GET, POST, PUT, DELETE handlers in Svelte

Introduction

These handlers let your Svelte app talk to servers to get, send, update, or delete data.

When you want to fetch data from a server to show on your page.

When a user submits a form and you want to save that data.

When you need to update existing information on the server.

When you want to remove data from the server.

Syntax

Svelte

export async function GET(event) {
  // handle GET request
}

export async function POST(event) {
  // handle POST request
}

export async function PUT(event) {
  // handle PUT request
}

export async function DELETE(event) {
  // handle DELETE request
}

Each function handles one HTTP method.

Use event to access request details like body or URL.

Examples

This responds to GET requests with a simple message.

Svelte

export async function GET(event) {
  return new Response('Hello from GET!');
}

This reads JSON data sent in a POST request and replies with it.

Svelte

export async function POST(event) {
  const data = await event.request.json();
  return new Response(`Received: ${JSON.stringify(data)}`);
}

This handles updating data sent via PUT.

Svelte

export async function PUT(event) {
  const data = await event.request.json();
  // pretend to update data
  return new Response('Data updated');
}

This handles deleting data on DELETE requests.

Svelte

export async function DELETE(event) {
  // pretend to delete data
  return new Response('Data deleted');
}

Sample Program

This Svelte module handles all four main HTTP methods. Each function returns a simple text response showing it worked.

Svelte

export async function GET(event) {
  return new Response('This is a GET response');
}

export async function POST(event) {
  const data = await event.request.json();
  return new Response(`POST received: ${JSON.stringify(data)}`);
}

export async function PUT(event) {
  const data = await event.request.json();
  return new Response('PUT request processed');
}

export async function DELETE(event) {
  return new Response('DELETE request processed');
}

Important Notes

Always return a Response object from each handler.

Use await event.request.json() to read JSON data sent by the client.

These handlers run on the server side in SvelteKit endpoints or +server.js files.

Summary

GET, POST, PUT, DELETE handlers let your app communicate with servers.

Each handler is an async function that returns a Response.

Use them to fetch, send, update, or delete data in your Svelte apps.