Implement complete content injection and enhancement pipeline

- Add content API client with HTTP and mock implementations
- Implement HTML content injection with database content replacement
- Create enhance command for build-time content injection
- Integrate enhancement with servedev for live development workflow
- Add editor asset injection and serving (/_insertr/ endpoints)
- Support on-the-fly HTML enhancement during development
- Enable complete 'Tailwind of CMS' workflow: parse → inject → serve

insertr-cli/assets/editor/insertr-editor.js

@@ -0,0 +1,85 @@
+/**
+ * Insertr Editor - Development Mode
+ * Loads editing capabilities for elements marked with data-insertr-enhanced="true"
+ */
+
+(function() {
+    'use strict';
+    
+    console.log('🔧 Insertr Editor loaded (development mode)');
+    
+    // Initialize editor when DOM is ready
+    if (document.readyState === 'loading') {
+        document.addEventListener('DOMContentLoaded', initEditor);
+    } else {
+        initEditor();
+    }
+    
+    function initEditor() {
+        console.log('🚀 Initializing Insertr Editor');
+        
+        // Find all enhanced elements
+        const enhancedElements = document.querySelectorAll('[data-insertr-enhanced="true"]');
+        console.log(`📝 Found ${enhancedElements.length} editable elements`);
+        
+        // Add visual indicators for development
+        enhancedElements.forEach(addEditIndicator);
+        
+        // Add global styles
+        addEditorStyles();
+    }
+    
+    function addEditIndicator(element) {
+        const contentId = element.getAttribute('data-content-id');
+        const contentType = element.getAttribute('data-content-type');
+        
+        // Add hover effect
+        element.style.cursor = 'pointer';
+        element.style.position = 'relative';
+        
+        // Add click handler for development demo
+        element.addEventListener('click', function(e) {
+            e.preventDefault();
+            alert(`Edit: ${contentId}\nType: ${contentType}\nCurrent: "${element.textContent.trim()}"`);
+        });
+        
+        // Add visual indicator on hover
+        element.addEventListener('mouseenter', function() {
+            element.classList.add('insertr-editing-hover');
+        });
+        
+        element.addEventListener('mouseleave', function() {
+            element.classList.remove('insertr-editing-hover');
+        });
+    }
+    
+    function addEditorStyles() {
+        const styles = `
+            .insertr-editing-hover {
+                outline: 2px dashed #007cba !important;
+                outline-offset: 2px !important;
+                background-color: rgba(0, 124, 186, 0.05) !important;
+            }
+            
+            [data-insertr-enhanced="true"]:hover::after {
+                content: "✏️ " attr(data-content-type);
+                position: absolute;
+                top: -25px;
+                left: 0;
+                background: #007cba;
+                color: white;
+                padding: 2px 6px;
+                font-size: 11px;
+                border-radius: 3px;
+                white-space: nowrap;
+                z-index: 1000;
+                font-family: monospace;
+            }
+        `;
+        
+        const styleSheet = document.createElement('style');
+        styleSheet.type = 'text/css';
+        styleSheet.innerHTML = styles;
+        document.head.appendChild(styleSheet);
+    }
+})();

