Stream Events

client.Beta.Sessions.Events.Stream(ctx, sessionID, params) (*BetaManagedAgentsStreamSessionEventsUnion, error)

GET/v1/sessions/{session_id}/events/stream

Stream Events

Parameters

sessionID string

params BetaSessionEventStreamParams

EventDeltas param.Field[[]BetaManagedAgentsDeltaType] Optional

Query param: 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.

const BetaManagedAgentsDeltaTypeAgentMessage BetaManagedAgentsDeltaType = "agent.message"

const BetaManagedAgentsDeltaTypeAgentThinking BetaManagedAgentsDeltaType = "agent.thinking"

Betas param.Field[[]AnthropicBeta] Optional

Header param: Optional header to specify the beta version(s) you want to use.

string

type AnthropicBeta string

One of the following:

const AnthropicBetaMessageBatches2024_09_24 AnthropicBeta = "message-batches-2024-09-24"

const AnthropicBetaPromptCaching2024_07_31 AnthropicBeta = "prompt-caching-2024-07-31"

const AnthropicBetaComputerUse2024_10_22 AnthropicBeta = "computer-use-2024-10-22"

const AnthropicBetaComputerUse2025_01_24 AnthropicBeta = "computer-use-2025-01-24"

const AnthropicBetaPDFs2024_09_25 AnthropicBeta = "pdfs-2024-09-25"

const AnthropicBetaTokenCounting2024_11_01 AnthropicBeta = "token-counting-2024-11-01"

const AnthropicBetaTokenEfficientTools2025_02_19 AnthropicBeta = "token-efficient-tools-2025-02-19"

const AnthropicBetaOutput128k2025_02_19 AnthropicBeta = "output-128k-2025-02-19"

const AnthropicBetaFilesAPI2025_04_14 AnthropicBeta = "files-api-2025-04-14"

const AnthropicBetaMCPClient2025_04_04 AnthropicBeta = "mcp-client-2025-04-04"

const AnthropicBetaMCPClient2025_11_20 AnthropicBeta = "mcp-client-2025-11-20"

const AnthropicBetaDevFullThinking2025_05_14 AnthropicBeta = "dev-full-thinking-2025-05-14"

const AnthropicBetaInterleavedThinking2025_05_14 AnthropicBeta = "interleaved-thinking-2025-05-14"

const AnthropicBetaCodeExecution2025_05_22 AnthropicBeta = "code-execution-2025-05-22"

const AnthropicBetaExtendedCacheTTL2025_04_11 AnthropicBeta = "extended-cache-ttl-2025-04-11"

const AnthropicBetaContext1m2025_08_07 AnthropicBeta = "context-1m-2025-08-07"

const AnthropicBetaContextManagement2025_06_27 AnthropicBeta = "context-management-2025-06-27"

const AnthropicBetaModelContextWindowExceeded2025_08_26 AnthropicBeta = "model-context-window-exceeded-2025-08-26"

const AnthropicBetaSkills2025_10_02 AnthropicBeta = "skills-2025-10-02"

const AnthropicBetaFastMode2026_02_01 AnthropicBeta = "fast-mode-2026-02-01"

const AnthropicBetaOutput300k2026_03_24 AnthropicBeta = "output-300k-2026-03-24"

const AnthropicBetaUserProfiles2026_03_24 AnthropicBeta = "user-profiles-2026-03-24"

const AnthropicBetaUserProfiles2026_08_18 AnthropicBeta = "user-profiles-2026-08-18"

const AnthropicBetaAdvisorTool2026_03_01 AnthropicBeta = "advisor-tool-2026-03-01"

const AnthropicBetaManagedAgents2026_04_01 AnthropicBeta = "managed-agents-2026-04-01"

const AnthropicBetaCacheDiagnosis2026_04_07 AnthropicBeta = "cache-diagnosis-2026-04-07"

const AnthropicBetaDreaming2026_04_21 AnthropicBeta = "dreaming-2026-04-21"

const AnthropicBetaThinkingTokenCount2026_05_13 AnthropicBeta = "thinking-token-count-2026-05-13"

const AnthropicBetaServerSideFallback2026_06_01 AnthropicBeta = "server-side-fallback-2026-06-01"

const AnthropicBetaServerSideFallback2026_07_01 AnthropicBeta = "server-side-fallback-2026-07-01"

const AnthropicBetaFallbackCredit2026_06_01 AnthropicBeta = "fallback-credit-2026-06-01"

const AnthropicBetaFallbackCredit2026_07_01 AnthropicBeta = "fallback-credit-2026-07-01"

const AnthropicBetaAgentMemory2026_07_22 AnthropicBeta = "agent-memory-2026-07-22"

const AnthropicBetaMidConversationToolChanges2026_07_01 AnthropicBeta = "mid-conversation-tool-changes-2026-07-01"

const AnthropicBetaCompact2026_01_12 AnthropicBeta = "compact-2026-01-12"

const AnthropicBetaComputerUse2025_11_24 AnthropicBeta = "computer-use-2025-11-24"

const AnthropicBetaMCPTunnels2026_06_22 AnthropicBeta = "mcp-tunnels-2026-06-22"

const AnthropicBetaStructuredOutputs2025_11_13 AnthropicBeta = "structured-outputs-2025-11-13"

const AnthropicBetaTaskBudgets2026_03_13 AnthropicBeta = "task-budgets-2026-03-13"

const AnthropicBetaThinkingDisplayUpdates2026_08_18 AnthropicBeta = "thinking-display-updates-2026-08-18"

const AnthropicBetaCEUserManagement2026_07_13 AnthropicBeta = "ce-user-management-2026-07-13"

Returns

type BetaManagedAgentsStreamSessionEventsUnion interface{…}

Server-sent event in the session stream.

One of the following:

type BetaManagedAgentsStreamSessionEventsUnion interface{…}

Server-sent event in the session stream.

One of the following:

Stream Events

package main

import (
	"context"
	"fmt"

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

func main() {
	client := anthropic.NewClient(
		option.WithAPIKey("my-anthropic-api-key"),
	)
	stream := client.Beta.Sessions.Events.StreamEvents(
		context.TODO(),
		"sesn_011CZkZAtmR3yMPDzynEDxu7",
		anthropic.BetaSessionEventStreamParams{},
	)
	for stream.Next() {
		fmt.Printf("%+v\n", stream.Current())
	}
	err := stream.Err()
	if err != nil {
		panic(err.Error())
	}
}

{
  "id": "sevt_011CZkZGOp0iBcp4kaQSihUmy",
  "content": [
    {
      "text": "Where is my order #1234?",
      "type": "text"
    }
  ],
  "type": "user.message",
  "processed_at": "2026-03-15T10:00:00Z"
}

Returns Examples

{
  "id": "sevt_011CZkZGOp0iBcp4kaQSihUmy",
  "content": [
    {
      "text": "Where is my order #1234?",
      "type": "text"
    }
  ],
  "type": "user.message",
  "processed_at": "2026-03-15T10:00:00Z"
}