diff --git a/causy/cli.py b/causy/cli.py
index f1ade70..caa2cc8 100644
--- a/causy/cli.py
+++ b/causy/cli.py
@@ -30,6 +30,10 @@
 
 @app.command()
 def eject(algorithm: str, output_file: str):
+    logging.warning(
+        f"Ejecting pipelines outside of workspace context is deprecated. Please use workspaces instead."
+    )
+
     typer.echo(f"💾 Loading algorithm {algorithm}")
     model = AVAILABLE_ALGORITHMS[algorithm]()
     result = serialize_algorithm(model, algorithm_name=algorithm)
@@ -46,6 +50,9 @@ def execute(
     output_file: str = None,
     log_level: str = "ERROR",
 ):
+    logging.warning(
+        f"Executing outside of workspaces is deprecated and will be removed in future versions. Please use workspaces instead."
+    )
     logging.basicConfig(level=log_level)
     if pipeline:
         typer.echo(f"💾 Loading pipeline from {pipeline}")
diff --git a/causy/graph.py b/causy/graph.py
index 41a1c1f..c8242ae 100644
--- a/causy/graph.py
+++ b/causy/graph.py
@@ -13,8 +13,10 @@
     NodeInterface,
     EdgeInterface,
     EdgeTypeInterface,
+    MetadataType,
 )
 from causy.models import TestResultAction, TestResult, ActionHistoryStep
+from causy.variables import VariableType
 
 logger = logging.getLogger(__name__)
 
@@ -28,7 +30,7 @@ class Node(NodeInterface):
     name: str
     id: str
     values: Optional[torch.Tensor] = None
-    metadata: Optional[Dict[str, Any]] = None
+    metadata: Optional[Dict[str, MetadataType]] = None
 
     def __hash__(self):
         return hash(self.id)
@@ -46,7 +48,7 @@ class Edge(EdgeInterface):
     u: NodeInterface
     v: NodeInterface
     edge_type: EdgeTypeInterface
-    metadata: Optional[Dict[str, Any]] = None
+    metadata: Optional[Dict[str, MetadataType]] = None
     deleted: Optional[bool] = False
 
     def __init__(self, *args, **kwargs):
diff --git a/causy/graph_model.py b/causy/graph_model.py
index 6d389fa..09d3368 100644
--- a/causy/graph_model.py
+++ b/causy/graph_model.py
@@ -3,7 +3,7 @@
 from abc import ABC
 from copy import deepcopy
 import time
-from typing import Optional, List, Dict, Callable, Union, Any
+from typing import Optional, List, Dict, Callable, Union, Any, Generator
 
 import torch.multiprocessing as mp
 
@@ -21,6 +21,8 @@
 from causy.variables import (
     resolve_variables_to_algorithm_for_pipeline_steps,
     resolve_variables,
+    VariableType,
+    VariableTypes,
 )
 
 logger = logging.getLogger(__name__)
@@ -188,19 +190,26 @@ def create_all_possible_edges(self):
                     continue
                 self.graph.add_edge(u, v, {})
 
-    def execute_pipeline_steps(self):
+    def execute_pipeline_steps(self) -> List[ActionHistoryStep]:
         """
         Execute all pipeline_steps
         :return: the steps taken during the step execution
         """
+        all(self.execute_pipeline_step_with_progress())
+        return self.graph.action_history
 
+    def execute_pipeline_step_with_progress(self) -> Generator:
+        started = time.time()
         for filter in self.pipeline_steps:
             logger.info(f"Executing pipeline step {filter.__class__.__name__}")
             if isinstance(filter, LogicStepInterface):
                 actions_taken = filter.execute(self.graph.graph, self)
                 self.graph.graph.action_history.append(actions_taken)
                 continue
-
+            yield {
+                "step": filter.__class__.__name__,
+                "previous_duration": time.time() - started,
+            }
             started = time.time()
             actions_taken = self.execute_pipeline_step(filter)
             self.graph.graph.action_history.append(
@@ -213,8 +222,6 @@ def execute_pipeline_steps(self):
 
             self.graph.purge_soft_deleted_edges()
 
-        return self.graph.action_history
-
     def _format_yield(self, test_fn, graph, generator):
         """
         Format the yield for the parallel processing
@@ -386,7 +393,7 @@ def execute_pipeline_step(
 
 def graph_model_factory(
     algorithm: Algorithm = None,
-    variables: Dict[str, Any] = None,
+    variables: Dict[str, VariableTypes] = None,
 ) -> type[AbstractGraphModel]:
     """
     Create a graph model based on a List of pipeline_steps
diff --git a/causy/interfaces.py b/causy/interfaces.py
index 543b14e..9c4483a 100644
--- a/causy/interfaces.py
+++ b/causy/interfaces.py
@@ -24,6 +24,11 @@
 
