Fix ActionController::RoutingError: No route matches [GET] "/api/v1/users" in Rails

This error means Rails cannot find a route matching the requested URL and HTTP method. Check your config/routes.rb file to ensure the route is defined with the correct path, HTTP verb, and namespace. Run bin/rails routes to see all available routes and compare them against the request URL.

Reading the Stack Trace

Here's what each line means:

• actionpack (7.1.3) lib/action_dispatch/middleware/debug_exceptions.rb:65:in `call': The debug exceptions middleware catches the routing error and displays a diagnostic page in development.
• actionpack (7.1.3) lib/action_dispatch/middleware/show_exceptions.rb:33:in `call': This middleware intercepts the error to render an appropriate error response.
• railties (7.1.3) lib/rails/rack/logger.rb:40:in `call_app': The request was logged before the routing failure occurred.

Common Causes

# config/routes.rb
Rails.application.routes.draw do
  resources :users  # maps to /users, not /api/v1/users
end

# config/routes.rb
Rails.application.routes.draw do
  namespace :api do
    namespace :v1 do
      post 'users', to: 'users#create'  # POST only, no GET
    end
  end
end

# config/routes.rb
Rails.application.routes.draw do
  get '*path', to: 'pages#not_found'
  namespace :api do
    namespace :v1 do
      resources :users
    end
  end
end

The Fix

Wrap the users resource inside the api/v1 namespace blocks so the generated routes match the expected URL pattern /api/v1/users. Use bin/rails routes to verify.

# config/routes.rb
Rails.application.routes.draw do
  resources :users
end

# config/routes.rb
Rails.application.routes.draw do
  namespace :api do
    namespace :v1 do
      resources :users, only: [:index, :show, :create, :update, :destroy]
    end
  end
end

Testing the Fix

require 'rails_helper'

RSpec.describe 'Users API', type: :request do
  describe 'GET /api/v1/users' do
    it 'returns a successful response' do
      get '/api/v1/users'
      expect(response).to have_http_status(:ok)
    end

    it 'returns JSON content type' do
      get '/api/v1/users'
      expect(response.content_type).to include('application/json')
    end
  end
end

Run your tests:

bundle exec rspec spec/requests/users_spec.rb

Pushing Through CI/CD

git checkout -b fix/rails-routing-error,git add config/routes.rb spec/requests/users_spec.rb,git commit -m "fix: add API v1 namespace to users routes",git push origin fix/rails-routing-error

Your CI config should look something like this:

name: CI
on:
  pull_request:
    branches: [main]
jobs:
  test:
    runs-on: ubuntu-latest
    services:
      postgres:
        image: postgres:16
        env:
          POSTGRES_PASSWORD: postgres
        ports: ['5432:5432']
    steps:
      - uses: actions/checkout@v4
      - uses: ruby/setup-ruby@v1
        with:
          ruby-version: '3.3'
          bundler-cache: true
      - run: bin/rails db:setup
      - run: bundle exec rspec

The Full Manual Process: 18 Steps

Here's every step you just went through to fix this one bug:

1. Notice the error alert or see it in your monitoring tool
2. Open the error dashboard and read the stack trace
3. Identify the file and line number from the stack trace
4. Open your IDE and navigate to the file
5. Read the surrounding code to understand context
6. Reproduce the error locally
7. Identify the root cause
8. Write the fix
9. Run the test suite locally
10. Fix any failing tests
11. Write new tests covering the edge case
12. Run the full test suite again
13. Create a new git branch
14. Commit and push your changes
15. Open a pull request
16. Wait for code review
17. Merge and deploy to production
18. Monitor production to confirm the error is resolved

Total time: 30-60 minutes. For one bug.

gem install bugstack

require 'bugstack'

Bugstack.init(api_key: ENV['BUGSTACK_API_KEY'])

Deploying the Fix (Manual Path)

1. Verify routes locally with bin/rails routes | grep users.
2. Run request specs to confirm the route resolves.
3. Open a pull request with the routes change.
4. Wait for CI to pass and get approval.
5. Merge to main and verify routes in staging.

Frequently Asked Questions