diff --git a/src/posit/connect/env.py b/src/posit/connect/env.py
index 41ce21f8..bd6ab65a 100644
--- a/src/posit/connect/env.py
+++ b/src/posit/connect/env.py
@@ -1,14 +1,6 @@
 from __future__ import annotations
 
-from typing import (
-    Any,
-    Dict,
-    List,
-    Iterable,
-    MutableMapping,
-    Optional,
-    overload,
-)
+from typing import Any, Iterator, List, Mapping, MutableMapping, Optional
 
 from requests import Session
 
@@ -17,48 +9,59 @@
 from .resources import Resources
 
 
-class EnvVars(Resources):
+class EnvVars(Resources, MutableMapping[str, Optional[str]]):
     def __init__(
         self, config: Config, session: Session, content_guid: str
     ) -> None:
         super().__init__(config, session)
         self.content_guid = content_guid
 
-    def __setitem__(self, key: str, value: str, /) -> None:
-        """Set environment variable.
-
-        Set the environment variable for content.
+    def __delitem__(self, key: str, /) -> None:
+        """Delete the environment variable.
 
         Parameters
         ----------
         key : str
-            The name of the environment variable to set.
-        value : str
-            The value assigned to the environment variable.
+            The name of the environment variable to delete.
 
         Examples
         --------
         >>> vars = EnvVars(config, session, content_guid)
-        >>> vars["DATABASE_URL"] = (
-        ...     "postgres://user:password@localhost:5432/database"
-        ... )
+        >>> del vars["DATABASE_URL"]
         """
-        self.update({key: value})
+        self.update({key: None})
 
-    def __delitem__(self, key: str, /) -> None:
-        """Delete the environment variable.
+    def __getitem__(self, key: Any) -> Any:
+        raise NotImplementedError(
+            "Since environment variables may contain sensitive information, the values are not accessible outside of Connect."
+        )
+
+    def __iter__(self) -> Iterator:
+        return iter(self.find())
+
+    def __len__(self):
+        return len(self.find())
+
+    def __setitem__(self, key: str, value: Optional[str], /) -> None:
+        """Set environment variable.
+
+        Set the environment variable for content.
 
         Parameters
         ----------
         key : str
-            The name of the environment variable to delete.
+            The name of the environment variable to set.
+        value : str
+            The value assigned to the environment variable.
 
         Examples
         --------
         >>> vars = EnvVars(config, session, content_guid)
-        >>> del vars["DATABASE_URL"]
+        >>> vars["DATABASE_URL"] = (
+        ...     "postgres://user:password@localhost:5432/database"
+        ... )
         """
-        self.update({key: None})
+        self.update({key: value})
 
     def clear(self) -> None:
         """Remove all environment variables.
@@ -130,20 +133,12 @@ def find(self) -> List[str]:
         response = self.session.get(url)
         return response.json()
 
-    @overload
-    def update(
-        self, other: MutableMapping[str, Optional[str]], /, **kwargs: str
-    ) -> None: ...
-
-    @overload
-    def update(
-        self, other: Iterable[tuple[str, Optional[str]]], /, **kwargs: str
-    ) -> None: ...
-
-    @overload
-    def update(self, /, **kwargs: str) -> None: ...
+    def items(self):
+        raise NotImplementedError(
+            "Since environment variables may contain sensitive information, the values are not accessible outside of Connect."
+        )
 
-    def update(self, other=None, /, **kwargs: str) -> None:
+    def update(self, other=(), /, **kwargs: Optional[str]):
         """
         Update environment variables.
 
@@ -193,26 +188,19 @@ def update(self, other=None, /, **kwargs: str) -> None:
         ...     ]
         ... )
         """
-        d: Dict[str, str] = {}
-        if other is not None:
-            if isinstance(other, MutableMapping):
-                d.update(other)
-            elif isinstance(other, Iterable) and not isinstance(
-                other, (str, bytes)
-            ):
-                try:
-                    d.update(other)
-                except (TypeError, ValueError):
-                    raise TypeError(
-                        f"update expected a {MutableMapping} or {Iterable}, got {type(other)}"
-                    )
-            else:
-                raise TypeError(
-                    f"update expected a {MutableMapping} or {Iterable}, got {type(other)}"
-                )
-
-        if kwargs:
-            d.update(kwargs)
+        d = dict()
+        if isinstance(other, Mapping):
+            for key in other:
+                d[key] = other[key]
+        elif hasattr(other, "keys"):
+            for key in other.keys():
+                d[key] = other[key]
+        else:
+            for key, value in other:
+                d[key] = value
+
+        for key, value in kwargs.items():
+            d[key] = value
 
         body = [{"name": key, "value": value} for key, value in d.items()]
         path = f"v1/content/{self.content_guid}/environment"
diff --git a/tests/posit/connect/test_env.py b/tests/posit/connect/test_env.py
index fb4a183c..a7fc0731 100644
--- a/tests/posit/connect/test_env.py
+++ b/tests/posit/connect/test_env.py
@@ -46,6 +46,102 @@ def test__delitem__():
     assert mock_patch.call_count == 1
 
