## Stream Session Thread Events `BetaManagedAgentsStreamSessionThreadEvents Beta.Sessions.Threads.Events.StreamStreaming(EventStreamParamsparameters, CancellationTokencancellationToken = default)` **get** `/v1/sessions/{session_id}/threads/{thread_id}/stream` Stream Session Thread Events ### Parameters - `EventStreamParams parameters` - `required string sessionID` Path param: Path parameter session_id - `required string threadID` Path param: Path parameter thread_id - `IReadOnlyList betas` Header param: Optional header to specify the beta version(s) you want to use. - `"message-batches-2024-09-24"MessageBatches2024_09_24` - `"prompt-caching-2024-07-31"PromptCaching2024_07_31` - `"computer-use-2024-10-22"ComputerUse2024_10_22` - `"computer-use-2025-01-24"ComputerUse2025_01_24` - `"pdfs-2024-09-25"Pdfs2024_09_25` - `"token-counting-2024-11-01"TokenCounting2024_11_01` - `"token-efficient-tools-2025-02-19"TokenEfficientTools2025_02_19` - `"output-128k-2025-02-19"Output128k2025_02_19` - `"files-api-2025-04-14"FilesApi2025_04_14` - `"mcp-client-2025-04-04"McpClient2025_04_04` - `"mcp-client-2025-11-20"McpClient2025_11_20` - `"dev-full-thinking-2025-05-14"DevFullThinking2025_05_14` - `"interleaved-thinking-2025-05-14"InterleavedThinking2025_05_14` - `"code-execution-2025-05-22"CodeExecution2025_05_22` - `"extended-cache-ttl-2025-04-11"ExtendedCacheTtl2025_04_11` - `"context-1m-2025-08-07"Context1m2025_08_07` - `"context-management-2025-06-27"ContextManagement2025_06_27` - `"model-context-window-exceeded-2025-08-26"ModelContextWindowExceeded2025_08_26` - `"skills-2025-10-02"Skills2025_10_02` - `"fast-mode-2026-02-01"FastMode2026_02_01` - `"output-300k-2026-03-24"Output300k2026_03_24` - `"user-profiles-2026-03-24"UserProfiles2026_03_24` - `"advisor-tool-2026-03-01"AdvisorTool2026_03_01` - `"managed-agents-2026-04-01"ManagedAgents2026_04_01` - `"cache-diagnosis-2026-04-07"CacheDiagnosis2026_04_07` - `"thinking-token-count-2026-05-13"ThinkingTokenCount2026_05_13` - `"server-side-fallback-2026-06-01"ServerSideFallback2026_06_01` - `"fallback-credit-2026-06-01"FallbackCredit2026_06_01` ### Returns - `class BetaManagedAgentsStreamSessionThreadEvents: A class that can be one of several variants.union` Server-sent event in a single thread's stream. - `class BetaManagedAgentsUserMessageEvent:` A user message event in the session conversation. - `required string ID` Unique identifier for this event. - `required IReadOnlyList Content` Array of content blocks comprising the user message. - `class BetaManagedAgentsTextBlock:` Regular text content. - `required string Text` The text content. - `required Type Type` - `"text"Text` - `class BetaManagedAgentsImageBlock:` Image content specified directly as base64 data or as a reference via a URL. - `required Source Source` Union type for image source variants. - `class BetaManagedAgentsBase64ImageSource:` Base64-encoded image data. - `required string Data` Base64-encoded image data. - `required string MediaType` MIME type of the image (e.g., "image/png", "image/jpeg", "image/gif", "image/webp"). - `required Type Type` - `"base64"Base64` - `class BetaManagedAgentsUrlImageSource:` Image referenced by URL. - `required Type Type` - `"url"Url` - `required string Url` URL of the image to fetch. - `class BetaManagedAgentsFileImageSource:` Image referenced by file ID. - `required string FileID` ID of a previously uploaded file. - `required Type Type` - `"file"File` - `required Type Type` - `"image"Image` - `class BetaManagedAgentsDocumentBlock:` Document content, either specified directly as base64 data, as text, or as a reference via a URL. - `required Source Source` Union type for document source variants. - `class BetaManagedAgentsBase64DocumentSource:` Base64-encoded document data. - `required string Data` Base64-encoded document data. - `required string MediaType` MIME type of the document (e.g., "application/pdf"). - `required Type Type` - `"base64"Base64` - `class BetaManagedAgentsPlainTextDocumentSource:` Plain text document content. - `required string Data` The plain text content. - `required MediaType MediaType` MIME type of the text content. Must be "text/plain". - `"text/plain"TextPlain` - `required Type Type` - `"text"Text` - `class BetaManagedAgentsUrlDocumentSource:` Document referenced by URL. - `required Type Type` - `"url"Url` - `required string Url` URL of the document to fetch. - `class BetaManagedAgentsFileDocumentSource:` Document referenced by file ID. - `required string FileID` ID of a previously uploaded file. - `required Type Type` - `"file"File` - `required Type Type` - `"document"Document` - `string? Context` Additional context about the document for the model. - `string? Title` The title of the document. - `required Type Type` - `"user.message"UserMessage` - `DateTimeOffset? ProcessedAt` A timestamp in RFC 3339 format - `class BetaManagedAgentsUserInterruptEvent:` An interrupt event that pauses agent execution and returns control to the user. - `required string ID` Unique identifier for this event. - `required Type Type` - `"user.interrupt"UserInterrupt` - `DateTimeOffset? ProcessedAt` A timestamp in RFC 3339 format - `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 BetaManagedAgentsUserToolConfirmationEvent:` A tool confirmation event that approves or denies a pending tool execution. - `required string ID` Unique identifier for this event. - `required Result Result` UserToolConfirmationResult enum - `"allow"Allow` - `"deny"Deny` - `required 