diff --git a/regex_humanizer/cli.py b/regex_humanizer/cli.py
new file mode 100644
index 0000000..e161842
--- /dev/null
+++ b/regex_humanizer/cli.py
@@ -0,0 +1,280 @@
+"""Command-line interface for Regex Humanizer."""
+
+import json
+import sys
+from typing import Optional
+import click
+from .parser import parse_regex
+from .translator import translate_regex
+from .test_generator import generate_test_cases
+from .flavors import get_flavor_manager, get_available_flavors
+from .interactive import start_interactive_mode
+
+
+@click.group()
+@click.option(
+    "--flavor",
+    type=click.Choice(["pcre", "javascript", "python"]),
+    default="pcre",
+    help="Regex flavor to use",
+)
+@click.pass_context
+def main(ctx: click.Context, flavor: str):
+    """Regex Humanizer CLI - Convert regex patterns to human-readable English and generate test cases."""
+    ctx.ensure_object(dict)
+    ctx.obj["flavor"] = flavor
+
+
+@main.command("explain")
+@click.argument("pattern", type=str)
+@click.option(
+    "--output",
+    "-o",
+    type=click.Choice(["text", "json"]),
+    default="text",
+    help="Output format",
+)
+@click.option(
+    "--verbose",
+    "-v",
+    is_flag=True,
+    help="Show detailed breakdown",
+)
+@click.option(
+    "--flavor",
+    "-f",
+    type=click.Choice(["pcre", "javascript", "python"]),
+    default=None,
+    help="Regex flavor to use",
+)
+@click.pass_context
+def explain(ctx: click.Context, pattern: str, output: str, verbose: bool, flavor: str):
+    """Explain a regex pattern in human-readable English."""
+    if ctx.obj is None:
+        ctx.obj = {}
+    flavor = flavor or ctx.obj.get("flavor", "pcre")
+
+    try:
+        ast = parse_regex(pattern, flavor)
+        translation = translate_regex(pattern, flavor)
+
+        if output == "json":
+            result = {
+                "pattern": pattern,
+                "flavor": flavor,
+                "explanation": translation,
+                "verbose": {
+                    "node_count": len(get_all_nodes(ast)),
+                    "features": identify_features(ast),
+                } if verbose else None,
+            }
+            click.echo(json.dumps(result, indent=2))
+        else:
+            click.echo(f"\nPattern: {pattern}")
+            click.echo(f"Flavor: {flavor}")
+            click.echo("\nEnglish Explanation:")
+            click.echo("-" * 50)
+            click.echo(translation)
+            click.echo()
+
+            if verbose:
+                features = identify_features(ast)
+                click.echo("\nFeatures detected:")
+                for feature in features:
+                    click.echo(f"  - {feature}")
+
+    except Exception as e:
+        click.echo(f"Error: {e}", err=True)
+        sys.exit(1)
+
+
+@main.command("test")
+@click.argument("pattern", type=str)
+@click.option(
+    "--output",
+    "-o",
+    type=click.Choice(["text", "json"]),
+    default="text",
+    help="Output format",
+)
+@click.option(
+    "--count",
+    "-n",
+    type=int,
+    default=5,
+    help="Number of test cases to generate",
+)
+@click.pass_context
+def test(ctx: click.Context, pattern: str, output: str, count: int):
+    """Generate test cases (matching and non-matching) for a regex pattern."""
+    if ctx.obj is None:
+        ctx.obj = {}
+    flavor = ctx.obj.get("flavor", "pcre")
+
+    try:
+        result = generate_test_cases(
+            pattern,
+            flavor,
+            matching_count=count,
+            non_matching_count=count
+        )
+
+        if output == "json":
+            click.echo(json.dumps(result, indent=2))
+        else:
+            click.echo(f"\nPattern: {pattern}")
+            click.echo(f"Flavor: {flavor}")
+            click.echo("\nMatching strings (should match the pattern):")
+            click.echo("-" * 50)
+            for i, s in enumerate(result["matching"], 1):
+                click.echo(f"  {i}. {s}")
+
+            click.echo("\nNon-matching strings (should NOT match the pattern):")
+            click.echo("-" * 50)
+            for i, s in enumerate(result["non_matching"], 1):
+                click.echo(f"  {i}. {s}")
+
+            click.echo()
+
+    except Exception as e:
+        click.echo(f"Error: {e}", err=True)
+        sys.exit(1)
+
+
+@main.command("interactive")
+@click.option(
+    "--flavor",
+    "-f",
+    type=click.Choice(["pcre", "javascript", "python"]),
+    default="pcre",
+    help="Regex flavor to use",
+)
+@click.pass_context
+def interactive(ctx: click.Context, flavor: str):
+    """Start an interactive REPL for exploring regex patterns."""
