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1---2title: Stream Session Thread Events3url: https://platform.claude.com/docs/en/api/beta/sessions/threads/events/stream4---56# Stream Session Thread Events78**GET** `/v1/sessions/{session_id}/threads/{thread_id}/stream`910Stream Session Thread Events1112## Path parameters1314- `session_id: string`1516- `thread_id: string`1718## Query parameters1920- `event_deltas: optional array of BetaManagedAgentsDeltaType`2122 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.2324 - `"agent.message"`2526 - `"agent.thinking"`2728## Headers2930- `"anthropic-beta": optional array of AnthropicBeta`3132 Optional header to specify the beta version(s) you want to use.3334 - `string`3536 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 43 more`3738 - `"message-batches-2024-09-24"`3940 - `"prompt-caching-2024-07-31"`4142 - `"computer-use-2024-10-22"`4344 - `"computer-use-2025-01-24"`4546 - `"pdfs-2024-09-25"`4748 - `"token-counting-2024-11-01"`4950 - `"token-efficient-tools-2025-02-19"`5152 - `"output-128k-2025-02-19"`5354 - `"files-api-2025-04-14"`5556 - `"mcp-client-2025-04-04"`5758 - `"mcp-client-2025-11-20"`5960 - `"dev-full-thinking-2025-05-14"`6162 - `"interleaved-thinking-2025-05-14"`6364 - `"code-execution-2025-05-22"`6566 - `"extended-cache-ttl-2025-04-11"`6768 - `"context-1m-2025-08-07"`6970 - `"context-management-2025-06-27"`7172 - `"model-context-window-exceeded-2025-08-26"`7374 - `"skills-2025-10-02"`7576 - `"fast-mode-2026-02-01"`7778 - `"output-300k-2026-03-24"`7980 - `"user-profiles-2026-03-24"`8182 - `"user-profiles-2026-08-18"`8384 - `"user-profiles-2026-09-04"`8586 - `"advisor-tool-2026-03-01"`8788 - `"managed-agents-2026-04-01"`8990 - `"cache-diagnosis-2026-04-07"`9192 - `"dreaming-2026-04-21"`9394 - `"thinking-token-count-2026-05-13"`9596 - `"server-side-fallback-2026-06-01"`9798 - `"server-side-fallback-2026-07-01"`99100 - `"fallback-credit-2026-06-01"`101102 - `"fallback-credit-2026-07-01"`103104 - `"agent-memory-2026-07-22"`105106 - `"mid-conversation-tool-changes-2026-07-01"`107108 - `"compact-2026-01-12"`109110 - `"computer-use-2025-11-24"`111112 - `"mcp-tunnels-2026-06-22"`113114 - `"structured-outputs-2025-11-13"`115116 - `"task-budgets-2026-03-13"`117118 - `"thinking-display-updates-2026-08-18"`119120 - `"ce-user-management-2026-07-13"`121122 - `"mid-conversation-output-config-2026-07-01"`123124 - `"thinking-binding-controls-2026-08-01"`125126 - `"mid-conversation-system-clear-at-2026-08-21"`127128 - `"compact-2026-09-04"`129130- `"anthropic-workspace-id": optional string`131132## Returns133134- `BetaManagedAgentsStreamSessionThreadEvents = BetaManagedAgentsUserMessageEvent or BetaManagedAgentsUserInterruptEvent or BetaManagedAgentsUserToolConfirmationEvent or 34 more`135136 Server-sent event in a single thread's stream.137138 - `BetaManagedAgentsUserMessageEvent object`139140 A user message event in the session conversation.141142 - `type: "user.message"`143144 - `id: string`145146 Unique identifier for this event.147148 - `content: array of BetaManagedAgentsTextBlock or BetaManagedAgentsImageBlock or BetaManagedAgentsDocumentBlock or BetaManagedAgentsRedactedBlock`149150 Array of content blocks comprising the user message.151152 - `BetaManagedAgentsTextBlock object`153154 Regular text content.155156 - `type: "text"`157158 - `text: string`159160 The text content.161162 minLength: 1163164 - `BetaManagedAgentsImageBlock object`165166 Image content specified directly as base64 data or as a reference via a URL.167168 - `type: "image"`169170 - `source: BetaManagedAgentsBase64ImageSource or BetaManagedAgentsURLImageSource or BetaManagedAgentsFileImageSource`171172 Union type for image source variants.173174 - `BetaManagedAgentsBase64ImageSource object`175176 Base64-encoded image data.177178 - `type: "base64"`179180 - `data: string`181182 Base64-encoded image data.183184 minLength: 1185186 - `media_type: string`187188 MIME type of the image (e.g., "image/png", "image/jpeg", "image/gif", "image/webp").189190 minLength: 1191192 - `BetaManagedAgentsURLImageSource object`193194 Image referenced by URL.195196 - `type: "url"`197198 - `url: string`199200 URL of the image to fetch.201202 minLength: 1203204 - `BetaManagedAgentsFileImageSource object`205206 Image referenced by file ID.207208 - `type: "file"`209210 - `file_id: string`211212 ID of a previously uploaded file.213214 minLength: 1215216 - `BetaManagedAgentsDocumentBlock object`217218 Document content, either specified directly as base64 data, as text, or as a reference via a URL.219220 - `type: "document"`221222 - `source: BetaManagedAgentsBase64DocumentSource or BetaManagedAgentsPlainTextDocumentSource or BetaManagedAgentsURLDocumentSource or BetaManagedAgentsFileDocumentSource`223224 Union type for document source variants.225226 - `BetaManagedAgentsBase64DocumentSource object`227228 Base64-encoded document data.229230 - `type: "base64"`231232 - `data: string`233234 Base64-encoded document data.235236 minLength: 1237238 - `media_type: string`239240 MIME type of the document (e.g., "application/pdf").241242 minLength: 1243244 - `BetaManagedAgentsPlainTextDocumentSource object`245246 Plain text document content.247248 - `type: "text"`249250 - `data: string`251252 The plain text content.253254 minLength: 1255256 - `media_type: "text/plain"`257258 MIME type of the text content. Must be "text/plain".259260 - `BetaManagedAgentsURLDocumentSource object`261262 Document referenced by URL.263264 - `type: "url"`265266 - `url: string`267268 URL of the document to fetch.269270 minLength: 1271272 - `BetaManagedAgentsFileDocumentSource object`273274 Document referenced by file ID.275276 - `type: "file"`277278 - `file_id: string`279280 ID of a previously uploaded file.281282 minLength: 1283284 - `context: optional string or null`285286 Additional context about the document for the model.287288 - `title: optional string or null`289290 The title of the document.291292 - `BetaManagedAgentsRedactedBlock object`293294 Placeholder for content withheld by Anthropic model policy.295296 - `type: "redacted"`297298 - `processed_at: optional string or null`299300 A timestamp in RFC 3339 format301302 format: date-time303304 - `BetaManagedAgentsUserInterruptEvent object`305306 An interrupt event that pauses agent execution and returns control to the user.307308 - `type: "user.interrupt"`309310 - `id: string`311312 Unique identifier for this event.313314 - `processed_at: optional string or null`315316 A timestamp in RFC 3339 format317318 format: date-time319320 - `session_thread_id: optional string or null`321322 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.323324 - `BetaManagedAgentsUserToolConfirmationEvent object`325326 A tool confirmation event that approves or denies a pending tool execution.327328 - `type: "user.tool_confirmation"`329330 - `id: string`331332 Unique identifier for this event.333334 - `result: "allow" or "deny"`335336 UserToolConfirmationResult enum337338 - `"allow"`339340 - `"deny"`341342 - `tool_use_id: string`343344 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.345346 - `deny_message: optional string or null`347348 Optional message providing context for a 'deny' decision. Only allowed when result is 'deny'.349350 maxLength: 10000351352 - `processed_at: optional string or null`353354 A timestamp in RFC 3339 format355356 format: date-time357358 - `session_thread_id: optional string or null`359360 Set by the server to the subagent thread this confirmation was routed to. Omitted when it was routed to the primary thread.361362 - `BetaManagedAgentsUserCustomToolResultEvent object`363364 Event sent by the client providing the result of a custom tool execution.365366 - `type: "user.custom_tool_result"`367368 - `id: string`369370 Unique identifier for this event.371372 - `custom_tool_use_id: string`373374 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.375376 - `content: optional array of BetaManagedAgentsTextBlock or BetaManagedAgentsImageBlock or BetaManagedAgentsDocumentBlock or BetaManagedAgentsSearchResultBlock`377378 The result content returned by the tool.379380 - `BetaManagedAgentsTextBlock object`381382 Regular text content.383384 - `BetaManagedAgentsImageBlock object`385386 Image content specified directly as base64 data or as a reference via a URL.387388 - `BetaManagedAgentsDocumentBlock object`389390 Document content, either specified directly as