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](https://platform.claude.com/docs/en/api/beta/sessions/events/list#beta_managed_agents_session_requires_action.event_ids) `stop_reason.event_ids` field. - `required Type Type` - `"user.tool_confirmation"UserToolConfirmation` - `string? DenyMessage` Optional message providing context for a 'deny' decision. Only allowed when result is 'deny'. - `DateTimeOffset? ProcessedAt` A timestamp in RFC 3339 format - `string? SessionThreadID` When set, the confirmation routes to this subagent's thread rather than the primary. Echo this from the `session_thread_id` on the `agent.tool_use` or `agent.mcp_tool_use` event that prompted the approval. - `class BetaManagedAgentsUserCustomToolResultEvent:` Event sent by the client providing the result of a custom tool execution. - `required string ID` Unique identifier for this event. - `required string CustomToolUseID` The id of the `agent.custom_tool_use` event this result corresponds to, which can be found in the last `session.status_idle` [event's](https://platform.claude.com/docs/en/api/beta/sessions/events/list#beta_managed_agents_session_requires_action.event_ids) `stop_reason.event_ids` field. - `required Type Type` - `"user.custom_tool_result"UserCustomToolResult` - `IReadOnlyList Content` The result content returned by the tool. - `class BetaManagedAgentsTextBlock:` Regular text content. - `class BetaManagedAgentsImageBlock:` Image content specified directly as base64 data or as a reference via a URL. - `class BetaManagedAgentsDocumentBlock:` Document content, either specified directly as base64 data, as text, or as a reference via a URL. - `class BetaManagedAgentsSearchResultBlock:` A block containing a web search result. - `required BetaManagedAgentsSearchResultCitations Citations` Citation settings for a search result. - `required Boolean Enabled` Whether citations are enabled for this search result. - `required IReadOnlyList Content` Array of text content blocks from the search result. - `required string Text` The text content. - `required Type Type` - `"text"Text` - `required string Source` The URL source of the search result. - `required string Title` The title of the search result. - `required Type Type` - `"search_result"SearchResult` - `Boolean? IsError` Whether the tool execution resulted in an error. - `DateTimeOffset? ProcessedAt` A timestamp in RFC 3339 format - `string? SessionThreadID` Routes this result to a subagent thread. Copy from the `agent.custom_tool_use` event's `session_thread_id`. - `class BetaManagedAgentsAgentCustomToolUseEvent:` Event emitted when the agent calls a custom tool. The session goes idle until the client sends a `user.custom_tool_result` event with the result. - `required string ID` Unique identifier for this event. - `required IReadOnlyDictionary Input` Input parameters for the tool call. - `required string Name` Name of the custom tool being called. - `required DateTimeOffset ProcessedAt` A timestamp in RFC 3339 format - `required Type Type` - `"agent.custom_tool_use"AgentCustomToolUse` - `string? SessionThreadID` When set, this event was cross-posted from a subagent's thread to surface its custom tool use on the primary thread's stream. Empty on the thread's own events. Echo this on a `user.custom_tool_result` event to route the result back. - `class BetaManagedAgentsAgentMessageEvent:` An agent response event in the session conversation. - `required string ID` Unique identifier for this event. - `required IReadOnlyList Content` Array of text blocks comprising the agent response. - `required string Text` The text content. - `required Type Type` - `required DateTimeOffset ProcessedAt` A timestamp in RFC 3339 format - `required Type Type` - `"agent.message"AgentMessage` - `class BetaManagedAgentsAgentThinkingEvent:` Indicates the agent is making forward progress via extended thinking. A progress signal, not a content carrier. - `required string ID` Unique identifier for this event. - `required DateTimeOffset ProcessedAt` A timestamp in RFC 3339 format - `required Type Type` - `"agent.thinking"AgentThinking` - `class BetaManagedAgentsAgentMcpToolUseEvent:` Event emitted when the agent invokes a tool provided by an MCP server. - `required string ID` Unique identifier for this event. - `required IReadOnlyDictionary Input` Input parameters for the tool call. - `required string McpServerName` Name of the MCP server providing the tool. - `required string Name` Name of the MCP tool being used. - `required DateTimeOffset ProcessedAt` A timestamp in RFC 3339 format - `required Type Type` - `"agent.mcp_tool_use"AgentMcpToolUse` - `EvaluatedPermission EvaluatedPermission` AgentEvaluatedPermission enum - `"allow"Allow` - `"ask"Ask` - `"deny"Deny` - `string? SessionThreadID` When set, this event was cross-posted from a subagent's thread to surface its permission request on the primary thread's stream. Empty on the thread's own events. Echo this on a `user.tool_confirmation` event to route the approval back. - `class BetaManagedAgentsAgentMcpToolResultEvent:` Event representing the result of an MCP tool execution. - `required string ID` Unique identifier for this event. - `required string McpToolUseID` The id of the `agent.mcp_tool_use` event this result corresponds to. - `required DateTimeOffset ProcessedAt` A timestamp in RFC 3339 format - `required Type Type` - `"agent.mcp_tool_result"AgentMcpToolResult` - `IReadOnlyList Content` The result content returned by the tool. - `class BetaManagedAgentsTextBlock:` Regular text content. - `class BetaManagedAgentsImageBlock:` Image content specified directly as base64 data or as a reference via a URL. - `class BetaManagedAgentsDocumentBlock:` Document content, either specified directly as base64 data, as text, or as a reference via a URL. - `class BetaManagedAgentsSearchResultBlock:` A block containing a web search result. - `Boolean? IsError` Whether the tool execution resulted in an error. - `class BetaManagedAgentsAgentToolUseEvent:` Event emitted when the agent invokes a built-in agent tool. - `required string ID` Unique identifier for this event. - `required IReadOnlyDictionary Input` Input parameters for the tool call. - `required string Name` Name of the agent tool being used. - `required DateTimeOffset ProcessedAt` A timestamp in RFC 3339 format - `required Type Type` - `"agent.tool_use"AgentToolUse` - `EvaluatedPermission EvaluatedPermission` AgentEvaluatedPermission enum - `"allow"Allow` - `"ask"Ask` - `"deny"Deny` - `string? SessionThreadID` When set, this event was cross-posted from a subagent's thread to surface its permission request on the primary thread's stream. Empty on the thread's own events. Echo this on a `user.tool_confirmation` event to route the approval back. - `class BetaManagedAgentsAgentToolResultEvent:` Event representing the result of an agent tool execution. - `required string ID` Unique identifier for this event. - `required DateTimeOffset ProcessedAt` A timestamp in RFC 3339 format - `required string ToolUseID` The id of the `agent.tool_use` event this result corresponds to. - `required Type Type` - `"agent.tool_result"AgentToolResult` - `IReadOnlyList Content` The result content returned by the tool. - `class BetaManagedAgentsTextBlock:` Regular text content. - `class BetaManagedAgentsImageBlock:` Image content specified directly as base64 data or as a reference via a URL. - `class BetaManagedAgentsDocumentBlock:` Document content, either specified directly as base64 data, as text, or as a reference via a URL. - `class BetaManagedAgentsSearchResultBlock:` A block containing a web search result. - `Boolean? IsError` Whether the tool execution resulted in an error. - `class BetaManagedAgentsAgentThreadMessageReceivedEvent:` Delivery event written to the target thread's input stream when an agent-to-agent message arrives. - `required string ID` Unique identifier for this event. - `required IReadOnlyList Content` Message content blocks. - `class BetaManagedAgentsTextBlock:` Regular text content. - `class BetaManagedAgentsImageBlock:` Image content specified directly as base64 data or as a reference via a URL. - `class BetaManagedAgentsDocumentBlock:` Document content, either specified directly as base64 data, as text, or as a reference via a URL. - `required string FromSessionThreadID` Public `sthr_` ID of the thread that sent the message. - `required DateTimeOffset ProcessedAt` A timestamp in RFC 3339 format - `required Type Type` - `"agent.thread_message_received"AgentThreadMessageReceived` - `string? FromAgentName` Name of the callable agent this message came from. Absent when received from the primary agent. - `class BetaManagedAgentsAgentThreadMessageSentEvent:` Observability event emitted to the sender's output stream when an agent-to-agent message is sent. - `required string ID` Unique identifier for this event. - `required IReadOnlyList Content` Message content blocks. - `class BetaManagedAgentsTextBlock:` Regular text content. - `class BetaManagedAgentsImageBlock:` Image content specified directly as base64 data or as a reference via a URL. - `class BetaManagedAgentsDocumentBlock:` Document content, either specified directly as base64 data, as text, or as a reference via a URL. - `required DateTimeOffset ProcessedAt` A timestamp in RFC 3339 format - `required string ToSessionThreadID` Public `sthr_` ID of the thread the message was sent to. - `required Type Type` - `"agent.thread_message_sent"AgentThreadMessageSent` - `string? ToAgentName` Name of the callable agent this message was sent to. Absent when sent to the primary agent. - `class BetaManagedAgentsAgentThreadContextCompactedEvent:` Indicates that context compaction (summarization) occurred during the session. - `required string ID` Unique identifier for this event. - `required DateTimeOffset ProcessedAt` A timestamp in RFC 3339 format - `required Type Type` - `"agent.thread_context_compacted"AgentThreadContextCompacted` - `class BetaManagedAgentsSessionErrorEvent:` An error event indicating a problem occurred during session execution. - `required string ID` Unique identifier for this event. - `required Error Error` An unknown or unexpected error occurred during session execution. A fallback variant; clients that don't recognize a new error code can match on `retry_status` and `message` alone. - `class BetaManagedAgentsUnknownError:` An unknown or unexpected error occurred during session execution. A fallback variant; clients that don't recognize a new error code can match on `retry_status` and `message` alone. - `required string Message` Human-readable error description. - `required RetryStatus RetryStatus` What the client should do next in response to this error. - `class BetaManagedAgentsRetryStatusRetrying:` The server is retrying automatically. Client should wait; the same error type may fire again as retrying, then once as exhausted when the retry budget runs out. - `required Type Type` - `"retrying"Retrying` - `class BetaManagedAgentsRetryStatusExhausted:` This turn is dead; queued inputs are flushed and the