diff --git a/tests/test_cli.py b/tests/test_cli.py
new file mode 100644
index 0000000..1878985
--- /dev/null
+++ b/tests/test_cli.py
@@ -0,0 +1,136 @@
+import pytest
+from unittest.mock import patch, MagicMock
+from typer.testing import CliRunner
+
+from confdoc.main import app
+
+
+runner = CliRunner()
+
+
+class TestCLIValidate:
+    def test_validate_valid_config(self):
+        with runner.isolated_filesystem():
+            config_content = '{"name": "test", "value": 123}'
+            schema_content = '''{
+                "type": "object",
+                "properties": {
+                    "name": {"type": "string"},
+                    "value": {"type": "integer"}
+                },
+                "required": ["name"]
+            }'''
+            
+            with open("config.json", "w") as f:
+                f.write(config_content)
+            with open("schema.json", "w") as f:
+                f.write(schema_content)
+            
+            result = runner.invoke(app, ["validate", "config.json", "--schema", "schema.json"])
+            assert result.exit_code == 0
+            assert "valid" in result.output.lower()
+    
+    def test_validate_file_not_found(self):
+        result = runner.invoke(app, ["validate", "nonexistent.json"])
+        assert result.exit_code == 1
+        assert "Error" in result.output
+    
+    def test_validate_invalid_config(self):
+        with runner.isolated_filesystem():
+            config_content = '{"name": 123}'
+            schema_content = '''{
+                "type": "object",
+                "properties": {
+                    "name": {"type": "string"}
+                },
+                "required": ["name"]
+            }'''
+            
+            with open("config.json", "w") as f:
+                f.write(config_content)
+            with open("schema.json", "w") as f:
+                f.write(schema_content)
+            
+            result = runner.invoke(app, ["validate", "config.json", "--schema", "schema.json"])
+            assert result.exit_code == 1
+            assert "validation failed" in result.output.lower() or "error" in result.output.lower()
+
+
+class TestCLIDoc:
+    def test_doc_generates_output(self):
+        with runner.isolated_filesystem():
+            schema_content = '''{
+                "title": "Test Schema",
+                "type": "object",
+                "properties": {"name": {"type": "string"}}
+            }'''
+            
+            with open("schema.json", "w") as f:
+                f.write(schema_content)
+            
+            result = runner.invoke(app, ["doc", "schema.json"])
+            assert result.exit_code == 0
+            assert "Test Schema" in result.output or "Configuration Documentation" in result.output
+    
+    def test_doc_writes_to_file(self):
+        with runner.isolated_filesystem():
+            schema_content = '{"title": "Test", "type": "object", "properties": {}}'
+            
+            with open("schema.json", "w") as f:
+                f.write(schema_content)
+            
+            result = runner.invoke(app, ["doc", "schema.json", "--output", "docs.md"])
+            assert result.exit_code == 0
+            import os
+            assert os.path.exists("docs.md")
+            
+            with open("docs.md") as f:
+                content = f.read()
+            assert "Test" in content or "Configuration" in content
+
+
+class TestCLIInit:
+    def test_init_creates_schema(self):
+        with runner.isolated_filesystem():
+            result = runner.invoke(app, ["init", "new_schema.json"])
+            assert result.exit_code == 0
+            
+            import os
+            assert os.path.exists("new_schema.json")
+            
+            import json
+            with open("new_schema.json") as f:
+                schema = json.load(f)
+            assert "properties" in schema
+    
+    def test_init_from_config(self):
+        with runner.isolated_filesystem():
+            config_content = '{"name": "test", "value": 123}'
+            
+            with open("config.json", "w") as f:
+                f.write(config_content)
+            
+            result = runner.invoke(app, ["init", "new_schema.json", "--config", "config.json"])
+            assert result.exit_code == 0
+
+
+class TestCLIHelp:
+    def test_main_help(self):
+        result = runner.invoke(app, ["--help"])
+        assert result.exit_code == 0
+        assert "ConfDoc" in result.output
+        assert "validate" in result.output
+        assert "doc" in result.output
+        assert "init" in result.output
+    
+    def test_validate_help(self):
+        result = runner.invoke(app, ["validate", "--help"])
+        assert result.exit_code == 0
+        assert "config" in result.output
+        assert "schema" in result.output
+    
+    def test_doc_help(self):
+        result = runner.invoke(app, ["doc", "--help"])
+        assert result.exit_code == 0
+        assert "schema" in result.output
+        assert "output" in result.output