diff --git a/.github/workflows/run-tests.yml b/.github/workflows/run-tests.yml
index 0156bd77b..c57598949 100644
--- a/.github/workflows/run-tests.yml
+++ b/.github/workflows/run-tests.yml
@@ -30,7 +30,7 @@ permissions:
 
 jobs:
   run_tests:
-    name: ${{ matrix.test-type }} w/ python ${{ matrix.python-version }} on ${{ matrix.os }}
+    name: ${{ matrix.test-type }} w/ python ${{ matrix.python-version }} | pydantic ${{ matrix.pydantic_version }} on ${{ matrix.os }}
     timeout-minutes: 15
     strategy:
       matrix:
@@ -38,12 +38,26 @@ jobs:
         python-version: ['3.9', '3.10', '3.11']
         test-type: ['not llm']
         llm_model: ['openai/gpt-3.5-turbo']
+        pydantic_version: ['>=2.4.2']
 
         include:
           - python-version: '3.9'
             os: 'ubuntu-latest'
             test-type: 'llm'
             llm_model: 'openai/gpt-3.5-turbo'
+            pydantic_version: '>=2.4.2'
+          
+          - python-version: '3.9'
+            os: 'ubuntu-latest'
+            test-type: 'llm'
+            llm_model: 'openai/gpt-3.5-turbo'
+            pydantic_version: '<2'
+
+          - python-version: '3.9'
+            os: 'ubuntu-latest'
+            test-type: 'not llm'
+            llm_model: 'openai/gpt-3.5-turbo'
+            pydantic_version: '<2'
 
     runs-on: ${{ matrix.os }}
 
@@ -60,6 +74,11 @@ jobs:
           cache: "pip"
       - name: Install Marvin
         run: pip install ".[tests]"
+
+      - name: Install pydantic
+        run: pip install "pydantic${{ matrix.pydantic_version }}"
+
+
       - name: Run ${{ matrix.test-type }} tests (${{ matrix.llm_model }})
         run: pytest -vv -m "${{ matrix.test-type }}"
         env:
diff --git a/pyproject.toml b/pyproject.toml
index f5405dbb6..3354339a6 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -39,6 +39,7 @@ dev = [
     "mkdocstrings[python]~=0.22",
     "pdbpp~=0.10",
     "pre-commit>=2.21,<4.0",
+    "pydantic",
     "ruff",
 ]
 tests = [
@@ -48,8 +49,8 @@ tests = [
     "pytest-rerunfailures>=10,<13",
     "pytest-sugar~=0.9",
     "pytest~=7.3.1",
-    "pydantic-settings>=2.0.0",
 ]
+
 framework = [
     "aiosqlite>=0.19.0",
     "alembic>=1.11.1",
diff --git a/src/marvin/_compat.py b/src/marvin/_compat.py
index c09e9ba7c..98066d76b 100644
--- a/src/marvin/_compat.py
+++ b/src/marvin/_compat.py
@@ -10,36 +10,45 @@
     get_origin,
 )
 
-from pydantic import BaseModel, create_model
 from pydantic.version import VERSION as PYDANTIC_VERSION
 
-_ModelT = TypeVar("_ModelT", bound="BaseModel")
-
 PYDANTIC_V2 = PYDANTIC_VERSION.startswith("2.")
 
 if PYDANTIC_V2:
     from pydantic.v1 import (
         BaseSettings,
-        Field,
+        PrivateAttr,
         SecretStr,
+        ValidationError,
         validate_arguments,
     )
 
     SettingsConfigDict = BaseSettings.Config
 
-    from pydantic import field_validator  # noqa # type: ignore
+    from pydantic import (
+        BaseModel,
+        Field,
+        create_model,
+        field_validator,
+    )
 
 else:
     from pydantic import (  # noqa # type: ignore
         BaseSettings,
+        BaseModel,
+        create_model,
         Field,
         SecretStr,
         validate_arguments,
         validator as field_validator,
+        ValidationError,
+        PrivateAttr,
     )
 