session returns to idle. Client may send a new prompt. - `required Type Type` - `"exhausted"Exhausted` - `class BetaManagedAgentsRetryStatusTerminal:` The session encountered a terminal error and will transition to `terminated` state. - `required Type Type` - `"terminal"Terminal` - `required Type Type` - `"unknown_error"UnknownError` - `class BetaManagedAgentsModelOverloadedError:` The model is currently overloaded. Emitted after automatic retries are exhausted. - `required string Message` Human-readable error description. - `required RetryStatus RetryStatus` What the client should do next in response to this error. - `class BetaManagedAgentsRetryStatusRetrying:` The server is retrying automatically. Client should wait; the same error type may fire again as retrying, then once as exhausted when the retry budget runs out. - `class BetaManagedAgentsRetryStatusExhausted:` This turn is dead; queued inputs are flushed and the session returns to idle. Client may send a new prompt. - `class BetaManagedAgentsRetryStatusTerminal:` The session encountered a terminal error and will transition to `terminated` state. - `required Type Type` - `"model_overloaded_error"ModelOverloadedError` - `class BetaManagedAgentsModelRateLimitedError:` The model request was rate-limited. - `required string Message` Human-readable error description. - `required RetryStatus RetryStatus` What the client should do next in response to this error. - `class BetaManagedAgentsRetryStatusRetrying:` The server is retrying automatically. Client should wait; the same error type may fire again as retrying, then once as exhausted when the retry budget runs out. - `class BetaManagedAgentsRetryStatusExhausted:` This turn is dead; queued inputs are flushed and the session returns to idle. Client may send a new prompt. - `class BetaManagedAgentsRetryStatusTerminal:` The session encountered a terminal error and will transition to `terminated` state. - `required Type Type` - `"model_rate_limited_error"ModelRateLimitedError` - `class BetaManagedAgentsModelRequestFailedError:` A model request failed for a reason other than overload or rate-limiting. - `required string Message` Human-readable error description. - `required RetryStatus RetryStatus` What the client should do next in response to this error. - `class BetaManagedAgentsRetryStatusRetrying:` The server is retrying automatically. Client should wait; the same error type may fire again as retrying, then once as exhausted when the retry budget runs out. - `class BetaManagedAgentsRetryStatusExhausted:` This turn is dead; queued inputs are flushed and the session returns to idle. Client may send a new prompt. - `class BetaManagedAgentsRetryStatusTerminal:` The session encountered a terminal error and will transition to `terminated` state. - `required Type Type` - `"model_request_failed_error"ModelRequestFailedError` - `class BetaManagedAgentsMcpConnectionFailedError:` Failed to connect to an MCP server. - `required string McpServerName` Name of the MCP server that failed to connect. - `required string Message` Human-readable error description. - `required RetryStatus RetryStatus` What the client should do next in response to this error. - `class BetaManagedAgentsRetryStatusRetrying:` The server is retrying automatically. Client should wait; the same error type may fire again as retrying, then once as exhausted when the retry budget runs out. - `class BetaManagedAgentsRetryStatusExhausted:` This turn is dead; queued inputs are flushed and the session returns to idle. Client may send a new prompt. - `class BetaManagedAgentsRetryStatusTerminal:` The session encountered a terminal error and will transition to `terminated` state. - `required Type Type` - `"mcp_connection_failed_error"McpConnectionFailedError` - `class BetaManagedAgentsMcpAuthenticationFailedError:` Authentication to an MCP server failed. - `required string McpServerName` Name of the MCP server that failed authentication. - `required string Message` Human-readable error description. - `required RetryStatus RetryStatus` What the client should do next in response to this error. - `class BetaManagedAgentsRetryStatusRetrying:` The server is retrying automatically. Client should wait; the same error type may fire again as retrying, then once as exhausted when the retry budget runs out. - `class BetaManagedAgentsRetryStatusExhausted:` This turn is dead; queued inputs are flushed and the session returns to idle. Client may send a new prompt. - `class BetaManagedAgentsRetryStatusTerminal:` The session encountered a terminal error and will transition to `terminated` state. - `required Type Type` - `"mcp_authentication_failed_error"McpAuthenticationFailedError` - `class BetaManagedAgentsBillingError:` The caller's organization or workspace cannot make model requests — out of credits or spend limit reached. Retrying with the same credentials will not succeed; the caller must resolve the billing state. - `required string Message` Human-readable error description. - `required RetryStatus RetryStatus` What the client should do next in response to this error. - `class BetaManagedAgentsRetryStatusRetrying:` The server is retrying automatically. Client should wait; the same error type may fire again as retrying, then once as exhausted when the retry budget runs out. - `class BetaManagedAgentsRetryStatusExhausted:` This turn is dead; queued inputs are flushed and the session returns to idle. Client may send a new prompt. - `class BetaManagedAgentsRetryStatusTerminal:` The session