diff --git a/openbb_platform/core/openbb_core/api/router/commands.py b/openbb_platform/core/openbb_core/api/router/commands.py
index c6a2f06b2d8..2ed68123fe7 100644
--- a/openbb_platform/core/openbb_core/api/router/commands.py
+++ b/openbb_platform/core/openbb_core/api/router/commands.py
@@ -7,8 +7,11 @@ from inspect import Parameter, Signature, signature
 from typing import Annotated, Any, TypeVar
 
 from fastapi import APIRouter, Depends, Header
+from fastapi.encoders import jsonable_encoder
+from fastapi.responses import JSONResponse
 from fastapi.routing import APIRoute
 from openbb_core.app.command_runner import CommandRunner
+from openbb_core.app.model.abstract.error import OpenBBError
 from openbb_core.app.model.command_context import CommandContext
 from openbb_core.app.model.obbject import OBBject
 from openbb_core.app.model.user_settings import UserSettings
@@ -140,7 +143,7 @@ def validate_output(c_out: OBBject) -> OBBject:
 
     def exclude_fields_from_api(key: str, value: Any):
         type_ = type(value)
-        field = c_out.model_fields.get(key, None)
+        field = getattr(type(c_out), "model_fields", {}).get(key, None)
         json_schema_extra = field.json_schema_extra if field else None
 
         # case where 1st layer field needs to be excluded
@@ -198,7 +201,9 @@ def build_api_wrapper(
         route.response_model = None
 
     @wraps(wrapped=func)
-    async def wrapper(*args: tuple[Any], **kwargs: dict[str, Any]) -> OBBject:
+    async def wrapper(
+        *args: tuple[Any], **kwargs: dict[str, Any]
+    ) -> OBBject | JSONResponse:
         user_settings: UserSettings = UserSettings.model_validate(
             kwargs.pop(
                 "__authenticated_user_settings",
@@ -213,7 +218,7 @@ def build_api_wrapper(
         )
 
         if defaults:
-            _provider = defaults.pop("provider", None)
+            _ = defaults.pop("provider", None)
             standard_params = getattr(
                 kwargs.pop("standard_params", None), "__dict__", {}
             )
@@ -243,6 +248,23 @@ def build_api_wrapper(
         execute = partial(command_runner.run, path, user_settings)
         output = await execute(*args, **kwargs)
 
+        # This is where we check for `on_command_output` extensions
+        mutated_output = getattr(output, "_extension_modified", False)
+        results_only = getattr(output, "_results_only", False)
+        try:
+            if results_only is True:
+                content = output.model_dump(exclude_unset=True).get("results", [])
+                return JSONResponse(content=jsonable_encoder(content), status_code=200)
+
+            if (mutated_output and isinstance(output, OBBject)) or (
+                isinstance(output, OBBject) and no_validate
+            ):
+                return JSONResponse(content=jsonable_encoder(output), status_code=200)
+        except Exception as exc:  # pylint: disable=W0703
+            raise OpenBBError(
+                f"Error serializing output for an extension-modified endpoint {path}: {exc}",
+            ) from exc
+
         if isinstance(output, OBBject) and not no_validate:
             return validate_output(output)
 
diff --git a/openbb_platform/core/openbb_core/app/command_runner.py b/openbb_platform/core/openbb_core/app/command_runner.py
index 6a96dc800b4..2c3c2ad487b 100644
--- a/openbb_platform/core/openbb_core/app/command_runner.py
+++ b/openbb_platform/core/openbb_core/app/command_runner.py
@@ -6,12 +6,13 @@ from collections.abc import Callable
 from copy import deepcopy
 from dataclasses import asdict, is_dataclass
 from datetime import datetime
-from inspect import Parameter, signature
+from inspect import Parameter, iscoroutinefunction, signature
 from sys import exc_info
 from time import perf_counter_ns
 from typing import TYPE_CHECKING, Any, Optional
 from warnings import catch_warnings, showwarning, warn
 
+from openbb_core.app.extension_loader import ExtensionLoader
 from openbb_core.app.model.abstract.error import OpenBBError
 from openbb_core.app.model.abstract.warning import OpenBBWarning, cast_warning
 from openbb_core.app.model.metadata import Metadata
@@ -272,6 +273,7 @@ class StaticCommandRunner:
 
             if chart_params:
                 kwargs.update(chart_params)
+
             obbject.charting.show(render=False, **kwargs)  # type: ignore[attr-defined]
         except Exception as e:  # pylint: disable=broad-exception-caught
             if Env().DEBUG_MODE:
@@ -311,6 +313,9 @@ class StaticCommandRunner:
                 # in the charting extension then we add it there. This way we can remove
                 # the chart parameter from the commands.py and package_builder, it will be
                 # added to the function signature in the router decorator
+                # If the ProviderInterface is not in use, we need to pass a copy of the
+                # kwargs dictionary before it is validated, otherwise we lose those items.
+                kwargs_copy = deepcopy(kwargs)
                 chart = kwargs.pop("chart", False)
 
