Resource routes for APIs in Remix

Introduction

Resource routes help organize API endpoints by grouping related actions for data in one place. This makes your API easier to understand and maintain.

When building an API that manages data like users, posts, or products.

When you want to follow a clear pattern for creating, reading, updating, and deleting data.

When you want to keep your API routes clean and consistent.

When you want to quickly add standard API actions without writing separate routes for each.

When you want to use Remix's built-in conventions to handle API requests efficiently.

Syntax

Remix

export const loader = async ({ params }) => { /* handle GET request */ };
export const action = async ({ request, params }) => { /* handle POST, PUT, DELETE */ };

// File path example: app/routes/api/posts.ts

Resource routes in Remix use loader for GET requests and action for other HTTP methods.

File names and folder structure define the API route paths automatically.

Examples

This loader handles GET requests to list all items in a resource.

Remix

export const loader = async () => {
  return new Response(JSON.stringify({ message: 'List all items' }), { status: 200 });
};

This action handles POST and DELETE requests for creating and deleting items.

Remix

export const action = async ({ request }) => {
  if (request.method === 'POST') {
    // create new item
    return new Response('Created', { status: 201 });
  }
  if (request.method === 'DELETE') {
    // delete item
    return new Response('Deleted', { status: 200 });
  }
};

Remix uses file and folder names to map resource routes automatically.

Remix

// File structure example:
// app/routes/api/posts.ts
// handles /api/posts route with GET and POST

// app/routes/api/posts/$postId.ts
// handles /api/posts/:postId route with GET, PUT, DELETE

Sample Program

This example shows a simple resource route for posts. The loader returns all posts on GET requests. The action handles POST requests to add a new post.

Remix

import { json } from '@remix-run/node';

// app/routes/api/posts.ts

let posts = [
  { id: '1', title: 'First Post' },
  { id: '2', title: 'Second Post' }
];

export const loader = async () => {
  return json(posts);
};

export const action = async ({ request }) => {
  if (request.method === 'POST') {
    const formData = await request.formData();
    const title = formData.get('title');
    if (typeof title !== 'string' || !title) {
      return json({ error: 'Title is required' }, { status: 400 });
    }
    const newPost = { id: String(posts.length + 1), title };
    posts.push(newPost);
    return json(newPost, { status: 201 });
  }
  return json({ error: 'Method not allowed' }, { status: 405 });
};

Important Notes

Remember to handle different HTTP methods inside the action function.

Use Remix's json helper to return JSON responses easily.

File and folder names define your API paths, so organize them clearly.

Summary

Resource routes group related API actions in one file using loader and action.

Remix uses file structure to map URLs to resource routes automatically.

This pattern keeps your API clean, consistent, and easy to maintain.

Practice

1. What is the main purpose of resource routes in Remix APIs?

easy

A. To group related API actions like loader and action in one file

B. To create separate files for each API endpoint

C. To handle only GET requests in the API

D. To define client-side routes only

Solution

1. Step 1: Understand resource routes concept

   Resource routes group related API actions such as loader and action in one file for better organization.

2. Step 2: Eliminate incorrect options

   Options describing only GET requests, separate files per endpoint, or client-side routes do not match the grouping feature.

3. Final Answer:

   To group related API actions like loader and action in one file -> Option A

4. Quick Check:

   Resource routes group API actions like loader/action [OK]

Hint: Resource routes group API actions in one file [OK]

Common Mistakes:

• Thinking resource routes create separate files per endpoint
• Assuming resource routes handle only GET requests
• Confusing resource routes with client-side routing

2. Which file structure correctly defines a resource route for a "posts" API in Remix?

easy

A. app/api/posts.js with only loader export

B. app/routes/api/posts.ts with loader and action exports

C. app/routes/posts/index.jsx with client-side code only

D. app/routes/api/posts/get.ts for GET requests

Solution

1. Step 1: Identify Remix resource route file location

   Remix maps resource routes inside app/routes folder, so app/routes/api/posts.ts is correct.

2. Step 2: Check for proper exports

   Resource routes export both loader and action to handle GET and POST (or other) requests in one file.

3. Final Answer:

   app/routes/api/posts.ts with loader and action exports -> Option B

4. Quick Check:

   Resource route file in app/routes with loader and action [OK]

Hint: Resource routes live in app/routes with loader and action [OK]

Common Mistakes:

• Placing API files outside app/routes folder
• Using separate files per HTTP method instead of one resource file
• Confusing client-side route files with API resource routes

3. Given this resource route file app/routes/api/user.ts with these exports:

export async function loader() { return new Response('User data') }
export async function action() { return new Response('User updated') }

What response will a POST request to /api/user return?

medium

A. "User data"

B. Error: Missing action export

C. 404 Not Found

D. "User updated"

Solution

1. Step 1: Identify HTTP method handling

   The loader handles GET requests, and action handles POST requests in Remix resource routes.

2. Step 2: Match POST request to action response

   A POST request to /api/user triggers the action function, which returns "User updated".

3. Final Answer:

   "User updated" -> Option D

4. Quick Check:

   POST request triggers action = "User updated" [OK]

Hint: POST calls action, GET calls loader in resource routes [OK]

Common Mistakes:

• Confusing loader with action for POST requests
• Expecting 404 if action exists
• Thinking action is optional for POST

4. You wrote a resource route file app/routes/api/item.ts with only a loader export. When you send a POST request to /api/item, what will happen?

medium

A. The server will respond with 405 Method Not Allowed

B. The server will crash with an error

C. The server will respond with 404 Not Found

D. The POST request will succeed and call the loader

Solution

1. Step 1: Understand HTTP method handling in resource routes

   In Remix, loader handles GET requests only. POST requests require an action export.

2. Step 2: Check behavior when action is missing

   If action is missing, Remix responds with 405 Method Not Allowed for POST requests.

3. Final Answer:

   The server will respond with 405 Method Not Allowed -> Option A

4. Quick Check:

   Missing action for POST = 405 error [OK]

Hint: POST needs action export; missing it causes 405 error [OK]

Common Mistakes:

• Assuming POST calls loader
• Expecting 404 instead of 405
• Thinking server crashes without action

5. You want to create a resource route for /api/products that supports GET, POST, and DELETE methods. How should you structure your Remix resource route file to handle all three methods correctly?

hard

A. Export only action and handle all methods inside it, no loader needed

B. Create separate files: products.get.ts, products.post.ts, products.delete.ts

C. Export a loader for GET, an action that checks request.method to handle POST and DELETE

D. Use client-side code to send GET, POST, DELETE requests to different URLs

Solution

1. Step 1: Understand Remix resource route method handling

   Remix uses loader for GET requests and action for other HTTP methods like POST and DELETE.

2. Step 2: Handle multiple methods in action

   Inside action, check request.method to differentiate POST and DELETE logic.

3. Final Answer:

   Export a loader for GET, an action that checks request.method to handle POST and DELETE -> Option C

4. Quick Check:

   loader for GET, action handles POST/DELETE by method check [OK]

Hint: Use loader for GET, action with method check for others [OK]

Common Mistakes:

• Trying to create separate files per HTTP method
• Not checking request.method inside action
• Ignoring loader for GET requests