Managed Deep Agents

Overview

Managed Deep Agents is a hosted runtime for creating, running, and operating Deep Agents in LangSmith. It packages the operational layer around the open-source Deep Agents harness: a versioned Context Hub agent repo, durable threads, streamed runs, MCP credential storage, managed files, and optional LangSmith sandboxes.

Use the Managed Deep Agents path when the user wants LangSmith to host and operate the agent. For self-hosted deployments, custom application routes, or the full Agent Server API surface, use a standard LangSmith Deployment via [[langgraph-cli]] instead.

When to use

Use this skill when the user wants to:

• Deploy a Managed Deep Agent from local project files.
• Create or update a Managed Deep Agent from Python, TypeScript, or REST.
• Run an agent on a durable thread and stream output.
• Build a React chat UI with @langchain/react useStream.
• Register MCP servers, list MCP tools, or configure tool interrupts.
• Choose between Managed Deep Agents and a self-hosted LangSmith Deployment.

Prerequisites

• Managed Deep Agents preview access in the target LangSmith workspace.
• A LangSmith API key for that workspace.
• One of the supported clients:

uv tool install "deepagents-cli>=0.2.2"
pip install managed-deepagents
npm install @langchain/managed-deepagents @langchain/react

Set the API key in the shell or server environment:

export LANGSMITH_API_KEY="<LANGSMITH_API_KEY>"

The SDKs default to https://api.smith.langchain.com/v1/deepagents. To use a different compatible endpoint, set LANGSMITH_ENDPOINT or pass api_url / apiUrl in the client.

For direct REST examples, set:

export DEEPAGENTS_BASE_URL="https://api.smith.langchain.com/v1/deepagents"

All REST requests authenticate with:

X-Api-Key: <LANGSMITH_API_KEY>

Never expose a long-lived LangSmith API key in browser code. For browser apps, route requests through your own backend or provide a custom fetch implementation that proxies requests server-side.

Choose an interface

Prefer the CLI for local agent projects. Prefer the SDKs for application code. Use REST only when you need exact request control.

Resource groups

Project file tree

The CLI uses a local project directory and deploys it into the managed Context Hub agent repo.

my-agent/
  agent.json
  AGENTS.md
  tools.json
  skills/<name>/SKILL.md
  subagents/<name>/agent.json
  subagents/<name>/AGENTS.md
  subagents/<name>/tools.json

At runtime, the agent can read and write managed files, including memory files created by the Deep Agents harness.

Backends

New projects should use the canonical backend names from deepagents-cli>=0.2.2.

Use state when the agent does not need sandbox-specific backend behavior:

{
  "backend": {
    "type": "state"
  }
}

Use sandbox when the agent needs a LangSmith sandbox for code execution, filesystem work, or long-running tasks:

{
  "backend": {
    "type": "sandbox",
    "sandbox_config": {
      "scope": "thread",
      "policy_ids": ["policy-id"],
      "idle_ttl_seconds": 900,
      "delete_after_stop_seconds": 300
    }
  }
}

sandbox_config.scope must be thread or agent.

CLI workflow

Use the CLI for most deploy workflows.

deepagents init research-assistant
cd research-assistant

Edit agent.json:

{
  "name": "research-assistant",
  "description": "Research assistant that can search the web and summarize sources.",
  "model": "openai:gpt-5.5",
  "backend": {
    "type": "state"
  }
}

Edit AGENTS.md with the main instructions, then deploy:

deepagents deploy

Useful CLI commands:

For shared repositories, put the target agent_id in agent.json; the CLI asks for confirmation before updating that remote agent. Use --yes only when the target is intentional.

MCP tools

Tools are configured with a tools array and an interrupt_config map. The same shape is used in tools.json and inline SDK/REST create or update payloads.

{
  "tools": [
    {
      "name": "read_url_content",
      "mcp_server_url": "https://example.com/mcp",
      "mcp_server_name": "my-tools",
      "display_name": "read_url_content"
    }
  ],
  "interrupt_config": {
    "https://example.com/mcp::read_url_content": false
  }
}

• tools[].mcp_server_url must match a registered workspace MCP server URL.
• tools[].name is the tool name exposed by the MCP server, not the workspace MCP-server display name.
• Use deepagents mcp-servers tools <server> or the SDK tool-listing methods to confirm exact tool names.
• interrupt_config keys use {mcp_server_url}::{tool_name}. Additional :: parts are accepted for compatibility, but do not rely on them for new configs.
• Set the interrupt value to true to require human approval before the tool runs.