                 kwargs = ParametersBuilder.build(
@@ -348,7 +353,21 @@ class StaticCommandRunner:
                         extra_params
                     )
                     if chart and obbject.results:
-                        cls._chart(obbject, **kwargs)
+                        if "extra_params" not in kwargs_copy:
+                            kwargs_copy["extra_params"] = {}
+                        # Restore any kwargs passed that were removed by the ParametersBuilder
+                        for k in kwargs_copy.copy():
+                            if k == "chart":
+                                kwargs_copy.pop("chart", None)
+                                continue
+                            if (
+                                not extra_params or k not in extra_params
+                            ) and k != "extra_params":
+                                kwargs_copy["extra_params"][k] = kwargs_copy.pop(
+                                    k, None
+                                )
+
+                        cls._chart(obbject, **kwargs_copy)
 
                 raised_warnings = warning_list if warning_list else []
         finally:
@@ -429,8 +448,79 @@ class StaticCommandRunner:
                     raise OpenBBError(e) from e
                 warn(str(e), OpenBBWarning)
 
+        try:
+            cls._trigger_command_output_callbacks(route, obbject)
+
+        except Exception as e:
+            if Env().DEBUG_MODE:
+                raise OpenBBError(e) from e
+            warn(str(e), OpenBBWarning)
+
         return obbject
 
+    @classmethod
+    def _trigger_command_output_callbacks(cls, route: str, obbject: OBBject) -> None:
+        """Trigger command output callbacks for extensions."""
+        loader = ExtensionLoader()
+        callbacks = loader.on_command_output_callbacks
+        results_only = False
+
+        # For each extension registered for all routes or the specific route,
+        # we call its accessor on the OBBject.
+        # We check if the accessor is immutable or not to decide whether to pass
+        # a copy of the OBBject or the original one.
+        # We set the _extension_modified attribute to True if any extension
+        # mutates the OBBject so we can pass this information to the interface.
+        # We also set the _results_only attribute to True if any extension
+        # indicates that only results should be returned.
+        if "*" in callbacks:
+            for ext in callbacks["*"]:
+                if ext.results_only is True:
+                    results_only = True
+                if ext.immutable is True:
+                    if hasattr(obbject, ext.name):
+                        obbject_copy = deepcopy(obbject)
+                        accessor = getattr(obbject_copy, ext.name)
+                        if iscoroutinefunction(accessor):
+                            run_async(accessor)
+                        elif callable(accessor):
+                            accessor()
+                elif ext.immutable is False:
+                    if ext.results_only is True:
+                        results_only = True
+                    if hasattr(obbject, ext.name):
+                        accessor = getattr(obbject, ext.name)
+                        if iscoroutinefunction(accessor):
+                            run_async(accessor)
+                        elif callable(accessor):
+                            accessor()
+                        setattr(obbject, "_extension_modified", True)
+
+        if route in callbacks:
+            for ext in callbacks[route]:
+                if ext.results_only is True:
+                    results_only = True
+
+                if ext.immutable is True:
+                    if hasattr(obbject, ext.name):
+                        obbject_copy = deepcopy(obbject)
+                        accessor = getattr(obbject_copy, ext.name)
+                        if iscoroutinefunction(accessor):
+                            run_async(accessor)
+                        elif callable(accessor):
+                            accessor()
+                elif ext.immutable is False and hasattr(obbject, ext.name):
+                    accessor = getattr(obbject, ext.name)
+                    if iscoroutinefunction(accessor):
+                        run_async(accessor)
+                    elif callable(accessor):
+                        accessor()
+                    setattr(obbject, "_extension_modified", True)
+
+        if results_only is True:
+            setattr(obbject, "_results_only", True)
+            setattr(obbject, "_extension_modified", True)
+
 
