Send Events

BetaManagedAgentsSendSessionEvents beta().sessions().events().send(, )

POST/v1/sessions/{session_id}/events

Send Events

Parameters

EventSendParams params

Optional<String> sessionId

Optional<List<AnthropicBeta>> betas

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

MESSAGE_BATCHES_2024_09_24("message-batches-2024-09-24")

PROMPT_CACHING_2024_07_31("prompt-caching-2024-07-31")

COMPUTER_USE_2024_10_22("computer-use-2024-10-22")

COMPUTER_USE_2025_01_24("computer-use-2025-01-24")

PDFS_2024_09_25("pdfs-2024-09-25")

TOKEN_COUNTING_2024_11_01("token-counting-2024-11-01")

TOKEN_EFFICIENT_TOOLS_2025_02_19("token-efficient-tools-2025-02-19")

OUTPUT_128K_2025_02_19("output-128k-2025-02-19")

FILES_API_2025_04_14("files-api-2025-04-14")

MCP_CLIENT_2025_04_04("mcp-client-2025-04-04")

MCP_CLIENT_2025_11_20("mcp-client-2025-11-20")

DEV_FULL_THINKING_2025_05_14("dev-full-thinking-2025-05-14")

INTERLEAVED_THINKING_2025_05_14("interleaved-thinking-2025-05-14")

CODE_EXECUTION_2025_05_22("code-execution-2025-05-22")

EXTENDED_CACHE_TTL_2025_04_11("extended-cache-ttl-2025-04-11")

CONTEXT_1M_2025_08_07("context-1m-2025-08-07")

CONTEXT_MANAGEMENT_2025_06_27("context-management-2025-06-27")

MODEL_CONTEXT_WINDOW_EXCEEDED_2025_08_26("model-context-window-exceeded-2025-08-26")

SKILLS_2025_10_02("skills-2025-10-02")

FAST_MODE_2026_02_01("fast-mode-2026-02-01")

OUTPUT_300K_2026_03_24("output-300k-2026-03-24")

USER_PROFILES_2026_03_24("user-profiles-2026-03-24")

USER_PROFILES_2026_08_18("user-profiles-2026-08-18")

ADVISOR_TOOL_2026_03_01("advisor-tool-2026-03-01")

MANAGED_AGENTS_2026_04_01("managed-agents-2026-04-01")

CACHE_DIAGNOSIS_2026_04_07("cache-diagnosis-2026-04-07")

DREAMING_2026_04_21("dreaming-2026-04-21")

THINKING_TOKEN_COUNT_2026_05_13("thinking-token-count-2026-05-13")

SERVER_SIDE_FALLBACK_2026_06_01("server-side-fallback-2026-06-01")

SERVER_SIDE_FALLBACK_2026_07_01("server-side-fallback-2026-07-01")

FALLBACK_CREDIT_2026_06_01("fallback-credit-2026-06-01")

FALLBACK_CREDIT_2026_07_01("fallback-credit-2026-07-01")

AGENT_MEMORY_2026_07_22("agent-memory-2026-07-22")

MID_CONVERSATION_TOOL_CHANGES_2026_07_01("mid-conversation-tool-changes-2026-07-01")

COMPACT_2026_01_12("compact-2026-01-12")

COMPUTER_USE_2025_11_24("computer-use-2025-11-24")

MCP_TUNNELS_2026_06_22("mcp-tunnels-2026-06-22")

STRUCTURED_OUTPUTS_2025_11_13("structured-outputs-2025-11-13")

TASK_BUDGETS_2026_03_13("task-budgets-2026-03-13")

THINKING_DISPLAY_UPDATES_2026_08_18("thinking-display-updates-2026-08-18")

CE_USER_MANAGEMENT_2026_07_13("ce-user-management-2026-07-13")

List<BetaManagedAgentsEventParams> events

Events to send to the session.

class BetaManagedAgentsUserMessageEventParams:

Parameters for sending a user message to the session.

class BetaManagedAgentsUserInterruptEventParams:

Parameters for sending an interrupt to pause the agent.

Type type

Optional<String> sessionThreadId

If absent, interrupts every non-archived thread in a multiagent session (or the primary alone in a single-agent session). If present, interrupts only the named thread.

class BetaManagedAgentsUserToolConfirmationEventParams:

Parameters for confirming or denying a tool execution request.

Result result

UserToolConfirmationResult enum

One of the following:

ALLOW("allow")

DENY("deny")

String toolUseId

The id of the agent.tool_use or agent.mcp_tool_use event this result corresponds to, which can be found in the last session.status_idle event's stop_reason.event_ids field.

minLength1

maxLength128

Type type

Optional<String> denyMessage

Optional message providing context for a 'deny' decision. Only allowed when result is 'deny'.

maxLength10000

class BetaManagedAgentsUserCustomToolResultEventParams:

Parameters for providing the result of a custom tool execution.

class BetaManagedAgentsUserDefineOutcomeEventParams:

Parameters for defining an outcome the agent should work toward. The agent begins work on receipt.

String description

What the agent should produce. This is the task specification.

Rubric rubric

Rubric for grading the quality of an outcome.

One of the following:

class BetaManagedAgentsFileRubricParams:

Rubric referenced by a file uploaded via the Files API.

String fileId

ID of the rubric file.

Type type

class BetaManagedAgentsTextRubricParams:

Rubric content provided inline as text.

String content

Rubric content. Plain text or markdown — the grader treats it as freeform text. Maximum 262144 characters.

maxLength262144

Type type

Optional<Long> maxIterations

Eval→revision cycles before giving up. Default 3, max 20.

formatint32

class BetaManagedAgentsUserToolResultEventParams:

Parameters for providing the result of an agent-toolset tool execution. Only valid on self_hosted environments, where sandbox-routed tools are executed by the client rather than the server.

class BetaManagedAgentsSystemMessageEventParams:

Privileged context for the accompanying turn and all subsequent turns, appended to the session's system context as a role: "system" turn rather than replacing the top-level system prompt. At most one per request: it must be the final event and immediately follow the user.message, user.tool_result, or user.custom_tool_result it accompanies. Only supported on models that accept mid-conversation system messages.

List<BetaManagedAgentsSystemContentBlock> content

System content blocks to append. Text-only.

String text

The text content.

minLength1

Type type

Returns

class BetaManagedAgentsSendSessionEvents:

Events that were successfully sent to the session.

Send Events

package com.anthropic.example;

import com.anthropic.client.AnthropicClient;
import com.anthropic.client.okhttp.AnthropicOkHttpClient;
import com.anthropic.models.beta.sessions.events.BetaManagedAgentsSendSessionEvents;
import com.anthropic.models.beta.sessions.events.BetaManagedAgentsTextBlock;
import com.anthropic.models.beta.sessions.events.BetaManagedAgentsUserMessageEventParams;
import com.anthropic.models.beta.sessions.events.EventSendParams;
import java.util.List;

public final class Main {
    private Main() {}

    public static void main(String[] args) {
        AnthropicClient client = AnthropicOkHttpClient.fromEnv();

        EventSendParams params = EventSendParams.builder()
            .sessionId("sesn_011CZkZAtmR3yMPDzynEDxu7")
            .addUserMessageEvent(List.of(BetaManagedAgentsUserMessageEventParams.Content.ofText(BetaManagedAgentsTextBlock.builder()
                .text("Where is my order #1234?")
                .type(BetaManagedAgentsTextBlock.Type.TEXT)
                .build())))
            .build();
        BetaManagedAgentsSendSessionEvents betaManagedAgentsSendSessionEvents = client.beta().sessions().events().send(params);
    }
}

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

Returns Examples

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