insertr-cli/cmd/enhance.go

@@ -0,0 +1,76 @@
+package cmd
+
+import (
+	"fmt"
+	"log"
+	"os"
+
+	"github.com/spf13/cobra"
+
+	"github.com/insertr/cli/pkg/content"
+)
+
+var enhanceCmd = &cobra.Command{
+	Use:   "enhance [input-dir]",
+	Short: "Enhance HTML files by injecting content from database",
+	Long: `Enhance processes HTML files and injects latest content from the database
+while adding editing capabilities. This is the core build-time enhancement
+process that transforms static HTML into an editable CMS.`,
+	Args: cobra.ExactArgs(1),
+	Run:  runEnhance,
+}
+
+var (
+	outputDir   string
+	apiURL      string
+	apiKey      string
+	siteID      string
+	mockContent bool
+)
+
+func init() {
+	rootCmd.AddCommand(enhanceCmd)
+
+	enhanceCmd.Flags().StringVarP(&outputDir, "output", "o", "./dist", "Output directory for enhanced files")
+	enhanceCmd.Flags().StringVar(&apiURL, "api-url", "", "Content API URL")
+	enhanceCmd.Flags().StringVar(&apiKey, "api-key", "", "API key for authentication")
+	enhanceCmd.Flags().StringVarP(&siteID, "site-id", "s", "demo", "Site ID for content lookup")
+	enhanceCmd.Flags().BoolVar(&mockContent, "mock", true, "Use mock content for development")
+}
+
+func runEnhance(cmd *cobra.Command, args []string) {
+	inputDir := args[0]
+
+	// Validate input directory
+	if _, err := os.Stat(inputDir); os.IsNotExist(err) {
+		log.Fatalf("Input directory does not exist: %s", inputDir)
+	}
+
+	// Create content client
+	var client content.ContentClient
+	if mockContent {
+		fmt.Printf("🧪 Using mock content for development\n")
+		client = content.NewMockClient()
+	} else {
+		if apiURL == "" {
+			log.Fatal("API URL required when not using mock content (use --api-url)")
+		}
+		fmt.Printf("🌐 Using content API: %s\n", apiURL)
+		client = content.NewHTTPClient(apiURL, apiKey)
+	}
+
+	// Create enhancer
+	enhancer := content.NewEnhancer(client, siteID)
+
+	fmt.Printf("🚀 Starting enhancement process...\n")
+	fmt.Printf("📁 Input: %s\n", inputDir)
+	fmt.Printf("📁 Output: %s\n", outputDir)
+	fmt.Printf("🏷️  Site ID: %s\n\n", siteID)
+
+	// Enhance directory
+	if err := enhancer.EnhanceDirectory(inputDir, outputDir); err != nil {
+		log.Fatalf("Enhancement failed: %v", err)
+	}
+
+	fmt.Printf("\n✅ Enhancement complete! Enhanced files available in: %s\n", outputDir)
+}

insertr-cli/cmd/servedev.go

@@ -9,6 +9,8 @@ import (
 	"strings"
 
 	"github.com/spf13/cobra"
+
+	"github.com/insertr/cli/pkg/content"
 )
 
 var servedevCmd = &cobra.Command{
@@ -21,8 +23,10 @@ with live rebuilds via Air.`,
 }
 
 var (
-	inputDir string
+	inputDir       string
-	port     int
+	port           int
+	useMockContent bool
+	devSiteID      string
 )
 
 func init() {
@@ -30,6 +34,8 @@ func init() {
 
 	servedevCmd.Flags().StringVarP(&inputDir, "input", "i", ".", "Input directory to serve")
 	servedevCmd.Flags().IntVarP(&port, "port", "p", 3000, "Port to serve on")
+	servedevCmd.Flags().BoolVar(&useMockContent, "mock", true, "Use mock content for development")
+	servedevCmd.Flags().StringVarP(&devSiteID, "site-id", "s", "demo", "Site ID for content lookup")
 }
 
 func runServedev(cmd *cobra.Command, args []string) {
@@ -44,18 +50,37 @@ func runServedev(cmd *cobra.Command, args []string) {
 		log.Fatalf("Input directory does not exist: %s", absInputDir)
 	}
 
-	fmt.Printf("🚀 Starting development server...\n")
+	// Create content client
+	var client content.ContentClient
+	if useMockContent {
+		fmt.Printf("🧪 Using mock content for development\n")
+		client = content.NewMockClient()
+	} else {
+		// For now, default to mock if no API URL provided
+		fmt.Printf("🧪 Using mock content for development (no API configured)\n")
+		client = content.NewMockClient()
+	}
+
+	fmt.Printf("🚀 Starting development server with content enhancement...\n")
 	fmt.Printf("📁 Serving directory: %s\n", absInputDir)
 	fmt.Printf("🌐 Server running at: http://localhost:%d\n", port)
+	fmt.Printf("🏷️  Site ID: %s\n", devSiteID)
 	fmt.Printf("🔄 Manually refresh browser to see changes\n\n")
 
-	// Create file server
+	// Create enhanced file server
 	fileServer := http.FileServer(&enhancedFileSystem{
-		fs:  http.Dir(absInputDir),
+		fs:       http.Dir(absInputDir),
-		dir: absInputDir,
+		dir:      absInputDir,
+		enhancer: content.NewEnhancer(client, devSiteID),
 	})
 
-	// Handle all requests with our enhanced file server
+	// Handle editor assets
+	http.HandleFunc("/_insertr/", func(w http.ResponseWriter, r *http.Request) {
+		assetPath := strings.TrimPrefix(r.URL.Path, "/_insertr/")
+		serveEditorAsset(w, r, assetPath)
+	})
+
+	// Handle all other requests with our enhanced file server
 	http.Handle("/", fileServer)
 
 	// Start server
@@ -63,25 +88,78 @@ func runServedev(cmd *cobra.Command, args []string) {
 	log.Fatal(http.ListenAndServe(addr, nil))
 }
 
