feat(mesh): AgentTopology pruning + last_updated (#2167)

autobot-backend/agents/agent_orchestration/topology.py

@@ -13,7 +13,8 @@
 """
 
 import logging
-from dataclasses import dataclass
+from dataclasses import dataclass, field
+from datetime import datetime, timedelta, timezone
 from itertools import combinations
 from typing import Optional, Protocol, runtime_checkable
 
@@ -36,6 +37,9 @@ class AgentConnection:
     weight: float
     co_success_count: int
     co_failure_count: int
+    last_updated: datetime = field(
+        default_factory=lambda: datetime.now(tz=timezone.utc)
+    )
 
 
 @runtime_checkable
@@ -82,6 +86,17 @@ async def record_agent_task(
         """Append a task history entry for *agent_id*."""
         ...
 
+    async def delete_weak_connections(
+        self,
+        min_weight: float,
+        inactive_since: datetime,
+    ) -> int:
+        """Delete connections below *min_weight* not updated since *inactive_since*.
+
+        Returns the number of rows deleted.
+        """
+        ...
+
 
 class AgentTopology:
     """Dynamic DAG of agent connections.  Evolves from task outcomes.
@@ -196,3 +211,28 @@ async def _update_pair(
                 weight=new_weight,
                 co_failure_count=conn.co_failure_count + 1,
             )
+
+    async def prune_weak_connections(
+        self,
+        min_weight: float = 0.1,
+        inactive_days: int = 60,
+    ) -> int:
+        """Remove weak, inactive agent connections. Returns count deleted.
+
+        Deletes every connection whose weight is below *min_weight* AND whose
+        *last_updated* timestamp is older than *inactive_days* days.
+
+        Issue #2167.
+        """
+        cutoff = datetime.now(tz=timezone.utc) - timedelta(days=inactive_days)
+        deleted = await self.db.delete_weak_connections(
+            min_weight=min_weight,
+            inactive_since=cutoff,
+        )
+        logger.info(
+            "Pruned %d weak connections (min_weight=%.3f, inactive_days=%d)",
+            deleted,
+            min_weight,
+            inactive_days,
+        )
+        return deleted

autobot-backend/agents/agent_orchestration/topology_test.py

@@ -9,6 +9,7 @@
 """
 
 import dataclasses
+from datetime import datetime, timedelta, timezone
 from unittest.mock import AsyncMock
 
 import pytest
@@ -39,13 +40,16 @@ def _make_connection(
     )
 
 
-def _make_db(connection: AgentConnection | None = None) -> AsyncMock:
+def _make_db(
+    connection: AgentConnection | None = None, delete_count: int = 0
+) -> AsyncMock:
     """Return a mock that satisfies the AgentTopologyDB Protocol."""
     db = AsyncMock()
     db.get_agent_connections.return_value = [connection] if connection else []
     db.get_or_create_agent_connection.return_value = connection or _make_connection()
     db.update_agent_connection.return_value = None
     db.record_agent_task.return_value = None
+    db.delete_weak_connections.return_value = delete_count
     return db
 
 
@@ -201,4 +205,37 @@ def test_agent_connection_dataclass_fields():
         "weight",
         "co_success_count",
         "co_failure_count",
+        "last_updated",
     }
+
+
+@pytest.mark.asyncio
+async def test_prune_weak_connections_calls_db():
+    """prune_weak_connections forwards min_weight and a UTC cutoff to delete_weak_connections."""
+    db = _make_db(delete_count=0)
+    topology = AgentTopology(db)
+
+    before_call = datetime.now(tz=timezone.utc)
+    await topology.prune_weak_connections(min_weight=0.2, inactive_days=30)
+    after_call = datetime.now(tz=timezone.utc)
+
+    db.delete_weak_connections.assert_awaited_once()
+    call_kwargs = db.delete_weak_connections.await_args.kwargs
+    assert call_kwargs["min_weight"] == 0.2
+
+    cutoff: datetime = call_kwargs["inactive_since"]
+    # The cutoff must be 30 days before the call, within a 1-second tolerance.
+    expected_low = before_call - timedelta(days=30) - timedelta(seconds=1)
+    expected_high = after_call - timedelta(days=30) + timedelta(seconds=1)
+    assert expected_low <= cutoff <= expected_high
+
+
+@pytest.mark.asyncio
+async def test_prune_returns_count():
+    """prune_weak_connections returns the integer row count reported by the db."""
+    db = _make_db(delete_count=7)
+    topology = AgentTopology(db)
+
+    result = await topology.prune_weak_connections()
+
+    assert result == 7