diff --git a/libs/langgraph/tests/test_pregel.py b/libs/langgraph/tests/test_pregel.py
index 67536deed3..570f725215 100644
--- a/libs/langgraph/tests/test_pregel.py
+++ b/libs/langgraph/tests/test_pregel.py
@@ -5491,3 +5491,241 @@ def invoke_sub_agent(state: AgentState):
             "invoke_sub_agent": {"input": True},
         },
     ]
+
+
+def test_map_reduce() -> None:
+    """Test map reduce with Graph API."""
+    import operator
+    from typing import Annotated, NotRequired, TypedDict
+
+    class OverallState(TypedDict):
+        subjects: list
+        # Notice here we use the operator.add
+        # This is because we want combine all the jokes we generate
+        # from individual nodes back into one list - this is essentially
+        # the "reduce" part
+        jokes_with_grades: Annotated[list, operator.add]
+        best_selected_joke: str
+
+    # This will be the state of the node that we will "map" all
+    # subjects to in order to generate a joke
+    class JokeState(TypedDict):
+        subject: str
+        joke: NotRequired[str]
+        joke_grade: NotRequired[int]
+
+    def generate_jokes(state: OverallState):
+        # Distribute the subjects to the generate_joke node
+        return [Send("generate_joke", {"subject": s}) for s in state["subjects"]]
+
+    def generate_joke(state: JokeState):
+        # Come up with a joke and continue to grade the joke
+        funny_joke = f"Funny joke about {state['subject']}"
+        return [Send("grade_joke", {"joke": funny_joke, "subject": state["subject"]})]
+
+    def grade_joke(state: JokeState):
+        # Grade the joke and then send it to the count_grade node which will reduce
+        if state["subject"].startswith("a"):
+            grade = 10
+        elif state["subject"].startswith("b"):
+            grade = 9
+        else:
+            grade = 1
+        return {
+            "jokes_with_grades": [
+                {
+                    "joke": state["joke"],
+                    "grade": grade,
+                }
+            ]
+        }
+
+    def count_grade(state: OverallState):
+        max_score = 0
+        best_joke = ""
+        for joke in state["jokes_with_grades"]:
+            if joke["grade"] > max_score:
+                max_score = joke["grade"]
+                best_joke = joke["joke"]
+        return {"best_selected_joke": best_joke}
+
+    builder = StateGraph(OverallState)
+    builder.add_conditional_edges("__start__", generate_jokes, ["generate_joke"])
+    builder.add_conditional_edges("generate_joke", grade_joke, ["count_grade"])
+    builder.add_node(grade_joke)
+    builder.add_node(count_grade)
+    builder.add_edge("count_grade", END)
+    graph = builder.compile()
+    result = graph.invoke({"subjects": ["apple", "banana", "carrot"]})
+    assert result == {
+        "subjects": ["apple", "banana", "carrot"],
+        "jokes_with_grades": [
+            {"joke": "Funny joke about apple", "grade": 10},
+            {"joke": "Funny joke about banana", "grade": 9},
+            {"joke": "Funny joke about carrot", "grade": 1},
+        ],
+        "best_selected_joke": "Funny joke about apple",
+    }
+
+
+def test_map_reduce_v2() -> None:
+    """Test map reduce with Graph API."""