+// serveEditorAsset serves editor JavaScript and CSS files
+func serveEditorAsset(w http.ResponseWriter, r *http.Request, assetPath string) {
+	// Get the path to the CLI binary directory
+	execPath, err := os.Executable()
+	if err != nil {
+		http.NotFound(w, r)
+		return
+	}
+
+	// Look for assets relative to the CLI binary (for built version)
+	assetsDir := filepath.Join(filepath.Dir(execPath), "assets", "editor")
+	assetFile := filepath.Join(assetsDir, assetPath)
+
+	// If not found, look for assets relative to source (for development)
+	if _, err := os.Stat(assetFile); os.IsNotExist(err) {
+		// Assume we're running from source
+		cwd, _ := os.Getwd()
+		assetsDir = filepath.Join(cwd, "assets", "editor")
+		assetFile = filepath.Join(assetsDir, assetPath)
+	}
+
+	// Set appropriate content type
+	if strings.HasSuffix(assetPath, ".js") {
+		w.Header().Set("Content-Type", "application/javascript")
+	} else if strings.HasSuffix(assetPath, ".css") {
+		w.Header().Set("Content-Type", "text/css")
+	}
+
+	// Serve the file
+	http.ServeFile(w, r, assetFile)
+}
+
 // enhancedFileSystem wraps http.FileSystem to provide enhanced HTML serving
 type enhancedFileSystem struct {
-	fs  http.FileSystem
+	fs       http.FileSystem
-	dir string
+	dir      string
+	enhancer *content.Enhancer
 }
 
 func (efs *enhancedFileSystem) Open(name string) (http.File, error) {
-	file, err := efs.fs.Open(name)
+	// For HTML files, enhance them on-the-fly
-	if err != nil {
-		return nil, err
-	}
-
-	// For HTML files, we'll eventually enhance them here
-	// For now, just serve them as-is
 	if strings.HasSuffix(name, ".html") {
-		fmt.Printf("📄 Serving HTML: %s\n", name)
+		fmt.Printf("📄 Enhancing HTML: %s\n", name)
-		fmt.Println("🔍 Parser ran!")
+		return efs.serveEnhancedHTML(name)
-		// TODO: Parse for insertr elements and enhance
 	}
 
-	return file, nil
+	// For non-HTML files, serve as-is
+	return efs.fs.Open(name)
+}
+
+// serveEnhancedHTML enhances an HTML file and returns it as an http.File
+func (efs *enhancedFileSystem) serveEnhancedHTML(name string) (http.File, error) {
+	// Get the full file path
+	inputPath := filepath.Join(efs.dir, name)
+
+	// Create a temporary output path (in-memory would be better, but this is simpler for now)
+	tempDir := filepath.Join(os.TempDir(), "insertr-dev")
+	outputPath := filepath.Join(tempDir, name)
+
+	// Ensure temp directory exists
+	if err := os.MkdirAll(filepath.Dir(outputPath), 0755); err != nil {
+		fmt.Printf("⚠️  Failed to create temp directory: %v\n", err)
+		return efs.fs.Open(name) // Fallback to original file
+	}
+
+	// Enhance the file
+	if err := efs.enhancer.EnhanceFile(inputPath, outputPath); err != nil {
+		fmt.Printf("⚠️  Enhancement failed for %s: %v\n", name, err)
+		return efs.fs.Open(name) // Fallback to original file
+	}
+
+	// Serve the enhanced file
+	tempFS := http.Dir(tempDir)
+	return tempFS.Open(name)
 }

