Get started with Claude Managed Agents

Create your first autonomous agent.

This guide walks you through creating an agent, setting up an environment, starting a session, and streaming agent responses.

Tip

Prefer an interactive walkthrough? Run /claude-api managed-agents-onboard in the latest version of Claude Code for a guided setup and interactive question-answering.

Core concepts

Concept	Description
Agent	The model, system prompt, tools, MCP servers, and skills
Environment	Configuration for where sessions run: an Anthropic-managed cloud container, or a self-hosted sandbox on your own infrastructure
Session	A running agent instance within an environment, performing a specific task and generating outputs
Events	Messages exchanged between your application and the agent (user turns, tool results, status updates)

Prerequisites

An Anthropic Console account
An API key

Install the CLI

brew install anthropics/tap/ant

For Linux environments, download the release binary directly.

VERSION=1.9.1
OS=$(uname -s | tr '[:upper:]' '[:lower:]')
ARCH=$(uname -m | sed -e 's/x86_64/amd64/' -e 's/aarch64/arm64/')
curl -fsSL "https://github.com/anthropics/anthropic-cli/releases/download/v${VERSION}/ant_${VERSION}_${OS}_${ARCH}.tar.gz" \
  | sudo tar -xz -C /usr/local/bin ant

You can find all releases on the GitHub releases page.

You may also install the CLI from source using go install. Requires Go 1.22 or later.

go install github.com/anthropics/anthropic-cli/cmd/ant@latest

The binary is placed in $(go env GOPATH)/bin. Add it to your PATH if it isn't already:

export PATH="$PATH:$(go env GOPATH)/bin"

Check the installation:

ant --version

Install the SDK

pip install anthropic

npm install @anthropic-ai/sdk

implementation("com.anthropic:anthropic-java:2.33.0")

go get github.com/anthropics/anthropic-sdk-go

dotnet add package Anthropic

bundle add anthropic

composer require anthropic-ai/sdk

Set your API key as an environment variable:

export ANTHROPIC_API_KEY="your-api-key-here"

Create your first session

Note

All Managed Agents API requests require the managed-agents-2026-04-01 beta header. The SDK sets the beta header automatically.

Create an agent

Create an agent that defines the model, system prompt, and available tools.

set -euo pipefail

agent=$(
  curl -sS --fail-with-body https://api.anthropic.com/v1/agents \
    -H "x-api-key: $ANTHROPIC_API_KEY" \
    -H "anthropic-version: 2023-06-01" \
    -H "anthropic-beta: managed-agents-2026-04-01" \
    -H "content-type: application/json" \
    -d @- <<'EOF'
{
  "name": "Coding Assistant",
  "model": "claude-opus-4-7",
  "system": "You are a helpful coding assistant. Write clean, well-documented code.",
  "tools": [
    {"type": "agent_toolset_20260401"}
  ]
}
EOF
)

AGENT_ID=$(jq -er '.id' <<<"$agent")
AGENT_VERSION=$(jq -er '.version' <<<"$agent")

echo "Agent ID: $AGENT_ID, version: $AGENT_VERSION"

ant beta:agents create \
  --name "Coding Assistant" \
  --model '{id: claude-opus-4-7}' \
  --system "You are a helpful coding assistant. Write clean, well-documented code." \
  --tool '{type: agent_toolset_20260401}'

from anthropic import Anthropic

client = Anthropic()

agent = client.beta.agents.create(
    name="Coding Assistant",
    model="claude-opus-4-7",
    system="You are a helpful coding assistant. Write clean, well-documented code.",
    tools=[
        {"type": "agent_toolset_20260401"},
    ],
)

print(f"Agent ID: \{agent.id\}, version: \{agent.version\}")

import Anthropic from "@anthropic-ai/sdk";

const client = new Anthropic();

const agent = await client.beta.agents.create({
  name: "Coding Assistant",
  model: "claude-opus-4-7",
  system: "You are a helpful coding assistant. Write clean, well-documented code.",
  tools: [
    { type: "agent_toolset_20260401" },
  ],
});

console.log(`Agent ID: ${agent.id}, version: ${agent.version}`);

using Anthropic;
using Anthropic.Models.Beta.Agents;
using Anthropic.Models.Beta.Environments;
using Anthropic.Models.Beta.Sessions;
using Anthropic.Models.Beta.Sessions.Events;

var client = new AnthropicClient();

var agent = await client.Beta.Agents.Create(new()
{
    Name = "Coding Assistant",
    Model = BetaManagedAgentsModel.ClaudeOpus4_7,
    System = "You are a helpful coding assistant. Write clean, well-documented code.",
    Tools =
    [
        new BetaManagedAgentsAgentToolset20260401Params
        {
            Type = "agent_toolset_20260401",
        },
    ],
});

