diff --git a/src/detectors/base.py b/src/detectors/base.py
new file mode 100644
index 0000000..2fb9048
--- /dev/null
+++ b/src/detectors/base.py
@@ -0,0 +1,114 @@
+"""Base detector class for project detection."""
+
+from abc import ABC, abstractmethod
+from pathlib import Path
+from typing import Dict, List, Optional
+
+
+class BaseDetector(ABC):
+    """Abstract base class for all detectors."""
+
+    @abstractmethod
+    def detect(self, project_path: Path) -> List[str]:
+        """Detect items from the project path.
+
+        Args:
+            project_path: Path to the project directory.
+
+        Returns:
+            List of detected item names (e.g., language names, framework names).
+        """
+        pass
+
+    @abstractmethod
+    def get_priority(self) -> int:
+        """Get the priority of this detector.
+
+        Higher priority detectors are run first.
+
+        Returns:
+            Integer priority value.
+        """
+        pass
+
+    def _find_files(self, project_path: Path, patterns: List[str]) -> List[Path]:
+        """Find files matching given patterns.
+
+        Args:
+            project_path: Root directory to search.
+            patterns: List of filename patterns to match.
+
+        Returns:
+            List of matching file paths.
+        """
+        if not project_path.exists() or not project_path.is_dir():
+            return []
+
+        found_files = []
+        try:
+            for pattern in patterns:
+                matches = list(project_path.rglob(pattern))
+                found_files.extend(matches)
+        except PermissionError:
+            pass
+        except OSError:
+            pass
+
+        return found_files
+
+    def _read_file_content(self, file_path: Path, max_size: int = 10240) -> Optional[str]:
+        """Read file content safely.
+
+        Args:
+            file_path: Path to the file.
+            max_size: Maximum file size to read in bytes.
+
+        Returns:
+            File content as string, or None if reading fails.
+        """
+        try:
+            if file_path.stat().st_size > max_size:
+                return None
+            with open(file_path, 'r', encoding='utf-8', errors='ignore') as f:
+                return f.read()
+        except (PermissionError, OSError, UnicodeDecodeError):
+            return None
+
+    def _check_file_exists(self, project_path: Path, filenames: List[str]) -> List[str]:
+        """Check if any of the given filenames exist.
+
+        Args:
+            project_path: Project root directory.
+            filenames: List of filenames to check.
+
+        Returns:
+            List of existing filenames.
+        """
+        existing = []
+        for filename in filenames:
+            if (project_path / filename).exists():
+                existing.append(filename)
+        return existing
+
+    def _check_content_markers(self, project_path: Path, markers: Dict[str, str]) -> List[str]:
+        """Check for content markers in source files.
+
+        Args:
+            project_path: Project root directory.
+            markers: Dict mapping marker names to search patterns.
+
+        Returns:
+            List of found marker names.
+        """
+        found = []
+        try:
+            for file_path in project_path.rglob("*"):
+                if file_path.is_file() and file_path.suffix in ['.py', '.js', '.ts', '.go', '.java', '.rb', '.php', '.rs']:
+                    content = self._read_file_content(file_path)
+                    if content:
+                        for name, pattern in markers.items():
+                            if name not in found and pattern.lower() in content.lower():
+                                found.append(name)
+        except (PermissionError, OSError):
+            pass
+        return found