 AS_MANY_AS_FIELDS = 0
 
+MetadataBaseType = Union[str, int, float, bool]
+MetadataType = Union[
+    str, int, float, bool, List[MetadataBaseType], Dict[str, MetadataBaseType]
+]
+
 
 class ComparisonSettingsInterface(BaseModel, ABC):
     min: IntegerParameter
@@ -85,7 +90,7 @@ class EdgeInterface(BaseModel, ABC):
     u: NodeInterface
     v: NodeInterface
     edge_type: EdgeTypeInterface
-    metadata: Dict[str, any] = None
+    metadata: Dict[str, MetadataType] = None
 
     class Config:
         arbitrary_types_allowed = True
diff --git a/causy/serialization.py b/causy/serialization.py
index a47dd6d..d907434 100644
--- a/causy/serialization.py
+++ b/causy/serialization.py
@@ -3,12 +3,13 @@
 import importlib
 import json
 from json import JSONEncoder
-from typing import Dict, Any
+from typing import Dict, Any, List
 import os
 
 import torch
 import yaml
-from pydantic import parse_obj_as
+from pydantic import TypeAdapter
+
 
 from causy.edge_types import EDGE_TYPES
 from causy.graph_utils import load_pipeline_steps_by_definition
@@ -38,7 +39,7 @@ def load_algorithm_from_specification(algorithm_dict: Dict[str, Any]):
     ]
     from causy.models import Algorithm
 
-    return parse_obj_as(Algorithm, algorithm_dict)
+    return TypeAdapter(Algorithm).validate_python(algorithm_dict)
 
 
 def load_algorithm_by_reference(reference_type: str, algorithm: str):
@@ -102,4 +103,5 @@ def deserialize_result(result: Dict[str, Any], klass=Result):
         result["edges"][i]["edge_type"] = EDGE_TYPES[edge["edge_type"]["name"]](
             **edge["edge_type"]
         )
-    return parse_obj_as(klass, result)
+
+    return TypeAdapter(klass).validate_python(result)
diff --git a/causy/ui/server.py b/causy/ui/server.py
index f75ac7e..202f3bb 100644
--- a/causy/ui/server.py
+++ b/causy/ui/server.py
@@ -182,6 +182,13 @@ def _set_workspace(workspace: Workspace):
     WORKSPACE = workspace
 
 
+def is_port_in_use(host: str, port: int) -> bool:
+    import socket
+
+    with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s:
+        return s.connect_ex((host, port)) == 0
+
+
 def server(result: Dict[str, Any] = None, workspace: Workspace = None):
     """Create the FastAPI server."""
     app = _create_ui_app()
@@ -196,7 +203,16 @@ def server(result: Dict[str, Any] = None, workspace: Workspace = None):
         raise ValueError("No model or workspace provided")
 
     host = os.getenv("HOST", "localhost")
-    port = int(os.getenv("PORT", "8000"))
+    is_port_from_env = os.getenv("PORT")
+    if is_port_from_env:
+        port = int(is_port_from_env)
+    else:
+        port = int(os.getenv("PORT", "8000"))
+        while is_port_in_use(host, port):
+            port += 1
+            if port > 65535:
+                raise ValueError("No free port available")
+
     cors_enabled = os.getenv("CORS_ENABLED", "false").lower() == "true"
 
     # cors e.g. for development of separate frontend
diff --git a/causy/variables.py b/causy/variables.py
index 2d3236f..1b74d31 100644
--- a/causy/variables.py
+++ b/causy/variables.py
@@ -8,6 +8,8 @@
 
 VariableInterfaceType = TypeVar("VariableInterfaceType")
 
+VariableType = Union[str, int, float, bool]
+
 
 class VariableTypes(enum.Enum):
     String = "string"
@@ -149,7 +151,7 @@ def type(self) -> str:
 CausyParameter = Union[BoolParameter, IntegerParameter, FloatParameter, StringParameter]
 
 
-def validate_variable_values(algorithm, variable_values: Dict[str, Any]):
+def validate_variable_values(algorithm, variable_values: Dict[str, VariableType]):
     """
     Validate the variable values for the algorithm.
     :param algorithm:
@@ -169,8 +171,8 @@ def validate_variable_values(algorithm, variable_values: Dict[str, Any]):
 
 
 def resolve_variables(
-    variables: List[BaseVariable], variable_values: Dict[str, Any]
-) -> Dict[str, Any]:
+    variables: List[BaseVariable], variable_values: Dict[str, VariableType]
+) -> Dict[str, VariableType]:
     """
     Resolve the variables from the list of variables and the variable values coming from the user.
     :param variables:
@@ -225,7 +227,7 @@ def resolve_variables_to_algorithm_for_pipeline_steps(pipeline_steps, variables)
     return pipeline_steps
 