encountered a terminal error and will transition to `terminated` state. - `required Type Type` - `"billing_error"BillingError` - `class BetaManagedAgentsCredentialHostUnreachableError:` An `environment_variable` credential's `auth.networking.allowed_hosts` includes a host the environment's network policy does not permit. - `required string CredentialID` ID of the affected credential. - `required string Message` Human-readable error description. - `required RetryStatus RetryStatus` What the client should do next in response to this error. - `class BetaManagedAgentsRetryStatusRetrying:` The server is retrying automatically. Client should wait; the same error type may fire again as retrying, then once as exhausted when the retry budget runs out. - `class BetaManagedAgentsRetryStatusExhausted:` This turn is dead; queued inputs are flushed and the session returns to idle. Client may send a new prompt. - `class BetaManagedAgentsRetryStatusTerminal:` The session encountered a terminal error and will transition to `terminated` state. - `required Type Type` - `"credential_host_unreachable_error"CredentialHostUnreachableError` - `required string VaultID` ID of the vault containing the affected credential. - `required DateTimeOffset ProcessedAt` A timestamp in RFC 3339 format - `required Type Type` - `"session.error"SessionError` - `class BetaManagedAgentsSessionStatusRescheduledEvent:` Indicates the session is recovering from an error state and is rescheduled for execution. - `required string ID` Unique identifier for this event. - `required DateTimeOffset ProcessedAt` A timestamp in RFC 3339 format - `required Type Type` - `"session.status_rescheduled"SessionStatusRescheduled` - `class BetaManagedAgentsSessionStatusRunningEvent:` Indicates the session is actively running and the agent is working. - `required string ID` Unique identifier for this event. - `required DateTimeOffset ProcessedAt` A timestamp in RFC 3339 format - `required Type Type` - `"session.status_running"SessionStatusRunning` - `class BetaManagedAgentsSessionStatusIdleEvent:` Indicates the agent has paused and is awaiting user input. - `required string ID` Unique identifier for this event. - `required DateTimeOffset ProcessedAt` A timestamp in RFC 3339 format - `required StopReason StopReason` The agent completed its turn naturally and is ready for the next user message. - `class BetaManagedAgentsSessionEndTurn:` The agent completed its turn naturally and is ready for the next user message. - `required Type Type` - `"end_turn"EndTurn` - `class BetaManagedAgentsSessionRequiresAction:` The agent is idle waiting on one or more blocking user-input events (tool confirmation, custom tool result, etc.). Resolving all of them transitions the session back to running. - `required IReadOnlyList EventIds` The ids of events the agent is blocked on. Resolving fewer than all re-emits `session.status_idle` with the remainder. - `required Type Type` - `"requires_action"RequiresAction` - `class BetaManagedAgentsSessionRetriesExhausted:` The turn ended because the retry budget was exhausted (`max_iterations` hit or an error escalated to `retry_status: 'exhausted'`). - `required Type Type` - `"retries_exhausted"RetriesExhausted` - `required Type Type` - `"session.status_idle"SessionStatusIdle` - `class BetaManagedAgentsSessionStatusTerminatedEvent:` Indicates the session has terminated, either due to an error or completion. - `required string ID` Unique identifier for this event. - `required DateTimeOffset ProcessedAt` A timestamp in RFC 3339 format - `required Type Type` - `"session.status_terminated"SessionStatusTerminated` - `class BetaManagedAgentsSessionThreadCreatedEvent:` Emitted when a subagent is spawned as a new thread. Written to the parent thread's output stream so clients observing the session see child creation. - `required string ID` Unique identifier for this event. - `required string AgentName` Name of the callable agent the thread runs. - `required DateTimeOffset ProcessedAt` A timestamp in RFC 3339 format - `required string SessionThreadID` Public `sthr_` ID of the newly created thread. - `required Type Type` - `"session.thread_created"SessionThreadCreated` - `class BetaManagedAgentsSpanOutcomeEvaluationStartEvent:` Emitted when an outcome evaluation cycle begins. - `required string ID` Unique identifier for this event. - `required Int Iteration` 0-indexed revision cycle. 0 is the first evaluation; 1 is the re-evaluation after the first revision; etc. - `required string OutcomeID` The `outc_` ID of the outcome being evaluated. - `required DateTimeOffset ProcessedAt` A timestamp in RFC 3339 format - `required Type Type` - `"span.outcome_evaluation_start"SpanOutcomeEvaluationStart` - `class BetaManagedAgentsSpanOutcomeEvaluationEndEvent:` Emitted when an outcome evaluation cycle completes. Carries the verdict and aggregate token usage. A verdict of `needs_revision` means another evaluation cycle follows; `satisfied`, `max_iterations_reached`, `failed`, or `interrupted` are terminal — no further evaluation cycles follow. - `required string ID` Unique identifier for this event. - `required string Explanation` Human-readable explanation of the verdict. For `needs_revision`, describes which criteria failed and why. - `required Int Iteration` 0-indexed revision cycle, matching the corresponding `span.outcome_evaluation_start`. - `required string OutcomeEvaluationStartID` The id of the corresponding `span.outcome_evaluation_start` event. - `required string OutcomeID` The `outc_` ID of the outcome being evaluated. - `required DateTimeOffset ProcessedAt` A timestamp in RFC 3339 format - `required string Result` Evaluation verdict. 