation examples
└── tests/
    ├── test_logging.py          # Test suite
    └── test_new_features.py     # Feature tests

Acknowledgments

This project uses the following open-source packages:

• FastAPI - Modern, fast web framework for building APIs (MIT License)
• Pydantic - Data validation using Python type annotations (MIT License)
• Pydantic Settings - Settings management using Pydantic (MIT License)

We are grateful to the maintainers and contributors of these projects for their excellent work.

License

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

Copyright (c) 2026 Angel Daniel Sanchez Castillo

Note: This package is designed and maintained by the Solautyc Team for internal use. While publicly available under MIT license, use at your own risk.