 class CommandRunner:
     """Command runner."""
diff --git a/openbb_platform/core/openbb_core/app/extension_loader.py b/openbb_platform/core/openbb_core/app/extension_loader.py
index 35938c59db6..4db8abea77a 100644
--- a/openbb_platform/core/openbb_core/app/extension_loader.py
+++ b/openbb_platform/core/openbb_core/app/extension_loader.py
@@ -49,6 +49,23 @@ class ExtensionLoader(metaclass=SingletonMeta):
         self._obbject_objects: dict[str, Extension] = {}
         self._core_objects: dict[str, Router] = {}
         self._provider_objects: dict[str, Provider] = {}
+        self._on_command_output_callbacks: dict[str, list[Extension]] = {}
+        self._register_command_output_callbacks()
+
+    @property
+    def on_command_output_callbacks(self) -> dict[str, list[Extension]]:
+        """Return the on command output callbacks."""
+        return self._on_command_output_callbacks
+
+    def _register_command_output_callbacks(self) -> None:
+        """Register extensions that act on command output."""
+        for ext in self.obbject_objects.values():
+            if ext.on_command_output:
+                paths = ext.command_output_paths or ["*"]
+                for path in paths:
+                    if path not in self._on_command_output_callbacks:
+                        self._on_command_output_callbacks[path] = []
+                    self._on_command_output_callbacks[path].append(ext)
 
     @property
     def obbject_entry_points(self) -> EntryPoints:
diff --git a/openbb_platform/core/openbb_core/app/model/abstract/tagged.py b/openbb_platform/core/openbb_core/app/model/abstract/tagged.py
index 80cfe1678e0..df250a8d9bd 100644
--- a/openbb_platform/core/openbb_core/app/model/abstract/tagged.py
+++ b/openbb_platform/core/openbb_core/app/model/abstract/tagged.py
@@ -1,10 +1,10 @@
 """OpenBB Core App Abstract Model Tagged."""
 
 from pydantic import BaseModel, Field
-from uuid_extensions import uuid7str  # type: ignore
+from uuid_extensions import uuid7str
 
 
 class Tagged(BaseModel):
     """Model for Tagged."""
 
-    id: str = Field(default_factory=uuid7str, alias="_id")
+    id: str = Field(default_factory=uuid7str)
diff --git a/openbb_platform/core/openbb_core/app/model/extension.py b/openbb_platform/core/openbb_core/app/model/extension.py
index 1f4f3357f7c..a6edb731c8e 100644
--- a/openbb_platform/core/openbb_core/app/model/extension.py
+++ b/openbb_platform/core/openbb_core/app/model/extension.py
@@ -8,14 +8,19 @@ class Extension:
     """
     Serves as OBBject extension entry point and must be created by each extension package.
 
-    See https://docs.openbb.co/platform/development/developer-guidelines/obbject_extensions.
+    See https://docs.openbb.co/developer/extension_types/obbject for more information.
     """
 
+    # pylint: disable=R0917
     def __init__(
         self,
         name: str,
         credentials: list[str] | None = None,
         description: str | None = None,
+        on_command_output: bool = False,
+        command_output_paths: list[str] | None = None,
+        immutable: bool = True,
+        results_only: bool = False,
     ) -> None:
         """Initialize the extension.
 
@@ -23,20 +28,76 @@ class Extension:
         ----------
         name : str
             Name of the extension.
-        credentials : Optional[List[str]], optional
+        credentials : list[str], optional
             List of required credentials, by default None
         description: Optional[str]
             Extension description.
+        on_command_output : bool, optional
+            Whether the extension acts on command output, by default False
+        command_output_paths : list[str], optional
+            List of endpoint paths the extension acts on, where None means all, by default None.
+        immutable : bool, optional
+            Whether the function output is immutable, by default True.
+        results_only : bool, optional
+            Whether the extension returns only the results instead of the OBBject, by default False.
         """
+        # pylint: disable=import-outside-toplevel
+        from openbb_core.app.service.system_service import SystemService
+
         self.name = name
         self.credentials = credentials or []
         self.description = description
+        self.on_command_output = on_command_output
+        self.command_output_paths = command_output_paths or []
+        self.immutable = immutable
+        self.results_only = results_only
+
+        # This must be explicitly enabled.
+        if self.on_command_output is False and (
+            self.command_output_paths
+            or self.results_only is True
+            or self.immutable is False
+        ):
+            raise ValueError(
+                "OBBject Extension Error -> 'on_command_output' must be set as True when"
+                + " 'command_output_paths', 'results_only' or 'immutable' is set.",
+            )
+
+        # The user must explicitly enable OBBject extensions that act on command output.
+        if (
+            self.on_command_output
+            and not SystemService().system_settings.allow_on_command_output
+        ):
+            raise RuntimeError(
+                "OBBject Extension Error -> \n\n"
+                + "An OBBject extension that acts on command output is installed "
+                + "but has not been enabled in `system_settings.json`.\n\n"
+                + "Set `allow_on_command_output` to True to enable it.\n"
+                + "Or, set the environment variable `OPENBB_ALLOW_ON_COMMAND_OUTPUT` to True."
+                + "\n\nProceed with caution as this may have security implications.\n\n"
+                + "Ensure the extension is installed from a trusted source.\n\n",
+            )
+
+        # The user must explicitly enable OBBject extensions that modify output.
+        if (
+            self.on_command_output
+            and self.immutable is False
+            and not SystemService().system_settings.allow_mutable_extensions
+        ):
+            raise RuntimeError(
+                "OBBject Extension Error -> \n\n"
+                + "An OBBject extension that modifies the output is installed "
+                + "but has not been enabled in `system_settings.json`.\n\n"
+                + "Set `allow_mutable_extensions` to True to enable it.\n"
+                + "Or, set the environment variable `OPENBB_ALLOW_MUTABLE_EXTENSIONS` to True."
+                + "\n\nProceed with caution as this may have security implications.\n\n"
+                + "Ensure the extension is installed from a trusted source.\n\n",
+            )
 