'satisfied': criteria met, session goes idle. 'needs_revision': criteria not met, another revision cycle follows. 'max_iterations_reached': evaluation budget exhausted with criteria still unmet — one final acknowledgment turn follows before the session goes idle, but no further evaluation runs. 'failed': grader determined the rubric does not apply to the deliverables. 'interrupted': user sent an interrupt while evaluation was in progress. - `required Type Type` - `"span.outcome_evaluation_end"SpanOutcomeEvaluationEnd` - `required BetaManagedAgentsSpanModelUsage Usage` Token usage for a single model request. - `required Int CacheCreationInputTokens` Tokens used to create prompt cache in this request. - `required Int CacheReadInputTokens` Tokens read from prompt cache in this request. - `required Int InputTokens` Input tokens consumed by this request. - `required Int OutputTokens` Output tokens generated by this request. - `Speed? Speed` Inference speed mode. `fast` provides significantly faster output token generation at premium pricing. Not all models support `fast`; invalid combinations are rejected at create time. - `"standard"Standard` - `"fast"Fast` - `class BetaManagedAgentsSpanModelRequestStartEvent:` Emitted when a model request is initiated by the agent. - `required string ID` Unique identifier for this event. - `required DateTimeOffset ProcessedAt` A timestamp in RFC 3339 format - `required Type Type` - `"span.model_request_start"SpanModelRequestStart` - `class BetaManagedAgentsSpanModelRequestEndEvent:` Emitted when a model request completes. - `required string ID` Unique identifier for this event. - `required Boolean? IsError` Whether the model request resulted in an error. - `required string ModelRequestStartID` The id of the corresponding `span.model_request_start` event. - `required BetaManagedAgentsSpanModelUsage ModelUsage` Token usage for a single model request. - `required DateTimeOffset ProcessedAt` A timestamp in RFC 3339 format - `required Type Type` - `"span.model_request_end"SpanModelRequestEnd` - `class BetaManagedAgentsSpanOutcomeEvaluationOngoingEvent:` Periodic heartbeat emitted while an outcome evaluation cycle is in progress. Distinguishes 'evaluation is actively running' from 'evaluation is stuck' between the corresponding `span.outcome_evaluation_start` and `span.outcome_evaluation_end` events. - `required string ID` Unique identifier for this event. - `required Int Iteration` 0-indexed revision cycle, matching the corresponding `span.outcome_evaluation_start`. - `required string OutcomeID` The `outc_` ID of the outcome being evaluated. - `required DateTimeOffset ProcessedAt` A timestamp in RFC 3339 format - `required Type Type` - `"span.outcome_evaluation_ongoing"SpanOutcomeEvaluationOngoing` - `class BetaManagedAgentsUserDefineOutcomeEvent:` Echo of a `user.define_outcome` input event. Carries the server-generated `outcome_id` that subsequent `span.outcome_evaluation_*` events reference. - `required string ID` Unique identifier for this event. - `required string Description` What the agent should produce. Copied from the input event. - `required Int? MaxIterations` Evaluate-then-revise cycles before giving up. Default 3, max 20. - `required string OutcomeID` Server-generated `outc_` ID for this outcome. Referenced by `span.outcome_evaluation_*` events and the session's `outcome_evaluations` list. - `required DateTimeOffset ProcessedAt` A timestamp in RFC 3339 format - `required Rubric Rubric` Rubric for grading the quality of an outcome. - `class BetaManagedAgentsFileRubric:` Rubric referenced by a file uploaded via the Files API. - `required string FileID` ID of the rubric file. - `required Type Type` - `"file"File` - `class BetaManagedAgentsTextRubric:` Rubric content provided inline as text. - `required string Content` Rubric content. Plain text or markdown — the grader treats it as freeform text. - `required Type Type` - `"text"Text` - `required Type Type` - `"user.define_outcome"UserDefineOutcome` - `class BetaManagedAgentsSessionDeletedEvent:` Emitted when a session has been deleted. Terminates any active event stream — no further events will be emitted for this session. - `required string ID` Unique identifier for this event. - `required DateTimeOffset ProcessedAt` A timestamp in RFC 3339 format - `required Type Type` - `"session.deleted"SessionDeleted` - `class BetaManagedAgentsSessionThreadStatusRunningEvent:` A session thread has begun executing. Emitted on the thread's own stream and cross-posted to the primary stream for child threads. - `required string ID` Unique identifier for this event. - `required string AgentName` Name of the agent the thread runs. - `required DateTimeOffset ProcessedAt` A timestamp in RFC 3339 format - `required string SessionThreadID` Public sthr_ ID of the thread that started running. - `required Type Type` - `"session.thread_status_running"SessionThreadStatusRunning` - `class BetaManagedAgentsSessionThreadStatusIdleEvent:` A session thread has yielded and is awaiting input. Emitted on the thread's own stream and cross-posted to the primary stream for child threads. - `required string ID` Unique identifier for this event. - `required string AgentName` Name of the agent the thread runs. - `required DateTimeOffset ProcessedAt` A timestamp in RFC 3339 format - `required string SessionThreadID` Public