diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index 879f741e..61928441 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -23,7 +23,7 @@ jobs:
       max-parallel: 1
       matrix:
         os: [ubuntu-latest] # TODO: add windows and macos to matrix
-        python-version: ["3.10", "3.11", "3.12"]
+        python-version: ["3.11", "3.12"] # xopt >= 3.0 requires python >= 3.11
     env:
       DISPLAY: ':99.0'
       QT_MAC_WANTS_LAYER: 1  # PyQT gui tests involving qtbot interaction on macOS will fail without this
diff --git a/pyproject.toml b/pyproject.toml
index 8ab2e6a3..43569f42 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -31,7 +31,10 @@ dependencies = [
     "pillow",
     "requests",
     "xopt>=2.6.11",
+    "xopt @ git+https://github.com/xopt-org/Xopt.git@v3.0",
 ]
+# ^ temporarily point to xopt 3.0 brach for testing (revert b4 this patch gets merged to main)
+
 dynamic = ["version"]
 [tool.setuptools_scm]
 version_file = "src/badger/_version.py"
diff --git a/src/badger/core.py b/src/badger/core.py
index f889f335..dbb6bd40 100644
--- a/src/badger/core.py
+++ b/src/badger/core.py
@@ -9,6 +9,8 @@
 from badger.routine import Routine
 from badger.utils import curr_ts_to_str, dump_state
 
+from xopt.vocs import select_best
+
 
 def check_run_status(active_callback):
     while True:
@@ -25,7 +27,7 @@ def check_run_status(active_callback):
 def convert_to_solution(result: DataFrame, routine: Routine):
     vocs = routine.vocs
     try:
-        best_idx, _, _ = vocs.select_best(routine.sorted_data, n=1)
+        best_idx, _, _ = select_best(vocs, routine.sorted_data, n=1)
         if best_idx.size > 0:
             best_idx = int(best_idx[0])  # convert numpy array to int
             if best_idx != len(routine.data) - 1:
diff --git a/src/badger/core_subprocess.py b/src/badger/core_subprocess.py
index efb86ad8..7cc24209 100644
--- a/src/badger/core_subprocess.py
+++ b/src/badger/core_subprocess.py
@@ -14,6 +14,8 @@
 from badger.routine import Routine
 from badger.log import configure_process_logging
 from xopt.errors import FeasibilityError, XoptError
+from xopt.vocs import select_best
+
 
 logger = logging.getLogger(__name__)
 
@@ -30,7 +32,7 @@ def convert_to_solution(result: DataFrame, routine: Routine):
     """
     vocs = routine.vocs
     try:
-        best_idx, _, _ = vocs.select_best(routine.sorted_data, n=1)
+        best_idx, _, _ = select_best(vocs, routine.sorted_data, n=1)
         logger.debug(f"Selected best index: {best_idx}")
         if best_idx.size > 0:
             if best_idx[0] != len(routine.data) - 1:
diff --git a/src/badger/gui/components/env_cbox.py b/src/badger/gui/components/env_cbox.py
index 944f272d..40d3f61f 100644
--- a/src/badger/gui/components/env_cbox.py
+++ b/src/badger/gui/components/env_cbox.py
@@ -32,7 +32,9 @@
     NoHoverFocusComboBox,
 )
 from badger.utils import strtobool
-from xopt.vocs import VOCS, ConstraintEnum
+from xopt.vocs import VOCS
+from gest_api.vocs import ContinuousVariable
+
 import logging
 
 LABEL_WIDTH = 96
@@ -617,7 +619,7 @@ def compose_vocs(self) -> tuple[VOCS, list[str]]:
             (rule,) = objective[obj_name]
             objectives[obj_name] = rule
 
