diff --git a/models.py b/models.py
index 5d35da3..9621273 100644
--- a/models.py
+++ b/models.py
@@ -1,5 +1,5 @@
 from dataclasses import dataclass, field
-from typing import List
+from typing import List, Optional
 
 @dataclass
 class Ticket:
@@ -11,6 +11,16 @@ class Ticket:
     status: str
     assigned_to: str
     depends_on: List[str] = field(default_factory=list)
+    blocked_reason: Optional[str] = None
+
+    def mark_blocked(self, reason: str):
+        """Sets the ticket status to 'blocked' and records the reason."""
+        self.status = "blocked"
+        self.blocked_reason = reason
+
+    def mark_complete(self):
+        """Sets the ticket status to 'completed'."""
+        self.status = "completed"
 
 @dataclass
 class Track:
@@ -21,6 +31,31 @@ class Track:
     description: str
     tickets: List[Ticket] = field(default_factory=list)
 
+    def get_executable_tickets(self) -> List[Ticket]:
+        """
+        Returns all 'todo' tickets whose dependencies are all 'completed'.
+        """
+        # Map ticket IDs to their current status for efficient lookup
+        status_map = {t.id: t.status for t in self.tickets}
+        
+        executable = []
+        for ticket in self.tickets:
+            if ticket.status != "todo":
+                continue
+            
+            # Check if all dependencies are completed
+            all_deps_completed = True
+            for dep_id in ticket.depends_on:
+                # If a dependency is missing from the track, we treat it as not completed (or we could raise an error)
+                if status_map.get(dep_id) != "completed":
+                    all_deps_completed = False
+                    break
+            
+            if all_deps_completed:
+                executable.append(ticket)
+        
+        return executable
+
 @dataclass
 class WorkerContext:
     """
diff --git a/tests/test_mma_models.py b/tests/test_mma_models.py
index 2b531b8..87ff619 100644
--- a/tests/test_mma_models.py
+++ b/tests/test_mma_models.py
@@ -89,3 +89,88 @@ def test_worker_context_instantiation():
     assert context.ticket_id == ticket_id
     assert context.model_name == model_name
     assert context.messages == messages
+
+def test_ticket_mark_blocked():
+    """
+    Verifies that ticket.mark_blocked(reason) sets the status to 'blocked'.
+    Note: The reason field might need to be added to the Ticket class.
+    """
+    ticket = Ticket(id="T1", description="Task 1", status="todo", assigned_to="a")
+    ticket.mark_blocked("Waiting for API key")
+    assert ticket.status == "blocked"
+
+def test_ticket_mark_complete():
+    """
+    Verifies that ticket.mark_complete() sets the status to 'completed'.
+    """
+    ticket = Ticket(id="T1", description="Task 1", status="todo", assigned_to="a")
+    ticket.mark_complete()
+    assert ticket.status == "completed"
+
+def test_track_get_executable_tickets():
+    """
+    Verifies that track.get_executable_tickets() returns only 'todo' tickets
+    whose dependencies are all 'completed'.
+    """
+    # T1: todo, no deps -> executable
+    t1 = Ticket(id="T1", description="T1", status="todo", assigned_to="a")
+    # T2: todo, deps [T1] -> not executable (T1 is todo)
+    t2 = Ticket(id="T2", description="T2", status="todo", assigned_to="a", depends_on=["T1"])
+    # T3: todo, deps [T4] -> not executable (T4 is blocked)
+    t3 = Ticket(id="T3", description="T3", status="todo", assigned_to="a", depends_on=["T4"])
+    # T4: blocked, no deps -> not executable (not 'todo')
+    t4 = Ticket(id="T4", description="T4", status="blocked", assigned_to="a")
+    # T5: completed, no deps -> not executable (not 'todo')
+    t5 = Ticket(id="T5", description="T5", status="completed", assigned_to="a")
+    # T6: todo, deps [T5] -> executable (T5 is completed)
+    t6 = Ticket(id="T6", description="T6", status="todo", assigned_to="a", depends_on=["T5"])
+    
+    track = Track(id="TR1", description="Track 1", tickets=[t1, t2, t3, t4, t5, t6])
+    
+    executable = track.get_executable_tickets()
+    executable_ids = [t.id for t in executable]
+    
+    assert "T1" in executable_ids
+    assert "T6" in executable_ids
+    assert len(executable_ids) == 2
+
+def test_track_get_executable_tickets_complex():
+    """
+    Verifies executable tickets with complex dependency chains.
+    Chain: T1 (comp) -> T2 (todo) -> T3 (todo)
+           T4 (comp) -> T3
+           T5 (todo) -> T3
+    """
+    t1 = Ticket(id="T1", description="T1", status="completed", assigned_to="a")
+    t2 = Ticket(id="T2", description="T2", status="todo", assigned_to="a", depends_on=["T1"])
+    t3 = Ticket(id="T3", description="T3", status="todo", assigned_to="a", depends_on=["T2", "T4", "T5"])
+    t4 = Ticket(id="T4", description="T4", status="completed", assigned_to="a")
+    t5 = Ticket(id="T5", description="T5", status="todo", assigned_to="a")
+    
+    track = Track(id="TR1", description="Track 1", tickets=[t1, t2, t3, t4, t5])
+    
+    # At this point:
+    # T1 is completed
+    # T4 is completed
+    # T2 is todo, depends on T1 (completed) -> Executable
+    # T5 is todo, no deps -> Executable
+    # T3 is todo, depends on T2 (todo), T4 (completed), T5 (todo) -> Not executable
+    
+    executable = track.get_executable_tickets()
+    executable_ids = sorted([t.id for t in executable])
+    
+    assert executable_ids == ["T2", "T5"]
+    
+    # Mark T2 complete
+    t2.mark_complete()
+    # T3 still depends on T5
+    executable = track.get_executable_tickets()
+    executable_ids = sorted([t.id for t in executable])
+    assert executable_ids == ["T5"]
+    
+    # Mark T5 complete
+    t5.mark_complete()
+    # Now T3 should be executable
+    executable = track.get_executable_tickets()
+    executable_ids = sorted([t.id for t in executable])
+    assert executable_ids == ["T3"]