feat: add sessions endpoint with session management enhancements (#8596)

* 📝 (monitor.py): Add endpoint to get sessions and handle session_id encoding for API requests
📝 (use-get-messages-mutation.ts): Implement a mutation function to fetch messages with query parameters and handle session_id encoding for API requests
📝 (use-get-messages-polling.ts): Ensure proper encoding of session_id for API requests in polling mutation
📝 (use-get-messages.ts): Handle session_id encoding for API requests in messages query
📝 (new-modal.tsx): Implement functions to handle session deletion and proper encoding of session_id for API requests
📝 (utils.ts): Add functions to encode, decode, validate, format, and prepare session IDs for API requests

* 📝 (constants.ts): Add SESSIONS constant to API URLs for monitoring sessions
🔧 (use-delete-messages.ts): Add queryClient to UseRequestProcessor to invalidate sessions query
✨ (use-get-sessions-from-flow.ts): Introduce useGetSessionsFromFlowQuery to fetch sessions from flow
🔧 (use-rename-session.ts): Change refetchQueries to invalidateQueries for useGetSessionsFromFlowQuery
🔧 (custom-new-modal.tsx): Update import path for IOModal to playground-modal
🔧 (session-selector.tsx): Add setActiveSession function to handle setting active session
🔧 (sidebar-open-view.tsx): Add setActiveSession function to handle setting active session
♻️ (new-modal.tsx): Refactor IOModal into playground-modal and update functionality
♻️ (playground-modal.tsx): Refactor IOModal to handle playground-specific functionality
⬆️ (flowStore.ts): Add newChatOnPlayground state and setNewChatOnPlayground function
⬆️ (index.ts): Update FlowStoreType to include newChatOnPlayground and setNewChatOnPlayground

* 🔧 (pyproject.toml): update testpaths to point to the correct directory for tests
✨ (test_session_endpoint.py): add unit tests for sessions endpoint with flow_id filtering
♻️ (session-selector.tsx): refactor to trim editedSession before setting it
♻️ (sidebar-open-view.tsx): refactor to set visibleSession instead of activeSession

* ✨ (use-get-sessions-from-flow.ts): Always include the flow ID as the default session if it's not already present
♻️ (playground-modal.tsx): Refactor setting sessions to include currentFlowId as the default session if not present, and handle visibility of sessions more efficiently

* ♻️ (use-get-messages-mutation.ts): remove unused imports and refactor code for better readability and maintainability

* ✨ (test_session_endpoint.py): refactor test function names for better clarity and consistency

* ✨ (create-new-session-name.ts): add function to generate a new session name based on the current date and time
🔧 (playground-modal.tsx): import createNewSessionName function to dynamically set a new session name when no session is visible

* [autofix.ci] apply automated fixes

* ✨ (monitor.py): rename get_sessions endpoint to get_message_sessions for clarity and consistency
🔧 (constants.ts): remove unused SESSIONS constant from API URLs
🔧 (use-delete-messages.ts): remove commented out code and unnecessary comments
✨ (use-delete-sessions.ts): add functionality to delete sessions in frontend
🔧 (use-get-sessions-from-flow.ts): update API endpoint for getting sessions to match backend changes
🔧 (playground-modal.tsx): add functionality to delete sessions and associated messages in the UI, update UI optimistically, and handle errors appropriately

* [autofix.ci] apply automated fixes

* 🐛 (monitor.py): Fix type hinting issue in delete_messages function
📝 (monitor.py): Add comments and improve readability in test_messages_endpoints.py
📝 (session_endpoint.py): Update endpoint paths for consistency and clarity in test_session_endpoint.py

* [autofix.ci] apply automated fixes

* fix: update SQL statement to use col() for session_id filtering in get_message_sessions function

---------

Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>
Co-authored-by: Gabriel Luiz Freitas Almeida <gabriel@langflow.org>

pyproject.toml

@@ -233,7 +233,7 @@ ignore-regex = '.*(Stati Uniti|Tense=Pres).*'
 timeout = 120
 timeout_method = "signal"
 minversion = "6.0"
-testpaths = ["tests", "integration"]
+testpaths = ["src/backend/tests"]
 console_output_style = "progress"
 filterwarnings = ["ignore::DeprecationWarning", "ignore::ResourceWarning"]
 log_cli = true

src/backend/base/langflow/api/v1/monitor.py

@@ -40,6 +40,24 @@ async def delete_vertex_builds(flow_id: Annotated[UUID, Query()], session: DbSes
         raise HTTPException(status_code=500, detail=str(e)) from e
 
 
+@router.get("/messages/sessions", dependencies=[Depends(get_current_active_user)])
+async def get_message_sessions(
+    session: DbSession,
+    flow_id: Annotated[UUID | None, Query()] = None,
+) -> list[str]:
+    try:
+        stmt = select(MessageTable.session_id).distinct()
+        stmt = stmt.where(col(MessageTable.session_id).isnot(None))
+
+        if flow_id:
+            stmt = stmt.where(MessageTable.flow_id == flow_id)
+
+        session_ids = await session.exec(stmt)
+        return list(session_ids)
+    except Exception as e:
+        raise HTTPException(status_code=500, detail=str(e)) from e
+
+
 @router.get("/messages")
 async def get_messages(
     session: DbSession,
@@ -54,7 +72,10 @@ async def get_messages(
         if flow_id:
             stmt = stmt.where(MessageTable.flow_id == flow_id)
         if session_id:
-            stmt = stmt.where(MessageTable.session_id == session_id)
+            from urllib.parse import unquote
+
+            decoded_session_id = unquote(session_id)
+            stmt = stmt.where(MessageTable.session_id == decoded_session_id)
         if sender:
             stmt = stmt.where(MessageTable.sender == sender)
         if sender_name:

src/backend/tests/unit/test_messages_endpoints.py

@@ -1,4 +1,5 @@
 from datetime import datetime, timezone
+from urllib.parse import quote
 from uuid import UUID
 
 import pytest
@@ -32,6 +33,20 @@ async def created_messages(session):  # noqa: ARG001
         return await aadd_messagetables(messagetables, _session)
 
