diff --git a/validator/go.mod b/validator/go.mod
new file mode 100644
index 0000000..29adddc
--- /dev/null
+++ b/validator/go.mod
@@ -0,0 +1,3 @@
+module github.com/dariubs/gobooks/validator
+
+go 1.21
diff --git a/validator/main.go b/validator/main.go
new file mode 100644
index 0000000..8912062
--- /dev/null
+++ b/validator/main.go
@@ -0,0 +1,284 @@
+// Validator for README.md structure in github.com/dariubs/gobooks.
+//
+// Checks: required sections, TOC link validity, no year prefixes in titles,
+// book metadata (*Last published*, *Authors*), cover images exist, covers linked.
+//
+// Usage: go run . [path/to/README.md]
+//        go run .              # uses README.md in parent dir (../README.md)
+package main
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+	"regexp"
+	"strings"
+)
+
+func main() {
+	readmePath := filepath.Join("..", "README.md")
+	if len(os.Args) > 1 {
+		readmePath = os.Args[1]
+	}
+
+	content, err := os.ReadFile(readmePath)
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "Error reading file: %v\n", err)
+		os.Exit(1)
+	}
+
+	lines := strings.Split(string(content), "\n")
+	errors := []string{}
+	warnings := []string{}
+
+	// 1. Check main sections exist
+	requiredSections := []string{"Starter Books", "Advanced Books", "Web Development", "Resources"}
+	foundSections := extractSections(lines)
+	for _, sec := range requiredSections {
+		if !foundSections[sec] {
+			errors = append(errors, fmt.Sprintf("Missing required section: ## %s", sec))
+		}
+	}
+	// Contributing and License may use ## or ==== format
+	hasContributing := foundSections["Contributing"]
+	hasLicense := foundSections["License"]
+	for i, line := range lines {
+		if strings.TrimSpace(line) == "Contributing" && i+1 < len(lines) && strings.HasPrefix(lines[i+1], "====") {
+			hasContributing = true
+		}
+		if strings.TrimSpace(line) == "License" && i+1 < len(lines) && strings.HasPrefix(lines[i+1], "====") {
+			hasLicense = true
+		}
+	}
+	if !hasContributing {
+		errors = append(errors, "Missing required section: Contributing")
+	}
+	if !hasLicense {
+		errors = append(errors, "Missing required section: License")
+	}
+
+	// 2. Extract TOC links and section headers
+	tocLinks := extractTOCLinks(lines)
+	headers := extractHeaders(lines)
+	// Add Contributing/License anchors when using ==== format
+	if hasContributing {
+		headers["contributing"] = true
+	}
+	if hasLicense {
+		headers["license"] = true
+	}
+
+	// 3. Verify TOC links point to existing headers
+	for link, anchor := range tocLinks {
+		if !headers[anchor] {
+			errors = append(errors, fmt.Sprintf("TOC link points to non-existent anchor: [%s](#%s)", truncate(link, 50), anchor))
+		}
+	}
+
+	// 4. Check section headers have no year prefix (### 2020 - [Title] is wrong)
+	yearPrefix := regexp.MustCompile(`^###\s+\d{4}\s+-\s+`)
+	for i, line := range lines {
+		if yearPrefix.MatchString(line) {
+			errors = append(errors, fmt.Sprintf("Line %d: Book title should not have year prefix: %s", i+1, strings.TrimSpace(line)[:min(60, len(strings.TrimSpace(line)))]+"..."))
+		}
+	}
+
+	// 5. Check book entries have required metadata (*Last published* and *Authors*) - only in book sections
+	bookBlocks := extractBookBlocks(lines)
+	inResourceSection := false
+	for i, line := range lines {
+		if strings.TrimSpace(line) == "## Resources" {
+			inResourceSection = true
+			break
+		}
+		_ = i
+	}
+	resourceTitles := map[string]bool{"A tour of Go": true, "Video: Learn Go Syntax in one video": true, "Tutorials: Go by Example": true, "Go Fundamentals Video Training": true, "More Books on the Go Wiki": true, "TutorialEdge.net Course": true, "Coursera Specialization: Programming with Go": true, "Course: Understand Go's In-Depth Mechanics": true, "Course: Mastering Go Programming": true, "Course: Web Development with Google's Go Programming Language": true, "Golangbot.com Articles": true, "Tuxerrante repo on go exercises": true}
+	for title, block := range bookBlocks {
+		if resourceTitles[title] || inResourceSection && (strings.Contains(title, "tour") || strings.Contains(title, "Video") || strings.Contains(title, "Tutorial") || strings.Contains(title, "Course") || strings.Contains(title, "Articles") || strings.Contains(title, "Wiki")) {
+			continue
+		}
+		hasLastPublished := strings.Contains(block, "*Last published*")
+		hasAuthors := strings.Contains(block, "*Authors:*")
+		if !hasLastPublished {
+			warnings = append(warnings, fmt.Sprintf("Book '%s' missing *Last published*", truncate(title, 50)))
+		}
+		if !hasAuthors {
+			warnings = append(warnings, fmt.Sprintf("Book '%s' missing *Authors:*", truncate(title, 50)))
+		}
+	}
+
+	// 6. Check cover images exist
+	coverRefs := extractCoverRefs(lines)
+	for _, ref := range coverRefs {