Python SDK tool listing:

from managed_deepagents import Client

with Client() as client:
    tools = client.mcp_servers.list_tools(
        url="https://example.com/mcp",
        force_refresh=True,
    )
    print(tools["tools"])

TypeScript SDK tool listing:

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

const client = new Client({ apiKey: process.env.LANGSMITH_API_KEY });
const tools = await client.mcpServers.listTools({
  url: "https://example.com/mcp",
  forceRefresh: true,
});
console.log(tools.tools);

Python SDK workflow

Use the Python SDK for server-side automation and streaming.

from managed_deepagents import Client

with Client() as client:
    agent = client.agents.create(
        name="research-assistant",
        description="Research assistant that can search the web and summarize sources.",
        model="openai:gpt-5.5",
        backend={"type": "state"},
        instructions=(
            "You are a careful research assistant. Search for sources, "
            "keep notes, and return concise answers with citations."
        ),
    )

    thread = client.threads.create(
        agent_id=agent["id"],
        options={
            "test_run": False,
            "skip_memory_write_protection": False,
        },
    )

    for event in client.threads.stream(
        thread["id"],
        agent_id=agent["id"],
        messages=[
            {
                "role": "user",
                "content": "Research recent approaches to agent memory and summarize the main tradeoffs.",
            }
        ],
        stream_mode=["values", "updates", "messages-tuple"],
        stream_subgraphs=True,
        user_timezone="America/Los_Angeles",
    ):
        print(event.event, event.data)

Async Python clients are available as AsyncClient with matching resource names.

TypeScript SDK workflow

Use the TypeScript SDK for server-side automation and LangGraph-compatible streaming.

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",
  description: "Research assistant that can search the web and summarize sources.",
  model: "openai:gpt-5.5",
  backend: { type: "state" },
  instructions:
    "You are a careful research assistant. Search for sources, keep notes, and return concise answers with citations.",
});

const thread = await client.threads.create({
  agent_id: agent.id,
  options: {
    test_run: false,
    skip_memory_write_protection: false,
  },
});

const langGraphClient = client.getLangGraphClient({ agentId: agent.id });
const stream = langGraphClient.runs.stream(thread.id, agent.id, {
  input: {
    messages: [
      {
        role: "user",
        content:
          "Research recent approaches to agent memory and summarize the main tradeoffs.",
      },
    ],
  },
  streamMode: ["values", "updates", "messages-tuple"],
  streamSubgraphs: true,
});

for await (const event of stream) {
  console.log(event.event, event.data);
}

The adapter translates LangGraph SDK request fields into Managed Deep Agents routes, headers, and payload fields.

React useStream

For React applications, use the TypeScript SDK's LangGraph client adapter with @langchain/react. useStream owns the thread, run, and state projection behavior while the Managed Deep Agents SDK handles auth, routes, and payload translation.

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

const agentId = "<agent_id>";

const managedDeepAgents = new Client({
  // Server-only or browser-safe proxy configuration.
  // Do not ship LANGSMITH_API_KEY to browser clients.
  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>
      ))}
    </section>
  );
}

stream.submit({ messages }) is the correct UI-level shape. The SDK adapter rewrites it to the Managed Deep Agents stream route as input.messages.

REST fallback

Use REST when a client does not expose a field yet or when debugging raw payloads. Prefer SDK helpers in normal application code.

Create an agent:

import os
import httpx

BASE_URL = os.environ["DEEPAGENTS_BASE_URL"]
HEADERS = {"X-Api-Key": os.environ["LANGSMITH_API_KEY"]}

response = httpx.post(
    f"{BASE_URL}/agents",
    headers=HEADERS,
    json={
        "name": "research-assistant",
        "description": "Research assistant that can search the web and summarize sources.",
        "runtime": {"model": {"model_id": "openai:gpt-5.5"}},
        "backend": {"type": "state"},
        "instructions": (
            "You are a careful research assistant. Search for sources, "
            "keep notes, and return concise answers with citations."
        ),
    },
)
response.raise_for_status()
agent_id = response.json()["id"]

Create a thread:

response = httpx.post(
    f"{BASE_URL}/threads",
    headers=HEADERS,
    json={
        "agent_id": agent_id,
        "options": {
            "test_run": False,
            "skip_memory_write_protection": False,
        },
    },
)
response.raise_for_status()
thread_id = response.json()["id"]