 
+@pytest.fixture
+async def messages_with_datetime_session_id(session):  # noqa: ARG001
+    """Create messages with datetime-like session IDs that contain characters requiring URL encoding."""
+    datetime_session_id = "2024-01-15 10:30:45 UTC"  # Contains spaces and colons
+    async with session_scope() as _session:
+        messages = [
+            MessageCreate(text="Datetime message 1", sender="User", sender_name="User", session_id=datetime_session_id),
+            MessageCreate(text="Datetime message 2", sender="AI", sender_name="AI", session_id=datetime_session_id),
+        ]
+        messagetables = [MessageTable.model_validate(message, from_attributes=True) for message in messages]
+        created_messages = await aadd_messagetables(messagetables, _session)
+        return created_messages, datetime_session_id
+
+
 @pytest.mark.api_key_required
 async def test_delete_messages(client: AsyncClient, created_messages, logged_in_headers):
     response = await client.request(
@@ -127,3 +142,96 @@ async def test_no_messages_found_with_given_session_id(client, logged_in_headers
 
     assert response.status_code == 404, response.text
     assert response.json()["detail"] == "Not Found"
+
+
+# Test for URL-encoded datetime session ID
+@pytest.mark.api_key_required
+async def test_get_messages_with_url_encoded_datetime_session_id(
+    client: AsyncClient, messages_with_datetime_session_id, logged_in_headers
+):
+    """Test that URL-encoded datetime session IDs are properly decoded and matched."""
+    created_messages, datetime_session_id = messages_with_datetime_session_id
+
+    # URL encode the datetime session ID (spaces become %20, colons become %3A)
+    encoded_session_id = quote(datetime_session_id)
+
+    # Test with URL-encoded session ID
+    response = await client.get(
+        "api/v1/monitor/messages", params={"session_id": encoded_session_id}, headers=logged_in_headers
+    )
+
+    assert response.status_code == 200, response.text
+    messages = response.json()
+    assert len(messages) == 2
+
+    # Verify all messages have the correct (decoded) session ID
+    for message in messages:
+        assert message["session_id"] == datetime_session_id
+
+    # Verify message content
+    assert messages[0]["text"] == "Datetime message 1"
+    assert messages[1]["text"] == "Datetime message 2"
+
+
+@pytest.mark.api_key_required
+async def test_get_messages_with_non_encoded_datetime_session_id(
+    client: AsyncClient, messages_with_datetime_session_id, logged_in_headers
+):
+    """Test that non-URL-encoded datetime session IDs also work correctly."""
+    created_messages, datetime_session_id = messages_with_datetime_session_id
+
+    # Test with non-encoded session ID (should still work due to unquote being safe for non-encoded strings)
+    response = await client.get(
+        "api/v1/monitor/messages", params={"session_id": datetime_session_id}, headers=logged_in_headers
+    )
+
+    assert response.status_code == 200, response.text
+    messages = response.json()
+    assert len(messages) == 2
+
+    # Verify all messages have the correct session ID
+    for message in messages:
+        assert message["session_id"] == datetime_session_id
+
+
+@pytest.mark.api_key_required
+async def test_get_messages_with_various_encoded_characters(client: AsyncClient, logged_in_headers):
+    """Test various URL-encoded characters in session IDs."""
+    # Create a session ID with various special characters
+    special_session_id = "test+session:2024@domain.com"
+
+    async with session_scope() as session:
+        message = MessageCreate(
+            text="Special chars message", sender="User", sender_name="User", session_id=special_session_id
+        )
+        messagetable = MessageTable.model_validate(message, from_attributes=True)
+        await aadd_messagetables([messagetable], session)
+
+    # URL encode the session ID
+    encoded_session_id = quote(special_session_id)
+
+    # Test with URL-encoded session ID
+    response = await client.get(
+        "api/v1/monitor/messages", params={"session_id": encoded_session_id}, headers=logged_in_headers
+    )
+
+    assert response.status_code == 200, response.text
+    messages = response.json()
+    assert len(messages) == 1
+    assert messages[0]["session_id"] == special_session_id
+    assert messages[0]["text"] == "Special chars message"
+
+
+@pytest.mark.api_key_required
+async def test_get_messages_empty_result_with_encoded_nonexistent_session(client: AsyncClient, logged_in_headers):
+    """Test that URL-encoded non-existent session IDs return empty results."""
+    nonexistent_session_id = "2024-12-31 23:59:59 UTC"
+    encoded_session_id = quote(nonexistent_session_id)
+
+    response = await client.get(
+        "api/v1/monitor/messages", params={"session_id": encoded_session_id}, headers=logged_in_headers
+    )
+
+    assert response.status_code == 200, response.text
+    messages = response.json()
+    assert len(messages) == 0

