React prompt template

Hi!

I am using Langchain v1 and the create_agent() function to build an ReAct agent.

In prior versions it was common to use a prompt template that used the React pattern:

Answer the following questions as best you can. You have access to the following tools:

{tools}

Use the following format:

Question: the input question you must answer
Thought: you should always think about what to do
Action: the action to take, should be one of [{tool_names}]
Action Input: the input to the action
Observation: the result of the action
… (this Thought/Action/Action Input/Observation can repeat N times)
Thought: I now know the final answer
Final Answer: the final answer to the original input question

Begin!

Question: {input}
Thought:{agent_scratchpad}

What happened to the prompt template? Is this not used anymore or something that it applied under the Hood and combined with a custom system prompt?

Thanks in advance ,

M