diff --git a/.github/copilot-instructions.md b/.github/copilot-instructions.md
new file mode 100644
index 0000000..e69de29
diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index 6300be1..4d5d470 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -7,7 +7,7 @@ on:
 
 permissions:
   contents: write
-  
+
 jobs:
   build-and-release:
     runs-on: ubuntu-latest
diff --git a/extension.js b/extension.js
new file mode 100644
index 0000000..a39abc2
--- /dev/null
+++ b/extension.js
@@ -0,0 +1,273 @@
+// The module 'vscode' contains the VS Code extensibility API
+// Import the module and reference it with the alias vscode in your code below
+const vscode = require('vscode');
+const sharp = require('sharp');
+const fs = require('fs');
+const path = require('path');
+
+const config = vscode.workspace.getConfiguration('responsiveImageGenerator');
+
+// This method is called when your extension is activated
+// Your extension is activated the very first time the command is executed
+
+/**
+ * @param {vscode.ExtensionContext} context
+ */
+
+
+/**
+ * Activates the Responsive Image Generator extension.
+ * Registers commands and completion providers.
+ * @param {vscode.ExtensionContext} context - The extension context provided by VS Code.
+ */
+function activate(context) {
+	const extensionPackageJson = require(path.join(context.extensionPath, 'package.json'));
+
+	// Register the main command for generating responsive images
+	const disposable = vscode.commands.registerCommand('responsive-image-generator.generate', async function () {
+		try {
+			const result = await promptForAllInputs();
+			if (!result) return;
+			const { imageUris, outputDir, sizesToGenerate } = result;
+
+			// Show progress while processing images
+			await vscode.window.withProgress({
+				location: vscode.ProgressLocation.Notification,
+				title: 'Generating responsive images...',
+				cancellable: false
+			}, async (progress) => {
+				progress.report({ message: 'Processing images...' });
+				// Process all images and sizes in parallel
+				await Promise.all(
+					imageUris.map(imageUri => {
+						const itemName = path.basename(imageUri.fsPath, path.extname(imageUri.fsPath));
+						return processImage(imageUri.fsPath, outputDir, itemName, sizesToGenerate);
+					})
+				);
+			});
+
+			vscode.window.showInformationMessage('Responsive images generated successfully!');
+		} catch (err) {
+			vscode.window.showErrorMessage(`Error: ${err.message}`);
+			console.error(err);
+		}
+	});
+	context.subscriptions.push(disposable);
+
+	// Supported languages for completion provider
+	// Dynamically fetch supported languages from package.json activationEvents
+	let supportedLanguages = [];
+	if (extensionPackageJson.activationEvents) {
+		supportedLanguages = extensionPackageJson.activationEvents
+			.filter(event => event.startsWith('onLanguage:'))
+			.map(event => event.replace('onLanguage:', ''));
+	}
+
+	const searchWord = 'responsive';
+	const triggerCharacters = ['<', '>', '!'];
+
+	// Register completion provider for responsive image tag
+	const provider = vscode.languages.registerCompletionItemProvider(
+		supportedLanguages,
+		{
+			/**
+			 * Provides completion items for responsive image tag.
+			 * @param {vscode.TextDocument} document
+			 * @param {vscode.Position} position
+			 * @returns {vscode.CompletionItem[]|undefined}
+			 */
+			provideCompletionItems(document, position) {
+				const linePrefix = document.lineAt(position).text.split(new RegExp(`[${triggerCharacters.join('')}]`)).at(1)?.trim() || '';
+				if (searchWord.includes(linePrefix) && linePrefix.length > 0) {
+					const completion = new vscode.CompletionItem('responsive_image_basic', vscode.CompletionItemKind.Snippet);
+					completion.command = {
+						command: 'responsive-image-generator.fillResponsiveTag',
+						title: 'Fill Responsive Image Tag',
+						arguments: [document, position.translate(0, -(linePrefix.length + 1))]
+					};
+					return [completion];
+				}
+				return undefined;
+			}
+		},
+		...triggerCharacters
+	);
+	context.subscriptions.push(provider);
+
+	// Register command to fill responsive tag after completion is selected
+	context.subscriptions.push(vscode.commands.registerCommand('responsive-image-generator.fillResponsiveTag', async (document, triggerStart) => {
+		const result = await promptForAllInputs();
+		if (!result) return;
+		const { imageUris, outputDir, sizesToGenerate } = result;
+
+		// Generate srcset string
+		let srcsetParts = [];
+		for (const imageUri of imageUris) {
+			const itemName = path.basename(imageUri.fsPath, path.extname(imageUri.fsPath));
+			for (const size of sizesToGenerate) {
+				const outputFile = path.join(outputDir, `${itemName}_${size}${path.extname(imageUri.fsPath)}`);
+				try {
+					// Resize and save image
+					await sharp(imageUri.fsPath)
+						.resize(size)
+						.toFile(outputFile);
+					// Use relative paths if configured
+					if(config.get('useRelativePaths')) {
+						const root = config.get('staticAssetsRoot') || vscode.workspace.workspaceFolders?.[0]?.uri.fsPath;
+						const relativeOutputFile = root ? `./${path.relative(root, outputFile)}` : outputFile;
+						srcsetParts.push(`${relativeOutputFile} ${size}w`);
+					} else {
+						srcsetParts.push(`${outputFile} ${size}w`);
+					}
+				} catch (err) {
+					vscode.window.showErrorMessage(`Error processing ${imageUri.fsPath} for size ${size}: ${err.message}`);
+				}
+			}
+		}
+		const srcset = srcsetParts.join(', ');
+
+		// Generate sizes attribute
+		const sizes = sizesToGenerate.map(size => `(max-width: ${size}px) ${size}px`).join(', ') + ', 100vw';
+
+		// Insert finished snippet, replacing the prefix
+		const editor = vscode.window.activeTextEditor;
+		if (editor) {
+			const snippet = new vscode.SnippetString(`<img src="${srcsetParts[0]?.split(' ')[0] || ''}" srcset="${srcset}" sizes="${sizes}" alt="$1">`);
+			const endPosition = triggerStart.translate(0, document.lineAt(triggerStart).text.length - triggerStart.character);
+			editor.edit(editBuilder => {
+				editBuilder.delete(new vscode.Range(triggerStart, endPosition));
+			}).then(() => {
+				editor.insertSnippet(snippet, triggerStart);
+			});
+		}
+		vscode.window.showInformationMessage('Add responsive image tag and generated images!');
+	}));
+}
+
+
+
+
+/**
+ * Prompts the user for all required inputs: image files, output directory, and sizes.