src/backend/tests/unit/test_session_endpoint.py

@@ -0,0 +1,142 @@
+from uuid import uuid4
+
+import pytest
+from httpx import AsyncClient
+from langflow.memory import aadd_messagetables
+from langflow.services.database.models.message.model import MessageTable
+from langflow.services.deps import session_scope
+
+
+@pytest.fixture
+async def messages_with_flow_ids(session):  # noqa: ARG001
+    """Create messages with different session_ids and flow_ids for testing sessions endpoint."""
+    async with session_scope() as _session:
+        flow_id_1 = uuid4()
+        flow_id_2 = uuid4()
+
+        # Create MessageTable objects directly since MessageCreate doesn't have flow_id field
+        messagetables = [
+            MessageTable(
+                text="Message 1", sender="User", sender_name="User", session_id="session_A", flow_id=flow_id_1
+            ),
+            MessageTable(text="Message 2", sender="AI", sender_name="AI", session_id="session_A", flow_id=flow_id_1),
+            MessageTable(
+                text="Message 3", sender="User", sender_name="User", session_id="session_B", flow_id=flow_id_1
+            ),
+            MessageTable(
+                text="Message 4", sender="User", sender_name="User", session_id="session_C", flow_id=flow_id_2
+            ),
+            MessageTable(text="Message 5", sender="AI", sender_name="AI", session_id="session_D", flow_id=flow_id_2),
+            MessageTable(
+                text="Message 6",
+                sender="User",
+                sender_name="User",
+                session_id="session_E",
+                flow_id=None,  # No flow_id
+            ),
+        ]
+        created_messages = await aadd_messagetables(messagetables, _session)
+
+        return {
+            "messages": created_messages,
+            "flow_id_1": flow_id_1,
+            "flow_id_2": flow_id_2,
+            "expected_sessions_flow_1": {"session_A", "session_B"},
+            "expected_sessions_flow_2": {"session_C", "session_D"},
+            "expected_all_sessions": {"session_A", "session_B", "session_C", "session_D", "session_E"},
+        }
+
+
+# Tests for /sessions endpoint
+@pytest.mark.api_key_required
+async def test_get_sessions_all(client: AsyncClient, logged_in_headers, messages_with_flow_ids):
+    """Test getting all sessions without any filter."""
+    response = await client.get("api/v1/monitor/messages/sessions", headers=logged_in_headers)
+
+    assert response.status_code == 200, response.text
+    sessions = response.json()
+    assert isinstance(sessions, list)
+
+    # Convert to set for easier comparison since order doesn't matter
+    returned_sessions = set(sessions)
+    expected_sessions = messages_with_flow_ids["expected_all_sessions"]
+
+    assert returned_sessions == expected_sessions
+    assert len(sessions) == len(expected_sessions)
+
+
+@pytest.mark.api_key_required
+async def test_get_sessions_with_flow_id_filter(client: AsyncClient, logged_in_headers, messages_with_flow_ids):
+    """Test getting sessions filtered by flow_id."""
+    flow_id_1 = messages_with_flow_ids["flow_id_1"]
+
+    response = await client.get(
+        "api/v1/monitor/messages/sessions", params={"flow_id": str(flow_id_1)}, headers=logged_in_headers
+    )
+
+    assert response.status_code == 200, response.text
+    sessions = response.json()
+    assert isinstance(sessions, list)
+
+    returned_sessions = set(sessions)
+    expected_sessions = messages_with_flow_ids["expected_sessions_flow_1"]
+
+    assert returned_sessions == expected_sessions
+    assert len(sessions) == len(expected_sessions)
+
+
+@pytest.mark.api_key_required
+async def test_get_sessions_with_different_flow_id(client: AsyncClient, logged_in_headers, messages_with_flow_ids):
+    """Test getting sessions filtered by a different flow_id."""
+    flow_id_2 = messages_with_flow_ids["flow_id_2"]
+
+    response = await client.get(
+        "api/v1/monitor/messages/sessions", params={"flow_id": str(flow_id_2)}, headers=logged_in_headers
+    )
+
+    assert response.status_code == 200, response.text
+    sessions = response.json()
+    assert isinstance(sessions, list)
+
+    returned_sessions = set(sessions)
+    expected_sessions = messages_with_flow_ids["expected_sessions_flow_2"]
+
+    assert returned_sessions == expected_sessions
+    assert len(sessions) == len(expected_sessions)
+
+
+@pytest.mark.api_key_required
+async def test_get_sessions_with_non_existent_flow_id(client: AsyncClient, logged_in_headers):
+    """Test getting sessions with a non-existent flow_id returns empty list."""
+    non_existent_flow_id = uuid4()
+
+    response = await client.get(
+        "api/v1/monitor/messages/sessions", params={"flow_id": str(non_existent_flow_id)}, headers=logged_in_headers
+    )
+
+    assert response.status_code == 200, response.text
+    sessions = response.json()
+    assert isinstance(sessions, list)
+    assert len(sessions) == 0
+
+
+@pytest.mark.api_key_required
+async def test_get_sessions_empty_database(client: AsyncClient, logged_in_headers):
+    """Test getting sessions when no messages exist in database."""
+    response = await client.get("api/v1/monitor/messages/sessions", headers=logged_in_headers)
+
+    assert response.status_code == 200, response.text
+    sessions = response.json()
+    assert isinstance(sessions, list)
+    assert len(sessions) == 0
+
+
+@pytest.mark.api_key_required
+async def test_get_sessions_invalid_flow_id_format(client: AsyncClient, logged_in_headers):
+    """Test getting sessions with invalid flow_id format returns 422."""
+    response = await client.get(
+        "api/v1/monitor/messages/sessions", params={"flow_id": "invalid-uuid"}, headers=logged_in_headers
+    )
+
+    assert response.status_code == 422, response.text
+    assert "detail" in response.json()

