Comparison
Function Calling vs ReAct
Function Calling and ReAct are both common AI/LLM terms but cover different ideas. Here is a quick side-by-side.
When you would reach for Function Calling
Function Calling comes up when the question is fundamentally about agents & tools.
OpenAI's tools parameter and tool_calls response.
When you would reach for ReAct
ReAct comes up when the question is fundamentally about agents & tools.
A search-augmented assistant: Thought, Search, Observation, Thought, Answer.
Frequently asked
What is the difference between Function Calling and ReAct?
Function Calling: Function calling is the specific API mechanism by which an LLM emits a structured request to invoke a named function with typed arguments. The OpenAI-popularized way to do tool use. ReAct: ReAct is a prompting pattern that interleaves reasoning ("Thought:") with actions ("Action:") and observations ("Observation:"). It is the foundation of most tool-using agents.
When should I use Function Calling vs ReAct?
Function Calling is the right concept when you are focused on agents & tools. ReAct applies when you are focused on agents & tools.
Are Function Calling and ReAct the same thing?
No. Function Calling is agents & tools; ReAct is agents & tools. They are related but address different parts of the AI stack.