# title: Stream Events url: https://platform.claude.com/docs/en/api/beta/sessions/events/stream

# Stream Events

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

Stream Events

# Path parameters

session_id: string

# Query parameters

event_deltas: optional array of BetaManagedAgentsDeltaType

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.
- "agent.message"
- "agent.thinking"

# Headers

"anthropic-beta": optional array of AnthropicBeta

Optional header to specify the beta version(s) you want to use.
- string
- "message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 43 more
  - "message-batches-2024-09-24"
  - "prompt-caching-2024-07-31"
  - "computer-use-2024-10-22"
  - "computer-use-2025-01-24"
  - "pdfs-2024-09-25"
  - "token-counting-2024-11-01"
  - "token-efficient-tools-2025-02-19"
  - "output-128k-2025-02-19"
  - "files-api-2025-04-14"
  - "mcp-client-2025-04-04"
  - "mcp-client-2025-11-20"
  - "dev-full-thinking-2025-05-14"
  - "interleaved-thinking-2025-05-14"
  - "code-execution-2025-05-22"
  - "extended-cache-ttl-2025-04-11"
  - "context-1m-2025-08-07"
  - "context-management-2025-06-27"
  - "model-context-window-exceeded-2025-08-26"
  - "skills-2025-10-02"
  - "fast-mode-2026-02-01"
  - "output-300k-2026-03-24"
  - "user-profiles-2026-03-24"
  - "user-profiles-2026-08-18"
  - "user-profiles-2026-09-04"
  - "advisor-tool-2026-03-01"
  - "managed-agents-2026-04-01"
  - "cache-diagnosis-2026-04-07"
  - "dreaming-2026-04-21"
  - "thinking-token-count-2026-05-13"
  - "server-side-fallback-2026-06-01"
  - "server-side-fallback-2026-07-01"
  - "fallback-credit-2026-06-01"
  - "fallback-credit-2026-07-01"
  - "agent-memory-2026-07-22"
  - "mid-conversation-tool-changes-2026-07-01"
  - "compact-2026-01-12"
  - "computer-use-2025-11-24"
  - "mcp-tunnels-2026-06-22"
  - "structured-outputs-2025-11-13"
  - "task-budgets-2026-03-13"
  - "thinking-display-updates-2026-08-18"
  - "ce-user-management-2026-07-13"
  - "mid-conversation-output-config-2026-07-01"
  - "thinking-binding-controls-2026-08-01"
  - "mid-conversation-system-clear-at-2026-08-21"
  - "compact-2026-09-04"
"anthropic-workspace-id": optional string

# Returns

BetaManagedAgentsStreamSessionEvents = BetaManagedAgentsUserMessageEvent or BetaManagedAgentsUserInterruptEvent or BetaManagedAgentsUserToolConfirmationEvent or 34 more

Server-sent event in the session stream.
- BetaManagedAgentsUserMessageEvent object
  
  A user message event in the session conversation.
  - type: "user.message"
  - id: string
    
    Unique identifier for this event.
  - content: array of BetaManagedAgentsTextBlock or BetaManagedAgentsImageBlock or BetaManagedAgentsDocumentBlock or BetaManagedAgentsRedactedBlock
    
    Array of content blocks comprising the user message.
    - BetaManagedAgentsTextBlock object
      
      Regular text content.
      - type: "text"
      - text: string
        
        The text content.
        
        minLength: 1
    - BetaManagedAgentsImageBlock object
      
      Image content specified directly as base64 data or as a reference via a URL.
      - type: "image"
      - source: BetaManagedAgentsBase64ImageSource or BetaManagedAgentsURLImageSource or BetaManagedAgentsFileImageSource
        
        Union type for image source variants.
        
        BetaManagedAgentsBase64ImageSource object
        
        Base64-encoded image data.
        
        type: "base64"
        
        data: string
        
        Base64-encoded image data.
        
        minLength: 1
        
        media_type: string
        
        MIME type of the image (e.g., "image/png", "image/jpeg", "image/gif", "image/webp").
        
        minLength: 1
        
        BetaManagedAgentsURLImageSource object
        
        Image referenced by URL.
        
        type: "url"
        
        url: string
        
        URL of the image to fetch.
        
        minLength: 1
        
        BetaManagedAgentsFileImageSource object
        
        Image referenced by file ID.
        
        type: "file"
        
        file_id: string
        
        ID of a previously uploaded file.
        
        minLength: 1
    - BetaManagedAgentsDocumentBlock object
      
      Document content, either specified directly as base64 data, as text, or as a reference via a URL.
      - type: "document"
      - source: BetaManagedAgentsBase64DocumentSource or BetaManagedAgentsPlainTextDocumentSource or BetaManagedAgentsURLDocumentSource or BetaManagedAgentsFileDocumentSource
        
        Union type for document source variants.
        
        BetaManagedAgentsBase64DocumentSource object
        
        Base64-encoded document data.
        
        type: "base64"
        
        data: string
        
        Base64-encoded document data.
        
        minLength: 1
        
        media_type: string
        
        MIME type of the document (e.g., "application/pdf").
        
        minLength: 1
        
        BetaManagedAgentsPlainTextDocumentSource object
        
        Plain text document content.
        
        type: "text"
        
        data: string
        
        The plain text content.
        
        minLength: 1
        
        media_type: "text/plain"
        
        MIME type of the text content. Must be "text/plain".
        
        BetaManagedAgentsURLDocumentSource object
        
        Document referenced by URL.
        
        type: "url"
        
        url: string
        
        URL of the document to fetch.
        
        minLength: 1
        
        BetaManagedAgentsFileDocumentSource object
        
        Document referenced by file ID.
        
        type: "file"
        
        file_id: string
        
        ID of a previously uploaded file.
        
        minLength: 1
      - context: optional string or null
        
        Additional context about the document for the model.
      - title: optional string or null
        
        The title of the document.
    - BetaManagedAgentsRedactedBlock object
      
      Placeholder for content withheld by Anthropic model policy.
      - type: "redacted"
  - processed_at: optional string or null
    
    A timestamp in RFC 3339 format
    
    format: date-time
- BetaManagedAgentsUserInterruptEvent object
  
  An interrupt event that pauses agent execution and returns control to the user.
  - type: "user.interrupt"
  - id: string
    
    Unique identifier for this event.
  - processed_at: optional string or null
    
    A timestamp in RFC 3339 format
    
    format: date-time
  - session_thread_id: optional string or null
    
    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.
- BetaManagedAgentsUserToolConfirmationEvent object
  
  A tool confirmation event that approves or denies a pending tool execution.
  - type: "user.tool_confirmation"
  - id: string
    
    Unique identifier for this event.
  - result: "allow" or "deny"
    
    UserToolConfirmationResult enum
    - "allow"
    - "deny"
  - tool_use_id: string
    
    The id of the agent.tool_use or agent.mcp_tool_use event this result corresponds to, which can be found in the last session.status_idle event's stop_reason.event_ids field.
  - deny_message: optional string or null
    
    Optional message providing context for a 'deny' decision. Only allowed when result is 'deny'.
    
    maxLength: 10000
  - processed_at: optional string or null
    
    A timestamp in RFC 3339 format
    
    format: date-time
  - session_thread_id: optional string or null
    
    Set by the server to the subagent thread this confirmation was routed to. Omitted when it was routed to the primary thread.
- BetaManagedAgentsUserCustomToolResultEvent object
  
  Event sent by the client providing the result of a custom tool execution.
  - type: "user.custom_tool_result"
  - id: string
    
    Unique identifier for this event.
  - custom_tool_use_id: string
    
    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 stop_reason.event_ids field.
  - content: optional array of BetaManagedAgentsTextBlock or BetaManagedAgentsImageBlock or BetaManagedAgentsDocumentBlock or BetaManagedAgentsSearchResultBlock
    
    The result content returned by the tool.
    - BetaManagedAgentsTextBlock object
      
      Regular text content.
    - BetaManagedAgentsImageBlock object
      
      Image content specified directly as base64 data or as a reference via a URL.
    - BetaManagedAgentsDocumentBlock object
      
      Document content, either specified directly as base64 data, as text, or as a reference via a URL.
    - BetaManagedAgentsSearchResultBlock object
      
      A block containing a web search result.
      - type: "search_result"
      - citations: BetaManagedAgentsSearchResultCitations
        