     @property
     def obbject_accessor(self) -> Callable:
         """Extend an OBBject, inspired by pandas."""
         # pylint: disable=import-outside-toplevel
-        # Avoid circular imports
 
         from openbb_core.app.model.obbject import OBBject
 
@@ -55,8 +116,8 @@ class Extension:
                     UserWarning,
                 )
             setattr(cls, name, CachedAccessor(name, accessor))
-            # pylint: disable=protected-access
             cls.accessors.add(name)
+
             return accessor
 
         return decorator
diff --git a/openbb_platform/core/openbb_core/app/model/obbject.py b/openbb_platform/core/openbb_core/app/model/obbject.py
index 1c7cab26ec2..ac7026884ad 100644
--- a/openbb_platform/core/openbb_core/app/model/obbject.py
+++ b/openbb_platform/core/openbb_core/app/model/obbject.py
@@ -60,7 +60,7 @@ class OBBject(Tagged, Generic[T]):
         default_factory=dict,
         description="Extra info.",
     )
-    _route: str = PrivateAttr(
+    _route: str | None = PrivateAttr(
         default=None,
     )
     _standard_params: dict[str, Any] | None = PrivateAttr(
@@ -178,9 +178,9 @@ class OBBject(Tagged, Generic[T]):
 
             # BaseModel
             if isinstance(res, BaseModel):
-                res_dict = res.model_dump(
+                res_dict = res.model_dump(  # pylint: disable=no-member
                     exclude_unset=True, exclude_none=True
-                )  # pylint: disable=no-member
+                )
                 # Model is serialized as a dict[str, list] or list[dict]
                 if (
                     (
@@ -322,13 +322,16 @@ class OBBject(Tagged, Generic[T]):
             orient == "list"
             and isinstance(self.results, dict)
             and all(
-                isinstance(value, dict) for value in self.results.values()
-            )  # pylint: disable=no-member
+                isinstance(value, dict)
+                for value in self.results.values()  # pylint: disable=no-member
+            )
         ):
             df = df.T
-        results = df.to_dict(orient=orient)
+        results: dict | list = df.to_dict(orient=orient)
+
         if isinstance(results, dict) and orient == "list" and "index" in results:
             del results["index"]
+
         return results
 
     def to_llm(self) -> dict[Hashable, Any] | list[dict[Hashable, Any]]:
diff --git a/openbb_platform/core/openbb_core/app/model/system_settings.py b/openbb_platform/core/openbb_core/app/model/system_settings.py
index 4d1bbe1e8dc..027c4aa3679 100644
--- a/openbb_platform/core/openbb_core/app/model/system_settings.py
+++ b/openbb_platform/core/openbb_core/app/model/system_settings.py
@@ -15,6 +15,7 @@ from openbb_core.app.model.abstract.tagged import Tagged
 from openbb_core.app.model.api_settings import APISettings
 from openbb_core.app.model.python_settings import PythonSettings
 from openbb_core.app.version import CORE_VERSION, VERSION
+from openbb_core.env import Env
 from pydantic import ConfigDict, Field, field_validator, model_validator
 
 
@@ -54,6 +55,8 @@ class SystemSettings(Tagged):
     debug_mode: bool = False
     test_mode: bool = False
     headless: bool = False
+    allow_mutable_extensions: bool = getattr(Env(), "ALLOW_MUTABLE_EXTENSIONS", False)
+    allow_on_command_output: bool = getattr(Env(), "ALLOW_ON_COMMAND_OUTPUT", False)
 
     model_config = ConfigDict(validate_assignment=True, frozen=True)
 
diff --git a/openbb_platform/core/openbb_core/app/service/system_service.py b/openbb_platform/core/openbb_core/app/service/system_service.py
index 6c3a86eff26..28dab9d256d 100644
--- a/openbb_platform/core/openbb_core/app/service/system_service.py
+++ b/openbb_platform/core/openbb_core/app/service/system_service.py
@@ -21,6 +21,8 @@ class SystemService(metaclass=SingletonMeta):
         "python_settings",
         "debug_mode",
         "logging_suppress",
+        "allow_mutable_extensions",
+        "allow_on_command_output",
     }
 