src/frontend/src/controllers/API/queries/messages/use-delete-messages.ts

@@ -12,7 +12,7 @@ export const useDeleteMessages: useMutationFunctionType<
   undefined,
   DeleteMessagesParams
 > = (options?) => {
-  const { mutate } = UseRequestProcessor();
+  const { mutate, queryClient } = UseRequestProcessor();
 
   const deleteMessage = async ({ ids }: DeleteMessagesParams): Promise<any> => {
     const response = await api.delete(`${getURL("MESSAGES")}`, {
@@ -26,7 +26,15 @@ export const useDeleteMessages: useMutationFunctionType<
     DeleteMessagesParams,
     any,
     DeleteMessagesParams
-  > = mutate(["useDeleteMessages"], deleteMessage, options);
+  > = mutate(["useDeleteMessages"], deleteMessage, {
+    ...options,
+    onSettled: (data, error, variables, context) => {
+      queryClient.invalidateQueries({
+        queryKey: ["useGetSessionsFromFlowQuery"],
+      });
+      options?.onSettled?.(data, error, variables, context);
+    },
+  });
 
   return mutation;
 };

src/frontend/src/controllers/API/queries/messages/use-delete-sessions.ts

@@ -0,0 +1,41 @@
+import { useMutationFunctionType } from "@/types/api";
+import { UseMutationResult } from "@tanstack/react-query";
+import { api } from "../../api";
+import { getURL } from "../../helpers/constants";
+import { UseRequestProcessor } from "../../services/request-processor";
+
+interface DeleteSessionParams {
+  sessionId: string;
+}
+
+export const useDeleteSession: useMutationFunctionType<
+  undefined,
+  DeleteSessionParams
+> = (options?) => {
+  const { mutate, queryClient } = UseRequestProcessor();
+
+  const deleteSession = async ({
+    sessionId,
+  }: DeleteSessionParams): Promise<any> => {
+    const response = await api.delete(
+      `${getURL("MESSAGES")}/session/${sessionId}`,
+    );
+    return response.data;
+  };
+
+  const mutation: UseMutationResult<
+    DeleteSessionParams,
+    any,
+    DeleteSessionParams
+  > = mutate(["useDeleteSession"], deleteSession, {
+    ...options,
+    onSettled: (data, error, variables, context) => {
+      queryClient.invalidateQueries({
+        queryKey: ["useGetSessionsFromFlowQuery"],
+      });
+      options?.onSettled?.(data, error, variables, context);
+    },
+  });
+
+  return mutation;
+};

src/frontend/src/controllers/API/queries/messages/use-get-messages-polling.ts

@@ -2,7 +2,10 @@ import { useMessagesStore } from "@/stores/messagesStore";
 import { UseMutationResult } from "@tanstack/react-query";
 import { ColDef, ColGroupDef } from "ag-grid-community";
 import { useEffect, useRef } from "react";
-import { extractColumnsFromRows } from "../../../../utils/utils";
+import {
+  extractColumnsFromRows,
+  prepareSessionIdForAPI,
+} from "../../../../utils/utils";
 import { api } from "../../api";
 import { getURL } from "../../helpers/constants";
 import { UseRequestProcessor } from "../../services/request-processor";
@@ -109,7 +112,14 @@ export const useGetMessagesPollingMutation = (
       }
 
       if (params) {
-        config["params"] = { ...config["params"], ...params };
+        // Process params to ensure session_id is properly encoded
+        const processedParams = { ...params } as any;
+        if (processedParams.session_id) {
+          processedParams.session_id = prepareSessionIdForAPI(
+            processedParams.session_id,
+          );
+        }
+        config["params"] = { ...config["params"], ...processedParams };
       }
 
       const data = await api.get<any>(`${getURL("MESSAGES")}`, config);

src/frontend/src/controllers/API/queries/messages/use-get-messages.ts

@@ -3,7 +3,10 @@ import { useMessagesStore } from "@/stores/messagesStore";
 import { keepPreviousData } from "@tanstack/react-query";
 import { ColDef, ColGroupDef } from "ag-grid-community";
 import { useQueryFunctionType } from "../../../../types/api";
-import { extractColumnsFromRows } from "../../../../utils/utils";
+import {
+  extractColumnsFromRows,
+  prepareSessionIdForAPI,
+} from "../../../../utils/utils";
 import { api } from "../../api";
 import { getURL } from "../../helpers/constants";
 import { UseRequestProcessor } from "../../services/request-processor";
@@ -33,7 +36,14 @@ export const useGetMessagesQuery: useQueryFunctionType<
       config["params"] = { flow_id: id };
     }
     if (params) {
-      config["params"] = { ...config["params"], ...params };
+      // Process params to ensure session_id is properly encoded
+      const processedParams = { ...params } as any;
+      if (processedParams.session_id) {
+        processedParams.session_id = prepareSessionIdForAPI(
+          processedParams.session_id,
+        );
+      }
+      config["params"] = { ...config["params"], ...processedParams };
     }
     if (!isPlaygroundPage) {
       return await api.get<any>(`${getURL("MESSAGES")}`, config);