-        constraints: dict[str, list[float | ConstraintEnum]] = {}
+        constraints: dict[str, list[float]] = {}
         critical_constraints: list[str] = []
         for constraint in self.con_table.export_data():
             con_name = next(iter(constraint))
@@ -632,6 +634,10 @@ def compose_vocs(self) -> tuple[VOCS, list[str]]:
             observables.append(obs_name)
 
         try:
+            variables = {
+                k: list(v) if not isinstance(v, ContinuousVariable) else v
+                for k, v in variables.items()
+            }
             vocs = VOCS(
                 variables=variables,
                 objectives=objectives,
diff --git a/src/badger/gui/components/pydantic_editor.py b/src/badger/gui/components/pydantic_editor.py
index 044d70b2..6c1e8a39 100644
--- a/src/badger/gui/components/pydantic_editor.py
+++ b/src/badger/gui/components/pydantic_editor.py
@@ -560,7 +560,7 @@ def get_parameters_dict(self):
 
 
 class BadgerPydanticEditor(QTreeWidget):
-    vocs: VOCS = VOCS()
+    vocs: VOCS = VOCS(variables={})
     defaults: dict[str, Any] = {}
     generator_name: str = ""
     model_class: type[BaseModel] | None = None
@@ -687,7 +687,7 @@ def set_params_from_generator(
     ):
         logger.debug(f"vocs: {vocs}")
         logger.debug(f"defaults: {defaults}")
-        self.vocs = vocs or VOCS()
+        self.vocs = vocs or VOCS(variables={})
         self.generator_name = generator_name
         self.defaults = defaults
 
diff --git a/src/badger/gui/components/routine_page.py b/src/badger/gui/components/routine_page.py
index 45954175..a9fa5125 100644
--- a/src/badger/gui/components/routine_page.py
+++ b/src/badger/gui/components/routine_page.py
@@ -15,12 +15,14 @@
 from PyQt5.QtWidgets import QTableWidgetItem, QPlainTextEdit
 from coolname import generate_slug
 from xopt import VOCS
+from xopt.vocs import random_inputs
 from xopt.generators import (
     get_generator_defaults,
     all_generator_names,
     get_generator_dynamic,
 )
 from xopt.utils import get_local_region
+from gest_api.vocs import GreaterThanConstraint, LessThanConstraint
 from pydantic import ValidationError
 
 from badger.gui.components.generator_cbox import BadgerAlgoBox
@@ -66,21 +68,13 @@
     ts_float_to_str,
 )
 
+
 import logging
 
 logger = logging.getLogger(__name__)
 
-LABEL_WIDTH = 96
-CONS_RELATION_DICT = {
-    ">": "GREATER_THAN",
-    "<": "LESS_THAN",
-}
-CONS_RELATION_DICT_INV = {
-    "GREATER_THAN": ">",
-    "LESS_THAN": "<",
-}
 
-logger = logging.getLogger(__name__)
+LABEL_WIDTH = 96
 
 
 def format_validation_error(e: ValidationError) -> str:
@@ -93,6 +87,15 @@ def format_validation_error(e: ValidationError) -> str:
     return "\n".join(messages)
 
 
+def extract_constraint_symbol_and_value(constraint):
+    if isinstance(constraint, GreaterThanConstraint):
+        return ">", constraint.value
+    if isinstance(constraint, LessThanConstraint):
+        return "<", constraint.value
+    else:  # Expand for other constraints if needed
+        return "", 0
+
+
 class BadgerRoutinePage(QWidget):
     sig_updated = pyqtSignal(str, str)  # routine name, routine description
     sig_load_template = pyqtSignal(str)  # template path
@@ -523,9 +526,8 @@ def set_options_from_template(self, template_dict: dict[str, Any]):
             status[name] = False  # selected
             constraints.append(cons)
         for name, val in vocs.constraints.items():
-            relation, thres = val
+            relation, thres = extract_constraint_symbol_and_value(val)
             critical = name in critical_constraint_names
-            relation = CONS_RELATION_DICT_INV[relation]
 
             idx = constraints_names_full.index(name)
             if idx == -1:
@@ -876,9 +878,8 @@ def refresh_ui(self, routine: Routine | None = None, silent: bool = False):
             status[name] = False  # selected
             constraints.append(cons)
         for name, val in routine.vocs.constraints.items():
-            relation, thres = val
+            relation, thres = extract_constraint_symbol_and_value(val)
             critical = name in routine.critical_constraint_names
-            relation = CONS_RELATION_DICT_INV[relation]
 