     PRO_VALIDATION_HASH = "300ac59fdcc8f899e0bc5c18cda8652220735da1a00e2af365efe9d8e5fe8306"  # pragma: allowlist secret
diff --git a/openbb_platform/core/openbb_core/app/static/container.py b/openbb_platform/core/openbb_core/app/static/container.py
index 5e53d3ec1e5..c4dabfa9517 100644
--- a/openbb_platform/core/openbb_core/app/static/container.py
+++ b/openbb_platform/core/openbb_core/app/static/container.py
@@ -43,9 +43,18 @@ class Container:
                     kwargs["extra_params"][k] = v
 
         obbject = self._command_runner.sync_run(*args, **kwargs)
+
+        results_only = getattr(obbject, "_results_only", False)
+
+        if results_only is True:
+            content = obbject.model_dump(exclude_unset=True).get("results", [])
+            return content
+
         output_type = self._command_runner.user_settings.preferences.output_type
+
         if output_type == "OBBject":
             return obbject
+
         return getattr(obbject, "to_" + output_type)()
 
     def _check_credentials(self, provider: str) -> bool | None:
diff --git a/openbb_platform/core/openbb_core/env.py b/openbb_platform/core/openbb_core/env.py
index 4b8c551a6e4..1dd2e85dbaa 100644
--- a/openbb_platform/core/openbb_core/env.py
+++ b/openbb_platform/core/openbb_core/env.py
@@ -54,9 +54,16 @@ class Env(metaclass=SingletonMeta):
         return self.str2bool(self._environ.get("OPENBB_DEV_MODE", False))
 
     @property
-    def HUB_BACKEND(self) -> str:
-        """Hub backend: sets the backend for the OpenBB Hub."""
-        return self._environ.get("OPENBB_HUB_BACKEND", "https://payments.openbb.co")
+    def ALLOW_MUTABLE_EXTENSIONS(self) -> bool:
+        """Allow mutable extensions: enables extensions that modify OBBject output."""
+        return self.str2bool(
+            self._environ.get("OPENBB_ALLOW_MUTABLE_EXTENSIONS", False)
+        )
+
+    @property
+    def ALLOW_ON_COMMAND_OUTPUT(self) -> bool:
+        """Allow on command output: enables extensions that act on command output."""
+        return self.str2bool(self._environ.get("OPENBB_ALLOW_ON_COMMAND_OUTPUT", False))
 
