diff --git a/src/core/parser.py b/src/core/parser.py
new file mode 100644
index 0000000..ed96e27
--- /dev/null
+++ b/src/core/parser.py
@@ -0,0 +1,126 @@
+import json
+import yaml
+from pathlib import Path
+from typing import Dict, Any, Optional
+from openapi_spec_validator import validate
+from openapi_spec_validator.versions.consts import OPENAPI_V3
+
+
+class ParseError(Exception):
+    """Custom exception for parsing errors."""
+    pass
+
+
+def load_spec_file(spec_path: str) -> Dict[str, Any]:
+    """Load an OpenAPI specification file.
+
+    Args:
+        spec_path: Path to the OpenAPI spec file (JSON or YAML)
+
+    Returns:
+        Parsed spec as a dictionary
+
+    Raises:
+        ParseError: If the file cannot be loaded or parsed
+    """
+    path = Path(spec_path)
+
+    if not path.exists():
+        raise ParseError(f"File not found: {spec_path}")
+
+    try:
+        if path.suffix == '.json':
+            with open(path, 'r') as f:
+                return json.load(f)
+        elif path.suffix in ['.yaml', '.yml']:
+            with open(path, 'r') as f:
+                return yaml.safe_load(f)
+        else:
+            raise ParseError(f"Unsupported file format: {path.suffix}. Expected .json, .yaml, or .yml")
+    except json.JSONDecodeError as e:
+        raise ParseError(f"Invalid JSON: {e}")
+    except yaml.YAMLError as e:
+        raise ParseError(f"Invalid YAML: {e}")
+
+
+def parse_openapi_spec(spec_path: str) -> Dict[str, Any]:
+    """Parse and validate an OpenAPI specification file.
+
+    Args:
+        spec_path: Path to the OpenAPI spec file
+
+    Returns:
+        Dictionary with 'valid' boolean and optional 'errors' list
+    """
+    try:
+        spec = load_spec_file(spec_path)
+
+        errors = []
+
+        if not isinstance(spec, dict):
+            return {'valid': False, 'errors': ['Spec is not a dictionary']}
+
+        openapi_version = spec.get('openapi', '')
+        if not openapi_version.startswith('3.'):
+            errors.append(f"Expected OpenAPI 3.x version, got: {openapi_version}")
+
+        if 'info' not in spec:
+            errors.append("Missing 'info' field")
+
+        if 'paths' not in spec:
+            errors.append("Missing 'paths' field")
+
+        if errors:
+            return {'valid': False, 'errors': errors}
+
+        try:
+            validate(spec)
+        except Exception as e:
+            return {'valid': False, 'errors': [str(e)]}
+
+        return {
+            'valid': True,
+            'spec': spec,
+            'version': openapi_version,
+            'title': spec.get('info', {}).get('title', 'Untitled'),
+            'version_num': spec.get('info', {}).get('version', '1.0.0'),
+            'endpoints_count': count_endpoints(spec),
+            'tags': spec.get('tags', [])
+        }
+
+    except ParseError as e:
+        return {'valid': False, 'errors': [str(e)]}
+    except Exception as e:
+        return {'valid': False, 'errors': [f"Unexpected error: {e}"]}
+
+
+def count_endpoints(spec: Dict[str, Any]) -> int:
+    """Count the total number of endpoints in the spec."""
+    count = 0
+    for path, methods in spec.get('paths', {}).items():
+        for method in methods:
+            if method.lower() in ['get', 'post', 'put', 'delete', 'patch', 'options', 'head']:
+                count += 1
+    return count
+
+
+def extract_endpoints(spec: Dict[str, Any]) -> list:
+    """Extract all endpoints from the spec."""
+    endpoints = []
+    for path, methods in spec.get('paths', {}).items():
+        for method, details in methods.items():
+            if method.lower() in ['get', 'post', 'put', 'delete', 'patch', 'options', 'head']:
+                endpoint = {
+                    'path': path,
+                    'method': method.upper(),
+                    'summary': details.get('summary'),
+                    'description': details.get('description'),
+                    'operation_id': details.get('operationId'),
+                    'tags': details.get('tags', []),
+                    'parameters': details.get('parameters', []),
+                    'request_body': details.get('requestBody'),
+                    'responses': details.get('responses', {}),
+                    'deprecated': details.get('deprecated', False)
+                }
+                endpoints.append(endpoint)
+    return endpoints