@langchain/managed-deepagents

TypeScript SDK for the LangSmith Managed Deep Agents API.

Managed Deep Agents is a hosted runtime for creating, running, and operating Deep Agents through LangSmith. This package is currently public beta software.

Installation

npm install @langchain/managed-deepagents

Requirements:

• Node.js 20 or newer
• A LangSmith API key with access to Managed Deep Agents

Configuration

The client reads LANGSMITH_API_KEY by default in server-side JavaScript runtimes.

export LANGSMITH_API_KEY="..."

The default API URL is https://api.smith.langchain.com/v1/deepagents. You can override it with LANGSMITH_ENDPOINT or the apiUrl client option.

For browser apps, avoid exposing long-lived API keys. Pass a custom fetch implementation that calls your own backend, or create server-side routes that own the LangSmith credentials.

Quickstart

import { Client } from "@langchain/managed-deepagents";

const client = new Client({
  apiKey: process.env.LANGSMITH_API_KEY,
});

const agent = await client.agents.create({
  name: "research-assistant",
  model: "openai:gpt-5.5",
  instructions: "You are a careful research assistant.",
});

const thread = await client.threads.create({ agent_id: agent.id });

const stream = client.threads.stream(thread.id, { agentId: agent.id });

await stream.run.start({
  input: {
    messages: [{ role: "user", content: "Summarize the latest notes." }],
  },
});

for await (const message of stream.messages) {
  for await (const token of message.text) {
    process.stdout.write(token);
  }
}

console.log(await stream.output);
await stream.close();

React useStream

The SDK includes a LangGraph client adapter for @langchain/react. Use getLangGraphClient() for React streaming so LangGraph owns the generic thread, run, and projection behavior; this SDK only translates Managed Deep Agents-specific routes, headers, and payload fields.

import { Client } from "@langchain/managed-deepagents";
import { useStream } from "@langchain/react";

const agentId = "agent-id";
const managedDeepAgents = new Client({
  apiKey: process.env.LANGSMITH_API_KEY,
});
const client = managedDeepAgents.getLangGraphClient({ agentId });

export function ManagedDeepAgentStream() {
  const stream = useStream({
    client,
    assistantId: agentId,
    fetchStateHistory: false,
  });

  return (
    <section>
      <button
        type="button"
        disabled={stream.isLoading}
        onClick={() => {
          void stream.submit({
            messages: [{ role: "user", content: "Write a short status update." }],
          });
        }}
      >
        Run agent
      </button>

      {stream.messages.map((message, index) => (
        <p key={message.id ?? index}>{String(message.content)}</p>
      ))}

      <p>State keys: {Object.keys(stream.values).join(", ")}</p>
    </section>
  );
}

Agent Files

Top-level files entries may be passed as raw strings; the SDK normalizes them to file entries before sending the request.

const agent = await client.agents.create(
  {
    name: "research-assistant",
    files: {
      "AGENTS.md": "You are a careful research assistant.",
      "skills/research/SKILL.md": "# Research\n\nGather context before answering.",
    },
  },
  { includeFiles: true }
);

API Surface

Resources exposed by the client:

• client.agents: list, create, get, update, delete, clone, health
• client.threads: list, create, search, count, get, update, delete, create run, invoke, stream, bulk update, resolve interrupt
• client.mcpServers: create, list, get, update, delete, register OAuth provider, list tools
• client.authSessions: create and get

Errors

import { ManagedDeepAgentsAPIError } from "@langchain/managed-deepagents";

try {
  await client.agents.get("missing-agent");
} catch (error) {
  if (error instanceof ManagedDeepAgentsAPIError) {
    console.log(error.status, error.code, error.detail);
  }
}

Links

• Repository: https://github.com/langchain-ai/managed-deepagents-sdk
• Issues: https://github.com/langchain-ai/managed-deepagents-sdk/issues
• Changelog: https://github.com/langchain-ai/managed-deepagents-sdk/blob/main/CHANGELOG.md