 
-def deserialize_variable(variable_dict: Dict[str, Any]) -> BaseVariable:
+def deserialize_variable(variable_dict: Dict[str, VariableType]) -> BaseVariable:
     """
     Deserialize the variable from the dictionary.
     :param variable_dict:
diff --git a/causy/workspaces/cli.py b/causy/workspaces/cli.py
index 01206e7..f486b7b 100644
--- a/causy/workspaces/cli.py
+++ b/causy/workspaces/cli.py
@@ -21,6 +21,7 @@
     PackageLoader,
 )
 from rich.console import Console
+from rich.progress import Progress, SpinnerColumn, TextColumn
 from rich.table import Table
 
 from causy.graph_model import graph_model_factory
@@ -280,7 +281,26 @@ def _execute_experiment(workspace: Workspace, experiment: Experiment) -> Result:
     model = graph_model_factory(pipeline, experiment.variables)()
     model.create_graph_from_data(data_loader)
     model.create_all_possible_edges()
-    model.execute_pipeline_steps()
+    task_count = len(model.pipeline_steps)
+    current = 0
+    with Progress(
+        SpinnerColumn(),
+        TextColumn("[progress.description]{task.description}"),
+        transient=True,
+    ) as progress:
+        prev_task = None
+        prev_task_data = None
+        for task in model.execute_pipeline_step_with_progress():
+            current += 1
+            if prev_task is not None:
+                progress.update(
+                    prev_task,
+                    completed=True,
+                    current=1,
+                    description=f"✅ {prev_task_data['step']} ({round(task['previous_duration'])}s)",
+                )
+            prev_task = progress.add_task(description=task["step"], total=1)
+            prev_task_data = task
 
     return Result(
         algorithm=workspace.pipelines[experiment.pipeline],
@@ -650,10 +670,12 @@ def init():
                 "Enter the name of the data loader"
             ).ask()
             data_loader_slug = slugify(data_loader_name, "_")
-            workspace.dataloaders[data_loader_slug] = {
-                "type": data_loader_type,
-                "reference": data_loader_path,
-            }
+            workspace.dataloaders[data_loader_slug] = DataLoaderReference(
+                **{
+                    "type": data_loader_type,
+                    "reference": data_loader_path,
+                }
+            )
         elif data_loader_type == "dynamic":
             data_loader_name = questionary.text(
                 "Enter the name of the data loader"
diff --git a/causy/workspaces/models.py b/causy/workspaces/models.py
index 18d881f..f404ab3 100644
--- a/causy/workspaces/models.py
+++ b/causy/workspaces/models.py
@@ -1,9 +1,10 @@
-from typing import Optional, Dict, Any
+from typing import Optional, Dict
 
 from pydantic import BaseModel
 
 from causy.data_loader import DataLoaderReference
 from causy.models import AlgorithmReference, Algorithm
+from causy.variables import VariableType
 
 
 class Experiment(BaseModel):
@@ -15,7 +16,7 @@ class Experiment(BaseModel):
 
     pipeline: str
     dataloader: str
-    variables: Optional[Dict[str, Any]] = None
+    variables: Optional[Dict[str, VariableType]]
 
 
 class Workspace(BaseModel):
diff --git a/poetry.lock b/poetry.lock
index 88ec134..b8b354a 100644
--- a/poetry.lock
+++ b/poetry.lock
@@ -1,4 +1,4 @@
-# This file is automatically @generated by Poetry 1.8.3 and should not be changed by hand.
+# This file is automatically @generated by Poetry 1.6.1 and should not be changed by hand.
 
 [[package]]
 name = "annotated-types"
@@ -863,13 +863,13 @@ files = [
 
 [[package]]
 name = "pdoc"
-version = "14.4.0"
+version = "14.5.1"
 description = "API Documentation for Python Projects"
 optional = false
 python-versions = ">=3.8"
 files = [
-    {file = "pdoc-14.4.0-py3-none-any.whl", hash = "sha256:6ea4fe07620b1f7601e2708a307a257636ec206e20b5611640b30f2e3cab47d6"},
-    {file = "pdoc-14.4.0.tar.gz", hash = "sha256:c92edc425429ccbe287ace2a027953c24f13de53eab484c1a6d31ca72dd2fda9"},
+    {file = "pdoc-14.5.1-py3-none-any.whl", hash = "sha256:fda6365a06e438b43ca72235b58a2e2ecd66445fcc444313f6ebbde4b0abd94b"},
+    {file = "pdoc-14.5.1.tar.gz", hash = "sha256:4ddd9c5123a79f511cedffd7231bf91a6e0bd0968610f768342ec5d00b5eefee"},
 ]
 
 [package.dependencies]
diff --git a/tests/utils.py b/tests/utils.py
index 39bde51..b473334 100644
--- a/tests/utils.py
+++ b/tests/utils.py
@@ -1,11 +1,12 @@
 import json
 import random
+from typing import List
 from unittest import TestCase
 from unittest.util import safe_repr
 
 import numpy as np
 import torch
-from pydantic import parse_obj_as
+from pydantic import TypeAdapter
 
 from causy.graph import Graph
 from causy.serialization import CausyJSONEncoder
@@ -25,7 +26,7 @@ def dump_fixture_graph(graph, file_path):
 def load_fixture_graph(file_path):
     with open(file_path, "r") as f:
         data = json.loads(f.read())
-        return parse_obj_as(Graph, data)
+        return TypeAdapter(Graph).validate_python(data)
 
 
 class CausyTestCase(TestCase):