LangGraph agents and Dome

from langchain_mcp_adapters.client import MultiServerMCPClient
from langgraph.graph import START, MessagesState, StateGraph
from langgraph.prebuilt import ToolNode, tools_condition
from dome_langchain import AgentIdentity, DomeChatOpenAI
 
 
async def build_researcher():
    # Tools: whatever this agent is granted on the Gateway
    mcp = MultiServerMCPClient({"dome": {
        "transport": "streamable_http",
        "url": f"{GATEWAY_URL}/mcp",
        "headers": {"Authorization": f"Bearer {DOME_AGENT_KEY}"},
    }})
    tools = await mcp.get_tools()
 
    # Model: a pool on the Broker, with failover across providers
    llm = DomeChatOpenAI.for_agent(
        AgentIdentity(token=DOME_AGENT_KEY, gateway_url=GATEWAY_URL),
        model="claude-opus-5-5",
    ).bind_tools(tools)
 
    async def think(state: MessagesState):
        return {"messages": [await llm.ainvoke(state["messages"])]}
 
    graph = StateGraph(MessagesState)
    graph.add_node("think", think)
    graph.add_node("tools", ToolNode(tools))
    graph.add_edge(START, "think")
    graph.add_conditional_edges("think", tools_condition)
    graph.add_edge("tools", "think")
    return graph.compile()
 
 
researcher = await build_researcher()
await researcher.ainvoke({"messages": [("user", "Where is rate limiting handled?")]})