Stream a run:

payload = {
    "agent_id": agent_id,
    "input": {
        "messages": [
            {
                "role": "user",
                "content": "Research recent approaches to agent memory and summarize the main tradeoffs.",
            }
        ]
    },
    "stream_mode": ["values", "updates", "messages-tuple"],
    "stream_subgraphs": True,
    "user_timezone": "America/Los_Angeles",
}

with httpx.stream(
    "POST",
    f"{BASE_URL}/threads/{thread_id}/runs/stream",
    headers={**HEADERS, "Accept": "text/event-stream"},
    json=payload,
    timeout=None,
) as response:
    response.raise_for_status()
    for line in response.iter_lines():
        if line:
            print(line)

Set Accept: text/event-stream for raw REST streaming. stream_mode accepts LangGraph stream modes such as values, updates, and messages-tuple. stream_subgraphs: true emits subagent events as well as parent events.

Human-in-the-loop interrupts

When interrupt_config flags a tool with true, the run pauses before the tool executes and emits an interrupt payload inside a values or updates event:

{
  "__interrupt__": [
    {
      "value": {
        "action_requests": [
          {
            "name": "read_url_content",
            "args": { "url": "https://example.com" },
            "description": "Tool execution requires approval"
          }
        ],
        "review_configs": [
          {
            "action_name": "read_url_content",
            "allowed_decisions": ["approve", "edit", "reject", "respond"]
          }
        ]
      },
      "id": "interrupt-id"
    }
  ]
}

The stream closes after the interrupt is emitted. To act on it, post a follow-up run with command.resume on the same thread.

Python SDK resume:

for event in client.threads.stream(
    thread_id,
    agent_id=agent_id,
    messages=[{"role": "system", "content": ""}],
    command={"resume": {"decisions": [{"type": "approve"}]}},
    stream_mode=["values", "updates", "messages-tuple"],
    stream_subgraphs=True,
):
    print(event.event, event.data)

REST resume:

payload = {
    "agent_id": agent_id,
    "input": {"messages": [{"role": "system", "content": ""}]},
    "command": {
        "resume": {
            "decisions": [{"type": "approve"}]
        }
    },
    "stream_mode": ["values", "updates", "messages-tuple"],
    "stream_subgraphs": True,
}

The resume value must be the HITL response object {"decisions": [...]}, not a bare decision list. Send exactly one decision per action_request, in the same order.

Each decision type must be allowed by the matching review_configs[i].allowed_decisions.

Resolve interrupt endpoint

POST /v1/deepagents/threads/{thread_id}/resolve-interrupt takes no body and returns 204. It terminates the paused run at the interrupt; it is not an approve shortcut. Use command.resume on /runs/stream for approve, edit, reject, or respond decisions.

When NOT to use Managed Deep Agents

Use a standard LangSmith Deployment via [[langgraph-cli]] (langgraph deploy) instead when you need:

• Custom application code or custom routes around the agent.
• Advanced authentication around your own app server.
• The full Agent Server API surface.
• Stronger isolation controls or maximum scalability.
• A region other than supported LangSmith Cloud regions, or self-hosted/Hybrid.

Gotchas

• Use deepagents-cli>=0.2.2 - older CLI versions generate stale backend names.
• Use canonical backends - new examples should use state or sandbox with sandbox_config.scope.
• REST stream payloads use input.messages - SDK helpers accept messages and normalize the request body.
• Do not ship API keys to browsers - proxy browser requests through your backend or custom fetch.
• PATCH can replace nested fields wholesale - when updating tools, pass the full desired tool set.
• Tool names must match MCP tool names - if tools[].name is wrong, the model will not see the tool.
• List tools before wiring tools.json - use the CLI or SDK tool-listing methods to avoid name mismatches.
• Resume interrupts with command.resume = {"decisions": [...]} - a bare list is invalid.
• Resume runs still need a non-empty message list - use [ {"role": "system", "content": ""} ] as a no-op message when needed.
• resolve-interrupt cancels/finalizes - it does not approve a pending action.
• Model IDs should include provider prefix - use openai:gpt-5.5, not a bare model name.
• MCP credentials are sensitive - avoid logging headers or raw credential payloads.
• Deleting an agent does not delete its threads - track and clean up threads explicitly.
• API stability - /v1/deepagents is still evolving; prefer SDK and CLI surfaces for user-facing workflows.