insertr-cli/pkg/content/client.go

@@ -0,0 +1,164 @@
+package content
+
+import (
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+	"net/url"
+	"strings"
+	"time"
+)
+
+// HTTPClient implements ContentClient for HTTP API access
+type HTTPClient struct {
+	BaseURL    string
+	APIKey     string
+	HTTPClient *http.Client
+}
+
+// NewHTTPClient creates a new HTTP content client
+func NewHTTPClient(baseURL, apiKey string) *HTTPClient {
+	return &HTTPClient{
+		BaseURL: strings.TrimSuffix(baseURL, "/"),
+		APIKey:  apiKey,
+		HTTPClient: &http.Client{
+			Timeout: 30 * time.Second,
+		},
+	}
+}
+
+// GetContent fetches a single content item by ID
+func (c *HTTPClient) GetContent(siteID, contentID string) (*ContentItem, error) {
+	url := fmt.Sprintf("%s/api/content/%s?site_id=%s", c.BaseURL, contentID, siteID)
+
+	req, err := http.NewRequest("GET", url, nil)
+	if err != nil {
+		return nil, fmt.Errorf("creating request: %w", err)
+	}
+
+	if c.APIKey != "" {
+		req.Header.Set("Authorization", "Bearer "+c.APIKey)
+	}
+
+	resp, err := c.HTTPClient.Do(req)
+	if err != nil {
+		return nil, fmt.Errorf("making request: %w", err)
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode == 404 {
+		return nil, nil // Content not found, return nil without error
+	}
+
+	if resp.StatusCode != 200 {
+		return nil, fmt.Errorf("API error: %s", resp.Status)
+	}
+
+	body, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return nil, fmt.Errorf("reading response: %w", err)
+	}
+
+	var item ContentItem
+	if err := json.Unmarshal(body, &item); err != nil {
+		return nil, fmt.Errorf("parsing response: %w", err)
+	}
+
+	return &item, nil
+}
+
+// GetBulkContent fetches multiple content items by IDs
+func (c *HTTPClient) GetBulkContent(siteID string, contentIDs []string) (map[string]ContentItem, error) {
+	if len(contentIDs) == 0 {
+		return make(map[string]ContentItem), nil
+	}
+
+	// Build query parameters
+	params := url.Values{}
+	params.Set("site_id", siteID)
+	for _, id := range contentIDs {
+		params.Add("ids", id)
+	}
+
+	url := fmt.Sprintf("%s/api/content/bulk?%s", c.BaseURL, params.Encode())
+
+	req, err := http.NewRequest("GET", url, nil)
+	if err != nil {
+		return nil, fmt.Errorf("creating request: %w", err)
+	}
+
+	if c.APIKey != "" {
+		req.Header.Set("Authorization", "Bearer "+c.APIKey)
+	}
+
+	resp, err := c.HTTPClient.Do(req)
+	if err != nil {
+		return nil, fmt.Errorf("making request: %w", err)
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != 200 {
+		return nil, fmt.Errorf("API error: %s", resp.Status)
+	}
+
+	body, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return nil, fmt.Errorf("reading response: %w", err)
+	}
+
+	var response ContentResponse
+	if err := json.Unmarshal(body, &response); err != nil {
+		return nil, fmt.Errorf("parsing response: %w", err)
+	}
+
+	// Convert slice to map for easy lookup
+	result := make(map[string]ContentItem)
+	for _, item := range response.Content {
+		result[item.ID] = item
+	}
+
+	return result, nil
+}
+
+// GetAllContent fetches all content for a site
+func (c *HTTPClient) GetAllContent(siteID string) (map[string]ContentItem, error) {
+	url := fmt.Sprintf("%s/api/content?site_id=%s", c.BaseURL, siteID)
+
+	req, err := http.NewRequest("GET", url, nil)
+	if err != nil {
+		return nil, fmt.Errorf("creating request: %w", err)
+	}
+
+	if c.APIKey != "" {
+		req.Header.Set("Authorization", "Bearer "+c.APIKey)
+	}
+
+	resp, err := c.HTTPClient.Do(req)
+	if err != nil {
+		return nil, fmt.Errorf("making request: %w", err)
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != 200 {
+		return nil, fmt.Errorf("API error: %s", resp.Status)
+	}
+
+	body, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return nil, fmt.Errorf("reading response: %w", err)
+	}
+
+	var response ContentResponse
+	if err := json.Unmarshal(body, &response); err != nil {
+		return nil, fmt.Errorf("parsing response: %w", err)
+	}
+
+	// Convert slice to map for easy lookup
+	result := make(map[string]ContentItem)
+	for _, item := range response.Content {
+		result[item.ID] = item
+	}
+
+	return result, nil
+}

