Configuration

Environment variables

Store all sensitive configuration in environment variables:

# Database connection
DB_HOST=your-database-host
DB_PORT=5432
DB_NAME=your-database
DB_USER=freshguard_readonly
DB_PASSWORD=secure-random-password

# Application
NODE_ENV=production
LOG_LEVEL=info

# Metadata storage (optional)
METADATA_STORAGE_TYPE=duckdb
METADATA_DATABASE_URL=postgresql://user:pass@host:5432/freshguard_metadata

See .env.example in the repository for the full list with security guidelines.

Connector configuration

All connectors accept a configuration object. Common options:

const connector = new PostgresConnector({
  host: process.env.DB_HOST!,
  port: Number(process.env.DB_PORT) || 5432,
  database: process.env.DB_NAME!,
  username: process.env.DB_USER!,
  password: process.env.DB_PASSWORD!,
  ssl: true,                    // Enable SSL (recommended for production)
  timeout: 30000,               // Connection timeout in ms
  queryTimeout: 10000,          // Query timeout in ms
});

For connector-specific options, see the Connectors guide.

Monitoring rule fields

Every MonitoringRule requires:

Field	Type	Description
id	string	Unique rule identifier
sourceId	string	Identifier for the data source
name	string	Human-readable rule name
tableName	string	Target table to monitor
ruleType	'freshness' | 'volume_anomaly' | 'schema_change'	Type of check
checkIntervalMinutes	number	How often to run the check
isActive	boolean	Whether the rule is enabled
createdAt	Date	Rule creation timestamp
updatedAt	Date	Rule last-updated timestamp

Freshness-specific fields

Field	Type	Description
toleranceMinutes	number	Maximum acceptable data lag
timestampColumn	string	Column to check for freshness

Schema-change-specific fields

Field	Type	Description
schemaChangeConfig.adaptationMode	'auto' | 'manual' | 'alert_only'	How to handle detected changes
schemaChangeConfig.monitoringMode	'full' | 'partial'	Monitor all or selected columns
schemaChangeConfig.trackedColumns.alertLevel	'low' | 'medium' | 'high'	Alert severity
schemaChangeConfig.trackedColumns.trackTypes	boolean	Track data type changes
schemaChangeConfig.trackedColumns.trackNullability	boolean	Track nullability changes
schemaChangeConfig.baselineRefreshDays	number	Auto-refresh baseline interval

Metadata storage configuration

// DuckDB (zero-setup, default)
const storage = await createMetadataStorage();
const storage = await createMetadataStorage({ type: 'duckdb', path: './my-data.db' });

// PostgreSQL (production)
const storage = await createMetadataStorage({
  type: 'postgresql',
  url: process.env.METADATA_DATABASE_URL,
});

See the Metadata Storage guide for details.