     @staticmethod
     def str2bool(value) -> bool:
diff --git a/openbb_platform/core/tests/app/model/test_extension.py b/openbb_platform/core/tests/app/model/test_extension.py
new file mode 100644
index 00000000000..f817aafda65
--- /dev/null
+++ b/openbb_platform/core/tests/app/model/test_extension.py
@@ -0,0 +1,121 @@
+"""Test Extension model and its functionalities."""
+
+import sys
+import types
+from types import SimpleNamespace
+
+import pytest
+from openbb_core.app.model.extension import CachedAccessor, Extension
+
+
+def test_init_raises_if_invalid_configuration():
+    # on_command_output False but other flags set -> should raise
+    with pytest.raises(ValueError):
+        Extension(
+            name="bad",
+            on_command_output=False,
+            command_output_paths=["/some/path"],
+        )
+
+    with pytest.raises(ValueError):
+        Extension(name="bad2", on_command_output=False, results_only=True)
+
+    with pytest.raises(ValueError):
+        Extension(name="bad3", on_command_output=False, immutable=False)
+
+
+def test_register_accessor_registers_and_warns_on_override():
+    class Dummy:
+        accessors = set()
+
+    def accessor_factory(obj):
+        return SimpleNamespace(called_with=obj)
+
+    # Register new accessor
+    decorator = Extension.register_accessor("foo", Dummy)
+    returned = decorator(accessor_factory)
+    assert returned is accessor_factory  # decorator returns the original accessor
+    assert hasattr(Dummy, "foo")
+    assert "foo" in Dummy.accessors
+    # descriptor instance is stored in the class __dict__; accessing via the
+    # class returns the result of descriptor.__get__, so inspect __dict__
+    assert isinstance(Dummy.__dict__["foo"], CachedAccessor)
+
+    # If attribute already exists, registration should warn
+    Dummy.existing = "I exist"  #  type: ignore
+    with pytest.warns(UserWarning):
+        Extension.register_accessor("existing", Dummy)(accessor_factory)
+
+    # Clean up
+    if "foo" in Dummy.accessors:
+        Dummy.accessors.remove("foo")
+    if hasattr(Dummy, "foo"):
+        delattr(Dummy, "foo")
+    if hasattr(Dummy, "existing"):
+        delattr(Dummy, "existing")
+
+
+def test_cached_accessor_descriptor_behavior_and_caching():
+    class Dummy:
+        accessors = set()
+
+        def __init__(self, name="n"):
+            self.name = name
+
+    def make_accessor(obj):
+        # returns an object instance to be cached on the target instance
+        return SimpleNamespace(result=f"accessed-{obj.name}")
+
+    Extension.register_accessor("myext", Dummy)(make_accessor)
+
+    inst = Dummy("alice")
+    # Accessing on instance should call accessor and cache the result on instance
+    returned = inst.myext  # type: ignore  # pylint: disable=E1101
+    assert isinstance(returned, SimpleNamespace)
+    assert returned.result == "accessed-alice"
+    # The attribute should now exist on the instance (cached)
+    assert getattr(inst, "myext") is returned
+
+    # The descriptor object itself lives in the class __dict__
+    cls_attr = Dummy.__dict__["myext"]
+    assert isinstance(cls_attr, CachedAccessor)
+
+    # Clean up
+    Dummy.accessors.discard("myext")
+    if hasattr(Dummy, "myext"):
+        delattr(Dummy, "myext")
+
+
+def test_obbject_accessor_registers_on_mocked_obbject_module(monkeypatch):
+    # Create a fake module to be imported in the property
+    mod_name = "openbb_core.app.model.obbject"
+    fake_mod = types.ModuleType(mod_name)
+
+    class FakeOBBject:
+        accessors = set()
+
+    fake_mod.OBBject = FakeOBBject  # type: ignore
+
+    # Install fake module into sys.modules so import inside property picks it up
+    monkeypatch.setitem(sys.modules, mod_name, fake_mod)
+
+    ext = Extension(name="ext_name")
+    decorator = (
+        ext.obbject_accessor
+    )  # should return the register decorator for FakeOBBject
+
+    def sample_accessor(obj):
+        return SimpleNamespace(tag=f"ext-{getattr(obj,'_marker',None)}")
+
+    decorator(sample_accessor)
+
+    assert "ext_name" in FakeOBBject.accessors
+    assert hasattr(FakeOBBject, "ext_name")
+    # descriptor instance must be in the class __dict__
+    assert isinstance(FakeOBBject.__dict__["ext_name"], CachedAccessor)
+
+    # cleanup
+    FakeOBBject.accessors.discard("ext_name")
+    if hasattr(FakeOBBject, "ext_name"):
+        delattr(FakeOBBject, "ext_name")
+    monkeypatch.delitem(sys.modules, mod_name)
diff --git a/openbb_platform/core/tests/app/test_command_runner.py b/openbb_platform/core/tests/app/test_command_runner.py
index cff9a9ea335..fb7940a8f4d 100644
--- a/openbb_platform/core/tests/app/test_command_runner.py
+++ b/openbb_platform/core/tests/app/test_command_runner.py
@@ -2,6 +2,7 @@
 
 from dataclasses import dataclass
 from inspect import Parameter
+from types import SimpleNamespace
 from unittest.mock import Mock, patch
 
 import pytest
@@ -15,6 +16,7 @@ from openbb_core.app.command_runner import (
 )
 from openbb_core.app.model.abstract.warning import OpenBBWarning
 from openbb_core.app.model.command_context import CommandContext
+from openbb_core.app.model.extension import Extension
 from openbb_core.app.model.obbject import OBBject
 from openbb_core.app.model.system_settings import SystemSettings
 from openbb_core.app.model.user_settings import UserSettings
@@ -49,7 +51,7 @@ class MockExecutionContext:
     @property
     def api_route(self) -> str:
         """Mock API route."""
-        return MockAPIRoute(self.route)
+        return MockAPIRoute(self.route)  # type: ignore
 
 
 @pytest.fixture()
@@ -303,9 +305,9 @@ def test_command_runner_run(_):
     """Test run."""
     runner = CommandRunner()
 
-    with patch(
+    with patch(  # type: ignore
         "openbb_core.app.command_runner.StaticCommandRunner",
-        **{"return_value.run": True},
+        **{"return_value.run": True},  # type: ignore
     ):
         assert runner.run("mock/route")
 
@@ -371,7 +373,7 @@ async def test_static_command_runner_execute_func(
     mock_command.return_value = OBBject(
         results=[1, 2, 3, 4],
         provider="mock_provider",
-        accessors={"charting": Mock()},
+        accessors={"charting": Mock()},  # type: ignore
     )
     mock_chart.return_value = None
 