sthr_ ID of the thread that went idle. - `required StopReason StopReason` The agent completed its turn naturally and is ready for the next user message. - `class BetaManagedAgentsSessionEndTurn:` The agent completed its turn naturally and is ready for the next user message. - `class BetaManagedAgentsSessionRequiresAction:` The agent is idle waiting on one or more blocking user-input events (tool confirmation, custom tool result, etc.). Resolving all of them transitions the session back to running. - `class BetaManagedAgentsSessionRetriesExhausted:` The turn ended because the retry budget was exhausted (`max_iterations` hit or an error escalated to `retry_status: 'exhausted'`). - `required Type Type` - `"session.thread_status_idle"SessionThreadStatusIdle` - `class BetaManagedAgentsSessionThreadStatusTerminatedEvent:` A session thread has terminated and will accept no further input. Emitted on the thread's own stream and cross-posted to the primary stream for child threads. - `required string ID` Unique identifier for this event. - `required string AgentName` Name of the agent the thread runs. - `required DateTimeOffset ProcessedAt` A timestamp in RFC 3339 format - `required string SessionThreadID` Public sthr_ ID of the thread that terminated. - `required Type Type` - `"session.thread_status_terminated"SessionThreadStatusTerminated` - `class BetaManagedAgentsUserToolResultEvent:` Event sent by the client 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. - `required string ID` Unique identifier for this event. - `required string ToolUseID` The id of the `agent.tool_use` event this result corresponds to, which can be found in the last `session.status_idle` [event's](https://platform.claude.com/docs/en/api/beta/sessions/events/list#beta_managed_agents_session_requires_action.event_ids) `stop_reason.event_ids` field. - `required Type Type` - `"user.tool_result"UserToolResult` - `IReadOnlyList Content` The result content returned by the tool. - `class BetaManagedAgentsTextBlock:` Regular text content. - `class BetaManagedAgentsImageBlock:` Image content specified directly as base64 data or as a reference via a URL. - `class BetaManagedAgentsDocumentBlock:` Document content, either specified directly as base64 data, as text, or as a reference via a URL. - `class BetaManagedAgentsSearchResultBlock:` A block containing a web search result. - `Boolean? IsError` Whether the tool execution resulted in an error. - `DateTimeOffset? ProcessedAt` A timestamp in RFC 3339 format - `string? SessionThreadID` Routes this result to a subagent thread. Copy from the `agent.tool_use` event's `session_thread_id`. - `class BetaManagedAgentsSessionThreadStatusRescheduledEvent:` A session thread hit a transient error and is retrying automatically. Emitted on the thread's own stream and cross-posted to the primary stream for child threads. - `required string ID` Unique identifier for this event. - `required string AgentName` Name of the agent the thread runs. - `required DateTimeOffset ProcessedAt` A timestamp in RFC 3339 format - `required string SessionThreadID` Public sthr_ ID of the thread that is retrying. - `required Type Type` - `"session.thread_status_rescheduled"SessionThreadStatusRescheduled` - `class BetaManagedAgentsSessionUpdatedEvent:` Emitted when an UpdateSession request changed at least one field. Carries only the fields that changed; absent fields were not part of the update. The new configuration applies from the next turn. - `required string ID` Unique identifier for this event. - `required DateTimeOffset ProcessedAt` A timestamp in RFC 3339 format - `required Type Type` - `"session.updated"SessionUpdated` - `BetaManagedAgentsSessionAgent? Agent` Resolved `agent` definition for a `session`. Snapshot of the `agent` at `session` creation time. - `required string ID` - `required string? Description` - `required IReadOnlyList McpServers` - `required string Name` - `required Type Type` - `"url"Url` - `required string Url` - `required BetaManagedAgentsModelConfig Model` Model identifier and configuration. - `required BetaManagedAgentsModel ID` The model that will power your agent. See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options. - `"claude-fable-5"ClaudeFable5` Next generation of intelligence for the hardest knowledge work and coding problems - `"claude-opus-4-8"ClaudeOpus4_8` Frontier intelligence for long-running agents and coding - `"claude-opus-4-7"ClaudeOpus4_7` Frontier intelligence for long-running agents and coding - `"claude-opus-4-6"ClaudeOpus4_6` Most intelligent model for building agents and coding - `"claude-sonnet-4-6"ClaudeSonnet4_6` Best combination of speed and intelligence - `"claude-haiku-4-5"ClaudeHaiku4_5` Fastest model with near-frontier intelligence - `"claude-haiku-4-5-20251001"ClaudeHaiku4_5_20251001` Fastest model with near-frontier intelligence - `"claude-opus-4-5"ClaudeOpus4_5` Premium model combining maximum intelligence with practical performance - `"claude-opus-4-5-20251101"ClaudeOpus4_5_20251101` Premium model combining maximum intelligence with practical performance - `"claude-sonnet-4-5"ClaudeSonnet4_5` High-performance model for agents and coding - `"claude-sonnet-4-5-20250929"ClaudeSonnet4_5_20250929` High-performance model for agents and coding - `Speed Speed` Inference speed mode. `fast` provides significantly faster output token generation at premium pricing. Not all models support `fast`; invalid combinations are rejected at create time. - `"standard"Standard` - `"fast"Fast` - `required