Console.WriteLine({{CONTENT}}quot;Agent ID: \{agent.ID\}, version: \{agent.Version\}");

package main

import (
	"context"
	"fmt"

	"github.com/anthropics/anthropic-sdk-go"
)

func main() {
	client := anthropic.NewClient()
	ctx := context.Background()

	agent, err := client.Beta.Agents.New(ctx, anthropic.BetaAgentNewParams{
		Name: "Coding Assistant",
		Model: anthropic.BetaManagedAgentsModelConfigParams{
			ID: anthropic.BetaManagedAgentsModelClaudeOpus4_7,
		},
		System: anthropic.String("You are a helpful coding assistant. Write clean, well-documented code."),
		Tools: []anthropic.BetaAgentNewParamsToolUnion{{
			OfAgentToolset20260401: &anthropic.BetaManagedAgentsAgentToolset20260401Params{
				Type: anthropic.BetaManagedAgentsAgentToolset20260401ParamsTypeAgentToolset20260401,
			},
		}},
	})
	if err != nil {
		panic(err)
	}

	fmt.Printf("Agent ID: %s, version: %d\n", agent.ID, agent.Version)

import com.anthropic.client.okhttp.AnthropicOkHttpClient;
import com.anthropic.models.beta.agents.AgentCreateParams;
import com.anthropic.models.beta.agents.BetaManagedAgentsAgentToolset20260401Params;
import com.anthropic.models.beta.agents.BetaManagedAgentsModel;
import com.anthropic.models.beta.environments.BetaCloudConfigParams;
import com.anthropic.models.beta.environments.EnvironmentCreateParams;
import com.anthropic.models.beta.environments.BetaUnrestrictedNetwork;
import com.anthropic.models.beta.sessions.SessionCreateParams;
import com.anthropic.models.beta.sessions.events.BetaManagedAgentsUserMessageEventParams;
import com.anthropic.models.beta.sessions.events.EventSendParams;
import com.anthropic.models.beta.sessions.events.BetaManagedAgentsStreamSessionEvents;

void main() {
    var client = AnthropicOkHttpClient.fromEnv();

    var agent = client.beta().agents().create(AgentCreateParams.builder()
        .name("Coding Assistant")
        .model(BetaManagedAgentsModel.CLAUDE_OPUS_4_7)
        .system("You are a helpful coding assistant. Write clean, well-documented code.")
        .addTool(BetaManagedAgentsAgentToolset20260401Params.builder()
            .type(BetaManagedAgentsAgentToolset20260401Params.Type.AGENT_TOOLSET_20260401)
            .build())
        .build());

    IO.println("Agent ID: " + agent.id() + ", version: " + agent.version());

use Anthropic\Client;

$client = new Client();

$agent = $client->beta->agents->create(
    name: 'Coding Assistant',
    model: 'claude-opus-4-7',
    system: 'You are a helpful coding assistant. Write clean, well-documented code.',
    tools: [
        ['type' => 'agent_toolset_20260401'],
    ],
);

echo "Agent ID: {$agent->id}, version: {$agent->version}\n";

require "anthropic"

client = Anthropic::Client.new

agent = client.beta.agents.create(
  name: "Coding Assistant",
  model: "claude-opus-4-7",
  system_: "You are a helpful coding assistant. Write clean, well-documented code.",
  tools: [{type: "agent_toolset_20260401"}]
)

puts "Agent ID: #\{agent.id\}, version: #\{agent.version\}"

The agent_toolset_20260401 tool type enables the full set of pre-built agent tools (bash, file operations, web search, and more). See Tools for the complete list and per-tool configuration options.

Save the returned agent.id. You'll reference it in every session you create.

Create an environment

An environment defines the container where your agent runs.

environment=$(
  curl -sS --fail-with-body https://api.anthropic.com/v1/environments \
    -H "x-api-key: $ANTHROPIC_API_KEY" \
    -H "anthropic-version: 2023-06-01" \
    -H "anthropic-beta: managed-agents-2026-04-01" \
    -H "content-type: application/json" \
    -d @- <<'EOF'
{
  "name": "quickstart-env",
  "config": {
    "type": "cloud",
    "networking": {"type": "unrestricted"}
  }
}
EOF
)

