diff --git a/gateway/platforms/base.py b/gateway/platforms/base.py
index 28615a006f..b6cf330258 100644
--- a/gateway/platforms/base.py
+++ b/gateway/platforms/base.py
@@ -613,6 +613,9 @@ class MessageEvent:
         raw = parts[0][1:].lower() if parts else None
         if raw and "@" in raw:
             raw = raw.split("@", 1)[0]
+        # Reject file paths: valid command names never contain /
+        if raw and "/" in raw:
+            return None
         return raw
     
     def get_command_args(self) -> str:
diff --git a/tests/test_cli_file_drop.py b/tests/test_cli_file_drop.py
new file mode 100644
index 0000000000..386aba5d17
--- /dev/null
+++ b/tests/test_cli_file_drop.py
@@ -0,0 +1,176 @@
+"""Tests for _detect_file_drop — file path detection that prevents
+dragged/pasted absolute paths from being mistaken for slash commands."""
+
+import os
+import tempfile
+from pathlib import Path
+
+import pytest
+
+from cli import _detect_file_drop
+
+
+# ---------------------------------------------------------------------------
+# Fixtures
+# ---------------------------------------------------------------------------
+
+@pytest.fixture()
+def tmp_image(tmp_path):
+    """Create a temporary .png file and return its path."""
+    img = tmp_path / "screenshot.png"
+    img.write_bytes(b"\x89PNG\r\n\x1a\n")  # minimal PNG header
+    return img
+
+
+@pytest.fixture()
+def tmp_text(tmp_path):
+    """Create a temporary .py file and return its path."""
+    f = tmp_path / "main.py"
+    f.write_text("print('hello')\n")
+    return f
+
+
+@pytest.fixture()
+def tmp_image_with_spaces(tmp_path):
+    """Create a file whose name contains spaces (like macOS screenshots)."""
+    img = tmp_path / "Screenshot 2026-04-01 at 7.25.32 PM.png"
+    img.write_bytes(b"\x89PNG\r\n\x1a\n")
+    return img
+
+
+# ---------------------------------------------------------------------------
+# Tests: returns None for non-file inputs
+# ---------------------------------------------------------------------------
+
+class TestNonFileInputs:
+    def test_regular_slash_command(self):
+        assert _detect_file_drop("/help") is None
+
+    def test_unknown_slash_command(self):
+        assert _detect_file_drop("/xyz") is None
+
+    def test_slash_command_with_args(self):
+        assert _detect_file_drop("/config set key value") is None
+
+    def test_empty_string(self):
+        assert _detect_file_drop("") is None
+
+    def test_non_slash_input(self):
+        assert _detect_file_drop("hello world") is None
+
+    def test_non_string_input(self):
+        assert _detect_file_drop(42) is None
+
+    def test_nonexistent_path(self):
+        assert _detect_file_drop("/nonexistent/path/to/file.png") is None
+
+    def test_directory_not_file(self, tmp_path):
+        """A directory path should not be treated as a file drop."""
+        assert _detect_file_drop(str(tmp_path)) is None
+
+
+# ---------------------------------------------------------------------------
+# Tests: image file detection
+# ---------------------------------------------------------------------------
+
+class TestImageFileDrop:
+    def test_simple_image_path(self, tmp_image):
+        result = _detect_file_drop(str(tmp_image))
+        assert result is not None
+        assert result["path"] == tmp_image
+        assert result["is_image"] is True
+        assert result["remainder"] == ""
+
+    def test_image_with_trailing_text(self, tmp_image):
+        user_input = f"{tmp_image} analyze this please"
+        result = _detect_file_drop(user_input)
+        assert result is not None
+        assert result["path"] == tmp_image
+        assert result["is_image"] is True
+        assert result["remainder"] == "analyze this please"
+
+    @pytest.mark.parametrize("ext", [".png", ".jpg", ".jpeg", ".gif", ".webp",
+                                      ".bmp", ".tiff", ".tif", ".svg", ".ico"])
+    def test_all_image_extensions(self, tmp_path, ext):
+        img = tmp_path / f"test{ext}"
+        img.write_bytes(b"fake")
+        result = _detect_file_drop(str(img))
+        assert result is not None
+        assert result["is_image"] is True
+
+    def test_uppercase_extension(self, tmp_path):
+        img = tmp_path / "photo.JPG"
+        img.write_bytes(b"fake")
+        result = _detect_file_drop(str(img))
+        assert result is not None
+        assert result["is_image"] is True
+
+
+# ---------------------------------------------------------------------------
+# Tests: non-image file detection
+# ---------------------------------------------------------------------------
+
+class TestNonImageFileDrop:
+    def test_python_file(self, tmp_text):
+        result = _detect_file_drop(str(tmp_text))
+        assert result is not None
+        assert result["path"] == tmp_text
+        assert result["is_image"] is False
+        assert result["remainder"] == ""
+
+    def test_non_image_with_trailing_text(self, tmp_text):
+        user_input = f"{tmp_text} review this code"
+        result = _detect_file_drop(user_input)
+        assert result is not None
+        assert result["is_image"] is False
+        assert result["remainder"] == "review this code"
+
+
+# ---------------------------------------------------------------------------
+# Tests: backslash-escaped spaces (macOS drag-and-drop)
+# ---------------------------------------------------------------------------
+
+class TestEscapedSpaces:
+    def test_escaped_spaces_in_path(self, tmp_image_with_spaces):
+        r"""macOS drags produce paths like /path/to/my\ file.png"""
+        escaped = str(tmp_image_with_spaces).replace(' ', '\\ ')
+        result = _detect_file_drop(escaped)
+        assert result is not None
+        assert result["path"] == tmp_image_with_spaces
+        assert result["is_image"] is True
+
+    def test_escaped_spaces_with_trailing_text(self, tmp_image_with_spaces):
+        escaped = str(tmp_image_with_spaces).replace(' ', '\\ ')
+        user_input = f"{escaped} what is this?"
+        result = _detect_file_drop(user_input)
+        assert result is not None
+        assert result["path"] == tmp_image_with_spaces
+        assert result["remainder"] == "what is this?"
+
+
+# ---------------------------------------------------------------------------
+# Tests: edge cases
+# ---------------------------------------------------------------------------
+
+class TestEdgeCases:
+    def test_path_with_no_extension(self, tmp_path):
+        f = tmp_path / "Makefile"
+        f.write_text("all:\n\techo hi\n")
+        result = _detect_file_drop(str(f))
+        assert result is not None
+        assert result["is_image"] is False
+
+    def test_path_that_looks_like_command_but_is_file(self, tmp_path):
+        """A file literally named 'help' inside a directory starting with /."""
+        f = tmp_path / "help"
+        f.write_text("not a command\n")
+        result = _detect_file_drop(str(f))
+        assert result is not None
+        assert result["is_image"] is False
+
+    def test_symlink_to_file(self, tmp_image, tmp_path):
+        link = tmp_path / "link.png"
+        link.symlink_to(tmp_image)
+        result = _detect_file_drop(str(link))
+        assert result is not None
+        assert result["is_image"] is True