langchain[patch]: agents check prompt partial vars (#20303)

libs/langchain/langchain/agents/json_chat/base.py

@@ -155,7 +155,7 @@ def create_json_chat_agent(
             )
     """  # noqa: E501
     missing_vars = {"tools", "tool_names", "agent_scratchpad"}.difference(
-        prompt.input_variables
+        prompt.input_variables + list(prompt.partial_variables)
     )
     if missing_vars:
         raise ValueError(f"Prompt missing required variables: {missing_vars}")

libs/langchain/langchain/agents/openai_functions_agent/base.py

@@ -298,7 +298,9 @@ def create_openai_functions_agent(
                 ]
             )
     """
-    if "agent_scratchpad" not in prompt.input_variables:
+    if "agent_scratchpad" not in (
+        prompt.input_variables + list(prompt.partial_variables)
+    ):
         raise ValueError(
             "Prompt must have input variable `agent_scratchpad`, but wasn't found. "
             f"Found {prompt.input_variables} instead."

libs/langchain/langchain/agents/openai_tools/base.py

@@ -78,7 +78,9 @@ def create_openai_tools_agent(
                 ]
             )
     """
-    missing_vars = {"agent_scratchpad"}.difference(prompt.input_variables)
+    missing_vars = {"agent_scratchpad"}.difference(
+        prompt.input_variables + list(prompt.partial_variables)
+    )
     if missing_vars:
         raise ValueError(f"Prompt missing required variables: {missing_vars}")
 

libs/langchain/langchain/agents/react/agent.py

@@ -108,7 +108,7 @@ def create_react_agent(
             prompt = PromptTemplate.from_template(template)
     """  # noqa: E501
     missing_vars = {"tools", "tool_names", "agent_scratchpad"}.difference(
-        prompt.input_variables
+        prompt.input_variables + list(prompt.partial_variables)
     )
     if missing_vars:
         raise ValueError(f"Prompt missing required variables: {missing_vars}")

libs/langchain/langchain/agents/self_ask_with_search/base.py

@@ -173,7 +173,9 @@ def create_self_ask_with_search_agent(
 
             prompt = PromptTemplate.from_template(template)
     """  # noqa: E501
-    missing_vars = {"agent_scratchpad"}.difference(prompt.input_variables)
+    missing_vars = {"agent_scratchpad"}.difference(
+        prompt.input_variables + list(prompt.partial_variables)
+    )
     if missing_vars:
         raise ValueError(f"Prompt missing required variables: {missing_vars}")
 

libs/langchain/langchain/agents/structured_chat/base.py

@@ -273,7 +273,7 @@ def create_structured_chat_agent(
             )
     """  # noqa: E501
     missing_vars = {"tools", "tool_names", "agent_scratchpad"}.difference(
-        prompt.input_variables
+        prompt.input_variables + list(prompt.partial_variables)
     )
     if missing_vars:
         raise ValueError(f"Prompt missing required variables: {missing_vars}")

libs/langchain/langchain/agents/tool_calling_agent/base.py

@@ -33,14 +33,14 @@ def create_tool_calling_agent(
 
             from langchain.agents import AgentExecutor, create_tool_calling_agent, tool
             from langchain_anthropic import ChatAnthropic
-            from langchain_core.prompts import ChatPromptTemplate, MessagesPlaceholder
+            from langchain_core.prompts import ChatPromptTemplate
 
             prompt = ChatPromptTemplate.from_messages(
                 [
                     ("system", "You are a helpful assistant"),
-                    MessagesPlaceholder("chat_history", optional=True),
+                    ("placeholder", "{chat_history}",
                     ("human", "{input}"),
-                    MessagesPlaceholder("agent_scratchpad"),
+                    ("placeholder", "{agent_scratchpad}"),
                 ]
             )
             model = ChatAnthropic(model="claude-3-opus-20240229")
@@ -75,7 +75,9 @@ def create_tool_calling_agent(
             ``MessagesPlaceholder``. Intermediate agent actions and tool output
             messages will be passed in here.
     """
-    missing_vars = {"agent_scratchpad"}.difference(prompt.input_variables)
+    missing_vars = {"agent_scratchpad"}.difference(
+        prompt.input_variables + list(prompt.partial_variables)
+    )
     if missing_vars:
         raise ValueError(f"Prompt missing required variables: {missing_vars}")
 

libs/langchain/langchain/agents/xml/base.py

@@ -203,7 +203,9 @@ def create_xml_agent(
             {agent_scratchpad}'''
             prompt = PromptTemplate.from_template(template)
     """  # noqa: E501
-    missing_vars = {"tools", "agent_scratchpad"}.difference(prompt.input_variables)
+    missing_vars = {"tools", "agent_scratchpad"}.difference(
+        prompt.input_variables + list(prompt.partial_variables)
+    )
     if missing_vars:
         raise ValueError(f"Prompt missing required variables: {missing_vars}")