        Citation settings for a search result.
        
        enabled: boolean
        
        Whether citations are enabled for this search result.
      - content: array of BetaManagedAgentsSearchResultContent
        
        Array of text content blocks from the search result.
        
        type: "text"
        
        text: string
        
        The text content.
        
        minLength: 1
      - source: string
        
        The URL source of the search result.
        
        minLength: 1
      - title: string
        
        The title of the search result.
        
        minLength: 1
  - is_error: optional boolean or null
    
    Whether the tool execution resulted in an error.
  - processed_at: optional string or null
    
    A timestamp in RFC 3339 format
    
    format: date-time
  - session_thread_id: optional string or null
    
    Set by the server to the subagent thread this result was routed to. Omitted when it was routed to the primary thread.
- BetaManagedAgentsAgentCustomToolUseEvent object
  
  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.
  - type: "agent.custom_tool_use"
  - id: string
    
    Unique identifier for this event.
  - input: map[unknown]
    
    Input parameters for the tool call.
  - name: string
    
    Name of the custom tool being called.
  - processed_at: string
    
    A timestamp in RFC 3339 format
    
    format: date-time
  - session_thread_id: optional string or null
    
    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.
- BetaManagedAgentsAgentMessageEvent object
  
  An agent response event in the session conversation.
  - type: "agent.message"
  - id: string
    
    Unique identifier for this event.
  - content: array of BetaManagedAgentsTextBlock or BetaManagedAgentsRedactedBlock
    
    Array of text blocks comprising the agent response.
    - BetaManagedAgentsTextBlock object
      
      Regular text content.
    - BetaManagedAgentsRedactedBlock object
      
      Placeholder for content withheld by Anthropic model policy.
  - processed_at: string
    
    A timestamp in RFC 3339 format
    
    format: date-time
- BetaManagedAgentsAgentThinkingEvent object
  
  Indicates the agent is making forward progress via extended thinking. A progress signal, not a content carrier.
  - type: "agent.thinking"
  - id: string
    
    Unique identifier for this event.
  - processed_at: string
    
    A timestamp in RFC 3339 format
    
    format: date-time
- BetaManagedAgentsAgentMCPToolUseEvent object
  
  Event emitted when the agent invokes a tool provided by an MCP server.
  - type: "agent.mcp_tool_use"
  - id: string
    
    Unique identifier for this event.
  - input: map[unknown]
    
    Input parameters for the tool call.
  - mcp_server_name: string
    
    Name of the MCP server providing the tool.
  - name: string
    
    Name of the MCP tool being used.
  - processed_at: string
    
    A timestamp in RFC 3339 format
    
    format: date-time
  - evaluated_permission: optional "allow" or "ask" or "deny"
    
    AgentEvaluatedPermission enum
    - "allow"
    - "ask"
    - "deny"
  - evaluation: optional BetaManagedAgentsAgentToolEvaluation
    
    Names the resolved permission_policy that produced evaluated_permission, and under auto carries the judgement. Open union: clients must tolerate unknown variants.
    - BetaManagedAgentsAgentToolEvaluationAlwaysAllow object
      
      The resolved permission_policy was always_allow; accompanies evaluated_permission "allow".
      - type: "always_allow"
    - BetaManagedAgentsAgentToolEvaluationAlwaysAsk object
      
      The resolved permission_policy was always_ask; accompanies evaluated_permission "ask".
      - type: "always_ask"
    - BetaManagedAgentsAgentToolEvaluationAuto object
      
      The resolved permission_policy was auto: the server judged this invocation individually.
      - type: "auto"
      - evaluated_permission: BetaManagedAgentsAgentAutoEvaluatedPermission
        
        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.
        
