From b530527a919f74e6479463adf8f74a623f404711 Mon Sep 17 00:00:00 2001
From: cthomas <caren@letta.com>
Date: Sun, 20 Jul 2025 22:11:46 -0700
Subject: [PATCH] feat: only load specified relationships for agents (#3438)

---
 letta/services/agent_manager.py               | 47 +++++++++++++++----
 .../services/helpers/agent_manager_helper.py  | 19 ++++++++
 2 files changed, 56 insertions(+), 10 deletions(-)

diff --git a/letta/services/agent_manager.py b/letta/services/agent_manager.py
index ff7abfba..e25d2203 100644
--- a/letta/services/agent_manager.py
+++ b/letta/services/agent_manager.py
@@ -71,6 +71,7 @@ from letta.services.helpers.agent_manager_helper import (
     _apply_identity_filters,
     _apply_pagination,
     _apply_pagination_async,
+    _apply_relationship_filters,
     _apply_tag_filter,
     _process_relationship,
     _process_relationship_async,
@@ -1005,7 +1006,8 @@ class AgentManager:
             identity_id (Optional[str]): Filter by identifier ID.
             identifier_keys (Optional[List[str]]): Search agents by identifier keys.
             include_relationships (Optional[List[str]]): List of fields to load for performance optimization.
-            ascending
+            ascending (bool): Sort agents in ascending order.
+            sort_by (Optional[str]): Sort agents by this field.
 
         Returns:
             List[PydanticAgentState]: The filtered list of matching agents.
@@ -1018,6 +1020,7 @@ class AgentManager:
             query = _apply_filters(query, name, query_text, project_id, template_id, base_template_id)
             query = _apply_identity_filters(query, identity_id, identifier_keys)
             query = _apply_tag_filter(query, tags, match_all_tags)
+            query = _apply_relationship_filters(query, include_relationships)
             query = await _apply_pagination_async(query, before, after, session, ascending=ascending, sort_by=sort_by)
 
             if limit:
@@ -1153,10 +1156,23 @@ class AgentManager:
         include_relationships: Optional[List[str]] = None,
     ) -> PydanticAgentState:
         """Fetch an agent by its ID."""
-
         async with db_registry.async_session() as session:
-            agent = await AgentModel.read_async(db_session=session, identifier=agent_id, actor=actor)
-            return await agent.to_pydantic_async(include_relationships=include_relationships)
+            try:
+                query = select(AgentModel)
+                query = AgentModel.apply_access_predicate(query, actor, ["read"], AccessType.ORGANIZATION)
+                query = query.where(AgentModel.id == agent_id)
+                query = _apply_relationship_filters(query, include_relationships)
+
+                result = await session.execute(query)
+                agent = result.scalar_one_or_none()
+
+                if agent is None:
+                    raise NoResultFound(f"Agent with ID {agent_id} not found")
+
+                return await agent.to_pydantic_async(include_relationships=include_relationships)
+            except Exception as e:
+                logger.error(f"Error fetching agent {agent_id}: {str(e)}")
+                raise
 
     @enforce_types
     @trace_method
@@ -1168,12 +1184,23 @@ class AgentManager:
     ) -> list[PydanticAgentState]:
         """Fetch a list of agents by their IDs."""
         async with db_registry.async_session() as session:
-            agents = await AgentModel.read_multiple_async(
-                db_session=session,
-                identifiers=agent_ids,
-                actor=actor,
-            )
-            return await asyncio.gather(*[agent.to_pydantic_async(include_relationships=include_relationships) for agent in agents])
+            try:
+                query = select(AgentModel)
+                query = AgentModel.apply_access_predicate(query, actor, ["read"], AccessType.ORGANIZATION)
+                query = query.where(AgentModel.id.in_(agent_ids))
+                query = _apply_relationship_filters(query, include_relationships)
+
+                result = await session.execute(query)
+                agents = result.scalars().all()
+
+                if not agents:
+                    logger.warning(f"No agents found with IDs: {agent_ids}")
+                    return []
+
+                return await asyncio.gather(*[agent.to_pydantic_async(include_relationships=include_relationships) for agent in agents])
+            except Exception as e:
+                logger.error(f"Error fetching agents with IDs {agent_ids}: {str(e)}")
+                raise
 
     @enforce_types
     @trace_method
diff --git a/letta/services/helpers/agent_manager_helper.py b/letta/services/helpers/agent_manager_helper.py
index 8c70f725..7c46219d 100644
--- a/letta/services/helpers/agent_manager_helper.py
+++ b/letta/services/helpers/agent_manager_helper.py
@@ -4,6 +4,7 @@ from typing import List, Literal, Optional, Set
 
 import numpy as np
 from sqlalchemy import Select, and_, asc, desc, func, literal, nulls_last, or_, select, union_all
+from sqlalchemy.orm import noload
 from sqlalchemy.sql.expression import exists
 
 from letta import system
@@ -669,6 +670,24 @@ def _apply_filters(
     return query
 
 
+def _apply_relationship_filters(query, include_relationships: Optional[List[str]] = None):
+    if include_relationships is None:
+        return query
+
+    if "memory" not in include_relationships:
+        query = query.options(noload(AgentModel.core_memory), noload(AgentModel.file_agents))
+    if "identity_ids" not in include_relationships:
+        query = query.options(noload(AgentModel.identities))
+
+    relationships = ["tool_exec_environment_variables", "tools", "sources", "tags", "multi_agent_group"]
+
+    for rel in relationships:
+        if rel not in include_relationships:
+            query = query.options(noload(getattr(AgentModel, rel)))
+
+    return query
+
+
 def build_passage_query(
     actor: User,
     agent_id: Optional[str] = None,