From 190372e137bf0494a0619dec6e7616dfedfd77cc Mon Sep 17 00:00:00 2001
From: vbarda <vadym@langchain.dev>
Date: Wed, 24 Jul 2024 21:22:19 -0400
Subject: [PATCH] update

---
 docs/docs/cloud/deployment/graph_rebuild.md | 69 +++++++++++++++++++--
 1 file changed, 64 insertions(+), 5 deletions(-)

diff --git a/docs/docs/cloud/deployment/graph_rebuild.md b/docs/docs/cloud/deployment/graph_rebuild.md
index d700b0822..c7853b30a 100644
--- a/docs/docs/cloud/deployment/graph_rebuild.md
+++ b/docs/docs/cloud/deployment/graph_rebuild.md
@@ -1,6 +1,9 @@
 # Rebuild Graph at Runtime
 
-You might need to rebuild your graph with a different configuration for a new run. This guide shows how you can do this.
+You might need to rebuild your graph with a different configuration for a new run. For example, you might need to use a different graph state or graph structure depending on the config. This guide shows how you can do this.
+
+!!! note "Note"
+    In most cases, customizing behavior based on the config should be handled by a single graph where each node can read a config and change its behavior based on it
 
 ## Prerequisites
 
@@ -52,24 +55,80 @@ To make the server aware of your graph, you need to specify a path to the variab
 
 ### Rebuild
 
-To make your graph rebuild on each new run with custom configuration, you need to rewrite `openai_agent.py` to instead provide a _function_ that takes a config and returns a graph (or compiled graph) instance as follows:
+To make your graph rebuild on each new run with custom configuration, you need to rewrite `openai_agent.py` to instead provide a _function_ that takes a config and returns a graph (or compiled graph) instance. Let's say we want to return our existing graph for user ID '1', and a tool-calling agent for other users. We can modify `openai_agent.py` as follows:
 
 ```python
+from typing import Annotated, TypedDict
 from langchain_openai import ChatOpenAI
 from langgraph.graph import END, MessageGraph
+from langgraph.graph.state import StateGraph
+from langgraph.graph.message import add_messages
+from langgraph.prebuilt import ToolNode
+from langchain_core.tools import tool
+from langchain_core.messages import BaseMessage
 from langchain_core.runnables import RunnableConfig
 
+
+class State(TypedDict):
+    messages: Annotated[list[BaseMessage], add_messages]
+
+
 model = ChatOpenAI(temperature=0)
 
-def make_graph(config: RunnableConfig)
-    graph_workflow = MessageGraph()
+def make_default_graph():
+    """Make a simple LLM agent"""
+    graph_workflow = StateGraph(State)
+    def call_model(state):
+        return {"messages": [model.invoke(state["messages"])]}
 
-    graph_workflow.add_node("agent", model)
+    graph_workflow.add_node("agent", call_model)
     graph_workflow.add_edge("agent", END)
     graph_workflow.set_entry_point("agent")
 
     agent = graph_workflow.compile()
     return agent
+
+
+def make_alternative_graph():
+    """Make a tool-calling agent"""
+
+    @tool
+    def add(a: float, b: float):
+        """Adds two numbers."""
+        return a + b
+
+    tool_node = ToolNode([add])
+    model_with_tools = model.bind_tools([add])
+    def call_model(state):
+        return {"messages": [model_with_tools.invoke(state["messages"])]}
+
+    def should_continue(state: State):
+        if state["messages"][-1].tool_calls:
+            return "tools"
+        else:
+            return END
+
+    graph_workflow = StateGraph(State)
+
+    graph_workflow.add_node("agent", call_model)
+    graph_workflow.add_node("tools", tool_node)
+    graph_workflow.add_edge("tools", "agent")
+    graph_workflow.set_entry_point("agent")
+    graph_workflow.add_conditional_edges("agent", should_continue)
+
+    agent = graph_workflow.compile()
+    return agent
+
+
+# this is the graph making function that will decide which graph to
+# build based on the provided config
+def make_graph(config: RunnableConfig):
+    user_id = config.get("configurable", {}).get("user_id")
+    # route to different graph state / structure based on the user ID
+    if user_id == "1":
+        return make_default_graph()
+    else:
+        return make_alternative_graph()
 ```
 
 Finally, you need to specify the path to your graph-making function (`make_graph`) in `langgraph.json`: