Fix AuthenticationError Error in Rails — In Production

What Is the AuthenticationError Error?

Struggling with AuthenticationError in your Rails project? This common error has a straightforward fix once you understand the cause.

Why It Happens

This typically means the authentication layer is rejecting requests — often due to expired tokens, missing API keys, or incorrect auth configuration. In production, this is often triggered by environment differences between local and deployed setups.

The Fix

token = ENV.fetch('AUTH_TOKEN') { raise 'AUTH_TOKEN not set' }

conn = Faraday.new(url: 'https://api.example.com') do |f|
  f.request :authorization, 'Bearer', token
  f.response :raise_error
end

Common Mistakes to Avoid

Many developers make the mistake of silently catching this error without logging it, which makes debugging much harder later. Another common pitfall is applying a fix that works locally but fails in production due to environment differences. Always verify your fix works in a staging environment before deploying. Additionally, ensure your error handling doesn't mask the original error — preserve the stack trace and error message for future debugging sessions.

Prevention

With Bugsly, you can monitor for this error in production and get alerted with full error context.

Key Takeaways

• Always handle this error gracefully with proper error handling
• Check your environment configuration — especially in production
• Test thoroughly before deploying to production