     SettingsConfigDict = BaseSettings.Config
 
+_ModelT = TypeVar("_ModelT", bound=BaseModel)
+
 
 def model_dump(model: _ModelT, **kwargs: Any) -> dict[str, Any]:
     if PYDANTIC_V2 and hasattr(model, "model_dump"):
diff --git a/src/marvin/components/ai_application.py b/src/marvin/components/ai_application.py
index 4cdbedebc..bb495e959 100644
--- a/src/marvin/components/ai_application.py
+++ b/src/marvin/components/ai_application.py
@@ -3,10 +3,9 @@
 from typing import Any, Callable, Optional, Union
 
 from jsonpatch import JsonPatch
-from pydantic import BaseModel, Field, validator
 
 import marvin
-from marvin._compat import PYDANTIC_V2, model_dump
+from marvin._compat import PYDANTIC_V2, BaseModel, Field, field_validator, model_dump
 from marvin.core.ChatCompletion.providers.openai import get_context_size
 from marvin.openai import ChatCompletion
 from marvin.prompts import library as prompt_library
@@ -218,17 +217,19 @@ class AIApplication(LoggerMixin, MarvinBaseModel):
     state_enabled: bool = True
     plan_enabled: bool = True
 
-    @validator("description")
+    @field_validator("description")
     def validate_description(cls, v):
         return inspect.cleandoc(v)
 
-    @validator("additional_prompts")
+    @field_validator("additional_prompts")
     def validate_additional_prompts(cls, v):
         if v is None:
             v = []
         return v
 
-    @validator("tools", pre=True, always=True)
+    @field_validator(
+        "tools", **(dict(pre=True, always=True) if not PYDANTIC_V2 else {})
+    )
     def validate_tools(cls, v):
         if v is None:
             v = []
@@ -245,7 +246,7 @@ def validate_tools(cls, v):
                 raise ValueError(f"Tool {tool} is not a `Tool` or callable.")
         return tools
 
-    @validator("name", always=True)
+    @field_validator("name")
     def validate_name(cls, v):
         if v is None:
             v = cls.__name__
@@ -351,8 +352,8 @@ class JSONPatchModel(
 
     op: str
     path: str
-    value: Union[str, float, int, bool, list, dict] = None
-    from_: str = Field(None, alias="from")
+    value: Union[str, float, int, bool, list, dict, None] = None
+    from_: Optional[str] = Field(None, alias="from")
 
 
 class UpdateState(Tool):
diff --git a/src/marvin/components/ai_classifier.py b/src/marvin/components/ai_classifier.py
index 98e0a69d2..88260b7a4 100644
--- a/src/marvin/components/ai_classifier.py
+++ b/src/marvin/components/ai_classifier.py
@@ -4,9 +4,9 @@
 from functools import partial
 from typing import Any, Callable, Literal, Optional, TypeVar
 
-from pydantic import BaseModel, Field
 from typing_extensions import ParamSpec, Self
 
+from marvin._compat import BaseModel, Field
 from marvin.core.ChatCompletion import ChatCompletion
 from marvin.core.ChatCompletion.abstract import AbstractChatCompletion
 from marvin.prompts import Prompt, prompt_fn
diff --git a/src/marvin/components/ai_function.py b/src/marvin/components/ai_function.py
index dd1287a21..1a2aca2ff 100644
--- a/src/marvin/components/ai_function.py
+++ b/src/marvin/components/ai_function.py
@@ -3,9 +3,9 @@
 from functools import partial
 from typing import Any, Awaitable, Callable, Generic, Optional, TypeVar, Union
 
-from pydantic import BaseModel, Field
 from typing_extensions import ParamSpec, Self
 
+from marvin._compat import BaseModel, Field
 from marvin.core.ChatCompletion import ChatCompletion
 from marvin.core.ChatCompletion.abstract import AbstractChatCompletion
 from marvin.prompts import Prompt, prompt_fn
@@ -42,7 +42,7 @@ def prompt_wrapper(*args: P.args, **kwargs: P.kwargs) -> None:  # type: ignore #
         {{'def' + ''.join(inspect.getsource(func).split('def')[1:])}}
 
         The user will provide function inputs (if any) and you must respond with
-        the most likely result.
+        the most likely result, which must be valid, double-quoted JSON.
 
         User: The function was called with the following inputs:
         {% set sig = inspect.signature(func) %}
@@ -118,20 +118,29 @@ def call(
         *args: P.args,
         **kwargs: P.kwargs,
     ) -> Any:
-        return getattr(
-            self.as_chat_completion(*args, **kwargs).create().to_model(),
-            self.response_model_field_name or "output",
-        )
+        model_instance = self.as_chat_completion(*args, **kwargs).create().to_model()
+        response_model_field_name = self.response_model_field_name or "output"
+
+        if not (output := getattr(model_instance, response_model_field_name, None)):
+            return model_instance
+
+        return output
 
     async def acall(
         self,
         *args: P.args,
         **kwargs: P.kwargs,
     ) -> Any:
-        return getattr(
-            (await self.as_chat_completion(*args, **kwargs).acreate()).to_model(),
-            self.response_model_field_name or "output",
-        )
+        model_instance = (
+            await self.as_chat_completion(*args, **kwargs).acreate()
+        ).to_model()
+
+        response_model_field_name = self.response_model_field_name or "output"
+
+        if not (output := getattr(model_instance, response_model_field_name, None)):
+            return model_instance
+
+        return output
 
     def map(self, *map_args: list[Any], **map_kwargs: list[Any]):
         """
diff --git a/src/marvin/components/ai_model.py b/src/marvin/components/ai_model.py
index 322e2758a..230172c00 100644
--- a/src/marvin/components/ai_model.py
+++ b/src/marvin/components/ai_model.py
@@ -3,9 +3,9 @@
 from functools import partial
 from typing import Any, Callable, Optional, TypeVar
 
-from pydantic import BaseModel
 from typing_extensions import ParamSpec, Self
 
+from marvin._compat import BaseModel
 from marvin.core.ChatCompletion import ChatCompletion
 from marvin.core.ChatCompletion.abstract import AbstractChatCompletion
 from marvin.prompts import Prompt, prompt_fn
diff --git a/src/marvin/components/ai_model_factory.py b/src/marvin/components/ai_model_factory.py
index 6c39359f9..33a6112a3 100644
--- a/src/marvin/components/ai_model_factory.py
+++ b/src/marvin/components/ai_model_factory.py
@@ -1,7 +1,6 @@
 from typing import Optional
 
-from pydantic import BaseModel
-
+from marvin._compat import BaseModel
 from marvin.components.ai_model import ai_model
 
 
diff --git a/src/marvin/components/library/ai_models.py b/src/marvin/components/library/ai_models.py
index 0b88ce2e8..cc149cab4 100644
--- a/src/marvin/components/library/ai_models.py
+++ b/src/marvin/components/library/ai_models.py
@@ -2,11 +2,10 @@
 from typing import Optional
 
 import httpx
-from pydantic import BaseModel
 from typing_extensions import Self
 
 from marvin import ai_model
-from marvin._compat import Field, SecretStr, field_validator
+from marvin._compat import BaseModel, Field, SecretStr, field_validator
 from marvin.settings import MarvinBaseSettings
 
 
diff --git a/src/marvin/core/ChatCompletion/__init__.py b/src/marvin/core/ChatCompletion/__init__.py
index b2e08a291..068c171ce 100644
--- a/src/marvin/core/ChatCompletion/__init__.py
+++ b/src/marvin/core/ChatCompletion/__init__.py
@@ -1,6 +1,7 @@
 from typing import Optional, Any, TypeVar
-from pydantic import BaseModel
 from .abstract import AbstractChatCompletion
+
+from marvin._compat import BaseModel
 from marvin.settings import settings
 
 T = TypeVar(
diff --git a/src/marvin/core/ChatCompletion/abstract.py b/src/marvin/core/ChatCompletion/abstract.py
index 2177e47c4..a01c50d22 100644
--- a/src/marvin/core/ChatCompletion/abstract.py
+++ b/src/marvin/core/ChatCompletion/abstract.py
@@ -1,9 +1,8 @@
 from abc import ABC, abstractmethod
 from typing import Any, Generic, Optional, TypeVar
 
-from marvin._compat import model_copy, model_dump
+from marvin._compat import BaseModel, Field, model_copy, model_dump
 from marvin.utilities.messages import Message
-from pydantic import BaseModel, Field
 from typing_extensions import Self
 
 from .handlers import Request, Response, Turn
diff --git a/src/marvin/core/ChatCompletion/handlers.py b/src/marvin/core/ChatCompletion/handlers.py
index 5a8e73015..4b8ced16a 100644
--- a/src/marvin/core/ChatCompletion/handlers.py
+++ b/src/marvin/core/ChatCompletion/handlers.py
@@ -12,11 +12,10 @@
     overload,
 )
 
-from marvin._compat import cast_to_json, model_dump
+from marvin._compat import BaseModel, Field, cast_to_json, model_dump
 from marvin.utilities.async_utils import run_sync
 from marvin.utilities.logging import get_logger
 from marvin.utilities.messages import Message, Role
-from pydantic import BaseModel, Field
 from typing_extensions import ParamSpec
 
 from .utils import parse_raw
@@ -84,6 +83,9 @@ class Choice(BaseModel):
     index: int
     finish_reason: str
 
+    class Config:
+        arbitrary_types_allowed = True
+
 
 class Usage(BaseModel):
     prompt_tokens: int
diff --git a/src/marvin/core/ChatCompletion/providers/openai.py b/src/marvin/core/ChatCompletion/providers/openai.py
index e9f244f76..6675c3ee0 100644
--- a/src/marvin/core/ChatCompletion/providers/openai.py
+++ b/src/marvin/core/ChatCompletion/providers/openai.py
@@ -1,14 +1,13 @@
 import inspect
 from typing import Any, AsyncGenerator, Callable, Optional, TypeVar, Union
 
-from marvin._compat import cast_to_json, model_dump
+from marvin._compat import BaseModel, cast_to_json, model_dump
 from marvin.settings import settings
 from marvin.types import Function
 from marvin.utilities.async_utils import create_task
 from marvin.utilities.messages import Message
 from marvin.utilities.streaming import StreamHandler
 from openai.openai_object import OpenAIObject
-from pydantic import BaseModel
 
 from ..abstract import AbstractChatCompletion
 from ..handlers import Request, Response, Usage
diff --git a/src/marvin/openai/ChatCompletion/__init__.py b/src/marvin/openai/ChatCompletion/__init__.py
index c39421a62..bd41d1135 100644
--- a/src/marvin/openai/ChatCompletion/__init__.py
+++ b/src/marvin/openai/ChatCompletion/__init__.py
@@ -1,13 +1,10 @@
-from pydantic import BaseModel, Field, validator, Extra, BaseSettings, root_validator
 from pydantic.main import ModelMetaclass
 
-from typing import Any, Callable, List, Optional, Type, Union, Literal
-from marvin import settings
-from marvin.types import Function
+from typing import Any, Callable, Optional
 from operator import itemgetter
-from marvin.utilities.module_loading import import_string
-import warnings
-import copy
+
+from marvin import settings
+from marvin._compat import BaseModel, Extra, Field
 from marvin.types.request import Request as BaseRequest
 from marvin.engine import ChatCompletionBase
 
diff --git a/src/marvin/openai/Function/Registry/__init__.py b/src/marvin/openai/Function/Registry/__init__.py
index b5f76533b..2f74ea661 100644
--- a/src/marvin/openai/Function/Registry/__init__.py
+++ b/src/marvin/openai/Function/Registry/__init__.py
@@ -1,8 +1,4 @@
-from typing import Any, Callable, Dict, List, Optional, Set, Type, Union
-from fastapi.routing import APIRouter
-from pydantic import BaseModel, validate_arguments
-from marvin.utilities.types import function_to_model
-from marvin.utilities.messages import Message
+from typing import Any
 from marvin.openai.Function import openai_fn
 from openai.openai_object import OpenAIObject
 from marvin.functions import FunctionRegistry
diff --git a/src/marvin/settings.py b/src/marvin/settings.py
index abeb05904..42372eeed 100644
--- a/src/marvin/settings.py
+++ b/src/marvin/settings.py
@@ -5,7 +5,6 @@
 
 from ._compat import (
     BaseSettings,
-    Field,
     SecretStr,
     model_dump,
 )
@@ -155,22 +154,19 @@ class Settings(MarvinBaseSettings):
     azure_openai: AzureOpenAI = AzureOpenAI()
 
     # SLACK
-    slack_api_token: Optional[SecretStr] = Field(
-        default=None,
-        description="The Slack API token to use for the Slack client",
-    )
+    slack_api_token: Optional[SecretStr] = None
 
     # TOOLS
 
     # chroma
-    chroma_server_host: Optional[str] = Field(default=None)
-    chroma_server_http_port: Optional[int] = Field(default=None)
+    chroma_server_host: Optional[str] = None
+    chroma_server_http_port: Optional[int] = None
 
     # github
-    github_token: Optional[SecretStr] = Field(default=None)
+    github_token: Optional[SecretStr] = None
 
     # wolfram
-    wolfram_app_id: Optional[SecretStr] = Field(default=None)
+    wolfram_app_id: Optional[SecretStr] = None
 
     def get_defaults(self, provider: Optional[str] = None) -> dict[str, Any]:
         response: dict[str, Any] = {}
diff --git a/src/marvin/types/function.py b/src/marvin/types/function.py
index d898bbefe..a9da6cd25 100644
--- a/src/marvin/types/function.py
+++ b/src/marvin/types/function.py
@@ -3,9 +3,7 @@
 import re
 from typing import Callable, Optional, Type
 
-from pydantic import BaseModel
-
-from marvin._compat import validate_arguments
+from marvin._compat import BaseModel, validate_arguments
 
 extraneous_fields = [
     "args",
diff --git a/src/marvin/utilities/messages.py b/src/marvin/utilities/messages.py
index 2807df5ab..ef70824cc 100644
--- a/src/marvin/utilities/messages.py
+++ b/src/marvin/utilities/messages.py
@@ -5,10 +5,9 @@
 from typing import Any, Optional
 from zoneinfo import ZoneInfo
 
-from pydantic import BaseModel, Field
 from typing_extensions import Self
 
-from marvin._compat import field_validator
+from marvin._compat import BaseModel, Field, field_validator
 from marvin.utilities.strings import split_text_by_tokens
 from marvin.utilities.types import MarvinBaseModel
 
@@ -34,6 +33,10 @@ class FunctionCall(BaseModel):
     arguments: str
 
 
+def utcnow():
+    return datetime.now(ZoneInfo("UTC"))
+
+
 class Message(MarvinBaseModel):
     role: Role
     content: Optional[str] = Field(default=None, description="The message content")
@@ -49,7 +52,7 @@ class Message(MarvinBaseModel):
     id: uuid.UUID = Field(default_factory=uuid.uuid4, exclude=True)
     data: Optional[dict[str, Any]] = Field(default_factory=dict, exclude=True)
     timestamp: datetime = Field(
-        default_factory=lambda: datetime.now(ZoneInfo("UTC")),
+        default_factory=utcnow,
         exclude=True,
     )
 
diff --git a/src/marvin/utilities/types.py b/src/marvin/utilities/types.py
index d5262b713..dbd7f1456 100644
--- a/src/marvin/utilities/types.py
+++ b/src/marvin/utilities/types.py
@@ -3,9 +3,7 @@
 from types import GenericAlias
 from typing import Any, Callable, _SpecialForm
 
-import pydantic
-from pydantic import BaseModel, PrivateAttr
-
+from marvin._compat import BaseModel, PrivateAttr, create_model
 from marvin.utilities.logging import get_logger
 
 
@@ -54,7 +52,7 @@ def function_to_model(
 
     # Create Pydantic model
     try:
-        Model = pydantic.create_model(name or function.__name__, **fields)
+        Model = create_model(name or function.__name__, **fields)
     except RuntimeError as exc:
         if "see `arbitrary_types_allowed` " in str(exc):
             raise ValueError(
@@ -85,7 +83,7 @@ def safe_issubclass(type_, classes):
 
 
 def type_to_schema(type_, set_root_type: bool = True) -> dict:
-    if safe_issubclass(type_, pydantic.BaseModel):
+    if safe_issubclass(type_, BaseModel):
         schema = type_.schema()
         # if the docstring was updated at runtime, make it the description
         if type_.__doc__ and type_.__doc__ != schema.get("description"):
@@ -94,13 +92,13 @@ def type_to_schema(type_, set_root_type: bool = True) -> dict:
 
     elif set_root_type:
 
-        class Model(pydantic.BaseModel):
+        class Model(BaseModel):
             __root__: type_
 
         return Model.schema()
     else:
 
-        class Model(pydantic.BaseModel):
+        class Model(BaseModel):
             data: type_
 
         return Model.schema()
diff --git a/tests/test_components/test_ai_functions.py b/tests/test_components/test_ai_functions.py
index 7019dca50..552bfab5c 100644
--- a/tests/test_components/test_ai_functions.py
+++ b/tests/test_components/test_ai_functions.py
@@ -1,7 +1,8 @@
 import inspect
 
 import pytest
-from marvin.components.ai_function import ai_fn
+from marvin import ai_fn
+from pydantic import BaseModel
 
 from tests.utils.mark import pytest_mark_class
 
@@ -44,6 +45,19 @@ def list_fruit(n: int) -> list[str]:
         result = list_fruit(3)
         assert len(result) == 3
 
+    def test_basemodel_response(self):
+        class Fruit(BaseModel):
+            name: str
+            color: str
+
+        @ai_fn
+        def get_fruit(description: str) -> Fruit:
+            """Returns a fruit with the provided description"""
+
+        fruit = get_fruit("loved by monkeys")
+        assert fruit.name.lower() == "banana"
+        assert fruit.color.lower() == "yellow"
+
 
 @pytest_mark_class("llm")
 class TestAIFunctionsMap: