Configuration¶

Compere is configured through environment variables. Set these before starting the server.

Quick Setup¶

Create a .env file in the project root (copy from .env.example):

cp .env.example .env

Environment Variables¶

Database¶

Variable	Default	Description
`DATABASE_URL`	`sqlite:///./compere.db`	Database connection string

Examples:

SQLite (Development)PostgreSQL (Production)MySQL

DATABASE_URL=sqlite:///./compere.db

DATABASE_URL=postgresql://user:password@localhost:5432/compere

DATABASE_URL=mysql://user:password@localhost:3306/compere

Elo Rating System¶

Variable	Default	Description
`ELO_K_FACTOR`	`32.0`	Rating sensitivity factor
`ELO_INITIAL_RATING`	`1500.0`	Starting rating for new entities

The K-factor controls how much ratings change after each comparison:

K-Factor	Use Case
40-50	New systems, rapid convergence needed
32	Standard (default)
16-24	Established rankings, stability preferred

UCB/MAB Algorithm¶

Variable	Default	Description
`UCB_EXPLORATION_CONSTANT`	`1.414`	Exploration factor (sqrt(2))
`UCB_UNEXPLORED_WEIGHT`	`1000.0`	Weight for entities with no comparisons

The exploration constant controls the exploration-exploitation tradeoff:

Higher values (2.0+): More exploration of uncertain entities
Default (1.414): Balanced (theoretically optimal)
Lower values (0.5-1.0): More exploitation of known good entities

Entity Pairing¶

Variable	Default	Description
`PAIRING_UCB_WEIGHT`	`0.3`	Weight for UCB score in pairing
`PAIRING_SIMILARITY_WEIGHT`	`0.4`	Weight for rating similarity
`PAIRING_RANDOM_WEIGHT`	`0.3`	Weight for random factor
`PAIRING_RATING_THRESHOLD`	`200.0`	Rating difference for similarity bonus
`RECENT_COMPARISON_LIMIT`	`5`	Recent comparisons to exclude

Note

Pairing weights should sum to 1.0 for consistent behavior.

Authentication¶

Variable	Default	Description
`AUTH_ENABLED`	`false`	Enable JWT authentication
`SECRET_KEY`	(none)	JWT signing secret (required if auth enabled)
`ACCESS_TOKEN_EXPIRE_MINUTES`	`30`	Token expiration time

Generate a secure secret:

python -c "import secrets; print(secrets.token_urlsafe(32))"

CORS Configuration¶

Variable	Default	Description
`CORS_ORIGINS`	(varies)	Comma-separated allowed origins

In development: defaults to ["*"] (all origins)
In production: must be explicitly set

CORS_ORIGINS=https://myapp.com,https://admin.myapp.com

Rate Limiting¶

Variable	Default	Description
`RATE_LIMIT_ENABLED`	`false`	Enable rate limiting
`RATE_LIMIT_REQUESTS`	`100`	Max requests per window
`RATE_LIMIT_WINDOW`	`60`	Window size in seconds

Logging¶

Variable	Default	Description
`LOG_LEVEL`	`INFO`	Logging verbosity
`LOG_REQUESTS`	`true`	Log HTTP requests
`ENVIRONMENT`	`development`	Environment name

Log levels: DEBUG, INFO, WARNING, ERROR, CRITICAL

Complete Configuration File¶

# Database
DATABASE_URL=postgresql://localhost/compere

# Elo Rating System
ELO_K_FACTOR=32.0
ELO_INITIAL_RATING=1500.0

# UCB/MAB Algorithm
UCB_EXPLORATION_CONSTANT=1.414
UCB_UNEXPLORED_WEIGHT=1000.0

# Entity Pairing (weights should sum to 1.0)
PAIRING_UCB_WEIGHT=0.3
PAIRING_SIMILARITY_WEIGHT=0.4
PAIRING_RANDOM_WEIGHT=0.3
PAIRING_RATING_THRESHOLD=200.0
RECENT_COMPARISON_LIMIT=5

# Authentication
AUTH_ENABLED=true
SECRET_KEY=your-secure-secret-key-here
ACCESS_TOKEN_EXPIRE_MINUTES=30

# CORS
CORS_ORIGINS=https://myapp.com

# Rate Limiting
RATE_LIMIT_ENABLED=true
RATE_LIMIT_REQUESTS=100
RATE_LIMIT_WINDOW=60

# Logging
LOG_LEVEL=INFO
LOG_REQUESTS=true
ENVIRONMENT=production

Frontend Configuration¶

The Vue.js frontend uses a separate .env file in compere-ui/:

VITE_API_BASE_URL=http://localhost:8090

Production Recommendations¶

Use PostgreSQL for production workloads
Enable authentication with a strong secret key
Enable rate limiting to prevent abuse
Set ENVIRONMENT=production for secure error handling
Configure CORS explicitly (don't use *)
Set LOG_LEVEL=WARNING to reduce log volume
Use a reverse proxy (nginx, Caddy) for HTTPS