src/frontend/src/controllers/API/queries/messages/use-get-sessions-from-flow.ts

@@ -0,0 +1,66 @@
+import useFlowStore from "@/stores/flowStore";
+import { keepPreviousData } from "@tanstack/react-query";
+import { useQueryFunctionType } from "../../../../types/api";
+import { api } from "../../api";
+import { getURL } from "../../helpers/constants";
+import { UseRequestProcessor } from "../../services/request-processor";
+
+interface SessionsQueryParams {
+  id?: string;
+}
+
+interface SessionsResponse {
+  sessions: string[];
+}
+
+export const useGetSessionsFromFlowQuery: useQueryFunctionType<
+  SessionsQueryParams,
+  SessionsResponse
+> = ({ id }, options) => {
+  const { query } = UseRequestProcessor();
+
+  const getSessionsFn = async (id?: string) => {
+    const isPlaygroundPage = useFlowStore.getState().playgroundPage;
+    const config = {};
+    if (id) {
+      config["params"] = { flow_id: id };
+    }
+
+    if (!isPlaygroundPage) {
+      return await api.get<string[]>(`${getURL("MESSAGES")}/sessions`, config);
+    } else {
+      // For playground mode, get sessions from sessionStorage
+      const data = JSON.parse(window.sessionStorage.getItem(id ?? "") || "[]");
+      // Extract unique session IDs from stored messages
+      const sessionIdsSet = new Set(
+        data.map((msg: any) => msg.session_id).filter(Boolean),
+      );
+      const sessionIds = Array.from(sessionIdsSet);
+
+      // Always include the flow ID as the default session if it's not already present
+      if (id && !sessionIds.includes(id)) {
+        sessionIds.unshift(id);
+      }
+
+      return {
+        data: sessionIds,
+      };
+    }
+  };
+
+  const responseFn = async () => {
+    const response = await getSessionsFn(id);
+    return { sessions: response.data };
+  };
+
+  const queryResult = query(
+    ["useGetSessionsFromFlowQuery", { id }],
+    responseFn,
+    {
+      placeholderData: keepPreviousData,
+      ...options,
+    },
+  );
+
+  return queryResult;
+};

src/frontend/src/controllers/API/queries/messages/use-rename-session.ts

@@ -48,10 +48,9 @@ export const useUpdateSessionName: useMutationFunctionType<
   const mutation: UseMutationResult<Message[], any, UpdateSessionParams> =
     mutate(["useUpdateSessionName"], updateSessionApi, {
       ...options,
-      onSettled: (data, variables, context) => {
+      onSettled: () => {
-        // Invalidate and refetch relevant queries
+        queryClient.invalidateQueries({
-        queryClient.refetchQueries({
+          queryKey: ["useGetSessionsFromFlowQuery"],
-          queryKey: ["useGetMessagesQuery"],
         });
       },
     });

src/frontend/src/customization/components/custom-new-modal.tsx

@@ -1,4 +1,4 @@
-import IOModal from "@/modals/IOModal/new-modal";
+import IOModal from "@/modals/IOModal/playground-modal";
 import { IOModalPropsType } from "@/types/components";
 
 export function CustomIOModal({

src/frontend/src/modals/IOModal/components/IOFieldView/components/session-selector.tsx

@@ -26,6 +26,7 @@ export default function SessionSelector({
   selectedView,
   setSelectedView,
   playgroundPage,
+  setActiveSession,
 }: {
   deleteSession: (session: string) => void;
   session: string;
@@ -36,6 +37,7 @@ export default function SessionSelector({
   selectedView?: { type: string; id: string };
   setSelectedView: (view: { type: string; id: string } | undefined) => void;
   playgroundPage: boolean;
+  setActiveSession: (session: string) => void;
 }) {
   const clientId = useUtilityStore((state) => state.clientId);
   let realFlowId = useFlowsManagerStore((state) => state.currentFlowId);
@@ -46,6 +48,9 @@ export default function SessionSelector({
   const [editedSession, setEditedSession] = useState(session);
   const { mutate: updateSessionName } = useUpdateSessionName();
   const inputRef = useRef<HTMLInputElement>(null);
+  const setNewChatOnPlayground = useFlowStore(
+    (state) => state.setNewChatOnPlayground,
+  );
 
   useEffect(() => {
     setEditedSession(session);
@@ -68,13 +73,13 @@ export default function SessionSelector({
         {
           onSuccess: () => {
             if (isVisible) {
-              updateVisibleSession(editedSession);
+              updateVisibleSession(editedSession.trim());
             }
             if (
               selectedView?.type === "Session" &&
               selectedView?.id === session
             ) {
-              setSelectedView({ type: "Session", id: editedSession });
+              setSelectedView({ type: "Session", id: editedSession.trim() });
             }
           },
         },

src/frontend/src/modals/IOModal/components/chatView/chatInput/components/voice-assistant/helpers/create-new-session-name.ts