        BetaManagedAgentsAgentAutoEvaluatedPermissionAllow object
        
        The server judged the invocation safe to execute without client approval.
        
        type: "allow"
        
        BetaManagedAgentsAgentAutoEvaluatedPermissionAsk object
        
        The server reached no judgement; the invocation is held for client approval.
        
        type: "ask"
        
        reason_code: string
        
        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.
        
        maxLength: 64
        
        BetaManagedAgentsAgentAutoEvaluatedPermissionDeny object
        
        The server judged the invocation high-risk; it does not execute and a synthetic error tool result is appended.
        
        type: "deny"
        
        reason_code: string
        
        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.
        
        maxLength: 64
  - session_thread_id: optional string or null
    
    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.
- BetaManagedAgentsAgentMCPToolResultEvent object
  
  Event representing the result of an MCP tool execution.
  - type: "agent.mcp_tool_result"
  - id: string
    
    Unique identifier for this event.
  - mcp_tool_use_id: string
    
    The id of the agent.mcp_tool_use event this result corresponds to.
  - processed_at: string
    
    A timestamp in RFC 3339 format
    
    format: date-time
  - content: optional array of BetaManagedAgentsTextBlock or BetaManagedAgentsImageBlock or BetaManagedAgentsDocumentBlock or BetaManagedAgentsSearchResultBlock
    
    The result content returned by the tool.
    - BetaManagedAgentsTextBlock object
      
      Regular text content.
    - BetaManagedAgentsImageBlock object
      
      Image content specified directly as base64 data or as a reference via a URL.
    - BetaManagedAgentsDocumentBlock object
      
      Document content, either specified directly as base64 data, as text, or as a reference via a URL.
    - BetaManagedAgentsSearchResultBlock object
      
      A block containing a web search result.
  - is_error: optional boolean or null
    
    Whether the tool execution resulted in an error.
- BetaManagedAgentsAgentToolUseEvent object
  
  Event emitted when the agent invokes a built-in agent tool.
  - type: "agent.tool_use"
  - id: string
    
    Unique identifier for this event.
  - input: map[unknown]
    
    Input parameters for the tool call.
  - name: string
    
    Name of the agent tool being used.
  - processed_at: string
    
    A timestamp in RFC 3339 format
    
    format: date-time
  - evaluated_permission: optional "allow" or "ask" or "deny"
    
    AgentEvaluatedPermission enum
    - "allow"
    - "ask"
    - "deny"
  - evaluation: optional BetaManagedAgentsAgentToolEvaluation
    
    Names the resolved permission_policy that produced evaluated_permission, and under auto carries the judgement. Open union: clients must tolerate unknown variants.
  - session_thread_id: optional string or null
    
    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.
- BetaManagedAgentsAgentToolResultEvent object
  
  Event representing the result of an agent tool execution.
  - type: "agent.tool_result"
  - id: string
    
    Unique identifier for this event.
  - processed_at: string
    
    A timestamp in RFC 3339 format
    
    format: date-time
  - tool_use_id: string
    
    The id of the agent.tool_use event this result corresponds to.
  - content: optional array of BetaManagedAgentsTextBlock or BetaManagedAgentsImageBlock or BetaManagedAgentsDocumentBlock or BetaManagedAgentsSearchResultBlock
    
    The result content returned by the tool.
    - BetaManagedAgentsTextBlock object
      
      Regular text content.
    - BetaManagedAgentsImageBlock object
      
      Image content specified directly as base64 data or as a reference via a URL.
    - BetaManagedAgentsDocumentBlock object
      
      Document content, either specified directly as base64 data, as text, or as a reference via a URL.
    - BetaManagedAgentsSearchResultBlock object
      
      A block containing a web search result.
  - is_error: optional boolean or null
    
    Whether the tool execution resulted in an error.
- BetaManagedAgentsAgentThreadMessageReceivedEvent object
  
  Delivery event written to the target thread's input stream when an agent-to-agent message arrives.
  - type: "agent.thread_message_received"
  - id: string
    
    Unique identifier for this event.
  - content: array of BetaManagedAgentsTextBlock or BetaManagedAgentsImageBlock or BetaManagedAgentsDocumentBlock or BetaManagedAgentsRedactedBlock
    
    Message content blocks.
    - BetaManagedAgentsTextBlock object
      
      Regular text content.
    - BetaManagedAgentsImageBlock object
      
      Image content specified directly as base64 data or as a reference via a URL.
    - BetaManagedAgentsDocumentBlock object
      
      Document content, either specified directly as base64 data, as text, or as a reference via a URL.
    - BetaManagedAgentsRedactedBlock object
      