base64 data, as text, or as a reference via a URL.391392 - `BetaManagedAgentsSearchResultBlock object`393394 A block containing a web search result.395396 - `type: "search_result"`397398 - `citations: BetaManagedAgentsSearchResultCitations`399400 Citation settings for a search result.401402 - `enabled: boolean`403404 Whether citations are enabled for this search result.405406 - `content: array of BetaManagedAgentsSearchResultContent`407408 Array of text content blocks from the search result.409410 - `type: "text"`411412 - `text: string`413414 The text content.415416 minLength: 1417418 - `source: string`419420 The URL source of the search result.421422 minLength: 1423424 - `title: string`425426 The title of the search result.427428 minLength: 1429430 - `is_error: optional boolean or null`431432 Whether the tool execution resulted in an error.433434 - `processed_at: optional string or null`435436 A timestamp in RFC 3339 format437438 format: date-time439440 - `session_thread_id: optional string or null`441442 Set by the server to the subagent thread this result was routed to. Omitted when it was routed to the primary thread.443444 - `BetaManagedAgentsAgentCustomToolUseEvent object`445446 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.447448 - `type: "agent.custom_tool_use"`449450 - `id: string`451452 Unique identifier for this event.453454 - `input: map[unknown]`455456 Input parameters for the tool call.457458 - `name: string`459460 Name of the custom tool being called.461462 - `processed_at: string`463464 A timestamp in RFC 3339 format465466 format: date-time467468 - `session_thread_id: optional string or null`469470 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. Informational only: the server routes the matching `user.custom_tool_result` by `custom_tool_use_id`, so clients do not send it back.471472 - `BetaManagedAgentsAgentMessageEvent object`473474 An agent response event in the session conversation.475476 - `type: "agent.message"`477478 - `id: string`479480 Unique identifier for this event.481482 - `content: array of BetaManagedAgentsTextBlock or BetaManagedAgentsRedactedBlock`483484 Array of text blocks comprising the agent response.485486 - `BetaManagedAgentsTextBlock object`487488 Regular text content.489490 - `BetaManagedAgentsRedactedBlock object`491492 Placeholder for content withheld by Anthropic model policy.493494 - `processed_at: string`495496 A timestamp in RFC 3339 format497498 format: date-time499500 - `BetaManagedAgentsAgentThinkingEvent object`501502 Indicates the agent is making forward progress via extended thinking. A progress signal, not a content carrier.503504 - `type: "agent.thinking"`505506 - `id: string`507508 Unique identifier for this event.509510 - `processed_at: string`511512 A timestamp in RFC 3339 format513514 format: date-time515516 - `BetaManagedAgentsAgentMCPToolUseEvent object`517518 Event emitted when the agent invokes a tool provided by an MCP server.519520 - `type: "agent.mcp_tool_use"`521522 - `id: string`523524 Unique identifier for this event.525526 - `input: map[unknown]`527528 Input parameters for the tool call.529530 - `mcp_server_name: string`531532 Name of the MCP server providing the tool.533534 - `name: string`535536 Name of the MCP tool being used.537538 - `processed_at: string`539540 A timestamp in RFC 3339 format541542 format: date-time543544 - `evaluated_permission: optional "allow" or "ask" or "deny"`545546 AgentEvaluatedPermission enum547548 - `"allow"`549550 - `"ask"`551552 - `"deny"`553554 - `evaluation: optional BetaManagedAgentsAgentToolEvaluation`555556 Names the resolved permission_policy that produced evaluated_permission, and under auto carries the judgement. Open union: clients must tolerate unknown variants.557558 - `BetaManagedAgentsAgentToolEvaluationAlwaysAllow object`559560 The resolved permission_policy was always_allow; accompanies evaluated_permission "allow".561562 - `type: "always_allow"`563564 - `BetaManagedAgentsAgentToolEvaluationAlwaysAsk object`565566 The resolved permission_policy was always_ask; accompanies evaluated_permission "ask".567568 - `type: "always_ask"`569570 - `BetaManagedAgentsAgentToolEvaluationAuto object`571572 The resolved permission_policy was auto: the server judged this invocation individually.573574 - `type: "auto"`575576 - `evaluated_permission: BetaManagedAgentsAgentAutoEvaluatedPermission`577578 The server's per-invocation judgement under the auto permission policy. Its type always equals the event's top-level evaluated_permission. Open union: clients must tolerate unknown variants.579580 - `BetaManagedAgentsAgentAutoEvaluatedPermissionAllow object`581582 The server judged the invocation safe to execute without client approval.583584 - `type: "allow"`585586 - `BetaManagedAgentsAgentAutoEvaluatedPermissionAsk object`587588 The server reached no judgement; the invocation is held for client approval.589590 - `type: "ask"`591592 - `reason_code: string`593594 The judgement's grounds in registry-bound terms, for client branching and audit rather than end-user display. Open registry; currently "indeterminate" (no judgement was reached). Clients must tolerate values outside this set.595596 maxLength: 64597598 - `BetaManagedAgentsAgentAutoEvaluatedPermissionDeny object`599600 The server judged the invocation high-risk; it does not execute and a synthetic error tool result is appended.601602 - `type: "deny"`603604 - `reason_code: string`605606 The judgement's grounds in registry-bound terms. Open registry; currently "high_risk" (judged high-risk; the call does not run). Clients must tolerate values outside this set.607608 maxLength: 64609610 - `session_thread_id: optional string or null`611612 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. Informational only: the server routes the matching `user.tool_confirmation` by `tool_use_id`, so clients do not send it back.613614 - `BetaManagedAgentsAgentMCPToolResultEvent object`615616 Event representing the result of an MCP tool execution.617618 - `type: "agent.mcp_tool_result"`619620 - `id: string`621622 Unique identifier for this event.623624 - `mcp_tool_use_id: string`625626 The id of the `agent.mcp_tool_use` event this result corresponds to.627628 - `processed_at: string`629630 A timestamp in RFC 3339 format631632 format: date-time633634 - `content: optional array of BetaManagedAgentsTextBlock or BetaManagedAgentsImageBlock or BetaManagedAgentsDocumentBlock or BetaManagedAgentsSearchResultBlock`635636 The result content returned by the tool.637638 - `BetaManagedAgentsTextBlock object`639640 Regular text content.641642 - `BetaManagedAgentsImageBlock object`643644 Image content specified directly as base64 data or as a reference via a URL.645646 - `BetaManagedAgentsDocumentBlock object`647648 Document content, either specified directly as base64 data, as text, or as a reference via a URL.649650 - `BetaManagedAgentsSearchResultBlock object`651652 A block containing a web search result.653654 - `is_error: optional boolean or null`655656 Whether the tool execution resulted in an error.657658 - `BetaManagedAgentsAgentToolUseEvent object`659660 Event emitted when the agent invokes a built-in agent tool.661662 - `type: "agent.tool_use"`663664 - `id: string`665666 Unique identifier for this event.667668 - `input: map[unknown]`669670 Input parameters for the tool call.671672 - `name: string`673674 Name of the agent tool being used.675676 - `processed_at: string`677678 A timestamp in RFC 3339 format679680 format: date-time681682 - `evaluated_permission: optional "allow" or "ask" or "deny"`683684 AgentEvaluatedPermission enum685686 - `"allow"`687688 - `"ask"`689690 - `"deny"`691692 - `evaluation: optional BetaManagedAgentsAgentToolEvaluation`693694 Names the resolved permission_policy that produced evaluated_permission, and under auto carries the judgement. Open union: clients must tolerate unknown variants.695696 - `session_thread_id: optional string or null`697698 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. Informational only: the server routes the matching `user.tool_confirmation` or `user.tool_result` by `tool_use_id`, so clients do not send it back.699700 - `BetaManagedAgentsAgentToolResultEvent object`701702 Event representing the result of an agent tool execution.703704 - `type: "agent.tool_result"`705706 - `id: string`707708 Unique identifier for this event.709710 - `processed_at: string`711712 A timestamp in RFC 3339 format713714 format: date-time715716 - `tool_use_id: string`717718 The id of the `agent.tool_use` event this result corresponds to.719720 - `content: optional array of BetaManagedAgentsTextBlock or BetaManagedAgentsImageBlock or BetaManagedAgentsDocumentBlock or BetaManagedAgentsSearchResultBlock`721722 The result content returned by the tool.723724 - `BetaManagedAgentsTextBlock object`725726 Regular text content.727728 - `BetaManagedAgentsImageBlock object`729730 Image content specified directly as base64 data or as a reference via a URL.731732 - `BetaManagedAgentsDocumentBlock object`733734 Document content, either specified directly as base64 data, as text, or as a reference via a URL.735736 - `BetaManagedAgentsSearchResultBlock object`737738 A block containing a web search result.739740 - `is_error: optional boolean or null`741742 Whether the tool execution resulted in an error.743744 - `BetaManagedAgentsAgentThreadMessageReceivedEvent object`745746 Delivery event written to the target thread's input stream when an agent-to-agent message arrives.747748 - `type: "agent.thread_message_received"`749750 - `id: string`751752 Unique identifier for this event.753754 - `content: array of BetaManagedAgentsTextBlock or BetaManagedAgentsImageBlock or BetaManagedAgentsDocumentBlock or BetaManagedAgentsRedactedBlock`755756 Message content blocks.757758 - `BetaManagedAgentsTextBlock object`759760 Regular text content.761762 - `BetaManagedAgentsImageBlock object`763764 Image content specified directly as base64 data or as a reference via a URL.765766 - `BetaManagedAgentsDocumentBlock object`767768 Document content, either specified directly as base64 data, as text, or as a reference via a URL.769770 - `BetaManagedAgentsRedactedBlock object`771772 Placeholder for content withheld by Anthropic model policy.773774 - `from_session_thread_id: string`775776 Public `sthr_` ID of the thread that sent the message.777778 - `processed_at: string`779780 A timestamp in RFC 3339 format781782 format: date-time783784 - `from_agent_name: optional string or null`785786 Name of the callable agent this message came from. Absent when received from the primary agent.787788 - `BetaManagedAgentsAgentThreadMessageSentEvent object`789790 Observability event emitted to the sender's output stream when an agent-to-agent message is sent.791792 - `type: "agent.thread_message_sent"`793794 - `id: string`795796 Unique identifier for this event.797798 - `content: array of BetaManagedAgentsTextBlock or BetaManagedAgentsImageBlock or BetaManagedAgentsDocumentBlock or BetaManagedAgentsRedactedBlock`799800 Message content blocks.801802 - `BetaManagedAgentsTextBlock object`803804 Regular text content.805806 - `BetaManagedAgentsImageBlock object`807808 Image content specified directly as base64 data or as a reference via a URL.809810 - `BetaManagedAgentsDocumentBlock object`811812 Document content, either specified directly as base64 data, as text, or as a reference via a URL.813814 - `BetaManagedAgentsRedactedBlock object`815816 Placeholder for content withheld by Anthropic model policy.817818 - `processed_at: string`819820 A timestamp in RFC 3339 format821822 format: date-time823824 - `to_session_thread_id: string`825826 Public `sthr_` ID of the thread the message was sent to.827828 - `to_agent_name: optional string or null`829830 Name of the callable agent this message was sent to. Absent when sent to the primary agent.831832 - `BetaManagedAgentsAgentThreadContextCompactedEvent object`833834 Indicates that context compaction (summarization) occurred during the session.835836 - `type: "agent.thread_context_compacted"`837838 - `id: string`839840 Unique identifier for this event.841842 - `processed_at: string`843844 A timestamp in RFC 3339 format845846 format: date-time847848 - `BetaManagedAgentsSessionErrorEvent object`849850 An error event indicating a problem occurred during session execution.851852 - `type: "session.error"`853854 - `id: string`855856 Unique identifier for this event.857858 - `error: BetaManagedAgentsUnknownError or BetaManagedAgentsModelOverloadedError or BetaManagedAgentsModelRateLimitedError or 5 more`859860 - `BetaManagedAgentsUnknownError object`861862 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.863864 - `type: "unknown_error"`865866 - `message: string`867868 Human-readable error description.869870 - `retry_status: BetaManagedAgentsRetryStatusRetrying or BetaManagedAgentsRetryStatusExhausted or BetaManagedAgentsRetryStatusTerminal`871872 What the client should do next in response to this error.873874 - `BetaManagedAgentsRetryStatusRetrying object`875876 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.877878 - `type: "retrying"`879880 - `BetaManagedAgentsRetryStatusExhausted object`881882 This turn is dead; queued inputs are flushed and the session returns to idle. Client may send a new prompt.883884 - `type: "exhausted"`885886 - `BetaManagedAgentsRetryStatusTerminal object`887888 The session encountered a terminal error and will transition to `terminated` state.889890 - `type: "terminal"`891892 - `BetaManagedAgentsModelOverloadedError object`893894 The model is currently overloaded. Emitted after automatic retries are exhausted.895896 - `type: "model_overloaded_error"`897898 - `message: string`899900 Human-readable error description.901902 - `retry_status: BetaManagedAgentsRetryStatusRetrying or BetaManagedAgentsRetryStatusExhausted or BetaManagedAgentsRetryStatusTerminal`903904 What the client should do next in response to this error.905906 - `BetaManagedAgentsRetryStatusRetrying object`907908 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.909910 - `BetaManagedAgentsRetryStatusExhausted object`911912 This turn is dead; queued inputs are flushed and the session returns to idle. Client may send a new prompt.913914 - `BetaManagedAgentsRetryStatusTerminal object`915916 The session encountered a terminal error and will transition to `terminated` state.917918 - `BetaManagedAgentsModelRateLimitedError object`919920 The model request was rate-limited.921922 - `type: "model_rate_limited_error"`923924 - `message: string`925926 Human-readable error description.927928 - `retry_status: BetaManagedAgentsRetryStatusRetrying or BetaManagedAgentsRetryStatusExhausted or BetaManagedAgentsRetryStatusTerminal`929930 What the client should do next in response to this error.931932 - `BetaManagedAgentsRetryStatusRetrying object`933934 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.935936 - `BetaManagedAgentsRetryStatusExhausted object`937938 This turn is dead; queued inputs are flushed and the session returns to idle. Client may send a new prompt.939940 - `BetaManagedAgentsRetryStatusTerminal object`941942 The session encountered a terminal error and will transition to `terminated` state.943944 - `BetaManagedAgentsModelRequestFailedError object`945946 A model request failed for a reason other than overload or rate-limiting.947948 - `type: "model_request_failed_error"`949950 - `message: string`951952 Human-readable error description.953954 - `retry_status: BetaManagedAgentsRetryStatusRetrying or BetaManagedAgentsRetryStatusExhausted or BetaManagedAgentsRetryStatusTerminal`955956 What the client should do next in response to this error.957958 - `BetaManagedAgentsRetryStatusRetrying object`959960 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.961962 - `BetaManagedAgentsRetryStatusExhausted object`963964 This turn is dead; queued inputs are flushed and the session returns to idle. Client may send a new prompt.965966 - `BetaManagedAgentsRetryStatusTerminal object`967968 The session encountered a terminal error and will transition to `terminated` state.969970 - `BetaManagedAgentsMCPConnectionFailedError object`971972 Failed to connect to an MCP server.973974 - `type: "mcp_connection_failed_error"`975976 - `mcp_server_name: string`977978 Name of the MCP server that failed to connect.979980 - `message: string`981982 Human-readable error description.983984 - `retry_status: BetaManagedAgentsRetryStatusRetrying or BetaManagedAgentsRetryStatusExhausted or BetaManagedAgentsRetryStatusTerminal`985986 What the client should do next in response to this error.987988 - `BetaManagedAgentsRetryStatusRetrying object`989990 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.991992 - `BetaManagedAgentsRetryStatusExhausted object`993994 This turn is dead; queued inputs are flushed and the session returns to