             idx = constraints_names_full.index(name)
             if idx == -1:
@@ -1250,7 +1251,8 @@ def add_rand_in_init_table(self, add_rand_config=None, record=True):
         # get small region around current point to sample
         try:
             vocs, _ = self.env_box.compose_vocs()
-        except Exception:
+        except Exception as e:
+            print(str(e))
             # Switch to manual mode to allow the user fixing the vocs issue
             QMessageBox.warning(
                 self,
@@ -1264,8 +1266,8 @@ def add_rand_in_init_table(self, add_rand_config=None, record=True):
         random_sample_region = get_local_region(var_curr, vocs, fraction=fraction)
         with warnings.catch_warnings(record=True) as caught_warnings:
             try:
-                random_points = vocs.random_inputs(
-                    n_point, custom_bounds=random_sample_region
+                random_points = random_inputs(
+                    vocs, n_point, custom_bounds=random_sample_region
                 )
             except ValueError:
                 raise VariableRangeError(
diff --git a/src/badger/gui/components/run_monitor.py b/src/badger/gui/components/run_monitor.py
index 113c0873..4c7d0f9c 100644
--- a/src/badger/gui/components/run_monitor.py
+++ b/src/badger/gui/components/run_monitor.py
@@ -23,7 +23,7 @@
     QVBoxLayout,
     QWidget,
 )
-from xopt import VOCS
+from xopt.vocs import VOCS, normalize_inputs, select_best
 
 from badger.archive import archive_run, BADGER_ARCHIVE_ROOT
 from badger.gui.components.pydantic_editor import BadgerPydanticEditor
@@ -532,7 +532,7 @@ def update(self, results: pd.DataFrame) -> None:
 
     def update_curves(self, results=None):
         use_time_axis = self.plot_x_axis == 1
-        normalize_inputs = self.x_plot_y_axis == 1
+        norm_inputs = self.x_plot_y_axis == 1
 
         if results is not None:
             self.routine.data = results
@@ -552,8 +552,8 @@ def update_curves(self, results=None):
         variable_names = self.vocs.variable_names
 
         # if normalize x, normalize using vocs
-        if normalize_inputs:
-            input_data = self.vocs.normalize_inputs(data_copy)
+        if norm_inputs:
+            input_data = normalize_inputs(self.vocs, data_copy)
         else:
             input_data = data_copy[variable_names]
 
@@ -905,8 +905,8 @@ def load_checkpoint(self):
 
     def jump_to_optimal(self):
         try:
-            best_idx, _, _ = self.routine.vocs.select_best(
-                self.routine.sorted_data, n=1
+            best_idx, _, _ = select_best(
+                self.routine.vocs, self.routine.sorted_data, n=1
             )
             # print(best_idx, _)
             best_idx = int(best_idx[0])
diff --git a/src/badger/gui/components/var_table.py b/src/badger/gui/components/var_table.py
index 006c48ba..5773a18f 100644
--- a/src/badger/gui/components/var_table.py
+++ b/src/badger/gui/components/var_table.py
@@ -31,6 +31,8 @@
 from badger.errors import BadgerInterfaceChannelError
 from badger.gui.windows.expandable_message_box import ExpandableMessageBox
 
+from gest_api.vocs import ContinuousVariable
+
 import logging
 
 logger = logging.getLogger(__name__)
@@ -309,7 +311,9 @@ def _convert_bounds_to_tuple(self, bounds: Any) -> dict[str, tuple[float, float]
         return {k: (v[0], v[1]) for k, v in bounds.items()}
 
     def update_variables(
-        self, variables: list[dict[str, tuple[float, float]]], filtered: int = 0
+        self,
+        variables: list[dict[str, tuple[float, float] | ContinuousVariable]],
+        filtered: int = 0,
     ):
         # filtered = 0: completely refresh
         # filtered = 1: filtered by keyword
@@ -364,12 +368,22 @@ def update_variables(
             self.setItem(i, 1, item)
 