+ * Handles duplicate logic and error messaging for missing selections.
+ * @returns {Promise<{imageUris: vscode.Uri[], outputDir: string, sizesToGenerate: number[]} | undefined>} Object with all inputs, or undefined if cancelled.
+ */
+async function promptForAllInputs() {
+	// Prompt for image file(s)
+	const imageUris = await promptForImageFiles();
+	if (!imageUris || imageUris.length === 0) {
+		vscode.window.showWarningMessage('No image selected. Operation cancelled.');
+		return undefined;
+	}
+
+	// Prompt for output directory
+	const outputDir = await promptForOutputDirectory();
+	if (!outputDir) {
+		vscode.window.showWarningMessage('No output directory selected. Operation cancelled.');
+		return undefined;
+	}
+
+	// Prompt for sizes
+	const sizesToGenerate = await promptForSizes();
+	if (!sizesToGenerate || sizesToGenerate.length === 0) {
+		vscode.window.showWarningMessage('No sizes selected. Operation cancelled.');
+		return undefined;
+	}
+
+	// Create output directory if it doesn't exist
+	if (!fs.existsSync(outputDir)) {
+		fs.mkdirSync(outputDir, { recursive: true });
+	}
+
+	return { imageUris, outputDir, sizesToGenerate };
+}
+
+/**
+ * Prompts the user to select image files.
+ * @returns {Promise<vscode.Uri[]|undefined>} Array of selected image URIs or undefined if cancelled.
+ */
+async function promptForImageFiles() {
+	return await vscode.window.showOpenDialog({
+		canSelectMany: true,
+		openLabel: 'Select Image(s)',
+		filters: {
+			'Images': ['png', 'jpg', 'jpeg', 'gif', 'bmp', 'webp', 'svg']
+		}
+	});
+}
+
+/**
+ * Prompts the user to select an output directory, preferring 'wwwroot' or 'public' if available.
+ * @returns {Promise<string|undefined>} Path to selected output directory or undefined if cancelled.
+ */
+async function promptForOutputDirectory() {
+	const workspaceFolders = vscode.workspace.workspaceFolders || [];
+	let staticContentFolder = workspaceFolders.find(folder => (folder.name.toLowerCase() === 'wwwroot') || (folder.name.toLowerCase() === 'public'));
+	let preselectUri = staticContentFolder ? staticContentFolder.uri : undefined;
+
+	const folder = await vscode.window.showWorkspaceFolderPick({
+		placeHolder: "Select output folder ('wwwroot' or 'public' will be preselected if available)",
+	});
+	if (folder) {
+		return folder.uri.fsPath;
+	} else if (preselectUri) {
+		return preselectUri.fsPath;
+	} else {
+		return undefined;
+	}
+}
+
+/**
+ * Prompts the user to select image sizes to generate.
+ * @returns {Promise<number[]|undefined>} Array of selected sizes or undefined if cancelled.
+ */
+async function promptForSizes() {
+	const sizes = config.get('defaultSizes') || [320, 480, 768, 1024, 1280, 1600, 1920, 2560, 3840, 5120, 7680];
+	const selectedSizes = await vscode.window.showQuickPick(sizes.map(size => size.toString()), {
+		placeHolder: 'Select sizes to generate (you can select multiple)',
+		canPickMany: true
+	});
+	return selectedSizes ? selectedSizes.map(size => parseInt(size)) : undefined;
+}
+
+
+/**
+ * Processes an image: resizes and saves to output directory with item name and size.
+ * @param {string} imagePath - Path to the source image file.
+ * @param {string} outputDir - Directory to save resized images.
+ * @param {string} itemName - Base name for output files.
+ * @param {number[]} sizesToGenerate - Array of sizes to generate.
+ * @returns {Promise<void>}
+ */
+async function processImage(imagePath, outputDir, itemName, sizesToGenerate) {
+	await Promise.all(
+		sizesToGenerate.map(async (size) => {
+			const outputFile = path.join(
+				outputDir,
+				`${itemName}_${size}${path.extname(imagePath)}`
+			);
+			try {
+				await sharp(imagePath)
+					.resize(size)
+					.toFile(outputFile);
+				console.log(`Generated ${outputFile}`);
+			} catch (err) {
+				vscode.window.showErrorMessage(`Error processing ${imagePath} for size ${size}: ${err.message}`);
+			}
+		})
+	);
+}
+
+// This method is called when your extension is deactivated
+
+
+/**
+ * Deactivates the extension.
+ * Called when the extension is deactivated.
+ */
+function deactivate() { }
+
+module.exports = {
+	activate,
+	deactivate
+}
\ No newline at end of file