ENVIRONMENT_ID=$(jq -er '.id' <<<"$environment")

echo "Environment ID: $ENVIRONMENT_ID"

ant beta:environments create \
  --name "quickstart-env" \
  --config '{type: cloud, networking: {type: unrestricted}}'

environment = client.beta.environments.create(
    name="quickstart-env",
    config={
        "type": "cloud",
        "networking": {"type": "unrestricted"},
    },
)

print(f"Environment ID: \{environment.id\}")

const environment = await client.beta.environments.create({
  name: "quickstart-env",
  config: {
    type: "cloud",
    networking: { type: "unrestricted" },
  },
});

console.log(`Environment ID: ${environment.id}`);

var environment = await client.Beta.Environments.Create(new()
{
    Name = "quickstart-env",
    Config = new BetaCloudConfigParams { Networking = new BetaUnrestrictedNetwork() },
});

Console.WriteLine({{CONTENT}}quot;Environment ID: \{environment.ID\}");

environment, err := client.Beta.Environments.New(ctx, anthropic.BetaEnvironmentNewParams{
	Name: "quickstart-env",
	Config: anthropic.BetaEnvironmentNewParamsConfigUnion{
		OfCloud: &anthropic.BetaCloudConfigParams{
			Networking: anthropic.BetaCloudConfigParamsNetworkingUnion{
				OfUnrestricted: &anthropic.BetaUnrestrictedNetworkParam{},
			},
		},
	},
})
if err != nil {
	panic(err)
}

fmt.Printf("Environment ID: %s\n", environment.ID)

var environment = client.beta().environments().create(EnvironmentCreateParams.builder()
    .name("quickstart-env")
    .config(BetaCloudConfigParams.builder()
        .networking(BetaUnrestrictedNetwork.builder().build())
        .build())
    .build());

IO.println("Environment ID: " + environment.id());

$environment = $client->beta->environments->create(
    name: 'quickstart-env',
    config: ['type' => 'cloud', 'networking' => ['type' => 'unrestricted']],
);

echo "Environment ID: {$environment->id}\n";

environment = client.beta.environments.create(
  name: "quickstart-env",
  config: {type: "cloud", networking: {type: "unrestricted"}}
)

puts "Environment ID: #\{environment.id\}"

Save the returned environment.id. You'll reference it in every session you create.

Tip

To run the sandbox on your own infrastructure instead of a cloud container, see Self-hosted sandboxes.

Start a session

Create a session that references your agent and environment.

session=$(
  curl -sS --fail-with-body https://api.anthropic.com/v1/sessions \
    -H "x-api-key: $ANTHROPIC_API_KEY" \
    -H "anthropic-version: 2023-06-01" \
    -H "anthropic-beta: managed-agents-2026-04-01" \
    -H "content-type: application/json" \
    -d @- <<EOF
{
  "agent": "$AGENT_ID",
  "environment_id": "$ENVIRONMENT_ID",
  "title": "Quickstart session"
}
EOF
)

SESSION_ID=$(jq -er '.id' <<<"$session")

echo "Session ID: $SESSION_ID"

session = client.beta.sessions.create(
    agent=agent.id,
    environment_id=environment.id,
    title="Quickstart session",
)

print(f"Session ID: \{session.id\}")

const session = await client.beta.sessions.create({
  agent: agent.id,
  environment_id: environment.id,
  title: "Quickstart session",
});

console.log(`Session ID: ${session.id}`);

var session = await client.Beta.Sessions.Create(new()
{
    Agent = agent.ID,
    EnvironmentID = environment.ID,
    Title = "Quickstart session",
});

Console.WriteLine({{CONTENT}}quot;Session ID: \{session.ID\}");

session, err := client.Beta.Sessions.New(ctx, anthropic.BetaSessionNewParams{
	Agent:         anthropic.BetaSessionNewParamsAgentUnion{OfString: anthropic.String(agent.ID)},
	EnvironmentID: environment.ID,
	Title:         anthropic.String("Quickstart session"),
})
if err != nil {
	panic(err)
}

fmt.Printf("Session ID: %s\n", session.ID)

var session = client.beta().sessions().create(SessionCreateParams.builder()
    .agent(agent.id())
    .environmentId(environment.id())
    .title("Quickstart session")
    .build());

IO.println("Session ID: " + session.id());

$session = $client->beta->sessions->create(
    agent: $agent->id,
    environmentID: $environment->id,
    title: 'Quickstart session',
);

echo "Session ID: {$session->id}\n";

session = client.beta.sessions.create(
  agent: agent.id,
  environment_id: environment.id,
  title: "Quickstart session"
)

puts "Session ID: #\{session.id\}"

Send a message and stream the response

Open a stream, send a user event, then process events as they arrive:

# Send the user message first; the API buffers events until the stream attaches
curl -sS --fail-with-body \
  "https://api.anthropic.com/v1/sessions/$SESSION_ID/events" \
  -H "x-api-key: $ANTHROPIC_API_KEY" \
  -H "anthropic-version: 2023-06-01" \
  -H "anthropic-beta: managed-agents-2026-04-01" \
  -H "content-type: application/json" \
  -d @- >/dev/null <<'EOF'
{
  "events": [
    {
      "type": "user.message",
      "content": [
        {
          "type": "text",
          "text": "Create a Python script that generates the first 20 Fibonacci numbers and saves them to fibonacci.txt"
        }
      ]
    }
  ]
}
EOF

# Open the SSE stream and process events as they arrive
while IFS= read -r line; do
  [[ $line == data:* ]] || continue
  json=${line#data: }
  case $(jq -r '.type' <<<"$json") in
    agent.message)
      jq -j '.content[] | select(.type == "text") | .text' <<<"$json"
      ;;
    agent.tool_use)
      printf '\n[Using tool: %s]\n' "$(jq -r '.name' <<<"$json")"
      ;;
    session.status_idle)
      printf '\n\nAgent finished.\n'
      break
      ;;
  esac
done < <(
  curl -sS -N --fail-with-body \
    "https://api.anthropic.com/v1/sessions/$SESSION_ID/stream" \
    -H "x-api-key: $ANTHROPIC_API_KEY" \
    -H "anthropic-version: 2023-06-01" \
    -H "anthropic-beta: managed-agents-2026-04-01" \
    -H "Accept: text/event-stream"
)

with client.beta.sessions.events.stream(session.id) as stream:
    # Send the user message after the stream opens
    client.beta.sessions.events.send(
        session.id,
        events=[
            {
                "type": "user.message",
                "content": [
                    {
                        "type": "text",
                        "text": "Create a Python script that generates the first 20 Fibonacci numbers and saves them to fibonacci.txt",
                    },
                ],
            },
        ],
    )

    # Process streaming events
    for event in stream:
        match event.type:
            case "agent.message":
                for block in event.content:
                    print(block.text, end="")
            case "agent.tool_use":
                print(f"\n[Using tool: \{event.name\}]")
            case "session.status_idle":
                print("\n\nAgent finished.")
                break

const stream = await client.beta.sessions.events.stream(session.id);

// Send the user message after the stream opens
await client.beta.sessions.events.send(session.id, {
  events: [
    {
      type: "user.message",
      content: [
        {
          type: "text",
          text: "Create a Python script that generates the first 20 Fibonacci numbers and saves them to fibonacci.txt",
        },
      ],
    },
  ],
});

// Process streaming events
for await (const event of stream) {
  if (event.type === "agent.message") {
    for (const block of event.content) {
      process.stdout.write(block.text);
    }
  } else if (event.type === "agent.tool_use") {
    console.log(`\n[Using tool: ${event.name}]`);
  } else if (event.type === "session.status_idle") {
    console.log("\n\nAgent finished.");
    break;
  }
}

var stream = client.Beta.Sessions.Events.StreamStreaming(session.ID);

// Send the user message after the stream opens
await client.Beta.Sessions.Events.Send(session.ID, new()
{
    Events =
    [
        new BetaManagedAgentsUserMessageEventParams
        {
            Type = "user.message",
            Content =
            [
                new BetaManagedAgentsTextBlock
                {
                    Type = "text",
                    Text = "Create a Python script that generates the first 20 Fibonacci numbers and saves them to fibonacci.txt",
                },
            ],
        },
    ],
});

// Process streaming events
await foreach (var ev in stream)
{
    if (ev.Value is BetaManagedAgentsAgentMessageEvent message)
    {
        foreach (var block in message.Content)
        {
            Console.Write(block.Text);
        }
    }
    else if (ev.Value is BetaManagedAgentsAgentToolUseEvent toolUse)
    {
        Console.WriteLine({{CONTENT}}quot;\n[Using tool: \{toolUse.Name\}]");
    }
    else if (ev.Value is BetaManagedAgentsSessionStatusIdleEvent)
    {
        Console.WriteLine("\n\nAgent finished.");
        break;
    }
}

	stream := client.Beta.Sessions.Events.StreamEvents(ctx, session.ID, anthropic.BetaSessionEventStreamParams{})
	defer stream.Close()