@@ -0,0 +1,11 @@
+export const createNewSessionName = () => {
+  return `Session ${new Date().toLocaleString("en-US", {
+    day: "2-digit",
+    month: "short",
+    hour: "2-digit",
+    minute: "2-digit",
+    hour12: false,
+    second: "2-digit",
+    timeZone: "UTC",
+  })}`;
+};

src/frontend/src/modals/IOModal/components/sidebar-open-view.tsx

@@ -1,5 +1,6 @@
 import ShadTooltip from "@/components/common/shadTooltipComponent";
 import { Button } from "@/components/ui/button";
+import useFlowStore from "@/stores/flowStore";
 import { useVoiceStore } from "@/stores/voiceStore";
 import IconComponent from "../../../components/common/genericIconComponent";
 import { SidebarOpenViewProps } from "../types/sidebar-open-view";
@@ -13,11 +14,16 @@ export const SidebarOpenView = ({
   visibleSession,
   selectedViewField,
   playgroundPage,
+  setActiveSession,
 }: SidebarOpenViewProps) => {
   const setNewSessionCloseVoiceAssistant = useVoiceStore(
     (state) => state.setNewSessionCloseVoiceAssistant,
   );
 
+  const setNewChatOnPlayground = useFlowStore(
+    (state) => state.setNewChatOnPlayground,
+  );
+
   return (
     <>
       <div className="flex flex-col pl-3">
@@ -40,6 +46,7 @@ export const SidebarOpenView = ({
                     setvisibleSession(undefined);
                     setSelectedViewField(undefined);
                     setNewSessionCloseVoiceAssistant(true);
+                    setNewChatOnPlayground(true);
                   }}
                 >
                   <IconComponent
@@ -78,6 +85,9 @@ export const SidebarOpenView = ({
                   type: "Session",
                 });
               }}
+              setActiveSession={(session) => {
+                setActiveSession(session);
+              }}
             />
           ))}
         </div>

src/frontend/src/modals/IOModal/playground-modal.tsx

@@ -1,18 +1,18 @@
 //import LangflowLogoColor from "@/assets/LangflowLogocolor.svg?react";
 import ThemeButtons from "@/components/core/appHeaderComponent/components/ThemeButtons";
-import { EventDeliveryType } from "@/constants/enums";
-import { useGetConfig } from "@/controllers/API/queries/config/use-get-config";
 import {
   useDeleteMessages,
   useGetMessagesQuery,
 } from "@/controllers/API/queries/messages";
+import { useDeleteSession } from "@/controllers/API/queries/messages/use-delete-sessions";
+import { useGetSessionsFromFlowQuery } from "@/controllers/API/queries/messages/use-get-sessions-from-flow";
 import { ENABLE_PUBLISH } from "@/customization/feature-flags";
 import { track } from "@/customization/utils/analytics";
 import { customOpenNewTab } from "@/customization/utils/custom-open-new-tab";
 import { LangflowButtonRedirectTarget } from "@/customization/utils/urls";
 import { useUtilityStore } from "@/stores/utilityStore";
 import { swatchColors } from "@/utils/styleUtils";
-import { useCallback, useEffect, useState } from "react";
+import { useCallback, useEffect, useRef, useState } from "react";
 import { v5 as uuidv5 } from "uuid";
 import { useShallow } from "zustand/react/shallow";
 import LangflowLogoColor from "../../assets/LangflowLogoColor.svg?react";
@@ -27,6 +27,7 @@ import { IOModalPropsType } from "../../types/components";
 import { cn, getNumberFromString } from "../../utils/utils";
 import BaseModal from "../baseModal";
 import { ChatViewWrapper } from "./components/chat-view-wrapper";
+import { createNewSessionName } from "./components/chatView/chatInput/components/voice-assistant/helpers/create-new-session-name";
 import { SelectedViewField } from "./components/selected-view-field";
 import { SidebarOpenView } from "./components/sidebar-open-view";
 
@@ -46,6 +47,13 @@ export default function IOModal({
   const buildFlow = useFlowStore((state) => state.buildFlow);
   const setIsBuilding = useFlowStore((state) => state.setIsBuilding);
   const isBuilding = useFlowStore((state) => state.isBuilding);
+  const newChatOnPlayground = useFlowStore(
+    (state) => state.newChatOnPlayground,
+  );
+  const setNewChatOnPlayground = useFlowStore(
+    (state) => state.setNewChatOnPlayground,
+  );
+
   const { flowIcon, flowId, flowGradient, flowName } = useFlowStore(
     useShallow((state) => ({
       flowIcon: state.currentFlow?.icon,
@@ -76,12 +84,36 @@ export default function IOModal({
     : realFlowId;
   const [sidebarOpen, setSidebarOpen] = useState(true);
 
-  const { mutate: deleteSessionFunction } = useDeleteMessages();
+  const { mutate: deleteMessagesFunction } = useDeleteMessages();
+  const { mutate: deleteSessionFunction } = useDeleteSession();
+
   const [visibleSession, setvisibleSession] = useState<string | undefined>(
     currentFlowId,
   );
   const PlaygroundTitle = playgroundPage && flowName ? flowName : "Playground";
 
+  const {
+    data: sessionsFromDb,
+    isLoading: sessionsLoading,
+    refetch: refetchSessions,
+  } = useGetSessionsFromFlowQuery(
+    {
+      id: currentFlowId,
+    },
+    { enabled: open },
+  );
+
+  useEffect(() => {
+    if (sessionsFromDb && !sessionsLoading) {
+      const sessions = [...sessionsFromDb.sessions];
+      // Always include the currentFlowId as the default session if it's not already present
+      if (!sessions.includes(currentFlowId)) {
+        sessions.unshift(currentFlowId);
+      }
+      setSessions(sessions);
+    }
+  }, [sessionsFromDb, sessionsLoading, currentFlowId]);
+
   useEffect(() => {
     setIOModalOpen(open);
     return () => {
@@ -90,25 +122,45 @@ export default function IOModal({
   }, [open]);
 