+    start_interactive_mode(flavor=flavor)
+
+
+@main.command("flavors")
+@click.pass_context
+def flavors(ctx: click.Context):
+    """List available regex flavors."""
+    manager = get_flavor_manager()
+    flavor_list = manager.list_flavors()
+
+    click.echo("\nAvailable Regex Flavors:")
+    click.echo("-" * 50)
+    for name, desc in flavor_list:
+        click.echo(f"\n  {name}:")
+        click.echo(f"    {desc}")
+    click.echo()
+
+
+@main.command("validate")
+@click.argument("pattern", type=str)
+@click.option(
+    "--flavor",
+    "-f",
+    type=click.Choice(["pcre", "javascript", "python"]),
+    default=None,
+    help="Specific flavor to validate against",
+)
+@click.pass_context
+def validate(ctx: click.Context, pattern: str, flavor: str):
+    """Validate a regex pattern."""
+    if ctx.obj is None:
+        ctx.obj = {}
+    check_flavor = flavor or ctx.obj.get("flavor", "pcre")
+
+    try:
+        ast = parse_regex(pattern, check_flavor)
+        click.echo(f"\nPattern: {pattern}")
+        click.echo(f"Flavor: {check_flavor}")
+        click.echo("\nValidation: PASSED")
+        click.echo(f"AST node count: {len(get_all_nodes(ast))}")
+    except Exception as e:
+        click.echo(f"\nPattern: {pattern}")
+        click.echo(f"Validation: FAILED")
+        click.echo(f"Error: {e}")
+        sys.exit(1)
+
+
+@main.command("convert")
+@click.argument("pattern", type=str)
+@click.option(
+    "--from-flavor",
+    "-s",
+    type=click.Choice(["pcre", "javascript", "python"]),
+    default="pcre",
+    help="Source flavor",
+)
+@click.option(
+    "--to-flavor",
+    "-t",
+    type=click.Choice(["pcre", "javascript", "python"]),
+    default="javascript",
+    help="Target flavor",
+)
+@click.pass_context
+def convert(ctx: click.Context, pattern: str, from_flavor: str, to_flavor: str):
+    """Convert a regex pattern between flavors."""
+    manager = get_flavor_manager()
+    converted, warnings = manager.convert(pattern, from_flavor, to_flavor)
+
+    click.echo(f"\nOriginal ({from_flavor}): {pattern}")
+    click.echo(f"Converted ({to_flavor}): {converted}")
+
+    if warnings:
+        click.echo("\nWarnings:")
+        for warning in warnings:
+            click.echo(f"  - {warning}")
+
+
+def get_all_nodes(ast) -> list:
+    """Get all nodes from AST."""
+    nodes = [ast]
+    for child in getattr(ast, 'children', []):
+        nodes.extend(get_all_nodes(child))
+    return nodes
+
+
+def identify_features(ast) -> list[str]:
+    """Identify features in a regex pattern."""
+    features = []
+    nodes = get_all_nodes(ast)
+
+    node_types = set(n.node_type.name for n in nodes)
+
+    if "LOOKAHEAD" in node_types or "NEGATIVE_LOOKAHEAD" in node_types:
+        features.append("Lookahead assertions")
+    if "LOOKBEHIND" in node_types or "NEGATIVE_LOOKBEHIND" in node_types:
+        features.append("Lookbehind assertions")
+    if "NAMED_GROUP" in node_types:
+        features.append("Named groups")
+    if "CAPTURING_GROUP" in node_types:
+        features.append("Capturing groups")
+    if "NON_CAPTURING_GROUP" in node_types:
+        features.append("Non-capturing groups")
+    if "QUANTIFIER" in node_types:
+        features.append("Quantifiers")
+        for n in nodes:
+            if n.node_type.name == "QUANTIFIER" and n.is_lazy:
+                features.append("Lazy quantifiers")
+                break
+            if n.node_type.name == "QUANTIFIER" and n.is_possessive:
+                features.append("Possessive quantifiers")
+                break
+    if "POSITIVE_SET" in node_types or "NEGATIVE_SET" in node_types:
+        features.append("Character classes")
+    if "ANCHOR_START" in node_types or "ANCHOR_END" in node_types:
+        features.append("Anchors")
+    if "DIGIT" in node_types or "WORD_CHAR" in node_types or "WHITESPACE" in node_types:
+        features.append("Shorthand character classes")
+    if "BACKREFERENCE" in node_types:
+        features.append("Backreferences")
+
+    return features
+
+
+if __name__ == "__main__":
+    main()