Logs

Learn how to send, filter, and analyze logs from your applications using Reasonable.

Log Levels

Reasonable supports standard log levels to help you categorize and filter your logs based on their severity and importance.

Level	Description	When to use
debug	Detailed information for debugging	During development or when troubleshooting issues
info	General information about system operation	For normal application events like user actions, successful operations
warn	Warning conditions that might need attention	For non-critical issues that don't prevent the application from working
error	Error conditions that need immediate attention	For errors that prevent a function from working correctly
fatal	Critical errors that cause the application to crash	For severe errors that prevent the application from continuing to run

If you don't specify a log level, Reasonable will default to the "info" level.

Sending Logs

Here's how to send logs to Reasonable using our SDKs:

// Basic logging
reasonable.debug('Debugging information');
reasonable.info('User logged in', { userId: '123' });
reasonable.warn('API rate limit approaching', { endpoint: '/api/users', remaining: 10 });
reasonable.error('Failed to process payment', { orderId: '456', error: 'Invalid card' });
reasonable.fatal('Database connection lost', { database: 'users' });

// Logging with context
const orderContext = reasonable.withContext({ orderId: '789' });
orderContext.info('Order created');
orderContext.info('Payment processed');
orderContext.info('Order shipped');

// Logging with tags
reasonable.info('User registered', { userId: '123' }, { tags: ['user', 'registration'] });

// Logging with a timestamp
reasonable.info('Event occurred', {}, { timestamp: new Date('2023-01-01T12:00:00Z') });

Structured Logging

Structured logging allows you to include additional context with your logs, making them more useful for debugging and analysis.

Best Practices

Be consistent with field names - Use the same field names across your application for the same types of data.
Use nested objects sparingly - While nested objects are supported, they can make filtering and searching more complex.
Include relevant context - Add fields that will help you understand the log entry later, such as user IDs, request IDs, and other identifiers.
Don't log sensitive information - Avoid logging passwords, API keys, or other sensitive data.

// Simple structured log
reasonable.info('User registered', {
  userId: '123',
  email: 'john@example.com',
  plan: 'pro',
  referrer: 'google'
});

// Structured log with nested objects
reasonable.info('Order completed', {
  order: {
    id: '456',
    amount: 99.99,
    currency: 'USD',
    items: [
      { id: '1', name: 'Product A', price: 49.99, quantity: 1 },
      { id: '2', name: 'Product B', price: 24.99, quantity: 2 }
    ]
  },
  customer: {
    id: '123',
    name: 'John Doe',
    email: 'john@example.com'
  },
  shipping: {
    method: 'express',
    address: {
      street: '123 Main St',
      city: 'New York',
      state: 'NY',
      zip: '10001'
    }
  }
});

Searching and Filtering Logs

Reasonable provides powerful search and filtering capabilities to help you find the logs you need.

Search Syntax

You can use the following syntax to search and filter your logs:

Syntax	Description	Example
field:value	Search for logs where the field equals the value	level:error
field:"value with spaces"	Search for logs where the field equals the value with spaces	message:"user logged in"
field:>value	Search for logs where the field is greater than the value	order.amount:>100
field:<value	Search for logs where the field is less than the value	order.amount:<50
field:value1 OR field:value2	Search for logs where the field equals value1 or value2	level:error OR level:fatal
field:value1 AND field:value2	Search for logs where the field equals value1 and value2	level:error AND service:api
field:value	Search for logs where the field contains the value	message:error
-field:value	Search for logs where the field does not equal the value	-level:debug

Common Search Examples

level:error - Find all error logs
userId:123 - Find all logs for a specific user
message:*payment* - Find all logs with "payment" in the message
level:error AND service:api - Find all error logs from the API service
timestamp:>2023-01-01 - Find all logs after January 1, 2023
level:error OR level:fatal - Find all error or fatal logs
-level:debug - Exclude debug logs

Log Retention

Reasonable retains your logs based on your subscription plan:

Plan	Retention Period
Free	7 days
Pro	30 days
Enterprise	Custom (up to 1 year)

Next Steps

Now that you understand how to work with logs in Reasonable, you might want to explore these related topics:

Alerts

Learn how to set up alerts to get notified when important events occur in your logs.

Dashboards

Create custom dashboards to visualize your log data and metrics.

API Reference

Learn how to use the Reasonable API directly for advanced use cases.

SDKs

Explore our SDKs for different programming languages and frameworks.

Documentation