             _bounds = self.bounds[name]
+            default_val = (
+                _bounds.domain[0]
+                if isinstance(_bounds, ContinuousVariable)
+                else _bounds[0]
+            )
             sb_lower = RobustSpinBox(
-                default_value=_bounds[0], lower_bound=vrange[0], upper_bound=vrange[1]
+                default_value=default_val, lower_bound=vrange[0], upper_bound=vrange[1]
             )
             sb_lower.valueChanged.connect(self.update_bounds)
+            default_val = (
+                _bounds.domain[1]
+                if isinstance(_bounds, ContinuousVariable)
+                else _bounds[0]
+            )
             sb_upper = RobustSpinBox(
-                default_value=_bounds[1], lower_bound=vrange[0], upper_bound=vrange[1]
+                default_value=default_val, lower_bound=vrange[0], upper_bound=vrange[1]
             )
             sb_upper.valueChanged.connect(self.update_bounds)
             self.setCellWidget(i, 2, sb_lower)
diff --git a/src/badger/settings.py b/src/badger/settings.py
index 7438f9d8..184529fe 100644
--- a/src/badger/settings.py
+++ b/src/badger/settings.py
@@ -157,7 +157,11 @@ def load_or_create_config(cls, config_path: str) -> BadgerConfig:
 
             # Convert each entry in config_data to an instance of Setting
             for key, value in config_data.items():
-                if isinstance(value, dict) and "value" in value:
+                if isinstance(value, dict):
+                    value_arg = None
+                    if "value" in value:
+                        value_arg = value["value"]
+
                     # Convert to Setting instance
                     config_data[key] = Setting(
                         display_name=value.get("display_name", key),
@@ -165,7 +169,7 @@ def load_or_create_config(cls, config_path: str) -> BadgerConfig:
                             "description",
                             f"Setting for {key.replace('_', ' ').lower()}",
                         ),
-                        value=value["value"],
+                        value=value_arg,
                         is_path=value.get("is_path", key),
                     )
                 else:
diff --git a/src/badger/tests/test_factory.py b/src/badger/tests/test_factory.py
index ef9ab54a..74732d57 100644
--- a/src/badger/tests/test_factory.py
+++ b/src/badger/tests/test_factory.py
@@ -3,6 +3,7 @@
 
 from xopt.generators import get_generator, get_generator_defaults
 from xopt.resources.testing import TEST_VOCS_BASE
+from gest_api.vocs import ExploreObjective
 
 
 class TestFactory:
@@ -16,7 +17,7 @@ def test_generator_generation(self):
             gen_config = get_generator_defaults(name)
             gen_class = get_generator(name)
 
-            if name in ["mobo"]:
+            if name == "mobo":
                 test_vocs = deepcopy(TEST_VOCS_BASE)
                 test_vocs.objectives = {"y1": "MINIMIZE", "y2": "MINIMIZE"}
                 gen_config["reference_point"] = {"y1": 10.0, "y2": 1.0}
@@ -29,12 +30,17 @@ def test_generator_generation(self):
                 json.dumps(gen_config)
 
                 gen_class(vocs=test_vocs, **gen_config)
-            elif name in ["bayesian_exploration"]:
+            elif name == "bayesian_exploration":
                 test_vocs = deepcopy(TEST_VOCS_BASE)
                 test_vocs.objectives = {}
                 test_vocs.observables = ["f"]
                 json.dumps(gen_config)
-
+                gen_class(vocs=test_vocs, **gen_config)
+            elif name == "latin_hypercube":
+                test_vocs = deepcopy(TEST_VOCS_BASE)
+                test_vocs.objectives = {
+                    k: ExploreObjective() for k in test_vocs.objectives.keys()
+                }
                 gen_class(vocs=test_vocs, **gen_config)
             else:
                 json.dumps(gen_config)
diff --git a/src/badger/tests/test_routine_page.py b/src/badger/tests/test_routine_page.py
index 8d2be96e..bcee0c60 100644
--- a/src/badger/tests/test_routine_page.py
+++ b/src/badger/tests/test_routine_page.py
@@ -1,8 +1,15 @@
+import json
 import pandas as pd
 import pytest
 from pytestqt.qtbot import QtBot
 from PyQt5.QtCore import Qt, QTimer
 from PyQt5.QtWidgets import QApplication
+from gest_api.vocs import (
+    LessThanConstraint,
+    ContinuousVariable,
+    MinimizeObjective,
+    Observable,
+)
 
