chore: import sqlite-vec even more conditionally (#2964)

letta/__init__.py

@@ -10,8 +10,16 @@ except PackageNotFoundError:
 if os.environ.get("LETTA_VERSION"):
     __version__ = os.environ["LETTA_VERSION"]
 
-# Import sqlite_functions early to ensure event handlers are registered
-from letta.orm import sqlite_functions
+# Import sqlite_functions early to ensure event handlers are registered (only for SQLite)
+# This is only needed for the server, not for client usage
+try:
+    from letta.settings import DatabaseChoice, settings
+
+    if settings.database_engine == DatabaseChoice.SQLITE:
+        from letta.orm import sqlite_functions
+except ImportError:
+    # If sqlite_vec is not installed, it's fine for client usage
+    pass
 
 # # imports for easier access
 from letta.schemas.agent import AgentState

letta/helpers/converters.py

@@ -44,8 +44,14 @@ from letta.schemas.tool_rule import (
 )
 from letta.settings import DatabaseChoice, settings
 
-if settings.database_engine == DatabaseChoice.SQLITE:
-    import sqlite_vec
+# Only import sqlite_vec if we're actually using SQLite database
+# This is a runtime dependency only needed for SQLite vector operations
+try:
+    if settings.database_engine == DatabaseChoice.SQLITE:
+        import sqlite_vec
+except ImportError:
+    # If sqlite_vec is not installed, it's fine for client usage
+    pass
 # --------------------------
 # LLMConfig Serialization
 # --------------------------

letta/orm/sqlalchemy_base.py

@@ -14,7 +14,6 @@ from sqlalchemy.orm.interfaces import ORMOption
 from letta.log import get_logger
 from letta.orm.base import Base, CommonSqlalchemyMetaMixins
 from letta.orm.errors import DatabaseTimeoutError, ForeignKeyConstraintViolationError, NoResultFound, UniqueConstraintViolationError
-from letta.orm.sqlite_functions import adapt_array
 from letta.settings import DatabaseChoice
 
 if TYPE_CHECKING:
@@ -401,6 +400,8 @@ class SqlalchemyBase(CommonSqlalchemyMetaMixins, Base):
                 query = query.order_by(cls.embedding.cosine_distance(query_embedding).asc())
             else:
                 # SQLite with custom vector type
+                from letta.orm.sqlite_functions import adapt_array
+
                 query_embedding_binary = adapt_array(query_embedding)
                 query = query.order_by(
                     func.cosine_distance(cls.embedding, query_embedding_binary).asc(),

letta/services/helpers/agent_manager_helper.py

@@ -29,7 +29,6 @@ from letta.orm.errors import NoResultFound
 from letta.orm.identity import Identity
 from letta.orm.passage import ArchivalPassage, SourcePassage
 from letta.orm.sources_agents import SourcesAgents
-from letta.orm.sqlite_functions import adapt_array
 from letta.otel.tracing import trace_method
 from letta.prompts import gpt_system
 from letta.prompts.prompt_generator import PromptGenerator
@@ -921,6 +920,8 @@ async def build_passage_query(
             main_query = main_query.order_by(combined_query.c.embedding.cosine_distance(embedded_text).asc())
         else:
             # SQLite with custom vector type
+            from letta.orm.sqlite_functions import adapt_array
+
             query_embedding_binary = adapt_array(embedded_text)
             main_query = main_query.order_by(
                 func.cosine_distance(combined_query.c.embedding, query_embedding_binary).asc(),
@@ -1054,6 +1055,8 @@ async def build_source_passage_query(
             query = query.order_by(SourcePassage.embedding.cosine_distance(embedded_text).asc())
         else:
             # SQLite with custom vector type
+            from letta.orm.sqlite_functions import adapt_array
+
             query_embedding_binary = adapt_array(embedded_text)
             query = query.order_by(
                 func.cosine_distance(SourcePassage.embedding, query_embedding_binary).asc(),
@@ -1151,6 +1154,8 @@ async def build_agent_passage_query(
             query = query.order_by(ArchivalPassage.embedding.cosine_distance(embedded_text).asc())
         else:
             # SQLite with custom vector type
+            from letta.orm.sqlite_functions import adapt_array
+
             query_embedding_binary = adapt_array(embedded_text)
             query = query.order_by(
                 func.cosine_distance(ArchivalPassage.embedding, query_embedding_binary).asc(),

tests/integration_test_async_tool_sandbox.py

@@ -36,14 +36,6 @@ user_name = str(uuid.uuid5(namespace, "test-tool-execution-sandbox-user"))
 # Set environment variable immediately to prevent pooling issues
 os.environ["LETTA_DISABLE_SQLALCHEMY_POOLING"] = "true"
 
-# Recreate settings instance to pick up the environment variable
-import letta.settings
-
-# Force settings reload after setting environment variable
-from letta.settings import Settings
-
-letta.settings.settings = Settings()
-
 
 # Disable SQLAlchemy connection pooling for tests to prevent event loop issues
 @pytest.fixture(scope="session", autouse=True)