From cc97fad7e5ab245f309e3e64f7bc6191b112459a Mon Sep 17 00:00:00 2001
From: Harrison Chase <hw.chase.17@gmail.com>
Date: Tue, 26 Aug 2025 20:26:34 -0700
Subject: [PATCH] cr

---
 .../agent/middleware/human_in_the_loop.py     | 99 ++++++++++++++++++-
 .../langgraph/agent/middleware/swarm.py       | 13 +++
 2 files changed, 111 insertions(+), 1 deletion(-)
 create mode 100644 libs/langgraph/langgraph/agent/middleware/swarm.py

diff --git a/libs/langgraph/langgraph/agent/middleware/human_in_the_loop.py b/libs/langgraph/langgraph/agent/middleware/human_in_the_loop.py
index a9608d2e4..08fc80596 100644
--- a/libs/langgraph/langgraph/agent/middleware/human_in_the_loop.py
+++ b/libs/langgraph/langgraph/agent/middleware/human_in_the_loop.py
@@ -1 +1,98 @@
-# Needs ability to jump to another node (back to model node, in case of reject or response from user)
\ No newline at end of file
+from langgraph.agent.types import AgentMiddleware, AgentState, AgentUpdate, AgentGoTo
+from typing import Dict, Any, List, Optional, Union
+from langgraph.types import interrupt
+from langgraph.prebuilt.interrupt import (
+    HumanInterruptConfig,
+    ActionRequest,
+    HumanInterrupt,
+    HumanResponse,
+)
+
+ToolInterruptConfig = Dict[str, HumanInterruptConfig]
+
+class HumanInTheLoopMiddleware(AgentMiddleware):
+
+    def __init__(self,
+    tool_configs: ToolInterruptConfig,
+    message_prefix: str = "Tool execution requires approval",):
+        super().__init__()
+        self.tool_configs = tool_configs
+        self.message_prefix = message_prefix
+
+    def after_model(self, state: AgentState) -> AgentUpdate | AgentGoTo | None:
+        messages = state.messages
+        if not messages:
+            return
+
+        last_message = messages[-1]
+
+        if not hasattr(last_message, "tool_calls") or not last_message.tool_calls:
+            return
+
+        # Separate tool calls that need interrupts from those that don't
+        interrupt_tool_calls = []
+        auto_approved_tool_calls = []
+
+        for tool_call in last_message.tool_calls:
+            tool_name = tool_call["name"]
+            if tool_name in self.tool_configs:
+                interrupt_tool_calls.append(tool_call)
+            else:
+                auto_approved_tool_calls.append(tool_call)
+
+        # If no interrupts needed, return early
+        if not interrupt_tool_calls:
+            return
+
+        approved_tool_calls = auto_approved_tool_calls.copy()
+
+        # Process all tool calls that need interrupts in parallel
+        requests = []
+
+        for tool_call in interrupt_tool_calls:
+            tool_name = tool_call["name"]
+            tool_args = tool_call["args"]
+            description = f"{self.message_prefix}\n\nTool: {tool_name}\nArgs: {tool_args}"
+            tool_config = self.tool_configs[tool_name]
+
+            request: HumanInterrupt = {
+                "action_request": ActionRequest(
+                    action=tool_name,
+                    args=tool_args,
+                ),
+                "config": tool_config,
+                "description": description,
+            }
+            requests.append(request)
+
+        responses: List[HumanResponse] = interrupt(requests)
+
+        for i, response in enumerate(responses):
+            tool_call = interrupt_tool_calls[i]
+
+            if response["type"] == "accept":
+                approved_tool_calls.append(tool_call)
+            elif response["type"] == "edit":
+                edited: ActionRequest = response["args"]
+                new_tool_call = {
+                    "name": tool_call["name"],
+                    "args": edited["args"],
+                    "id": tool_call["id"],
+                }
+                approved_tool_calls.append(new_tool_call)
+            elif response["type"] == "ignore":
+                # NOTE: does not work with multiple interrupts
+                return {"goto": "__end__"}
+            elif response["type"] == "response":
+                # NOTE: does not work with multiple interrupts
+                tool_message = {"role": "tool", "tool_call_id": tool_call["id"], "content": response["args"]}
+                return {
+                    "messages": [tool_message],
+                    "goto": "model"
+                }
+            else:
+                raise ValueError(f"Unknown response type: {response['type']}")
+
+        last_message.tool_calls = approved_tool_calls
+
+        return {"messages": [last_message]}
diff --git a/libs/langgraph/langgraph/agent/middleware/swarm.py b/libs/langgraph/langgraph/agent/middleware/swarm.py
new file mode 100644
index 000000000..8af362cb0
--- /dev/null
+++ b/libs/langgraph/langgraph/agent/middleware/swarm.py
@@ -0,0 +1,13 @@
+from langgraph.agent.types import AgentMiddleware, AgentState, ModelRequest
+from typing import Dict, Any, List, Optional, Union
+from langgraph.types import interrupt
+
+
+class SwarmMiddleWare(AgentMiddleware):
+
+    def __init__(self, model_configs: dict[str, dict]):
+        super().__init__()
+
+    def modify_model_request(
+        self, request: ModelRequest, state: AgentState
+    ) -> ModelRequest:
\ No newline at end of file