+		if strings.HasPrefix(ref, "http") {
+			continue // external URL, skip
+		}
+		path := filepath.Join(filepath.Dir(readmePath), ref)
+		if _, err := os.Stat(path); os.IsNotExist(err) {
+			errors = append(errors, fmt.Sprintf("Cover image not found: %s", ref))
+		}
+	}
+
+	// 7. Check cover images are linked (wrapped in <a href>)
+	unlinkedCovers := findUnlinkedCovers(lines)
+	for _, img := range unlinkedCovers {
+		warnings = append(warnings, fmt.Sprintf("Cover image not linked to book: %s", img))
+	}
+
+	// Report
+	if len(errors) > 0 {
+		fmt.Println("❌ ERRORS:")
+		for _, e := range errors {
+			fmt.Println("  ", e)
+		}
+	}
+	if len(warnings) > 0 {
+		fmt.Println("\n⚠️  WARNINGS:")
+		for _, w := range warnings {
+			fmt.Println("  ", w)
+		}
+	}
+
+	if len(errors) > 0 {
+		os.Exit(1)
+	}
+	if len(warnings) > 0 {
+		fmt.Println("\n✓ Structure OK (with warnings)")
+	} else {
+		fmt.Println("\n✓ Structure OK")
+	}
+}
+
+func extractSections(lines []string) map[string]bool {
+	m := make(map[string]bool)
+	r := regexp.MustCompile(`^##\s+(.+)$`)
+	for _, line := range lines {
+		if match := r.FindStringSubmatch(line); match != nil {
+			m[strings.TrimSpace(match[1])] = true
+		}
+	}
+	return m
+}
+
+func extractHeaders(lines []string) map[string]bool {
+	m := make(map[string]bool)
+	r := regexp.MustCompile(`^#{1,6}\s+(.+)$`)
+	for _, line := range lines {
+		if match := r.FindStringSubmatch(line); match != nil {
+			text := strings.TrimSpace(match[1])
+			// Extract link text from [Title](url) or [Title](url) *Free*
+			linkMatch := regexp.MustCompile(`^\[([^\]]+)\][^\)]*\)`).FindStringSubmatch(text)
+			if linkMatch != nil {
+				text = linkMatch[1]
+			}
+			// Remove *Free* suffix
+			text = regexp.MustCompile(`\s*\*Free\*\s*$`).ReplaceAllString(text, "")
+			text = strings.TrimSpace(text)
+			anchor := toAnchor(text)
+			m[anchor] = true
+			// Add -free variant (TOC often uses this for free books even when header omits *Free*)
+			m[anchor+"-free"] = true
+		}
+	}
+	return m
+}
+
+func toAnchor(s string) string {
+	s = strings.ToLower(s)
+	s = regexp.MustCompile(`[^a-z0-9\s-]`).ReplaceAllString(s, "")
+	s = regexp.MustCompile(`\s+`).ReplaceAllString(s, "-")
+	return strings.Trim(s, "-")
+}
+
+func extractTOCLinks(lines []string) map[string]string {
+	m := make(map[string]string)
+	r := regexp.MustCompile(`^\s*-\s+\[([^\]]+)\]\(#([^\)]+)\)`)
+	for _, line := range lines {
+		if match := r.FindStringSubmatch(line); match != nil {
+			title := strings.TrimSpace(match[1])
+			anchor := strings.TrimSpace(match[2])
+			m[title] = anchor
+		}
+	}
+	return m
+}
+
+func extractBookBlocks(lines []string) map[string]string {
+	m := make(map[string]string)
+	bookR := regexp.MustCompile(`^###\s+\[([^\]]+)\].*$`)
+	var currentTitle string
+	var currentBlock strings.Builder
+
+	for _, line := range lines {
+		if match := bookR.FindStringSubmatch(line); match != nil {
+			if currentTitle != "" {
+				m[currentTitle] = currentBlock.String()
+			}
+			currentTitle = match[1]
+			currentBlock.Reset()
+			currentBlock.WriteString(line)
+			currentBlock.WriteString("\n")
+		} else if currentTitle != "" && (strings.HasPrefix(line, "###") || strings.HasPrefix(line, "##")) {
+			m[currentTitle] = currentBlock.String()
+			currentTitle = ""
+			currentBlock.Reset()
+		} else if currentTitle != "" && line != "-----" {
+			currentBlock.WriteString(line)
+			currentBlock.WriteString("\n")
+		}
+	}
+	if currentTitle != "" {
+		m[currentTitle] = currentBlock.String()
+	}
+	return m
+}
+
+func extractCoverRefs(lines []string) []string {
+	var refs []string
+	r := regexp.MustCompile(`src="(covers/[^"]+)"`)
+	for _, line := range lines {
+		if match := r.FindStringSubmatch(line); match != nil {
+			refs = append(refs, match[1])
+		}
+	}
+	// Also check cover/ path
+	r2 := regexp.MustCompile(`src="(cover/[^"]+)"`)
+	for _, line := range lines {
+		if match := r2.FindStringSubmatch(line); match != nil {
+			refs = append(refs, match[1])
+		}
+	}
+	return refs
+}
+
+func findUnlinkedCovers(lines []string) []string {
+	var unlinked []string
+	r := regexp.MustCompile(`<img\s+src="(covers/[^"]+)"`)
+	for _, line := range lines {
+		// Skip if img is inside <a href> or markdown link [<img...>](url)
+		if (strings.Contains(line, "<a href=") || strings.Contains(line, "](http")) && strings.Contains(line, "<img") {
+			continue
+		}
+		if match := r.FindStringSubmatch(line); match != nil {
+			unlinked = append(unlinked, match[1])
+		}
+	}
+	return unlinked
+}
+
+func truncate(s string, max int) string {
+	s = strings.Split(s, "(")[0]
+	s = strings.TrimSpace(s)
+	if len(s) > max {
+		return s[:max] + "..."
+	}
+	return s
+}
+
+func min(a, b int) int {
+	if a < b {
+		return a
+	}
+	return b
+}