Models¶
This page describes how to configure the chat model used by an agent.
Tool calling support¶
To enable tool-calling agents, the underlying LLM must support tool calling.
Compatible models can be found in the LangChain integrations directory.
Specifying a model by name¶
You can configure an agent with a model name string:
API Reference: create_react_agent
from langgraph.prebuilt import create_react_agent
agent = create_react_agent(
model="anthropic:claude-3-7-sonnet-latest",
# other parameters
)
Using init_chat_model¶
The init_chat_model utility simplifies model initialization with configurable parameters:
API Reference: init_chat_model
from langchain.chat_models import init_chat_model
model = init_chat_model(
"anthropic:claude-3-7-sonnet-latest",
temperature=0,
max_tokens=2048
)
Refer to the API reference for advanced options.
Using provider-specific LLMs¶
If a model provider is not available via init_chat_model, you can instantiate the provider's model class directly. The model must implement the BaseChatModel interface and support tool calling:
API Reference: ChatAnthropic | create_react_agent
from langchain_anthropic import ChatAnthropic
from langgraph.prebuilt import create_react_agent
model = ChatAnthropic(
model="claude-3-7-sonnet-latest",
temperature=0,
max_tokens=2048
)
agent = create_react_agent(
model=model,
# other parameters
)
Illustrative example
The example above uses ChatAnthropic, which is already supported by init_chat_model. This pattern is shown to illustrate how to manually instantiate a model not available through init_chat_model.