+    import operator
+    from typing import Annotated, NotRequired, TypedDict
+    from langgraph.graph import StateGraph
+    from langgraph.types import Send, Command
+
+    class OverallState(TypedDict):
+        subjects: list
+        # Notice here we use the operator.add
+        # This is because we want combine all the jokes we generate
+        # from individual nodes back into one list - this is essentially
+        # the "reduce" part
+        jokes_with_grades: Annotated[list, operator.add]
+        best_selected_joke: str
+
+    # This will be the state of the node that we will "map" all
+    # subjects to in order to generate a joke
+    class JokeState(TypedDict):
+        subject: str
+        joke: NotRequired[str]
+        joke_grade: NotRequired[int]
+
+    def generate_jokes(state: OverallState):
+        # Distribute the subjects to the generate_joke node
+        return [Send("generate_joke", {"subject": s}) for s in state["subjects"]]
+
+    def generate_joke(state: JokeState):
+        # Come up with a joke and continue to grade the joke
+        funny_joke = f"Funny joke about {state['subject']}"
+        return Command(
+            goto=[Send("grade_joke", {"joke": funny_joke, "subject": state["subject"]})]
+        )
+
+    def grade_joke(state: JokeState):
+        # Grade the joke and then send it to the count_grade node which will reduce
+        if state["subject"].startswith("a"):
+            grade = 10
+        elif state["subject"].startswith("b"):
+            grade = 9
+        else:
+            grade = 1
+        return {
+            "jokes_with_grades": [
+                {
+                    "joke": state["joke"],
+                    "grade": grade,
+                }
+            ]
+        }
+
+    def count_grade(state: OverallState):
+        max_score = 0
+        best_joke = ""
+        for joke in state["jokes_with_grades"]:
+            if joke["grade"] > max_score:
+                max_score = joke["grade"]
+                best_joke = joke["joke"]
+        return {"best_selected_joke": best_joke}
+
+    builder = StateGraph(OverallState)
+    builder.add_node(generate_joke)
+    builder.add_node(grade_joke)
+    builder.add_node(count_grade)
+    builder.add_conditional_edges("__start__", generate_jokes, ["generate_joke"])
+    builder.add_edge("grade_joke", "count_grade")
+    builder.add_edge("count_grade", END)
+    graph = builder.compile()
+    result = graph.invoke({"subjects": ["apple", "banana", "carrot"]})
+    assert result == {
+        "subjects": ["apple", "banana", "carrot"],
+        "jokes_with_grades": [
+            {"joke": "Funny joke about apple", "grade": 10},
+            {"joke": "Funny joke about banana", "grade": 9},
+            {"joke": "Funny joke about carrot", "grade": 1},
+        ],
+        "best_selected_joke": "Funny joke about apple",
+    }
+
+
+def test_map_reduce_v3() -> None:
+    """Test map reduce with Graph API."""
+    import operator
+    from typing import Annotated, NotRequired, TypedDict
+    from langgraph.graph import StateGraph
+    from langgraph.types import Send, Command
+
+    class OverallState(TypedDict):
+        subjects: list
+        # Notice here we use the operator.add
+        # This is because we want combine all the jokes we generate
+        # from individual nodes back into one list - this is essentially
+        # the "reduce" part
+        jokes_with_grades: Annotated[list, operator.add]
+        best_selected_joke: str
+
+    # This will be the state of the node that we will "map" all
+    # subjects to in order to generate a joke
+    class JokeState(TypedDict):
+        subject: str
+        joke: NotRequired[str]
+        joke_grade: NotRequired[int]
+
+    def generate_jokes(state: OverallState):
+        # Distribute the subjects to the generate_joke node
+        sends = [Send("generate_joke", {"subject": s}) for s in state["subjects"]]
+        return Command(goto=sends)
+
+    def generate_joke(state: JokeState):
+        # Come up with a joke and continue to grade the joke
+        funny_joke = f"Funny joke about {state['subject']}"
+        return Command(
+            goto=[Send("grade_joke", {"joke": funny_joke, "subject": state["subject"]})]
+        )
+
+    def grade_joke(state: JokeState):
+        # Grade the joke and then send it to the count_grade node which will reduce
+        if state["subject"].startswith("a"):
+            grade = 10
+        elif state["subject"].startswith("b"):
+            grade = 9
+        else:
+            grade = 1
+        return {
+            "jokes_with_grades": [
+                {
+                    "joke": state["joke"],
+                    "grade": grade,
+                }
+            ]
+        }
+
+    def count_grade(state: OverallState):
+        max_score = 0
+        best_joke = ""
+        for joke in state["jokes_with_grades"]:
+            if joke["grade"] > max_score:
+                max_score = joke["grade"]
+                best_joke = joke["joke"]
+        return {"best_selected_joke": best_joke}
+
+    builder = StateGraph(OverallState)
+    builder.add_node(generate_jokes)
+    builder.add_node(generate_joke)
+    builder.add_node(grade_joke)
+    builder.add_node(count_grade)
+    builder.add_edge("__start__", "generate_jokes")
+    builder.add_edge("generate_jokes", "generate_joke")
+    builder.add_edge("grade_joke", "count_grade")
+    builder.add_edge("count_grade", END)
+    graph = builder.compile()
+    result = graph.invoke({"subjects": ["apple", "banana", "carrot"]})
+    assert result == {
+        "subjects": ["apple", "banana", "carrot"],
+        "jokes_with_grades": [
+            {"joke": "Funny joke about apple", "grade": 10},
+            {"joke": "Funny joke about banana", "grade": 9},
+            {"joke": "Funny joke about carrot", "grade": 1},
+        ],
+        "best_selected_joke": "Funny joke about apple",
+    }