   function handleDeleteSession(session_id: string) {
+    // Update UI optimistically
+    if (visibleSession === session_id) {
+      const remainingSessions = sessions.filter((s) => s !== session_id);
+      if (remainingSessions.length > 0) {
+        setvisibleSession(remainingSessions[0]);
+      } else {
+        setvisibleSession(currentFlowId);
+      }
+    }
+
+    // Delete the session (which will delete all associated messages on the backend)
     deleteSessionFunction(
-      {
+      { sessionId: session_id },
-        ids: messages
-          .filter((msg) => msg.session_id === session_id)
-          .map((msg) => msg.id),
-      },
       {
         onSuccess: () => {
+          // Remove the session from local state
+          deleteSession(session_id);
+
+          // Remove all messages for this session from local state
+          const messageIdsToRemove = messages
+            .filter((msg) => msg.session_id === session_id)
+            .map((msg) => msg.id);
+
+          if (messageIdsToRemove.length > 0) {
+            removeMessages(messageIdsToRemove);
+          }
+
           setSuccessData({
             title: "Session deleted successfully.",
           });
-          deleteSession(session_id);
-          if (visibleSession === session_id) {
-            setvisibleSession(undefined);
-          }
         },
         onError: () => {
+          // Revert optimistic UI update on error
+          if (visibleSession !== session_id) {
+            setvisibleSession(session_id);
+          }
+
           setErrorData({
-            title: "Error deleting Session.",
+            title: "Error deleting session.",
           });
         },
       },
@@ -132,27 +184,24 @@ export default function IOModal({
   >(startView());
 
   const messages = useMessagesStore((state) => state.messages);
-  const [sessions, setSessions] = useState<string[]>(
+  const removeMessages = useMessagesStore((state) => state.removeMessages);
-    Array.from(
+  const [sessions, setSessions] = useState<string[]>([]);
-      new Set(
-        messages
-          .filter((message) => message.flow_id === currentFlowId)
-          .map((message) => message.session_id),
-      ),
-    ),
-  );
   const [sessionId, setSessionId] = useState<string>(currentFlowId);
   const setCurrentSessionId = useUtilityStore(
     (state) => state.setCurrentSessionId,
   );
 
-  const { isFetched: messagesFetched } = useGetMessagesQuery(
+  const { isFetched: messagesFetched, refetch: refetchMessages } =
-    {
+    useGetMessagesQuery(
-      mode: "union",
+      {
-      id: currentFlowId,
+        mode: "union",
-    },
+        id: currentFlowId,
-    { enabled: open },
+        params: {
-  );
+          session_id: visibleSession,
+        },
+      },
+      { enabled: open },
+    );
 
   const chatValue = useUtilityStore((state) => state.chatValueStore);
   const setChatValue = useUtilityStore((state) => state.setChatValueStore);
@@ -185,28 +234,28 @@ export default function IOModal({
   );
 
   useEffect(() => {
-    const sessions = new Set<string>();
+    if (newChatOnPlayground && !sessionsLoading) {
-    messages
+      const handleRefetchAndSetSession = async () => {
-      .filter((message) => message.flow_id === currentFlowId)
+        try {
-      .forEach((row) => {
+          const result = await refetchSessions();
-        sessions.add(row.session_id);
+          if (result.data?.sessions && result.data.sessions.length > 0) {
-      });
+            setvisibleSession(
-    setSessions((prev) => {
+              result.data.sessions[result.data.sessions.length - 1],
-      if (prev.length < Array.from(sessions).length) {
+            );
-        // set the new session as visible
+          }
-        setvisibleSession(
+        } catch (error) {
-          Array.from(sessions)[Array.from(sessions).length - 1],
+          console.error("Error refetching sessions:", error);
-        );
+        }
-      }
+      };
-      return Array.from(sessions);
+
-    });
+      handleRefetchAndSetSession();
+      setNewChatOnPlayground(false);
+    }
   }, [messages]);
 
   useEffect(() => {
     if (!visibleSession) {
-      setSessionId(
+      setSessionId(createNewSessionName());
-        `Session ${new Date().toLocaleString("en-US", { day: "2-digit", month: "short", hour: "2-digit", minute: "2-digit", hour12: false, second: "2-digit", timeZone: "UTC" })}`,
-      );
       setCurrentSessionId(currentFlowId);
     } else if (visibleSession) {
       setSessionId(visibleSession);
@@ -271,6 +320,35 @@ export default function IOModal({
       : getNumberFromString(flowGradient ?? flowId ?? "")) %
     swatchColors.length;
 
+  const setActiveSession = (session: string) => {
+    setvisibleSession((prev) => {
+      if (prev === session) {
+        return undefined;
+      }
+      return session;
+    });
+  };
+
+  const [hasInitialized, setHasInitialized] = useState(false);
+  const prevVisibleSessionRef = useRef<string | undefined>(visibleSession);
+
+  useEffect(() => {
+    if (!hasInitialized) {
+      setHasInitialized(true);
+      prevVisibleSessionRef.current = visibleSession;
+      return;
+    }
+    if (
+      open &&
+      visibleSession &&
+      prevVisibleSessionRef.current !== visibleSession
+    ) {
+      refetchMessages();
+    }
+
+    prevVisibleSessionRef.current = visibleSession;
+  }, [visibleSession]);
+
   return (
     <BaseModal
       open={open}
@@ -336,7 +414,7 @@ export default function IOModal({
                     </Button>
                   </ShadTooltip>
                 </div>
-                {sidebarOpen && (
+                {sidebarOpen && !sessionsLoading && (
                   <SidebarOpenView
                     sessions={sessions}
                     setSelectedViewField={setSelectedViewField}
@@ -345,6 +423,7 @@ export default function IOModal({
                     visibleSession={visibleSession}
                     selectedViewField={selectedViewField}
                     playgroundPage={!!playgroundPage}
+                    setActiveSession={setActiveSession}
                   />
                 )}
                 {sidebarOpen && showPublishOptions && (
@@ -383,7 +462,7 @@ export default function IOModal({
               </div>
             )}
             <div className="flex h-full min-w-96 flex-grow bg-background">
-              {selectedViewField && (
+              {selectedViewField && !sessionsLoading && (
                 <SelectedViewField
                   selectedViewField={selectedViewField}
                   setSelectedViewField={setSelectedViewField}

