Google Gemini chat adapter with function calling support.
Supports Gemini models via the /v1beta/models/{model}:generateContent endpoint.
Tool Calling
Pass :tools (list of %LangEx.Tool{}) to enable function calling.
The adapter returns {:ok, %Message.AI{tool_calls: [...]}} when the
model requests a function call. Use LangEx.Tool.Node to execute them.
LangEx.LLM.Gemini.chat(messages,
model: "gemini-2.5-flash",
tools: [%LangEx.Tool{name: "get_weather", ...}]
)Options
:tool_choice— force function calling::auto(default),:required/:any(must call some function), or{:tool, name}(must call that one)