 
 def test_routine_page_init(qtbot: QtBot):
@@ -60,8 +67,10 @@ def test_routine_generation(qtbot: QtBot):
     qtbot.mouseClick(window.env_box.btn_add_curr, Qt.LeftButton)
 
     routine = window._compose_routine()
-    assert routine.vocs.variables == {"x0": (-1, 1)}
-    assert routine.vocs.objectives == {"f": "MINIMIZE"}
+    assert routine.vocs.variables == {
+        "x0": ContinuousVariable(dtype=None, default_value=None, domain=[-1.0, 1.0])
+    }
+    assert routine.vocs.objectives == {"f": MinimizeObjective(dtype=None)}
     # assert routine.initial_points.empty
 
     # Test if badger and xopt version match with the current version
@@ -156,10 +165,21 @@ def test_ui_update(qtbot: QtBot):
     idx = window.generators.index(routine.generator.name)
     window.select_generator(idx)
 
-    assert (
-        window.generator_box.edit.get_parameters_yaml()
-        == '{"vocs":{"variables":{"x0":"(-1.0, 1.0)","x1":"(-1.0, 1.0)","x2":"(-1.0, 1.0)","x3":"(-1.0, 1.0)"},"constraints":{"c":"(\'GREATER_THAN\', 0.0)"},"objectives":{"f":"MAXIMIZE"},"constants":{},"observables":[]}}'
-    )
+    expected_params = {
+        "returns_id": False,
+        "vocs": {
+            "variables": "{'x0': {'dtype': None, 'default_value': None, 'domain': [-1.0, 1.0], 'type': 'ContinuousVariable'}, "
+            "'x1': {'dtype': None, 'default_value': None, 'domain': [-1.0, 1.0], 'type': 'ContinuousVariable'}, "
+            "'x2': {'dtype': None, 'default_value': None, 'domain': [-1.0, 1.0], 'type': 'ContinuousVariable'}, "
+            "'x3': {'dtype': None, 'default_value': None, 'domain': [-1.0, 1.0], 'type': 'ContinuousVariable'}}",
+            "constraints": "{'c': {'dtype': None, 'value': 0.0, 'type': 'GreaterThanConstraint'}}",
+            "objectives": "{'f': {'dtype': None, 'type': 'MaximizeObjective'}}",
+            "constants": "{}",
+            "observables": "{}",
+        },
+    }
+    actual_params = json.loads(window.generator_box.edit.get_parameters_yaml())
+    assert actual_params == expected_params
 
 
 def test_constraints(qtbot: QtBot):
@@ -181,7 +201,7 @@ def test_constraints(qtbot: QtBot):
     con_widget_critical.setChecked(True)
 
     routine = window._compose_routine()
-    assert routine.vocs.constraints == {"c": ("LESS_THAN", 0.0)}
+    assert routine.vocs.constraints == {"c": LessThanConstraint(dtype=None, value=0.0)}
     assert routine.critical_constraint_names == ["c"]
 
 
@@ -204,7 +224,7 @@ def test_observables(qtbot: QtBot):
     window.env_box.sta_table.cellWidget(1, 0).setChecked(True)
 
     routine = window._compose_routine()
-    assert routine.vocs.observables == ["c"]
+    assert routine.vocs.observables == {"c": Observable(dtype=None)}
 
 
 def test_add_random_points(qtbot: QtBot):