LangGraph Adapter

Capture LangGraph nodes, state checkpoints, chat models, streams, messages, tool events, updates, and tool wrappers.

@isplay/adapter-langgraph combines adapter-kit primitives with LangGraph-specific wrappers.

Install for LangGraph

npm install isplay @isplay/sdk @isplay/adapter-langgraph @langchain/langgraph

Exports

Export	Purpose
`createLangGraphAdapter(options?)`	Returns adapter-kit plus LangGraph helpers.
`wrapNode(client, name, node, options?)`	Capture node input, completion/error, and before/after checkpoints.
`checkpointState(client, name, state, metadata?)`	Annotate and checkpoint state.
`wrapChatModel(client, model, options?)`	Capture `invoke` and `stream` model calls.
`instrumentStream(client, stream, options?)`	Record stream chunks while yielding original chunks.
`recordStreamChunk(client, chunk, options?)`	Record one stream chunk.

Basic Setup

import { init } from "@isplay/sdk";
import { createLangGraphAdapter } from "@isplay/adapter-langgraph";

const client = init({
  projectId: process.env.ISPLAY_PROJECT_ID!,
  baseUrl: process.env.ISPLAY_API_URL,
});

const isplay = createLangGraphAdapter({ client });

Wrap Nodes

const triageNode = isplay.wrapNode(
  "triage",
  async (state) => {
    return { decision: await triage(state.claim) };
  },
  { checkpointState: "both" }
);

wrapNode:

Checkpoints langgraph:<name>:before and langgraph:<name>:after by default.
Annotates node input as state_field.
Records langgraph.node.completed or langgraph.node.error.

Checkpoint State

await isplay.checkpointState("before-risk-tool", state, {
  node: "risk",
  phase: "before",
});

This emits a state_field annotation and a checkpoint named langgraph:<name>.

Wrap Chat Models

const model = isplay.wrapChatModel(rawModel, {
  provider: "openai",
  model: "gpt-5.4-mini",
  operation: "planner",
});

const output = await model.invoke(messages);

invoke is captured as a generate model call. stream is captured as a stream model call and finishes when the async iterable is consumed.

Instrument Streams

for await (const chunk of isplay.instrumentStream(graph.stream(input), {
  recordValuesAsCheckpoints: true,
})) {
  yield chunk;
}

Supported stream modes include updates, values, messages, custom, tools, checkpoints, tasks, and debug.

Stream mode	Captured behavior
`messages`	Annotates assistant message chunks.
`tools`	Tracks tool start/end/error when event shape is available.
`updates`	Annotates state updates as `state_field`.
`values` / `checkpoints`	Optional checkpoints when `recordValuesAsCheckpoints` is true.
other modes	Records `langgraph.stream.<mode>` events.

Wrap Tools

const lookupPolicy = isplay.wrapTool(
  {
    name: "lookup_policy",
    sideEffectClass: "read",
    schemaVersion: "1",
  },
  async (args: { section: string }) => {
    return policyStore.get(args.section);
  }
);

LangGraph adapter tool wrapping records proposals by default.

Gotchas

LangGraphAdapterOptions.checkpointState is declared, but checkpoint behavior is controlled by the options passed directly to wrapNode.
Stream model calls finish only after the stream is consumed.
If LangGraph emits tool events without matching start events, the adapter records observed tool events rather than full tool execution records.

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