diff --git a/src/apm_cli/cli.py b/src/apm_cli/cli.py
index 97c70c4b..1f93c2e0 100644
--- a/src/apm_cli/cli.py
+++ b/src/apm_cli/cli.py
@@ -336,6 +336,7 @@ def _validate_and_add_packages_to_apm_yml(packages, dry_run=False):
     
     current_deps = data['dependencies']['apm'] or []
     validated_packages = []
+    conflicts = []
     
     # First, validate all packages
     _rich_info(f"Validating {len(packages)} package(s)...")
@@ -346,9 +347,10 @@ def _validate_and_add_packages_to_apm_yml(packages, dry_run=False):
             _rich_error(f"Invalid package format: {package}. Use 'owner/repo' format.")
             continue
             
-        # Check if package is already in dependencies
+        # Check if package is already in dependencies -> treat as conflict
         if package in current_deps:
-            _rich_warning(f"Package {package} already exists in apm.yml")
+            conflicts.append(package)
+            _rich_error(f"Package conflict: {package} already exists in apm.yml")
             continue
             
         # Validate package exists and is accessible
@@ -359,6 +361,10 @@ def _validate_and_add_packages_to_apm_yml(packages, dry_run=False):
             _rich_error(f"✗ {package} - not accessible or doesn't exist")
     
     if not validated_packages:
+        if conflicts and not dry_run:
+            _rich_error(f"Aborting due to {len(conflicts)} package conflict(s)")
+            sys.exit(1)
+
         if dry_run:
             _rich_warning("No new valid packages to add")
         return []
@@ -445,10 +451,25 @@ def install(ctx, packages, runtime, exclude, only, update, dry_run):
         apm install --dry-run                   # Show what would be installed
     """
     try:
-        # Check if apm.yml exists
-        if not Path('apm.yml').exists():
-            _rich_error("No apm.yml found. Run 'apm init' first.")
-            sys.exit(1)
+        # Check if apm.yml exists. If packages were provided, create a minimal
+        # project (apm.yml + .apm/ structure) so the install command can add
+        # package entries automatically. Otherwise, require the user to run
+        # 'apm init' first.
+        apm_yml_path = Path('apm.yml')
+        if not apm_yml_path.exists():
+            if packages:
+                _rich_info("No apm.yml found - creating minimal project so packages can be added")
+                # Create a minimal default config and project files
+                try:
+                    default_config = _get_default_config(Path.cwd().name)
+                    _create_project_files(default_config)
+                    _rich_success("Created minimal apm.yml and .apm/ structure")
+                except Exception as e:
+                    _rich_error(f"Failed to create minimal project files: {e}")
+                    sys.exit(1)
+            else:
+                _rich_error("No apm.yml found. Run 'apm init' first.")
+                sys.exit(1)
         
         # If packages are specified, validate and add them to apm.yml first
         if packages:
diff --git a/tests/test_install_auto_init.py b/tests/test_install_auto_init.py
new file mode 100644
index 00000000..d8680c03
--- /dev/null
+++ b/tests/test_install_auto_init.py
@@ -0,0 +1,65 @@
+import os
+from pathlib import Path
+
+import yaml
+import pytest
+from click.testing import CliRunner
+
+import apm_cli.cli as cli_mod
+from apm_cli.cli import cli
+
+
+def test_install_creates_minimal_project(tmp_path, monkeypatch):
+    """When apm.yml is missing and a package is passed to `apm install`,
+    the CLI should create a minimal apm.yml and .apm/ structure so the
+    installation can proceed (dry-run used to avoid network operations).
+    """
+    runner = CliRunner()
+    # Avoid network/git checks during validation
+    monkeypatch.setattr(cli_mod, "_validate_package_exists", lambda pkg: True)
+
+    # CliRunner.invoke in this environment does not accept cwd reliably, so
+    # change directory manually for the duration of the invocation.
+    old_cwd = Path.cwd()
+    try:
+        os.chdir(tmp_path)
+        result = runner.invoke(cli, ["install", "owner/repo", "--dry-run"])
+    finally:
+        os.chdir(old_cwd)
+    assert result.exit_code == 0, result.output
+
+    apm_yml = tmp_path / "apm.yml"
+    assert apm_yml.exists(), "apm.yml should be created when running install with packages"
+
+    # Load config to ensure it is valid YAML and contains expected keys
+    cfg = yaml.safe_load(apm_yml.read_text())
+    assert isinstance(cfg, dict)
+    assert "dependencies" in cfg
+
+
+def test_install_conflict_aborts(tmp_path, monkeypatch):
+    """If the package already exists in apm.yml, `apm install <pkg>` should
+    report a conflict and abort (non-zero exit)."""
+    runner = CliRunner()
+    # Create an apm.yml that already contains the package
+    content = {
+        "name": "proj",
+        "version": "1.0.0",
+        "dependencies": {"apm": ["owner/repo"], "mcp": []},
+    }
+    apm_yml = tmp_path / "apm.yml"
+    apm_yml.write_text(yaml.safe_dump(content))
+
+    # Avoid network/git checks during validation
+    monkeypatch.setattr(cli_mod, "_validate_package_exists", lambda pkg: True)
+
+    old_cwd = Path.cwd()
+    try:
+        os.chdir(tmp_path)
+        result = runner.invoke(cli, ["install", "owner/repo"])
+    finally:
+        os.chdir(old_cwd)
+
+    # The CLI should exit with non-zero status due to conflict
+    assert result.exit_code != 0
+    assert "Package conflict" in result.output or "Aborting due to" in result.output