LangGraph

AxonPushLangGraphHandler extends AxonPushCallbackHandler with two extra events that record per-node traversal of a StateGraph. LangGraph still consumes LangChain.js’s callback interface, so everything the LangChain handler emits is emitted here too.

Tested against @langchain/langgraph@^0.4.

Install

npm install @axonpush/sdk @langchain/langgraph

Attach the handler

import { AxonPush, AxonPushLangGraphHandler } from "@axonpush/sdk";

const client = new AxonPush();
const handler = new AxonPushLangGraphHandler({
  client,
  channelId: process.env.AXONPUSH_CHANNEL_ID!,
  agentId: "research-graph",
});

Then pass it wherever LangGraph accepts callbacks:

import { StateGraph } from "@langchain/langgraph";

const graph = new StateGraph({ channels })
  .addNode("agent", agentNode)
  .addNode("tools", toolNode)
  .compile();

const result = await graph.invoke(input, { callbacks: [handler] });

agentId defaults to "langgraph".

What gets emitted

Everything from the LangChain handler, plus:

Identifier	axonpush eventType	Payload
graph.node.start	agent.start	node_name, truncated inputs
graph.node.end	agent.end	truncated outputs

graph.node.start only fires when a node name can be resolved, from LangChain’s runName, then metadata.langgraph_node, then serialized.name. Graph-level events carry metadata.framework: "langgraph" and metadata.node; the inherited chain and LLM events carry metadata.framework: "langchain".

Reading node identity

LangGraph compiles nodes into anonymous Runnables: handleChainStart receives serialized = {} and the node’s identity arrives in the trailing runName argument and metadata.langgraph_node. Before 0.0.7 the handler read only serialized.name, so every step in every graph was labelled chain_type: "unknown". It now falls through the full chain of derivations and also propagates langgraph_node, langgraph_step, langgraph_triggers, and thread_id into event metadata, enough to group a trace by node or by conversation thread in the UI.

No code change is needed to pick this up; upgrade the package.