insertr-cli/pkg/content/enhancer.go

@@ -0,0 +1,215 @@
+package content
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+	"strings"
+
+	"golang.org/x/net/html"
+
+	"github.com/insertr/cli/pkg/parser"
+)
+
+// Enhancer combines parsing and content injection
+type Enhancer struct {
+	parser   *parser.Parser
+	injector *Injector
+}
+
+// NewEnhancer creates a new HTML enhancer
+func NewEnhancer(client ContentClient, siteID string) *Enhancer {
+	return &Enhancer{
+		parser:   parser.New(),
+		injector: NewInjector(client, siteID),
+	}
+}
+
+// EnhanceFile processes an HTML file and injects content
+func (e *Enhancer) EnhanceFile(inputPath, outputPath string) error {
+	// Use parser to get elements from file
+	result, err := e.parser.ParseDirectory(filepath.Dir(inputPath))
+	if err != nil {
+		return fmt.Errorf("parsing file: %w", err)
+	}
+
+	// Filter elements for this specific file
+	var fileElements []parser.Element
+	inputBaseName := filepath.Base(inputPath)
+	for _, elem := range result.Elements {
+		elemBaseName := filepath.Base(elem.FilePath)
+		if elemBaseName == inputBaseName {
+			fileElements = append(fileElements, elem)
+		}
+	}
+
+	if len(fileElements) == 0 {
+		// No insertr elements found, copy file as-is
+		return e.copyFile(inputPath, outputPath)
+	}
+
+	// Read and parse HTML for modification
+	htmlContent, err := os.ReadFile(inputPath)
+	if err != nil {
+		return fmt.Errorf("reading file %s: %w", inputPath, err)
+	}
+
+	doc, err := html.Parse(strings.NewReader(string(htmlContent)))
+	if err != nil {
+		return fmt.Errorf("parsing HTML: %w", err)
+	}
+
+	// Find and inject content for each element
+	for _, elem := range fileElements {
+		// Find the node in the parsed document
+		// Note: This is a simplified approach - in production we'd need more robust node matching
+		if err := e.injectElementContent(doc, elem); err != nil {
+			fmt.Printf("⚠️  Warning: failed to inject content for %s: %v\n", elem.ContentID, err)
+		}
+	}
+
+	// Inject editor assets for development
+	e.injector.InjectEditorAssets(doc, true)
+
+	// Write enhanced HTML
+	if err := e.writeHTML(doc, outputPath); err != nil {
+		return fmt.Errorf("writing enhanced HTML: %w", err)
+	}
+
+	fmt.Printf("✅ Enhanced: %s → %s (%d elements)\n",
+		filepath.Base(inputPath),
+		filepath.Base(outputPath),
+		len(fileElements))
+
+	return nil
+}
+
+// injectElementContent finds and injects content for a specific element
+func (e *Enhancer) injectElementContent(doc *html.Node, elem parser.Element) error {
+	// Fetch content from database
+	contentItem, err := e.injector.client.GetContent(e.injector.siteID, elem.ContentID)
+	if err != nil {
+		return fmt.Errorf("fetching content: %w", err)
+	}
+
+	// Find nodes with insertr class and inject content
+	e.findAndInjectNodes(doc, elem, contentItem)
+	return nil
+}
+
+// findAndInjectNodes recursively finds nodes and injects content
+func (e *Enhancer) findAndInjectNodes(node *html.Node, elem parser.Element, contentItem *ContentItem) {