src/frontend/src/modals/IOModal/types/sidebar-open-view.ts

@@ -8,4 +8,5 @@ export type SidebarOpenViewProps = {
   visibleSession: string | undefined;
   selectedViewField: { type: string; id: string } | undefined;
   playgroundPage: boolean;
+  setActiveSession: (session: string) => void;
 };

src/frontend/src/stores/flowStore.ts

@@ -1061,6 +1061,10 @@ const useFlowStore = create<FlowStoreType>((set, get) => ({
     );
     set({ dismissedNodes: newDismissedNodes });
   },
+  setNewChatOnPlayground: (newChat: boolean) => {
+    set({ newChatOnPlayground: newChat });
+  },
+  newChatOnPlayground: false,
 }));
 
 export default useFlowStore;

src/frontend/src/types/zustand/flow/index.ts

@@ -285,4 +285,6 @@ export type FlowStoreType = {
   setCurrentBuildingNodeId: (nodeIds: string[] | undefined) => void;
   clearEdgesRunningByNodes: () => Promise<void>;
   updateToolMode: (nodeId: string, toolMode: boolean) => void;
+  newChatOnPlayground: boolean;
+  setNewChatOnPlayground: (newChat: boolean) => void;
 };

src/frontend/src/utils/utils.ts

@@ -902,3 +902,93 @@ export function getOS() {
 
   return os;
 }
+
+/**
+ * Encodes a session ID for safe URL transmission
+ * Handles both UUID format and date-time format session IDs
+ * @param {string} session_id - The session ID to encode
+ * @returns {string} The URL-encoded session ID
+ */
+export function encodeSessionId(session_id: string): string {
+  if (!session_id) return "";
+  // Use encodeURIComponent to properly encode spaces, commas, colons, etc.
+  return encodeURIComponent(session_id);
+}
+
+/**
+ * Decodes a session ID from URL encoding
+ * @param {string} encoded_session_id - The URL-encoded session ID
+ * @returns {string} The decoded session ID
+ */
+export function decodeSessionId(encoded_session_id: string): string {
+  if (!encoded_session_id) return "";
+  try {
+    return decodeURIComponent(encoded_session_id);
+  } catch (error) {
+    console.warn("Failed to decode session ID:", encoded_session_id, error);
+    return encoded_session_id; // Return as-is if decoding fails
+  }
+}
+
+/**
+ * Validates if a string is a valid UUID format
+ * @param {string} str - The string to validate
+ * @returns {boolean} True if the string is a valid UUID format
+ */
+export function isUUID(str: string): boolean {
+  const uuidRegex =
+    /^[0-9a-f]{8}-[0-9a-f]{4}-[1-5][0-9a-f]{3}-[89ab][0-9a-f]{3}-[0-9a-f]{12}$/i;
+  return uuidRegex.test(str);
+}
+
+/**
+ * Validates if a string is a date-time session format
+ * @param {string} str - The string to validate
+ * @returns {boolean} True if the string appears to be a date-time session format
+ */
+export function isDateTimeSession(str: string): boolean {
+  // Check for patterns like "Session Jun 16, 15:44:08" or similar
+  const dateTimeSessionRegex =
+    /^Session\s+\w{3}\s+\d{1,2},\s+\d{2}:\d{2}:\d{2}$/;
+  return dateTimeSessionRegex.test(str);
+}
+
+/**
+ * Formats and normalizes session IDs for consistent handling
+ * Handles both UUID format and date-time format session IDs
+ * @param {string} session_id - The session ID to format
+ * @returns {string} The formatted session ID
+ */
+export function sessionIdFormatted(session_id: string): string {
+  if (!session_id) return "";
+
+  // Decode if it appears to be URL encoded
+  let decodedId = session_id;
+  if (session_id.includes("%") || session_id.includes("+")) {
+    decodedId = decodeSessionId(session_id);
+  }
+
+  // If it's a UUID, return as-is (already in good format)
+  if (isUUID(decodedId)) {
+    return decodedId;
+  }
+
+  // If it's a date-time session, return as-is
+  if (isDateTimeSession(decodedId)) {
+    return decodedId;
+  }
+
+  // For any other format, return as-is but ensure it's properly trimmed
+  return decodedId.trim();
+}
+
+/**
+ * Safely prepares a session ID for API requests
+ * This function should be used when adding session_id to API parameters
+ * @param {string} session_id - The session ID to prepare
+ * @returns {string} The properly encoded session ID for API use
+ */
+export function prepareSessionIdForAPI(session_id: string): string {
+  const formatted = sessionIdFormatted(session_id);
+  return encodeSessionId(formatted);
+}