diff --git a/src/models/data_structures.py b/src/models/data_structures.py
new file mode 100644
index 0000000..5203b62
--- /dev/null
+++ b/src/models/data_structures.py
@@ -0,0 +1,104 @@
+from dataclasses import dataclass, field
+from datetime import datetime
+from typing import List, Optional
+
+from dataclasses_json import dataclass_json
+
+
+@dataclass_json
+@dataclass
+class Author:
+    """Represents a git author."""
+    name: str
+    email: str
+    commit_count: int = 0
+    lines_added: int = 0
+    lines_deleted: int = 0
+
+
+@dataclass_json
+@dataclass
+class Commit:
+    """Represents a git commit."""
+    sha: str
+    message: str
+    author: str
+    author_email: str
+    timestamp: datetime
+    lines_added: int = 0
+    lines_deleted: int = 0
+    files_changed: List[str] = field(default_factory=list)
+    is_merge: bool = False
+    is_revert: bool = False
+
+
+@dataclass_json
+@dataclass
+class FileChange:
+    """Represents changes to a file in a commit."""
+    filepath: str
+    lines_added: int
+    lines_deleted: int
+    change_type: str
+
+
+@dataclass_json
+@dataclass
+class CommitAnalysis:
+    """Analysis of commit patterns."""
+    total_commits: int
+    unique_authors: int
+    commits_by_hour: dict
+    commits_by_day: dict
+    commits_by_week: dict
+    top_authors: List[Author]
+    average_commits_per_day: float
+
+
+@dataclass_json
+@dataclass
+class CodeChurnAnalysis:
+    """Analysis of code churn."""
+    total_lines_added: int
+    total_lines_deleted: int
+    net_change: int
+    churn_by_file: dict
+    churn_by_author: dict
+    high_churn_commits: List[Commit]
+    average_churn_per_commit: float
+
+
+@dataclass_json
+@dataclass
+class RiskyCommitAnalysis:
+    """Analysis of risky commits."""
+    total_risky_commits: int
+    large_change_commits: List[Commit]
+    merge_commits: List[Commit]
+    revert_commits: List[Commit]
+    risk_score: float
+
+
+@dataclass_json
+@dataclass
+class VelocityAnalysis:
+    """Analysis of team velocity."""
+    commits_per_day: float
+    commits_per_week: float
+    commits_per_month: float
+    velocity_trend: str
+    top_contributors: List[Author]
+    most_active_day: str
+    most_active_hour: str
+
+
+@dataclass_json
+@dataclass
+class ProductivityReport:
+    """Comprehensive productivity report."""
+    repository_path: str
+    analysis_days: int
+    commit_analysis: Optional[CommitAnalysis]
+    code_churn_analysis: Optional[CodeChurnAnalysis]
+    risky_commit_analysis: Optional[RiskyCommitAnalysis]
+    velocity_analysis: Optional[VelocityAnalysis]