Stream Session Thread Events

$client->beta->sessions->threads->events->streamStream(string threadID, string sessionID, ?list<BetaManagedAgentsDeltaType> eventDeltas, ?list<AnthropicBeta> betas, ?string workspaceID): BaseStream<ManagedAgentsStreamSessionThreadEvents>

GET/v1/sessions/{session_id}/threads/{thread_id}/stream

Requires anthropic-beta: managed-agents-2026-04-01. How to send beta headers

Parameters

sessionID: string⁠Path

threadID: string⁠Path

eventDeltas?: optional list<BetaManagedAgentsDeltaType>⁠Query

When set, this connection also receives streaming deltas (event_start, event_delta) while an event is being produced, before the event itself arrives. Deltas are best-effort; when the final event is produced it carries the complete content. A model request that ends early (an error or interrupt) produces no final event — its terminal span.model_request_end closes the preview. Accepts one or more event types to preview and may be repeated: agent.message streams content_delta fragments; agent.thinking is start-only — a signal that the agent has begun extended thinking, concluded by the agent.thinking event itself. Only previews of the requested event types are sent.

betas?: optional list<AnthropicBeta>⁠Header

This endpoint is in beta: requests must send managed-agents-2026-04-01 in this header.

workspaceID?: optional string⁠Header

Optional header to select the Workspace for this request. The value is a Workspace ID (for example, wrkspc_011CZkZaBF1tNoB5wlCeusgy).

Only needed for credentials that can act on more than one Workspace. A credential that belongs to a specific Workspace may omit it; if sent, it must match that Workspace.

Returns

class ManagedAgentsStreamSessionThreadEvents

One of the following:

Stream Session Thread Events

<?php

require_once dirname(__DIR__) . '/vendor/autoload.php';

use Anthropic\Client;
use Anthropic\Beta\AnthropicBeta;
use Anthropic\Beta\Sessions\BetaManagedAgentsDeltaType;

$client = new Client(apiKey: 'my-anthropic-api-key');

$betaManagedAgentsStreamSessionThreadEvents = $client
  ->beta
  ->sessions
  ->threads
  ->events
  ->streamStream(
  'sthr_011CZkZVWa6oJjw1rgXZpnBt',
  sessionID: 'sesn_011CZkZAtmR3yMPDzynEDxu7',
  eventDeltas: [BetaManagedAgentsDeltaType::AGENT_MESSAGE],
  betas: [AnthropicBeta::MESSAGE_BATCHES_2024_09_24],
  workspaceID: 'wrkspc_011CZkZaBF1tNoB5wlCeusgy',
);

var_dump($betaManagedAgentsStreamSessionThreadEvents);

Response 200

{
  "id": "sevt_011CZkZGPp1iBcp4kaQSihUm",
  "content": [
    {
      "text": "Where is my order #1234?",
      "type": "text"
    }
  ],
  "type": "user.message",
  "processed_at": "2026-03-15T10:00:00Z"
}

Returns Examples

Response 200

{
  "id": "sevt_011CZkZGPp1iBcp4kaQSihUm",
  "content": [
    {
      "text": "Where is my order #1234?",
      "type": "text"
    }
  ],
  "type": "user.message",
  "processed_at": "2026-03-15T10:00:00Z"
}