@@ -396,13 +398,13 @@ def test_static_command_runner_chart():
             {"date": "1992", "value": 300},
         ],
         provider="mock_provider",
-        accessors={"charting": Mock()},
+        accessors={"charting": Mock()},  # type: ignore
     )
-    mock_obbject.charting.show = Mock()
+    mock_obbject.charting.show = Mock()  # type: ignore
 
     StaticCommandRunner._chart(mock_obbject)  # pylint: disable=protected-access
 
-    mock_obbject.charting.show.assert_called_once()
+    mock_obbject.charting.show.assert_called_once()  # type: ignore
 
 
 @pytest.mark.asyncio
@@ -415,7 +417,7 @@ async def test_static_command_runner_command():
         def __init__(self, results, **kwargs):
             self.results = results
             self.extra = {}
-            self.provider = kwargs.get("provider_choices").provider
+            self.provider = kwargs.get("provider_choices").provider  # type: ignore
 
     class MockProviderChoices:
         """Mock ProviderChoices"""
@@ -435,3 +437,116 @@ async def test_static_command_runner_command():
 
     assert result.results == [1, 2, 3, 4]
     assert result.provider == "mock_provider"
+
+
+def test_extension_immutable_preserves_original_and_does_not_set_extension_modified(
+    monkeypatch,
+):
+    """Immutable extensions must run against a copy and must not mutate the original OBBject."""
+    monkeypatch.setattr(
+        "openbb_core.app.service.system_service.SystemService",
+        lambda: SimpleNamespace(
+            system_settings=SimpleNamespace(
+                allow_on_command_output=True, allow_mutable_extensions=False
+            )
+        ),
+    )
+    ext = Extension(name="imm_ext_test", on_command_output=True, immutable=True)
+
+    def imm_accessor(self):
+        # Mutate the (copied) obbject if called
+        if isinstance(getattr(self, "results", None), list):
+            self.results.append("modified_by_imm")
+
+    # Attach accessor to OBBject class for binding on instances (monkeypatch will revert)
+    monkeypatch.setattr(OBBject, ext.name, imm_accessor, raising=False)
+
+    fake_loader = SimpleNamespace(on_command_output_callbacks={"*": [ext]})
+    monkeypatch.setattr(
+        "openbb_core.app.command_runner.ExtensionLoader", lambda: fake_loader
+    )
+
+    obb = OBBject(results=[1], provider="mock_provider")
+
+    StaticCommandRunner._trigger_command_output_callbacks("any/route", obb)
+
+    # original must remain unchanged
+    assert obb.results == [1]
+    # immutable extension should not mark the original as modified
+    assert getattr(obb, "_extension_modified", False) is False
+
+
+def test_extension_mutable_modifies_original_and_sets_extension_modified_and_route_scoping(
+    monkeypatch,
+):
+    """Mutable extensions must modify the original OBBject and set the modification flag;
+    registration must be route-scoped."""
+    monkeypatch.setattr(
+        "openbb_core.app.service.system_service.SystemService",
+        lambda: SimpleNamespace(
+            system_settings=SimpleNamespace(
+                allow_mutable_extensions=True, allow_on_command_output=True
+            )
+        ),
+    )
+    ext = Extension(name="mut_ext_test", on_command_output=True, immutable=False)
+
+    def mut_accessor(self):
+        if isinstance(getattr(self, "results", None), list):
+            self.results.append("modified_by_mut")
+
+    monkeypatch.setattr(OBBject, ext.name, mut_accessor, raising=False)
+
+    # register the extension only for "mock/route"
+    fake_loader = SimpleNamespace(on_command_output_callbacks={"mock/route": [ext]})
+    monkeypatch.setattr(
+        "openbb_core.app.command_runner.ExtensionLoader", lambda: fake_loader
+    )
+
+    obb = OBBject(results=[], provider="mock_provider")
+
+    # not executed for other routes
+    StaticCommandRunner._trigger_command_output_callbacks("other/route", obb)
+    assert obb.results == []
+
+    # executed for the registered route and should mutate original
+    StaticCommandRunner._trigger_command_output_callbacks("mock/route", obb)
+    assert obb.results == ["modified_by_mut"]
+    assert getattr(obb, "_extension_modified", False) is True
+
+
+def test_results_only_flag_sets_attribute_and_accessor_runs(monkeypatch):
+    """Extensions that declare results_only should toggle the _results_only attribute
+    and still run their accessor."""
+    monkeypatch.setattr(
+        "openbb_core.app.service.system_service.SystemService",
+        lambda: SimpleNamespace(
+            system_settings=SimpleNamespace(
+                allow_on_command_output=True, allow_mutable_extensions=False
+            )
+        ),
+    )
+    ext = Extension(
+        name="ro_ext_test", on_command_output=True, results_only=True, immutable=True
+    )
+
+    called = {"hit": False}
+
+    def ro_accessor(self):
+        called["hit"] = True
+
+    monkeypatch.setattr(OBBject, ext.name, ro_accessor, raising=False)
+
+    fake_loader = SimpleNamespace(on_command_output_callbacks={"*": [ext]})
+    monkeypatch.setattr(
+        "openbb_core.app.command_runner.ExtensionLoader", lambda: fake_loader
+    )
+
+    obb = OBBject(results=[1, 2, 3], provider="mock_provider")
+
+    StaticCommandRunner._trigger_command_output_callbacks("any/route", obb)
+
+    # results_only attribute must be set on the output OBBject
+    assert getattr(obb, "_results_only", False) is True
+    # accessor should have been called (even if on a copy for immutable extensions)
+    assert called["hit"] is True
diff --git a/openbb_platform/obbject_extensions/charting/openbb_charting/charting.py b/openbb_platform/obbject_extensions/charting/openbb_charting/charting.py
index 6ee3ed5bd95..6b31261c786 100644
--- a/openbb_platform/obbject_extensions/charting/openbb_charting/charting.py
+++ b/openbb_platform/obbject_extensions/charting/openbb_charting/charting.py
@@ -472,24 +472,63 @@ class Charting:
 