	// Send the user message after the stream opens
	_, err = client.Beta.Sessions.Events.Send(ctx, session.ID, anthropic.BetaSessionEventSendParams{
		Events: []anthropic.BetaManagedAgentsEventParamsUnion{{
			OfUserMessage: &anthropic.BetaManagedAgentsUserMessageEventParams{
				Type: anthropic.BetaManagedAgentsUserMessageEventParamsTypeUserMessage,
				Content: []anthropic.BetaManagedAgentsUserMessageEventParamsContentUnion{{
					OfText: &anthropic.BetaManagedAgentsTextBlockParam{
						Type: anthropic.BetaManagedAgentsTextBlockTypeText,
						Text: "Create a Python script that generates the first 20 Fibonacci numbers and saves them to fibonacci.txt",
					},
				}},
			},
		}},
	})
	if err != nil {
		panic(err)
	}

	// Process streaming events
loop:
	for stream.Next() {
		switch event := stream.Current().AsAny().(type) {
		case anthropic.BetaManagedAgentsAgentMessageEvent:
			for _, block := range event.Content {
				fmt.Print(block.Text)
			}
		case anthropic.BetaManagedAgentsAgentToolUseEvent:
			fmt.Printf("\n[Using tool: %s]\n", event.Name)
		case anthropic.BetaManagedAgentsSessionStatusIdleEvent:
			fmt.Print("\n\nAgent finished.\n")
			break loop
		}
	}
	if err := stream.Err(); err != nil {
		panic(err)
	}

try (var stream = client.beta().sessions().events().streamStreaming(session.id())) {
    // Send the user message after the stream opens
    client.beta().sessions().events().send(session.id(), EventSendParams.builder()
        .addEvent(BetaManagedAgentsUserMessageEventParams.builder()
            .type(BetaManagedAgentsUserMessageEventParams.Type.USER_MESSAGE)
            .addTextContent("Create a Python script that generates the first 20 Fibonacci numbers and saves them to fibonacci.txt")
            .build())
        .build());

    // Process streaming events
    for (var event : (Iterable<BetaManagedAgentsStreamSessionEvents>) stream.stream()::iterator) {
        if (event.isAgentMessage()) {
            event.asAgentMessage().content().forEach(block -> IO.print(block.text()));
        } else if (event.isAgentToolUse()) {
            IO.println("\n[Using tool: " + event.asAgentToolUse().name() + "]");
        } else if (event.isSessionStatusIdle()) {
            IO.println("\n\nAgent finished.");
            break;
        }
    }
}

$stream = $client->beta->sessions->events->streamStream($session->id);

// Send the user message after the stream opens
$client->beta->sessions->events->send(
    $session->id,
    events: [
        [
            'type' => 'user.message',
            'content' => [
                ['type' => 'text', 'text' => 'Create a Python script that generates the first 20 Fibonacci numbers and saves them to fibonacci.txt'],
            ],
        ],
    ],
);

// Process streaming events
foreach ($stream as $event) {
    match ($event->type) {
        'agent.message' => print(implode('', array_map(fn($block) => $block->text, $event->content))),
        'agent.tool_use' => print("\n[Using tool: {$event->name}]\n"),
        'session.status_idle' => print("\n\nAgent finished.\n"),
        default => null,
    };
    if ($event->type === 'session.status_idle') {
        break;
    }
}

stream = client.beta.sessions.events.stream_events(session.id)

# Send the user message after the stream opens
client.beta.sessions.events.send_(
  session.id,
  events: [{
    type: "user.message",
    content: [{type: "text", text: "Create a Python script that generates the first 20 Fibonacci numbers and saves them to fibonacci.txt"}]
  }]
)

# Process streaming events
stream.each do |event|
  case event.type
  in :"agent.message"
    event.content.each { print it.text }
  in :"agent.tool_use"
    puts "\n[Using tool: #\{event.name\}]"
  in :"session.status_idle"
    puts "\n\nAgent finished."
    break
  else
    # ignore other event types
  end
end

The agent will write a Python script, execute it in the container, and verify the output file was created. Your output will look similar to this:

I'll create a Python script that generates the first 20 Fibonacci numbers and saves them to a file.
[Using tool: write]
[Using tool: bash]
The script ran successfully. Let me verify the output file.
[Using tool: bash]
fibonacci.txt contains the first 20 Fibonacci numbers (0 through 4181).

Agent finished.

What's happening

When you send a user event, Claude Managed Agents:

Provisions a container: Your environment configuration determines how it's built.
Runs the agent loop: Claude decides which tools to use based on your message
Executes tools: File writes, bash commands, and other tool calls run inside the container
Streams events: You receive real-time updates as the agent works
Goes idle: The agent emits a session.status_idle event when it has nothing more to do

Next steps

◆Define your agent

Create reusable, versioned agent configurations

◆Configure environments

Customize networking and container settings

◆Agent tools

Enable specific tools for your agent

◆Events and streaming

Handle events and steer the agent mid-execution