BetaManagedAgentsSessionMultiagentCoordinator? Multiagent` Resolved coordinator topology with full agent definitions for each roster member. - `required IReadOnlyList Agents` Full `agent` definitions the coordinator may spawn as session threads. - `required string ID` - `required string? Description` - `required IReadOnlyList McpServers` - `required string Name` - `required Type Type` - `required string Url` - `required BetaManagedAgentsModelConfig Model` Model identifier and configuration. - `required string Name` - `required IReadOnlyList Skills` - `class BetaManagedAgentsAnthropicSkill:` A resolved Anthropic-managed skill. - `required string SkillID` - `required Type Type` - `"anthropic"Anthropic` - `required string Version` - `class BetaManagedAgentsCustomSkill:` A resolved user-created custom skill. - `required string SkillID` - `required Type Type` - `"custom"Custom` - `required string Version` - `required string? System` - `required IReadOnlyList Tools` - `class BetaManagedAgentsAgentToolset20260401:` - `required IReadOnlyList Configs` - `required Boolean Enabled` - `required Name Name` Built-in agent tool identifier. - `"bash"Bash` - `"edit"Edit` - `"read"Read` - `"write"Write` - `"glob"Glob` - `"grep"Grep` - `"web_fetch"WebFetch` - `"web_search"WebSearch` - `required PermissionPolicy PermissionPolicy` Permission policy for tool execution. - `class BetaManagedAgentsAlwaysAllowPolicy:` Tool calls are automatically approved without user confirmation. - `required Type Type` - `"always_allow"AlwaysAllow` - `class BetaManagedAgentsAlwaysAskPolicy:` Tool calls require user confirmation before execution. - `required Type Type` - `"always_ask"AlwaysAsk` - `required BetaManagedAgentsAgentToolsetDefaultConfig DefaultConfig` Resolved default configuration for agent tools. - `required Boolean Enabled` - `required PermissionPolicy PermissionPolicy` Permission policy for tool execution. - `class BetaManagedAgentsAlwaysAllowPolicy:` Tool calls are automatically approved without user confirmation. - `class BetaManagedAgentsAlwaysAskPolicy:` Tool calls require user confirmation before execution. - `required Type Type` - `"agent_toolset_20260401"AgentToolset20260401` - `class BetaManagedAgentsMcpToolset:` - `required IReadOnlyList Configs` - `required Boolean Enabled` - `required string Name` - `required PermissionPolicy PermissionPolicy` Permission policy for tool execution. - `class BetaManagedAgentsAlwaysAllowPolicy:` Tool calls are automatically approved without user confirmation. - `class BetaManagedAgentsAlwaysAskPolicy:` Tool calls require user confirmation before execution. - `required BetaManagedAgentsMcpToolsetDefaultConfig DefaultConfig` Resolved default configuration for all tools from an MCP server. - `required Boolean Enabled` - `required PermissionPolicy PermissionPolicy` Permission policy for tool execution. - `class BetaManagedAgentsAlwaysAllowPolicy:` Tool calls are automatically approved without user confirmation. - `class BetaManagedAgentsAlwaysAskPolicy:` Tool calls require user confirmation before execution. - `required string McpServerName` - `required Type Type` - `"mcp_toolset"McpToolset` - `class BetaManagedAgentsCustomTool:` A custom tool as returned in API responses. - `required string Description` - `required BetaManagedAgentsCustomToolInputSchema InputSchema` JSON Schema for custom tool input parameters. - `JsonElement Type "object"constant` - `IReadOnlyDictionary? Properties` - `IReadOnlyList? Required` - `required string Name` - `required Type Type` - `"custom"Custom` - `required Type Type` - `"agent"Agent` - `required Int Version` - `required Type Type` - `"coordinator"Coordinator` - `required string Name` - `required IReadOnlyList Skills` - `class BetaManagedAgentsAnthropicSkill:` A resolved Anthropic-managed skill. - `class BetaManagedAgentsCustomSkill:` A resolved user-created custom skill. - `required string? System` - `required IReadOnlyList Tools` - `class BetaManagedAgentsAgentToolset20260401:` - `class BetaManagedAgentsMcpToolset:` - `class BetaManagedAgentsCustomTool:` A custom tool as returned in API responses. - `required Type Type` - `"agent"Agent` - `required Int Version` - `IReadOnlyDictionary Metadata` The session's full metadata bag after the update. Present when the update set non-empty metadata; absent when metadata was unchanged or cleared to empty. - `string? Title` The session's new title. Present only when the update changed it. - `class BetaManagedAgentsSystemMessageEvent:` A mid-conversation system message event. Carries system-role content that is appended to the session as a `role: "system"` turn. - `required string ID` Unique identifier for this event. - `required IReadOnlyList Content` System content blocks. Text-only. - `required string Text` The text content. - `required Type Type` - `"text"Text` - `required Type Type` - `"system.message"SystemMessage` - `DateTimeOffset? ProcessedAt` A timestamp in RFC 3339 format ### Example ```csharp EventStreamParams parameters = new() { SessionID = "sesn_011CZkZAtmR3yMPDzynEDxu7", ThreadID = "sthr_011CZkZVWa6oIjw0rgXZpnBt", }; await foreach (var betaManagedAgentsStreamSessionThreadEvents in client.Beta.Sessions.Threads.Events.StreamStreaming(parameters)) { Console.WriteLine(betaManagedAgentsStreamSessionThreadEvents); } ``` #### Response ```json { "id": "sevt_011CZkZGOp0iBcp4kaQSihUmy", "content": [ { "text": "Where is my order #1234?", "type": "text" } ], "type": "user.message", "processed_at": "2026-03-15T10:00:00Z" } ```