idle. Client may send a new prompt.995996 - `BetaManagedAgentsRetryStatusTerminal object`997998 The session encountered a terminal error and will transition to `terminated` state.9991000 - `BetaManagedAgentsMCPAuthenticationFailedError object`10011002 Authentication to an MCP server failed.10031004 - `type: "mcp_authentication_failed_error"`10051006 - `mcp_server_name: string`10071008 Name of the MCP server that failed authentication.10091010 - `message: string`10111012 Human-readable error description.10131014 - `retry_status: BetaManagedAgentsRetryStatusRetrying or BetaManagedAgentsRetryStatusExhausted or BetaManagedAgentsRetryStatusTerminal`10151016 What the client should do next in response to this error.10171018 - `BetaManagedAgentsRetryStatusRetrying object`10191020 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.10211022 - `BetaManagedAgentsRetryStatusExhausted object`10231024 This turn is dead; queued inputs are flushed and the session returns to idle. Client may send a new prompt.10251026 - `BetaManagedAgentsRetryStatusTerminal object`10271028 The session encountered a terminal error and will transition to `terminated` state.10291030 - `BetaManagedAgentsBillingError object`10311032 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.10331034 - `type: "billing_error"`10351036 - `message: string`10371038 Human-readable error description.10391040 - `retry_status: BetaManagedAgentsRetryStatusRetrying or BetaManagedAgentsRetryStatusExhausted or BetaManagedAgentsRetryStatusTerminal`10411042 What the client should do next in response to this error.10431044 - `BetaManagedAgentsRetryStatusRetrying object`10451046 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.10471048 - `BetaManagedAgentsRetryStatusExhausted object`10491050 This turn is dead; queued inputs are flushed and the session returns to idle. Client may send a new prompt.10511052 - `BetaManagedAgentsRetryStatusTerminal object`10531054 The session encountered a terminal error and will transition to `terminated` state.10551056 - `BetaManagedAgentsCredentialHostUnreachableError object`10571058 An `environment_variable` credential's `auth.networking.allowed_hosts` includes a host the environment's network policy does not permit.10591060 - `type: "credential_host_unreachable_error"`10611062 - `credential_id: string`10631064 ID of the affected credential.10651066 - `message: string`10671068 Human-readable error description.10691070 - `retry_status: BetaManagedAgentsRetryStatusRetrying or BetaManagedAgentsRetryStatusExhausted or BetaManagedAgentsRetryStatusTerminal`10711072 What the client should do next in response to this error.10731074 - `BetaManagedAgentsRetryStatusRetrying object`10751076 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.10771078 - `BetaManagedAgentsRetryStatusExhausted object`10791080 This turn is dead; queued inputs are flushed and the session returns to idle. Client may send a new prompt.10811082 - `BetaManagedAgentsRetryStatusTerminal object`10831084 The session encountered a terminal error and will transition to `terminated` state.10851086 - `vault_id: string`10871088 ID of the vault containing the affected credential.10891090 - `processed_at: string`10911092 A timestamp in RFC 3339 format10931094 format: date-time10951096 - `BetaManagedAgentsSessionStatusRescheduledEvent object`10971098 Indicates the session is recovering from an error state and is rescheduled for execution.10991100 - `type: "session.status_rescheduled"`11011102 - `id: string`11031104 Unique identifier for this event.11051106 - `processed_at: string`11071108 A timestamp in RFC 3339 format11091110 format: date-time11111112 - `BetaManagedAgentsSessionStatusRunningEvent object`11131114 Indicates the session is actively running and the agent is working.11151116 - `type: "session.status_running"`11171118 - `id: string`11191120 Unique identifier for this event.11211122 - `processed_at: string`11231124 A timestamp in RFC 3339 format11251126 format: date-time11271128 - `BetaManagedAgentsSessionStatusIdleEvent object`11291130 Indicates the agent has paused and is awaiting user input.11311132 - `type: "session.status_idle"`11331134 - `id: string`11351136 Unique identifier for this event.11371138 - `processed_at: string`11391140 A timestamp in RFC 3339 format11411142 format: date-time11431144 - `stop_reason: BetaManagedAgentsSessionEndTurn or BetaManagedAgentsSessionRequiresAction or BetaManagedAgentsSessionRetriesExhausted or BetaManagedAgentsSessionBudgetReached`11451146 - `BetaManagedAgentsSessionEndTurn object`11471148 The agent completed its turn naturally and is ready for the next user message.11491150 - `type: "end_turn"`11511152 - `BetaManagedAgentsSessionRequiresAction object`11531154 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.11551156 - `type: "requires_action"`11571158 - `event_ids: array of string`11591160 The ids of events the agent is blocked on. Resolving fewer than all re-emits `session.status_idle` with the remainder.11611162 - `BetaManagedAgentsSessionRetriesExhausted object`11631164 The turn ended because repeated errors exhausted the retry budget or an error escalated to `retry_status: 'exhausted'`.11651166 - `type: "retries_exhausted"`11671168 - `BetaManagedAgentsSessionBudgetReached object`11691170 The agent stopped because the session's tracked list cost reached its budget, or because its usage includes a model with no list price (which the budget cannot measure). Raise the budget to continue — or, if raising is rejected because a model has no list price, remove the budget.11711172 - `type: "budget_reached"`11731174 - `BetaManagedAgentsSessionStatusTerminatedEvent object`11751176 Indicates the session has terminated, either due to an error or completion.11771178 - `type: "session.status_terminated"`11791180 - `id: string`11811182 Unique identifier for this event.11831184 - `processed_at: string`11851186 A timestamp in RFC 3339 format11871188 format: date-time11891190 - `BetaManagedAgentsSessionThreadCreatedEvent object`11911192 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.11931194 - `type: "session.thread_created"`11951196 - `id: string`11971198 Unique identifier for this event.11991200 - `agent_name: string`12011202 Name of the callable agent the thread runs.12031204 - `processed_at: string`12051206 A timestamp in RFC 3339 format12071208 format: date-time12091210 - `session_thread_id: string`12111212 Public `sthr_` ID of the newly created thread.12131214 - `BetaManagedAgentsSpanOutcomeEvaluationStartEvent object`12151216 Emitted when an outcome evaluation cycle begins.12171218 - `type: "span.outcome_evaluation_start"`12191220 - `id: string`12211222 Unique identifier for this event.12231224 - `iteration: number`12251226 0-indexed revision cycle. 0 is the first evaluation; 1 is the re-evaluation after the first revision; etc.12271228 format: int3212291230 - `outcome_id: string`12311232 The `outc_` ID of the outcome being evaluated.12331234 - `processed_at: string`12351236 A timestamp in RFC 3339 format12371238 format: date-time12391240 - `BetaManagedAgentsSpanOutcomeEvaluationEndEvent object`12411242 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.12431244 - `type: "span.outcome_evaluation_end"`12451246 - `id: string`12471248 Unique identifier for this event.12491250 - `explanation: string`12511252 Human-readable explanation of the verdict. For `needs_revision`, describes which criteria failed and why.12531254 - `iteration: number`12551256 0-indexed revision cycle, matching the corresponding `span.outcome_evaluation_start`.12571258 format: int3212591260 - `outcome_evaluation_start_id: string`12611262 The id of the corresponding `span.outcome_evaluation_start` event.12631264 - `outcome_id: string`12651266 The `outc_` ID of the outcome being evaluated.12671268 - `processed_at: string`12691270 A timestamp in RFC 3339 format12711272 format: date-time12731274 - `result: string`12751276 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.12771278 - `usage: BetaManagedAgentsSpanModelUsage`12791280 Token usage for a single model request.12811282 - `cache_creation_input_tokens: number`12831284 Tokens used to create prompt cache in this request.12851286 format: int3212871288 - `cache_read_input_tokens: number`12891290 Tokens read from prompt cache in this request.12911292 format: int3212931294 - `input_tokens: number`12951296 Input tokens consumed by this request.12971298 format: int3212991300 - `output_tokens: number`13011302 Output tokens generated by this request.13031304 format: int3213051306 - `speed: optional "standard" or "fast" or null`13071308 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.13091310 - `"standard"`13111312 - `"fast"`13131314 - `BetaManagedAgentsSpanModelRequestStartEvent object`13151316 Emitted when a model request is initiated by the agent.13171318 - `type: "span.model_request_start"`13191320 - `id: string`13211322 Unique identifier for this event.13231324 - `processed_at: string`13251326 A timestamp in RFC 3339 format13271328 format: date-time13291330 - `BetaManagedAgentsSpanModelRequestEndEvent object`13311332 Emitted when a model request completes.13331334 - `type: "span.model_request_end"`13351336 - `id: string`13371338 Unique identifier for this event.13391340 - `is_error: boolean or null`13411342 Whether the model request resulted in an error.13431344 - `model_request_start_id: string`13451346 The id of the corresponding `span.model_request_start` event.13471348 - `model_usage: BetaManagedAgentsSpanModelUsage`13491350 Token usage for a single model request.13511352 - `processed_at: string`13531354 A timestamp in RFC 3339 format13551356 format: date-time13571358 - `BetaManagedAgentsSpanOutcomeEvaluationOngoingEvent object`13591360 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.13611362 - `type: "span.outcome_evaluation_ongoing"`13631364 - `id: string`13651366 Unique identifier for this event.13671368 - `iteration: number`13691370 0-indexed revision cycle, matching the corresponding `span.outcome_evaluation_start`.13711372 format: int3213731374 - `outcome_id: string`13751376 The `outc_` ID of the outcome being evaluated.13771378 - `processed_at: string`13791380 A timestamp in RFC 3339 format13811382 format: date-time13831384 - `BetaManagedAgentsUserDefineOutcomeEvent object`13851386 Echo of a `user.define_outcome` input event. Carries the server-generated `outcome_id` that subsequent `span.outcome_evaluation_*` events reference.13871388 - `type: "user.define_outcome"`13891390 - `id: string`13911392 Unique identifier for this event.13931394 - `description: string`13951396 What the agent should produce. Copied from the input event.13971398 - `max_iterations: number or null`13991400 Evaluate-then-revise cycles before giving up. Default 3, max 20.14011402 format: int3214031404 - `outcome_id: string`14051406 Server-generated `outc_` ID for this outcome. Referenced by `span.outcome_evaluation_*` events and the session's `outcome_evaluations` list.14071408 - `processed_at: string`14091410 A timestamp in RFC 3339 format14111412 format: date-time14131414 - `rubric: BetaManagedAgentsFileRubric or BetaManagedAgentsTextRubric`14151416 Rubric for grading the quality of an outcome.14171418 - `BetaManagedAgentsFileRubric object`14191420 Rubric referenced by a file uploaded via the Files API.14211422 - `type: "file"`14231424 - `file_id: string`14251426 ID of the rubric file.14271428 - `BetaManagedAgentsTextRubric object`14291430 Rubric content provided inline as text.14311432 - `type: "text"`14331434 - `content: string`14351436 Rubric content. Plain text or markdown — the grader treats it as freeform text.14371438 - `BetaManagedAgentsSessionDeletedEvent object`14391440 Emitted when a session has been deleted. Terminates any active event stream — no further events will be emitted for this session.14411442 - `type: "session.deleted"`14431444 - `id: string`14451446 Unique identifier for this event.14471448 - `processed_at: string`14491450 A timestamp in RFC 3339 format14511452 format: date-time14531454 - `BetaManagedAgentsSessionThreadStatusRunningEvent object`14551456 A session thread has begun executing. Emitted on the thread's own stream and cross-posted to the primary stream for child threads.14571458 - `type: "session.thread_status_running"`14591460 - `id: string`14611462 Unique identifier for this event.14631464 - `agent_name: string`14651466 Name of the agent the thread runs.14671468 - `processed_at: string`14691470 A timestamp in RFC 3339 format14711472 format: date-time14731474 - `session_thread_id: string`14751476 Public sthr_ ID of the thread that started running.14771478 - `BetaManagedAgentsSessionThreadStatusIdleEvent object`14791480 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.14811482 - `type: "session.thread_status_idle"`14831484 - `id: string`14851486 Unique identifier for this event.14871488 - `agent_name: string`14891490 Name of the agent the thread runs.14911492 - `processed_at: string`14931494 A timestamp in RFC 3339 format14951496 format: date-time14971498 - `session_thread_id: string`14991500 Public sthr_ ID of the thread that went idle.15011502 - `stop_reason: BetaManagedAgentsSessionEndTurn or BetaManagedAgentsSessionRequiresAction or BetaManagedAgentsSessionRetriesExhausted or BetaManagedAgentsSessionBudgetReached`15031504 - `BetaManagedAgentsSessionEndTurn object`15051506 The agent completed its turn naturally and is ready for the next user message.15071508 - `BetaManagedAgentsSessionRequiresAction object`15091510 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.15111512 - `BetaManagedAgentsSessionRetriesExhausted object`15131514 The turn ended because repeated errors exhausted the retry budget or an error escalated to `retry_status: 'exhausted'`.15151516 - `BetaManagedAgentsSessionBudgetReached object`15171518 The agent stopped because the session's tracked list cost reached its budget, or because its usage includes a model with no list price (which the budget cannot measure). Raise the budget to continue — or, if raising is rejected because a model has no list price, remove the budget.15191520 - `BetaManagedAgentsSessionThreadStatusTerminatedEvent object`15211522 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.15231524 - `type: "session.thread_status_terminated"`15251526 - `id: string`15271528 Unique identifier for this event.15291530 - `agent_name: string`15311532 Name of the agent the thread runs.15331534 - `processed_at: string`15351536 A timestamp in RFC 3339 format15371538 format: date-time15391540 - `session_thread_id: string`15411542 Public sthr_ ID of the thread that terminated.15431544 - `BetaManagedAgentsUserToolResultEvent object`15451546 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.15471548 - `type: "user.tool_result"`15491550 - `id: string`15511552 Unique identifier for this event.15531554 - `tool_use_id: string`15551556 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.15571558 - `content: optional array of BetaManagedAgentsTextBlock or BetaManagedAgentsImageBlock or BetaManagedAgentsDocumentBlock or BetaManagedAgentsSearchResultBlock`15591560 The result content returned by the tool.15611562 - `BetaManagedAgentsTextBlock object`15631564 Regular text content.15651566 - `BetaManagedAgentsImageBlock object`15671568 Image content specified directly as base64 data or as a reference via a URL.15691570 - `BetaManagedAgentsDocumentBlock object`15711572 Document content, either specified directly as base64 data, as text, or as a reference via a URL.15731574 - `BetaManagedAgentsSearchResultBlock object`15751576 A block containing a web search result.15771578 - `is_error: optional boolean or null`15791580 Whether the tool execution resulted in an error.15811582 - `processed_at: optional string or null`15831584 A timestamp in RFC 3339 format15851586 format: date-time15871588 - `session_thread_id: optional string or null`15891590 Set by the server to the subagent thread this result was routed to. Omitted when it was routed to the primary thread.15911592 - `BetaManagedAgentsSessionThreadStatusRescheduledEvent object`15931594 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.15951596 - `type: "session.thread_status_rescheduled"`15971598 - `id: string`15991600 Unique identifier for this event.16011602 - `agent_name: string`16031604 Name of the agent the thread runs.16051606 - `processed_at: string`16071608 A timestamp in RFC 3339 format16091610 format: date-time16111612 - `session_thread_id: string`16131614 Public sthr_ ID of the thread that is retrying.16151616 - `BetaManagedAgentsSessionUpdatedEvent object`16171618 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.16191620 - `type: "session.updated"`16211622 - `id: string`16231624 Unique identifier for this event.16251626 - `processed_at: string`16271628 A timestamp in RFC 3339 format16291630 format: date-time16311632 - `agent: optional BetaManagedAgentsSessionAgent or null`16331634 Resolved `agent` definition for a `session`. Snapshot of the `agent` at `session` creation time.16351636 - `type: "agent"`16371638 - `id: string`16391640 - `description: string or null`16411642 - `mcp_servers: array of BetaManagedAgentsMCPServerURLDefinition`16431644 - `type: "url"`16451646 - `name: string`16471648 - `url: string`16491650 - `model: BetaManagedAgentsModelConfig`16511652 Model identifier and configuration.16531654 - `id: BetaManagedAgentsModel`16551656 The model that will power your agent.16571658 See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options.16591660 - `"claude-fable-5-1" or "claude-sonnet-5" or "claude-fable-5" or 11 more`16611662 The model that will power your agent.16631664 See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options.16651666 - `"claude-fable-5-1"`16671668 Frontier intelligence for ambitious tasks across coding, scientific discovery, and enterprise workflows16691670 - `"claude-sonnet-5"`16711672 High-performance model for coding and agents16731674 - `"claude-fable-5"`16751676 Next generation of intelligence for the hardest knowledge work and coding problems16771678 - `"claude-opus-5"`16791680 Powerful intelligence for long-running agents and coding16811682 - `"claude-opus-4-8"`16831684 Powerful intelligence for long-running agents and coding16851686 - `"claude-opus-4-7"`16871688 Powerful intelligence for long-running agents and coding16891690 - `"claude-opus-4-6"`16911692 Powerful intelligence for long-running agents and coding16931694 - `"claude-sonnet-4-6"`16951696 Best combination of speed and intelligence16971698 - `"claude-haiku-4-5"`16991700 Fastest model with near-frontier intelligence17011702 - `"claude-haiku-4-5-20251001"`17031704 Fastest model with near-frontier intelligence17051706 - `"claude-opus-4-5"`17071708 Powerful intelligence for long-running agents and coding17091710 - `"claude-opus-4-5-20251101"`17111712 Powerful intelligence for long-running agents and coding17131714 - `"claude-sonnet-4-5"`17151716 High-performance model for agents and coding17171718 - `"claude-sonnet-4-5-20250929"`17191720 High-performance model for agents and coding17211722 - `string`17231724 - `effort: optional BetaManagedAgentsEffortLow or BetaManagedAgentsEffortMedium or BetaManagedAgentsEffortHigh or 2 more`17251726 How hard Claude works on each turn. Sets `output_config.effort` on every Messages call the session makes.17271728 - `BetaManagedAgentsEffortLow object`17291730 Low effort. Favors latency over reasoning depth.17311732 - `type: "low"`17331734 - `BetaManagedAgentsEffortMedium object`17351736 Medium effort. Balances latency and reasoning depth.17371738 - `type: "medium"`17391740 - `BetaManagedAgentsEffortHigh object`17411742 High effort. Favors reasoning depth.17431744 - `type: "high"`17451746 - `BetaManagedAgentsEffortXhigh object`17471748 Extra-high effort. Not all models accept this level.17491750 - `type: "xhigh"`17511752 - `BetaManagedAgentsEffortMax object`17531754 Maximum effort. Favors reasoning depth over latency.17551756 - `type: "max"`17571758 - `inference_geo: optional string`17591760 Geographic region for model inference. When unset, requests fall through to the workspace's default_inference_geo.17611762 - `speed: optional "standard" or "fast"`17631764 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.17651766 - `"standard"`17671768 - `"fast"`17691770 - `multiagent: BetaManagedAgentsSessionMultiagentCoordinator or null`17711772 Resolved coordinator topology with full agent definitions for each roster member.17731774 - `type: "coordinator"`17751776 - `agents: array of BetaManagedAgentsSessionThreadAgent or BetaManagedAgentsAdvisor`17771778 Full `agent` definitions the coordinator may spawn as session threads.17791780 - `BetaManagedAgentsSessionThreadAgent object`17811782 Resolved `agent` definition for a single `session_thread`. Snapshot of the agent at thread creation time. The multiagent roster is not repeated here; read it from `Session.agent`.17831784 - `type: "agent"`17851786 - `id: string`17871788 - `description: string or null`17891790 - `mcp_servers: array of BetaManagedAgentsMCPServerURLDefinition`17911792 - `type: "url"`17931794 - `name: string`17951796 - `url: string`17971798 - `model: BetaManagedAgentsModelConfig`17991800 Model identifier and configuration.18011802 - `name: string`18031804 - `skills: array of BetaManagedAgentsAnthropicSkill or BetaManagedAgentsCustomSkill`18051806 - `BetaManagedAgentsAnthropicSkill object`18071808 A resolved Anthropic-managed skill.18091810 - `type: "anthropic"`18111812 - `skill_id: string`18131814 - `version: string`18151816 - `BetaManagedAgentsCustomSkill object`18171818 A resolved user-created custom skill.18191820 - `type: "custom"`18211822 - `skill_id: string`18231824 - `version: string`18251826 - `system: string or null`18271828 - `tools: array of BetaManagedAgentsAgentToolset20260401 or BetaManagedAgentsMCPToolset or BetaManagedAgentsCustomTool`18291830 - `BetaManagedAgentsAgentToolset20260401 object`18311832 - `type: "agent_toolset_20260401"`18331834 - `configs: array of BetaManagedAgentsAgentToolConfig`18351836 - `BetaManagedAgentsBashToolConfig object`18371838 Configuration for the bash tool.18391840 - `type: "bash"`18411842 - `enabled: boolean`18431844 - `name: "bash"`18451846 - `permission_policy: BetaManagedAgentsAlwaysAllowPolicy or BetaManagedAgentsAlwaysAskPolicy or BetaManagedAgentsAutoPolicy`18471848 Permission policy for tool execution.18491850 - `BetaManagedAgentsAlwaysAllowPolicy object`18511852 Tool calls are automatically approved without user confirmation.18531854 - `type: "always_allow"`18551856 - `BetaManagedAgentsAlwaysAskPolicy object`18571858 Tool calls require user confirmation before execution.18591860 - `type: "always_ask"`18611862 - `BetaManagedAgentsAutoPolicy object`18631864 The server decides each tool call individually: it judges, from the tool, its input, and the session content so far, whether the call is safe to execute or high-risk, and evaluates it to allow when judged safe and to deny when judged high-risk. A call the server cannot reach a judgement on evaluates to ask.18651866 - `type: "auto"`18671868 - `BetaManagedAgentsEditToolConfig object`18691870 Configuration for the edit tool.18711872 - `type: "edit"`18731874 - `enabled: boolean`18751876 - `name: "edit"`18771878 - `permission_policy: BetaManagedAgentsAlwaysAllowPolicy or BetaManagedAgentsAlwaysAskPolicy or BetaManagedAgentsAutoPolicy`18791880 Permission policy for tool execution.18811882 - `BetaManagedAgentsAlwaysAllowPolicy object`18831884 Tool calls are automatically approved without user confirmation.18851886 - `BetaManagedAgentsAlwaysAskPolicy object`18871888 Tool calls require user confirmation before execution.18891890 - `BetaManagedAgentsAutoPolicy object`18911892 The server decides each tool call individually: it judges, from the tool, its input, and the session content so far, whether the call is safe to execute or high-risk, and evaluates it to allow when judged safe and to deny when judged high-risk. A call the server cannot reach a judgement on evaluates to ask.18931894 - `BetaManagedAgentsReadToolConfig object`18951896 Configuration for the read tool.18971898 - `type: "read"`18991900 - `enabled: boolean`19011902 - `name: "read"`19031904 - `permission_policy: BetaManagedAgentsAlwaysAllowPolicy or BetaManagedAgentsAlwaysAskPolicy or BetaManagedAgentsAutoPolicy`19051906 Permission policy for tool execution.19071908 - `BetaManagedAgentsAlwaysAllowPolicy object`19091910 Tool calls are automatically approved without user confirmation.19111912 - `BetaManagedAgentsAlwaysAskPolicy object`19131914 Tool calls require user confirmation before execution.19151916 - `BetaManagedAgentsAutoPolicy object`19171918 The server decides each tool call individually: it judges, from the tool, its input, and the session content so far, whether the call is safe to execute or high-risk, and evaluates it to allow when judged safe and to deny when judged high-risk. A call the server cannot reach a judgement on evaluates to ask.19191920 - `BetaManagedAgentsWriteToolConfig object`19211922 Configuration for the write tool.19231924 - `type: "write"`19251926 - `enabled: boolean`19271928 - `name: "write"`19291930 - `permission_policy: BetaManagedAgentsAlwaysAllowPolicy or BetaManagedAgentsAlwaysAskPolicy or