     def show(self, render: bool = True, **kwargs):
         """Display chart and save it to the OBBject."""
+        # pylint: disable=import-outside-toplevel
+        from openbb_charting.core.openbb_figure import OpenBBFigure
+
         try:
             charting_function = self._get_chart_function(
-                self._obbject._route  # pylint: disable=protected-access
+                self._obbject._route  # pylint: disable=protected-access   # type: ignore
             )
             kwargs["obbject_item"] = self._obbject.results
             kwargs["charting_settings"] = self._charting_settings
             kwargs["standard_params"] = (
                 self._obbject._standard_params  # pylint: disable=protected-access
             )
-            kwargs["extra_params"] = (
-                self._obbject._extra_params  # pylint: disable=protected-access
+            # If the provider interface isn't used, endpoint kwargs are already here.
+            # Don't overwrite them.
+            obb_kwargs = (
+                self._obbject._extra_params or {}  # pylint: disable=protected-access
             )
+            if obb_kwargs:
+                for k, v in obb_kwargs.items():
+                    kwargs["extra_params"].update({k: v})
+
             kwargs["provider"] = self._obbject.provider
             kwargs["extra"] = self._obbject.extra
-            fig, content = charting_function(**kwargs)
-            content = fig.show(external=True, **kwargs).to_plotly_json()  # type: ignore
-            self._obbject.chart = Chart(fig=fig, content=content, format=self._format)
-            if render:
+
+            # Handle different types of output from the charting endpoint.
+            chart_response: Any = charting_function(**kwargs)
+
+            # If returned a Chart object, set as-is.
+            if isinstance(chart_response, Chart):
+                self._obbject.chart = chart_response
+            # If just an OpenBBFigure gets returned, create the serialized version for the API.
+            elif isinstance(chart_response, OpenBBFigure):
+                fig = chart_response
+                content = fig.show(external=True, **kwargs).to_plotly_json()
+                self._obbject.chart = Chart(
+                    fig=fig, content=content, format=self._format
+                )
+            # Current functions return this.
+            elif isinstance(chart_response, tuple) and len(chart_response) == 2:
+                fig, content = chart_response
+
+                if isinstance(fig, OpenBBFigure):
+                    content = fig.show(external=True, **kwargs).to_plotly_json()  # type: ignore
+                    self._obbject.chart = Chart(
+                        fig=fig, content=content, format=self._format
+                    )
+                else:
+                    self._obbject.chart = Chart(
+                        fig=fig, content=content, format=type(fig).__name__
+                    )
+
+            else:
+                self._obbject.chart = Chart(
+                    fig=chart_response, content=None, format="unknown"
+                )
+
+            if render and hasattr(fig, "show"):
                 fig.show(**kwargs)
 
         except (RuntimeError, OpenBBError) as e:
@@ -712,8 +751,9 @@ class Charting:
                 self._backend.send_table(
                     df_table=data_as_df,
                     title=title
-                    or self._obbject._route,  # pylint: disable=protected-access
-                    theme=self._charting_settings.table_style,
+                    or ""
+                    or self._obbject._route,  # pylint: disable=protected-access  # type: ignore
+                    theme=self._charting_settings.table_style,  # pylint: disable=protected-access
                 )
             except Exception as e:  # pylint: disable=W0718
                 warn(f"Failed to show figure with backend. {e}")