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](https://bugsly.dev), 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