BetaManagedAgentsAutoPolicy`19311932 Permission policy for tool execution.19331934 - `BetaManagedAgentsAlwaysAllowPolicy object`19351936 Tool calls are automatically approved without user confirmation.19371938 - `BetaManagedAgentsAlwaysAskPolicy object`19391940 Tool calls require user confirmation before execution.19411942 - `BetaManagedAgentsAutoPolicy object`19431944 The server decides each tool call individually: it judges, from the tool, its input, and the session content so far, whether the call is safe to execute or high-risk, and evaluates it to allow when judged safe and to deny when judged high-risk. A call the server cannot reach a judgement on evaluates to ask.19451946 - `BetaManagedAgentsGlobToolConfig object`19471948 Configuration for the glob tool.19491950 - `type: "glob"`19511952 - `enabled: boolean`19531954 - `name: "glob"`19551956 - `permission_policy: BetaManagedAgentsAlwaysAllowPolicy or BetaManagedAgentsAlwaysAskPolicy or BetaManagedAgentsAutoPolicy`19571958 Permission policy for tool execution.19591960 - `BetaManagedAgentsAlwaysAllowPolicy object`19611962 Tool calls are automatically approved without user confirmation.19631964 - `BetaManagedAgentsAlwaysAskPolicy object`19651966 Tool calls require user confirmation before execution.19671968 - `BetaManagedAgentsAutoPolicy object`19691970 The server decides each tool call individually: it judges, from the tool, its input, and the session content so far, whether the call is safe to execute or high-risk, and evaluates it to allow when judged safe and to deny when judged high-risk. A call the server cannot reach a judgement on evaluates to ask.19711972 - `BetaManagedAgentsGrepToolConfig object`19731974 Configuration for the grep tool.19751976 - `type: "grep"`19771978 - `enabled: boolean`19791980 - `name: "grep"`19811982 - `permission_policy: BetaManagedAgentsAlwaysAllowPolicy or BetaManagedAgentsAlwaysAskPolicy or BetaManagedAgentsAutoPolicy`19831984 Permission policy for tool execution.19851986 - `BetaManagedAgentsAlwaysAllowPolicy object`19871988 Tool calls are automatically approved without user confirmation.19891990 - `BetaManagedAgentsAlwaysAskPolicy object`19911992 Tool calls require user confirmation before execution.19931994 - `BetaManagedAgentsAutoPolicy object`19951996 The server decides each tool call individually: it judges, from the tool, its input, and the session content so far, whether the call is safe to execute or high-risk, and evaluates it to allow when judged safe and to deny when judged high-risk. A call the server cannot reach a judgement on evaluates to ask.19971998 - `BetaManagedAgentsWebFetchToolConfig object`19992000 Configuration for the web_fetch tool.20012002 - `type: "web_fetch"`20032004 - `enabled: boolean`20052006 - `name: "web_fetch"`20072008 - `permission_policy: BetaManagedAgentsAlwaysAllowPolicy or BetaManagedAgentsAlwaysAskPolicy or BetaManagedAgentsAutoPolicy`20092010 Permission policy for tool execution.20112012 - `BetaManagedAgentsAlwaysAllowPolicy object`20132014 Tool calls are automatically approved without user confirmation.20152016 - `BetaManagedAgentsAlwaysAskPolicy object`20172018 Tool calls require user confirmation before execution.20192020 - `BetaManagedAgentsAutoPolicy object`20212022 The server decides each tool call individually: it judges, from the tool, its input, and the session content so far, whether the call is safe to execute or high-risk, and evaluates it to allow when judged safe and to deny when judged high-risk. A call the server cannot reach a judgement on evaluates to ask.20232024 - `allowed_domains: optional array of string`20252026 - `blocked_domains: optional array of string`20272028 - `max_content_tokens: optional number or null`20292030 format: int3220312032 - `BetaManagedAgentsWebSearchToolConfig object`20332034 Configuration for the web_search tool.20352036 - `type: "web_search"`20372038 - `enabled: boolean`20392040 - `name: "web_search"`20412042 - `permission_policy: BetaManagedAgentsAlwaysAllowPolicy or BetaManagedAgentsAlwaysAskPolicy or BetaManagedAgentsAutoPolicy`20432044 Permission policy for tool execution.20452046 - `BetaManagedAgentsAlwaysAllowPolicy object`20472048 Tool calls are automatically approved without user confirmation.20492050 - `BetaManagedAgentsAlwaysAskPolicy object`20512052 Tool calls require user confirmation before execution.20532054 - `BetaManagedAgentsAutoPolicy object`20552056 The server decides each tool call individually: it judges, from the tool, its input, and the session content so far, whether the call is safe to execute or high-risk, and evaluates it to allow when judged safe and to deny when judged high-risk. A call the server cannot reach a judgement on evaluates to ask.20572058 - `allowed_domains: optional array of string`20592060 - `blocked_domains: optional array of string`20612062 - `user_location: optional BetaManagedAgentsUserLocation or null`20632064 Approximate user location for search result localization.20652066 - `type: "approximate"`20672068 Location precision. Only "approximate" is supported.20692070 - `city: optional string or null`20712072 City name.20732074 minLength: 1, maxLength: 25520752076 - `country: optional string or null`20772078 Two-letter ISO 3166-1 country code, uppercase.20792080 - `region: optional string or null`20812082 Region or state name.20832084 minLength: 1, maxLength: 25520852086 - `timezone: optional string or null`20872088 IANA timezone identifier, e.g. "America/Los_Angeles".20892090 minLength: 1, maxLength: 25520912092 - `default_config: BetaManagedAgentsAgentToolsetDefaultConfig`20932094 Resolved default configuration for agent tools.20952096 - `enabled: boolean`20972098 - `permission_policy: BetaManagedAgentsAlwaysAllowPolicy or BetaManagedAgentsAlwaysAskPolicy or BetaManagedAgentsAutoPolicy`20992100 Permission policy for tool execution.21012102 - `BetaManagedAgentsAlwaysAllowPolicy object`21032104 Tool calls are automatically approved without user confirmation.21052106 - `BetaManagedAgentsAlwaysAskPolicy object`21072108 Tool calls require user confirmation before execution.21092110 - `BetaManagedAgentsAutoPolicy object`21112112 The server decides each tool call individually: it judges, from the tool, its input, and the session content so far, whether the call is safe to execute or high-risk, and evaluates it to allow when judged safe and to deny when judged high-risk. A call the server cannot reach a judgement on evaluates to ask.21132114 - `BetaManagedAgentsMCPToolset object`21152116 - `type: "mcp_toolset"`21172118 - `configs: array of BetaManagedAgentsMCPToolConfig`21192120 - `enabled: boolean`21212122 - `name: string`21232124 - `permission_policy: BetaManagedAgentsAlwaysAllowPolicy or BetaManagedAgentsAlwaysAskPolicy or BetaManagedAgentsAutoPolicy`21252126 Permission policy for tool execution.21272128 - `BetaManagedAgentsAlwaysAllowPolicy object`21292130 Tool calls are automatically approved without user confirmation.21312132 - `BetaManagedAgentsAlwaysAskPolicy object`21332134 Tool calls require user confirmation before execution.21352136 - `BetaManagedAgentsAutoPolicy object`21372138 The server decides each tool call individually: it judges, from the tool, its input, and the session content so far, whether the call is safe to execute or high-risk, and evaluates it to allow when judged safe and to deny when judged high-risk. A call the server cannot reach a judgement on evaluates to ask.21392140 - `default_config: BetaManagedAgentsMCPToolsetDefaultConfig`21412142 Resolved default configuration for all tools from an MCP server.21432144 - `enabled: boolean`21452146 - `permission_policy: BetaManagedAgentsAlwaysAllowPolicy or BetaManagedAgentsAlwaysAskPolicy or BetaManagedAgentsAutoPolicy`21472148 Permission policy for tool execution.21492150 - `BetaManagedAgentsAlwaysAllowPolicy object`21512152 Tool calls are automatically approved without user confirmation.21532154 - `BetaManagedAgentsAlwaysAskPolicy object`21552156 Tool calls require user confirmation before execution.21572158 - `BetaManagedAgentsAutoPolicy object`21592160 The server decides each tool call individually: it judges, from the tool, its input, and the session content so far, whether the call is safe to execute or high-risk, and evaluates it to allow when judged safe and to deny when judged high-risk. A call the server cannot reach a judgement on evaluates to ask.21612162 - `mcp_server_name: string`21632164 - `BetaManagedAgentsCustomTool object`21652166 A custom tool as returned in API responses.21672168 - `type: "custom"`21692170 - `description: string`21712172 - `input_schema: BetaManagedAgentsCustomToolInputSchema`21732174 JSON Schema for custom tool input parameters.21752176 - `type: "object"`21772178 - `properties: optional map[unknown] or null`21792180 - `required: optional array of string or null`21812182 - `name: string`21832184 - `version: number`21852186 format: int3221872188 - `BetaManagedAgentsAdvisor object`21892190 Platform advisor roster entry: a model the session's primary thread may consult mid-turn.21912192 - `type: "advisor"`21932194 - `model: string`21952196 The advisor model id.21972198 - `name: string`21992200 - `skills: array of BetaManagedAgentsAnthropicSkill or BetaManagedAgentsCustomSkill`22012202 - `BetaManagedAgentsAnthropicSkill object`22032204 A resolved Anthropic-managed skill.22052206 - `BetaManagedAgentsCustomSkill object`22072208 A resolved user-created custom skill.22092210 - `system: string or null`22112212 - `tools: array of BetaManagedAgentsAgentToolset20260401 or BetaManagedAgentsMCPToolset or BetaManagedAgentsCustomTool`22132214 - `BetaManagedAgentsAgentToolset20260401 object`22152216 - `BetaManagedAgentsMCPToolset object`22172218 - `BetaManagedAgentsCustomTool object`22192220 A custom tool as returned in API responses.22212222 - `version: number`22232224 format: int3222252226 - `budget: optional BetaManagedAgentsBudgetLimit or null`22272228 A hard spend ceiling. The session stops issuing new model requests once the tracked list cost reaches `max_list_cost`.22292230 - `type: "limit"`22312232 - `max_list_cost: BetaMonetaryAmount`22332234 A monetary amount in a specific currency.22352236 - `amount: string`22372238 Amount in minor units of the currency, as an integer decimal string with no leading zeros: "2500" is $25.00 and "50" is fifty cents. A string rather than a number so no float rounding is ever applied.22392240 - `currency: BetaCurrency`22412242 Uppercase ISO-4217 currency code. `USD` is the only currency currently supported; the accepted set is closed and grows only when a new currency is priced.22432244 - `metadata: optional map[string]`22452246 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.22472248 - `title: optional string or null`22492250 The session's new title. Present only when the update changed it.22512252 - `BetaManagedAgentsStartEvent object`22532254 Opens a preview of a buffered event. Carries the previewed event's type and id only. Followed by zero or more event_delta events with the same event id, normally concluded by the buffered event carrying that id. If the producing model request ends without that event (an error or interrupt mid-stream), its terminal span.model_request_end closes the preview. Only sent on stream connections that opt in via event_deltas; never appears in event history.22552256 - `type: "event_start"`22572258 - `event: BetaManagedAgentsStartEventPreview`22592260 The previewed event's type and id. The event type determines which delta types the preview's event_delta events carry: agent.message events stream content_delta fragments; agent.thinking previews are start-only — no deltas follow, and the buffered agent.thinking with the same id concludes them.22612262 - `BetaManagedAgentsAgentMessagePreview object`22632264 - `type: "agent.message"`22652266 - `id: string`22672268 The id the buffered agent.message will carry if it is emitted. Matches the event_id on this preview's event_delta events.22692270 - `BetaManagedAgentsAgentThinkingPreview object`22712272 - `type: "agent.thinking"`22732274 - `id: string`22752276 The id the buffered agent.thinking will carry if it is emitted. Start-only — no event_delta events follow.22772278 - `BetaManagedAgentsDeltaEvent object`22792280 An incremental update to an event that is still being streamed. Deltas are best-effort and may stop early; when the buffered event with id == event_id is produced it carries the complete content. A model request that ends early (an error or interrupt) produces no buffered event — its terminal span.model_request_end closes the preview. Only sent on stream connections that opt in via event_deltas; never appears in event history.22812282 - `type: "event_delta"`22832284 - `delta: BetaManagedAgentsDeltaContent`22852286 One fragment of the previewed event. The delta type is named for the previewed event's field it streams into: agent.message events stream content_delta fragments, each a partial element of the content array.22872288 - `type: "content_delta"`22892290 - `content: BetaManagedAgentsTextBlock`22912292 Regular text content.22932294 - `index: optional number`22952296 Which entry in the previewed event's content array this fragment lands in. Insert content as that entry when the index is new; append to the existing entry otherwise.22972298 format: uint3222992300 - `event_id: string`23012302 The id of the event being previewed. Matches event.id on the corresponding event_start and the buffered event that reconciles the preview.23032304 - `BetaManagedAgentsSystemMessageEvent object`23052306 A mid-conversation system message event. Carries system-role content that is appended to the session as a `role: "system"` turn.23072308 - `type: "system.message"`23092310 - `id: string`23112312 Unique identifier for this event.23132314 - `content: array of BetaManagedAgentsSystemContentBlock`23152316 System content blocks. Text-only.23172318 - `type: "text"`23192320 - `text: string`23212322 The text content.23232324 minLength: 123252326 - `processed_at: optional string or null`23272328 A timestamp in RFC 3339 format23292330 format: date-time23312332 - `BetaManagedAgentsSessionUsageEvent object`23332334 Periodic snapshot of the session's cumulative usage and tracked list cost.23352336 - `type: "session.usage"`23372338 - `id: string`23392340 Unique identifier for this event.23412342 - `processed_at: string`23432344 A timestamp in RFC 3339 format23452346 format: date-time23472348 - `usage: BetaManagedAgentsSessionUsageSnapshot`23492350 Point-in-time snapshot of a session's cumulative usage.23512352 - `active_seconds: optional number`23532354 Cumulative time in seconds during which the session had at least one thread in running status. Overlapping activity from concurrent threads is counted once. This is the duration the session's runtime cost is priced on.23552356 format: double23572358 - `cache_creation: optional BetaManagedAgentsCacheCreationUsage`23592360 Prompt-cache creation token usage broken down by cache lifetime.23612362 - `ephemeral_1h_input_tokens: optional number`23632364 Tokens used to create 1-hour ephemeral cache entries.23652366 format: int3223672368 - `ephemeral_5m_input_tokens: optional number`23692370 Tokens used to create 5-minute ephemeral cache entries.23712372 format: int3223732374 - `cache_read_input_tokens: optional number`23752376 Total tokens read from prompt cache.23772378 format: int3223792380 - `input_tokens: optional number`23812382 Total input tokens consumed across all turns.23832384 format: int3223852386 - `list_cost: optional BetaMonetaryAmount`23872388 A monetary amount in a specific currency.23892390 - `output_tokens: optional number`23912392 Total output tokens generated across all turns.23932394 format: int3223952396 - `server_tool_use: optional BetaManagedAgentsServerToolUsage`23972398 Cumulative count of server-executed tool invocations, broken down by tool.23992400 - `web_fetch_requests: optional number`24012402 Number of server-executed web fetch requests.24032404 format: int3224052406 - `web_search_requests: optional number`24072408 Number of server-executed web search requests.24092410 format: int3224112412 - `budget: optional BetaManagedAgentsBudgetLimit or null`24132414 A hard spend ceiling. The session stops issuing new model requests once the tracked list cost reaches `max_list_cost`.24152416## Example24172418```bash2419curl https://api.anthropic.com/v1/sessions/$SESSION_ID/threads/$THREAD_ID/stream \2420 -H 'anthropic-version: 2023-06-01' \2421 -H 'anthropic-beta: managed-agents-2026-04-01' \2422 -H "X-Api-Key: $ANTHROPIC_API_KEY"2423```24242425### Response (200)24262427```json2428{2429 "id": "sevt_011CZkZGOp0iBcp4kaQSihUmy",2430 "content": [2431 {2432 "text": "Where is my order #1234?",2433 "type": "text"2434 }2435 ],2436 "type": "user.message",2437 "processed_at": "2026-03-15T10:00:00Z"2438}2439```2440