LangGraph

LangGraph applications can use Dome in two ways: call the content Guards inside your graph nodes, or wrap the whole graph with secure_agent() for the full trust stack.

Install

pip install "vijil-dome[trust-adapters]"

The trust-adapters extra installs LangGraph along with the Trust Runtime dependencies. See Install Dome for every extra. For content Guards alone, pip install "vijil-dome[local]" next to your existing LangGraph install is enough.

Guard Graph Nodes

Create the Dome instance once and scan at the graph boundaries. A scanning node can end the run early by routing to a terminal node:

from langgraph.graph import END, StateGraph

from vijil_dome import Dome

dome = Dome()


def guard_input_node(state):
    scan = dome.guard_input(state["query"])
    return {
        **state,
        "query": scan.guarded_response(),
        "blocked": not scan.is_safe(),
    }


def guard_output_node(state):
    scan = dome.guard_output(state["answer"])
    return {**state, "answer": scan.guarded_response()}


builder = StateGraph(AgentState)
builder.add_node("guard_input", guard_input_node)
builder.add_node("agent", agent_node)
builder.add_node("guard_output", guard_output_node)

builder.set_entry_point("guard_input")
builder.add_conditional_edges(
    "guard_input",
    lambda state: END if state["blocked"] else "agent",
)
builder.add_edge("agent", "guard_output")
builder.add_edge("guard_output", END)

graph = builder.compile()

Use async_guard_input() and async_guard_output() in asynchronous nodes.

Add the Full Trust Stack

secure_agent() accepts a StateGraph and returns a SecureGraph, which replaces graph.compile():

from vijil_dome import secure_agent

app = secure_agent(
    builder,
    agent_id="travel-agent",
    constraints=constraints,
    mode="enforce",
)

The secured graph applies content Guards on model calls, checks tool calls against the Agent’s permission policy, and emits audit events. Pass compile_kwargs through secure_agent() when your graph needs compile options such as a checkpoint saver.

LangGraph tool access control is best-effort. The compiled graph must expose tool functions that the adapter can discover and wrap. Streaming output is checked only after chunks are yielded, so an output Guard cannot retract content that a client already received.

Get Started

Evaluate Agents

Protect Agents

Reference

Install

Guard Graph Nodes

Add the Full Trust Stack

Next Steps

Trust Runtime

Use Guardrails

​Install

​Guard Graph Nodes

​Add the Full Trust Stack

​Next Steps

Trust Runtime

Use Guardrails

Install

Guard Graph Nodes

Add the Full Trust Stack

Next Steps