 
+@responses.activate
+def test__getitem__():
+    # data
+    guid = "f2f37341-e21d-3d80-c698-a935ad614066"
+
+    # behavior
+    responses.get(
+        f"https://connect.example.com/__api__/v1/content/{guid}",
+        json=load_mock(f"v1/content/{guid}.json"),
+    )
+
+    responses.patch(
+        f"https://connect.example.com/__api__/v1/content/{guid}/environment",
+        json=[],
+        match=[
+            matchers.json_params_matcher(
+                [
+                    {
+                        "name": "TEST",
+                        "value": None,
+                    }
+                ]
+            )
+        ],
+    )
+
+    # setup
+    c = Client("https://connect.example.com", "12345")
+    content = c.content.get(guid)
+
+    # invoke
+    with pytest.raises(NotImplementedError):
+        content.environment_variables["TEST"]
+
+
+@responses.activate
+def test__iter__():
+    # data
+    guid = "f2f37341-e21d-3d80-c698-a935ad614066"
+
+    # behavior
+    mock_get_content = responses.get(
+        f"https://connect.example.com/__api__/v1/content/{guid}",
+        json=load_mock(f"v1/content/{guid}.json"),
+    )
+
+    mock_get_environment = responses.get(
+        f"https://connect.example.com/__api__/v1/content/{guid}/environment",
+        json=["TEST"],
+    )
+
+    # setup
+    c = Client("https://connect.example.com", "12345")
+    content = c.content.get(guid)
+
+    # invoke
+    iterator = iter(content.environment_variables)
+
+    # assert
+    assert next(iterator) == "TEST"
+    with pytest.raises(StopIteration):
+        next(iterator)
+
+    assert mock_get_content.call_count == 1
+    assert mock_get_environment.call_count == 1
+
+
+@responses.activate
+def test__len__():
+    # data
+    guid = "f2f37341-e21d-3d80-c698-a935ad614066"
+
+    # behavior
+    mock_get_content = responses.get(
+        f"https://connect.example.com/__api__/v1/content/{guid}",
+        json=load_mock(f"v1/content/{guid}.json"),
+    )
+
+    mock_get_environment = responses.get(
+        f"https://connect.example.com/__api__/v1/content/{guid}/environment",
+        json=["TEST"],
+    )
+
+    # setup
+    c = Client("https://connect.example.com", "12345")
+    content = c.content.get(guid)
+
+    # invoke
+    length = len(content.environment_variables)
+
+    # assert
+    assert length == 1
+    assert mock_get_content.call_count == 1
+    assert mock_get_environment.call_count == 1
+
+
 @responses.activate
 def test__setitem__():
     # data
@@ -218,6 +314,31 @@ def test_find():
     assert mock_get_environment.call_count == 1
 
 
+@responses.activate
+def test_items():
+    # data
+    guid = "f2f37341-e21d-3d80-c698-a935ad614066"
+
+    # behavior
+    mock_get_content = responses.get(
+        f"https://connect.example.com/__api__/v1/content/{guid}",
+        json=load_mock(f"v1/content/{guid}.json"),
+    )
+
+    mock_get_environment = responses.get(
+        f"https://connect.example.com/__api__/v1/content/{guid}/environment",
+        json=["TEST"],
+    )
+
+    # setup
+    c = Client("https://connect.example.com", "12345")
+    content = c.content.get(guid)
+
+    # invoke
+    with pytest.raises(NotImplementedError):
+        content.environment_variables.items()
+
+
 class TestUpdate:
     @responses.activate
     def test(self):
@@ -257,7 +378,7 @@ def test(self):
         assert mock_patch.call_count == 1
 
     @responses.activate
-    def test_other_is_mutable_mapping(self):
+    def test_other_is_mapping(self):
         # data
         guid = "f2f37341-e21d-3d80-c698-a935ad614066"
 
@@ -293,6 +414,50 @@ def test_other_is_mutable_mapping(self):
         assert mock_get.call_count == 1
         assert mock_patch.call_count == 1
 
+    @responses.activate
+    def test_other_hasattr_keys(self):
+        # data
+        guid = "f2f37341-e21d-3d80-c698-a935ad614066"
+
+        # behavior
+        mock_get = responses.get(
+            f"https://connect.example.com/__api__/v1/content/{guid}",
+            json=load_mock(f"v1/content/{guid}.json"),
+        )
+
+        mock_patch = responses.patch(
+            f"https://connect.example.com/__api__/v1/content/{guid}/environment",
+            json=load_mock(f"v1/content/{guid}.json"),
+            match=[
+                matchers.json_params_matcher(
+                    [
+                        {
+                            "name": "TEST",
+                            "value": "TEST",
+                        }
+                    ]
+                )
+            ],
+        )
+
+        # setup
+        c = Client("https://connect.example.com", "12345")
+        content = c.content.get(guid)
+
+        class Test:
+            def __getitem__(self, key):
+                return "TEST"
+
+            def keys(self):
+                return ["TEST"]
+
+        # invoke
+        content.environment_variables.update(Test())
+
+        # assert
+        assert mock_get.call_count == 1
+        assert mock_patch.call_count == 1
+
     @responses.activate
     def test_other_is_iterable(self):
         # data
@@ -380,7 +545,7 @@ def test_other_is_str(self):
         content = c.content.get(guid)
 
         # invoke
-        with pytest.raises(TypeError):
+        with pytest.raises(ValueError):
             content.environment_variables.update("TEST")
 
     @responses.activate