+	if node.Type == html.ElementNode {
+		// Check if this node matches our element criteria
+		classes := getClasses(node)
+		if containsClass(classes, "insertr") && node.Data == elem.Tag {
+			// This might be our target node - inject content
+			e.injector.addContentAttributes(node, elem.ContentID, string(elem.Type))
+
+			if contentItem != nil {
+				switch elem.Type {
+				case parser.ContentText:
+					e.injector.injectTextContent(node, contentItem.Value)
+				case parser.ContentMarkdown:
+					e.injector.injectMarkdownContent(node, contentItem.Value)
+				case parser.ContentLink:
+					e.injector.injectLinkContent(node, contentItem.Value)
+				}
+			}
+		}
+	}
+
+	// Recursively process children
+	for child := node.FirstChild; child != nil; child = child.NextSibling {
+		e.findAndInjectNodes(child, elem, contentItem)
+	}
+}
+
+// Helper functions from parser package
+func getClasses(node *html.Node) []string {
+	for _, attr := range node.Attr {
+		if attr.Key == "class" {
+			return strings.Fields(attr.Val)
+		}
+	}
+	return []string{}
+}
+
+func containsClass(classes []string, target string) bool {
+	for _, class := range classes {
+		if class == target {
+			return true
+		}
+	}
+	return false
+}
+
+// EnhanceDirectory processes all HTML files in a directory
+func (e *Enhancer) EnhanceDirectory(inputDir, outputDir string) error {
+	// Create output directory
+	if err := os.MkdirAll(outputDir, 0755); err != nil {
+		return fmt.Errorf("creating output directory: %w", err)
+	}
+
+	// Walk input directory
+	return filepath.Walk(inputDir, func(path string, info os.FileInfo, err error) error {
+		if err != nil {
+			return err
+		}
+
+		// Calculate relative path and output path
+		relPath, err := filepath.Rel(inputDir, path)
+		if err != nil {
+			return err
+		}
+		outputPath := filepath.Join(outputDir, relPath)
+
+		// Handle directories
+		if info.IsDir() {
+			return os.MkdirAll(outputPath, info.Mode())
+		}
+
+		// Handle HTML files
+		if strings.HasSuffix(strings.ToLower(path), ".html") {
+			return e.EnhanceFile(path, outputPath)
+		}
+
+		// Copy other files as-is
+		return e.copyFile(path, outputPath)
+	})
+}
+
+// copyFile copies a file from src to dst
+func (e *Enhancer) copyFile(src, dst string) error {
+	// Create directory for destination
+	if err := os.MkdirAll(filepath.Dir(dst), 0755); err != nil {
+		return err
+	}
+
+	// Read source
+	data, err := os.ReadFile(src)
+	if err != nil {
+		return err
+	}
+
+	// Write destination
+	return os.WriteFile(dst, data, 0644)
+}
+
+// writeHTML writes an HTML document to a file
+func (e *Enhancer) writeHTML(doc *html.Node, outputPath string) error {
+	// Create directory for output
+	if err := os.MkdirAll(filepath.Dir(outputPath), 0755); err != nil {
+		return err
+	}
+
+	// Create output file
+	file, err := os.Create(outputPath)
+	if err != nil {
+		return err
+	}
+	defer file.Close()
+
+	// Write HTML
+	return html.Render(file, doc)
+}

insertr-cli/pkg/content/injector.go

@@ -0,0 +1,204 @@
+package content
+
+import (
+	"fmt"
+
+	"golang.org/x/net/html"
+)
+
+// Injector handles content injection into HTML elements
+type Injector struct {
+	client ContentClient
+	siteID string
+}
+
+// NewInjector creates a new content injector
+func NewInjector(client ContentClient, siteID string) *Injector {
+	return &Injector{
+		client: client,
+		siteID: siteID,
+	}
+}
+
+// InjectContent replaces element content with database values and adds content IDs
+func (i *Injector) InjectContent(element *Element, contentID string) error {
+	// Fetch content from database/API
+	contentItem, err := i.client.GetContent(i.siteID, contentID)
+	if err != nil {
+		return fmt.Errorf("fetching content for %s: %w", contentID, err)
+	}
+
+	// If no content found, keep original content but add data attributes
+	if contentItem == nil {
+		i.addContentAttributes(element.Node, contentID, element.Type)
+		return nil
+	}
+
+	// Replace element content based on type
+	switch element.Type {
+	case "text":
+		i.injectTextContent(element.Node, contentItem.Value)
+	case "markdown":
+		i.injectMarkdownContent(element.Node, contentItem.Value)
+	case "link":
+		i.injectLinkContent(element.Node, contentItem.Value)
+	default:
+		i.injectTextContent(element.Node, contentItem.Value)
+	}
+
+	// Add data attributes for editor functionality
+	i.addContentAttributes(element.Node, contentID, element.Type)
+
+	return nil
+}
+
+// InjectBulkContent efficiently injects multiple content items
+func (i *Injector) InjectBulkContent(elements []ElementWithID) error {
+	// Extract content IDs for bulk fetch
+	contentIDs := make([]string, len(elements))
+	for idx, elem := range elements {
+		contentIDs[idx] = elem.ContentID
+	}
+
+	// Bulk fetch content
+	contentMap, err := i.client.GetBulkContent(i.siteID, contentIDs)
+	if err != nil {
+		return fmt.Errorf("bulk fetching content: %w", err)
+	}
+
+	// Inject each element
+	for _, elem := range elements {
+		contentItem, exists := contentMap[elem.ContentID]
+
+		// Add content attributes regardless
+		i.addContentAttributes(elem.Element.Node, elem.ContentID, elem.Element.Type)
+
+		if !exists {
+			// Keep original content if not found in database
+			continue
+		}
+
+		// Replace content based on type
+		switch elem.Element.Type {
+		case "text":
+			i.injectTextContent(elem.Element.Node, contentItem.Value)
+		case "markdown":
+			i.injectMarkdownContent(elem.Element.Node, contentItem.Value)
+		case "link":
+			i.injectLinkContent(elem.Element.Node, contentItem.Value)
+		default:
+			i.injectTextContent(elem.Element.Node, contentItem.Value)
+		}
+	}
+
+	return nil
+}
+
+// injectTextContent replaces text content in an element
+func (i *Injector) injectTextContent(node *html.Node, content string) {
+	// Remove all child nodes
+	for child := node.FirstChild; child != nil; {
+		next := child.NextSibling
+		node.RemoveChild(child)
+		child = next
+	}
+
+	// Add new text content
+	textNode := &html.Node{
+		Type: html.TextNode,
+		Data: content,
+	}
+	node.AppendChild(textNode)
+}
+
+// injectMarkdownContent handles markdown content (for now, just as text)
+func (i *Injector) injectMarkdownContent(node *html.Node, content string) {
+	// For now, treat markdown as text content
+	// TODO: Implement markdown to HTML conversion
+	i.injectTextContent(node, content)
+}
+
+// injectLinkContent handles link/button content with URL extraction
+func (i *Injector) injectLinkContent(node *html.Node, content string) {
+	// For now, just inject the text content
+	// TODO: Parse content for URL and text components
+	i.injectTextContent(node, content)
+}
+
+// addContentAttributes adds necessary data attributes for editor functionality
+func (i *Injector) addContentAttributes(node *html.Node, contentID string, contentType string) {
+	i.setAttribute(node, "data-content-id", contentID)
+	i.setAttribute(node, "data-content-type", contentType)
+	i.setAttribute(node, "data-insertr-enhanced", "true")
+}
+
+// InjectEditorAssets adds editor JavaScript and CSS to HTML document
+func (i *Injector) InjectEditorAssets(doc *html.Node, isDevelopment bool) {
+	if !isDevelopment {
+		return // Only inject in development mode for now
+	}
+
+	// Find the head element
+	head := i.findHeadElement(doc)
+	if head == nil {
+		return
+	}
+
+	// Add editor JavaScript
+	script := &html.Node{
+		Type: html.ElementNode,
+		Data: "script",
+		Attr: []html.Attribute{
+			{Key: "src", Val: "/_insertr/insertr-editor.js"},
+			{Key: "defer", Val: ""},
+		},
+	}
+	head.AppendChild(script)
+}
+
+// findHeadElement finds the <head> element in the document
+func (i *Injector) findHeadElement(node *html.Node) *html.Node {
+	if node.Type == html.ElementNode && node.Data == "head" {
+		return node
+	}
+
+	for child := node.FirstChild; child != nil; child = child.NextSibling {
+		if result := i.findHeadElement(child); result != nil {
+			return result
+		}
+	}
+
+	return nil
+}
+
+// setAttribute safely sets an attribute on an HTML node
+func (i *Injector) setAttribute(node *html.Node, key, value string) {
+	// Remove existing attribute if present
+	for idx, attr := range node.Attr {
+		if attr.Key == key {
+			node.Attr = append(node.Attr[:idx], node.Attr[idx+1:]...)
+			break
+		}
+	}
+
+	// Add new attribute
+	node.Attr = append(node.Attr, html.Attribute{
+		Key: key,
+		Val: value,
+	})
+}
+
+// Element represents a parsed HTML element with metadata
+type Element struct {
+	Node    *html.Node
+	Type    string
+	Tag     string
+	Classes []string
+	Content string
+}
+
+// ElementWithID combines an element with its generated content ID
+type ElementWithID struct {
+	Element   *Element
+	ContentID string
+}

insertr-cli/pkg/content/mock.go

@@ -0,0 +1,147 @@
+package content
+
+import (
+	"fmt"
+	"time"
+)
+
+// MockClient implements ContentClient with mock data for development
+type MockClient struct {
+	data map[string]ContentItem
+}
+
+// NewMockClient creates a new mock content client with sample data
+func NewMockClient() *MockClient {
+	// Generate realistic mock content based on actual generated IDs
+	data := map[string]ContentItem{
+		// Navigation (index.html has collision suffix)
+		"navbar-logo-2b10ad": {
+			ID:        "navbar-logo-2b10ad",
+			SiteID:    "demo",
+			Value:     "Acme Consulting Solutions",
+			Type:      "text",
+			UpdatedAt: time.Now().Format(time.RFC3339),
+		},
+		"navbar-logo-2b10ad-a44bad": {
+			ID:        "navbar-logo-2b10ad-a44bad",
+			SiteID:    "demo",
+			Value:     "Acme Business Advisors",
+			Type:      "text",
+			UpdatedAt: time.Now().Format(time.RFC3339),
+		},
+
+		// Hero Section - index.html (updated with actual IDs)
+		"hero-title-7cfeea": {
+			ID:        "hero-title-7cfeea",
+			SiteID:    "demo",
+			Value:     "Transform Your Business with Strategic Expertise",
+			Type:      "text",
+			UpdatedAt: time.Now().Format(time.RFC3339),
+		},
+		"hero-lead-e47475": {
+			ID:        "hero-lead-e47475",
+			SiteID:    "demo",
+			Value:     "We help **ambitious businesses** grow through strategic planning, process optimization, and digital transformation. Our team brings 20+ years of experience to accelerate your success.",
+			Type:      "markdown",
+			UpdatedAt: time.Now().Format(time.RFC3339),
+		},
+		"hero-link-76c620": {
+			ID:        "hero-link-76c620",
+			SiteID:    "demo",
+			Value:     "Schedule Free Consultation",
+			Type:      "link",
+			UpdatedAt: time.Now().Format(time.RFC3339),
+		},
+
+		// Hero Section - about.html
+		"hero-title-c70343": {
+			ID:        "hero-title-c70343",
+			SiteID:    "demo",
+			Value:     "About Our Consulting Expertise",
+			Type:      "text",
+			UpdatedAt: time.Now().Format(time.RFC3339),
+		},
+		"hero-lead-673026": {
+			ID:        "hero-lead-673026",
+			SiteID:    "demo",
+			Value:     "We're a team of **experienced consultants** dedicated to helping small businesses thrive in today's competitive marketplace through proven strategies.",
+			Type:      "markdown",
+			UpdatedAt: time.Now().Format(time.RFC3339),
+		},
+
+		// Services Section
+		"services-subtitle-c8927c": {
+			ID:        "services-subtitle-c8927c",
+			SiteID:    "demo",
+			Value:     "Our Story",
+			Type:      "text",
+			UpdatedAt: time.Now().Format(time.RFC3339),
+		},
+		"services-text-0d96da": {
+			ID:        "services-text-0d96da",
+			SiteID:    "demo",
+			Value:     "**Founded in 2020**, Acme Consulting emerged from a simple observation: small businesses needed access to the same high-quality strategic advice that large corporations receive, but in a format that was accessible, affordable, and actionable.",
+			Type:      "markdown",
+			UpdatedAt: time.Now().Format(time.RFC3339),
+		},
+
+		// Default fallback for any missing content
+		"default": {
+			ID:        "default",
+			SiteID:    "demo",
+			Value:     "[Enhanced Content]",
+			Type:      "text",
+			UpdatedAt: time.Now().Format(time.RFC3339),
+		},
+	}
+
+	return &MockClient{data: data}
+}
+
+// GetContent fetches a single content item by ID
+func (m *MockClient) GetContent(siteID, contentID string) (*ContentItem, error) {
+	if item, exists := m.data[contentID]; exists && item.SiteID == siteID {
+		return &item, nil
+	}
+
+	// Return fallback content for missing items during development
+	fallback := &ContentItem{
+		ID:        contentID,
+		SiteID:    siteID,
+		Value:     fmt.Sprintf("[Mock: %s]", contentID),
+		Type:      "text",
+		UpdatedAt: time.Now().Format(time.RFC3339),
+	}
+
+	return fallback, nil
+}
+
+// GetBulkContent fetches multiple content items by IDs
+func (m *MockClient) GetBulkContent(siteID string, contentIDs []string) (map[string]ContentItem, error) {
+	result := make(map[string]ContentItem)
+
+	for _, id := range contentIDs {
+		item, err := m.GetContent(siteID, id)
+		if err != nil {
+			return nil, err
+		}
+		if item != nil {
+			result[id] = *item
+		}
+	}
+
+	return result, nil
+}
+
+// GetAllContent fetches all content for a site
+func (m *MockClient) GetAllContent(siteID string) (map[string]ContentItem, error) {
+	result := make(map[string]ContentItem)
+
+	for _, item := range m.data {
+		if item.SiteID == siteID {
+			result[item.ID] = item
+		}
+	}
+
+	return result, nil
+}

insertr-cli/pkg/content/types.go

@@ -0,0 +1,28 @@
+package content
+
+// ContentItem represents a piece of content from the database
+type ContentItem struct {
+	ID        string `json:"id"`
+	SiteID    string `json:"site_id"`
+	Value     string `json:"value"`
+	Type      string `json:"type"`
+	UpdatedAt string `json:"updated_at"`
+}
+
+// ContentResponse represents the API response structure
+type ContentResponse struct {
+	Content []ContentItem `json:"content"`
+	Error   string        `json:"error,omitempty"`
+}
+
+// ContentClient interface for content retrieval
+type ContentClient interface {
+	// GetContent fetches content by ID
+	GetContent(siteID, contentID string) (*ContentItem, error)
+
+	// GetBulkContent fetches multiple content items by IDs
+	GetBulkContent(siteID string, contentIDs []string) (map[string]ContentItem, error)
+
+	// GetAllContent fetches all content for a site
+	GetAllContent(siteID string) (map[string]ContentItem, error)
+}