      Placeholder for content withheld by Anthropic model policy.
  - from_session_thread_id: string
    
    Public sthr_ ID of the thread that sent the message.
  - processed_at: string
    
    A timestamp in RFC 3339 format
    
    format: date-time
  - from_agent_name: optional string or null
    
    Name of the callable agent this message came from. Absent when received from the primary agent.
- BetaManagedAgentsAgentThreadMessageSentEvent object
  
  Observability event emitted to the sender's output stream when an agent-to-agent message is sent.
  - type: "agent.thread_message_sent"
  - id: string
    
    Unique identifier for this event.
  - content: array of BetaManagedAgentsTextBlock or BetaManagedAgentsImageBlock or BetaManagedAgentsDocumentBlock or BetaManagedAgentsRedactedBlock
    
    Message content blocks.
    - BetaManagedAgentsTextBlock object
      
      Regular text content.
    - BetaManagedAgentsImageBlock object
      
      Image content specified directly as base64 data or as a reference via a URL.
    - BetaManagedAgentsDocumentBlock object
      
      Document content, either specified directly as base64 data, as text, or as a reference via a URL.
    - BetaManagedAgentsRedactedBlock object
      
      Placeholder for content withheld by Anthropic model policy.
  - processed_at: string
    
    A timestamp in RFC 3339 format
    
    format: date-time
  - to_session_thread_id: string
    
    Public sthr_ ID of the thread the message was sent to.
  - to_agent_name: optional string or null
    
    Name of the callable agent this message was sent to. Absent when sent to the primary agent.
- BetaManagedAgentsAgentThreadContextCompactedEvent object
  
  Indicates that context compaction (summarization) occurred during the session.
  - type: "agent.thread_context_compacted"
  - id: string
    
    Unique identifier for this event.
  - processed_at: string
    
    A timestamp in RFC 3339 format
    
    format: date-time
- BetaManagedAgentsSessionErrorEvent object
  
  An error event indicating a problem occurred during session execution.
  - type: "session.error"
  - id: string
    
    Unique identifier for this event.
  - error: BetaManagedAgentsUnknownError or BetaManagedAgentsModelOverloadedError or BetaManagedAgentsModelRateLimitedError or 5 more
    - BetaManagedAgentsUnknownError object
      
      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.
      - type: "unknown_error"
      - message: string
        
        Human-readable error description.
      - retry_status: BetaManagedAgentsRetryStatusRetrying or BetaManagedAgentsRetryStatusExhausted or BetaManagedAgentsRetryStatusTerminal
        
        What the client should do next in response to this error.
        
        BetaManagedAgentsRetryStatusRetrying object
        
        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.
        
        type: "retrying"
        
        BetaManagedAgentsRetryStatusExhausted object
        
        This turn is dead; queued inputs are flushed and the session returns to idle. Client may send a new prompt.
        
        type: "exhausted"
        
        BetaManagedAgentsRetryStatusTerminal object
        
        The session encountered a terminal error and will transition to terminated state.
        
        type: "terminal"
    - BetaManagedAgentsModelOverloadedError object
      
      The model is currently overloaded. Emitted after automatic retries are exhausted.
      - type: "model_overloaded_error"
      - message: string
        
        Human-readable error description.
      - retry_status: BetaManagedAgentsRetryStatusRetrying or BetaManagedAgentsRetryStatusExhausted or BetaManagedAgentsRetryStatusTerminal
        
        What the client should do next in response to this error.
        
        BetaManagedAgentsRetryStatusRetrying object
        
        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.
        
        BetaManagedAgentsRetryStatusExhausted object
        
        This turn is dead; queued inputs are flushed and the session returns to idle. Client may send a new prompt.
        
        BetaManagedAgentsRetryStatusTerminal object
        
        The session encountered a terminal error and will transition to terminated state.
    - BetaManagedAgentsModelRateLimitedError object
      
      The model request was rate-limited.
      - type: "model_rate_limited_error"
      - message: string
        
        Human-readable error description.
      - retry_status: BetaManagedAgentsRetryStatusRetrying or BetaManagedAgentsRetryStatusExhausted or BetaManagedAgentsRetryStatusTerminal
        
        What the client should do next in response to this error.
        
        BetaManagedAgentsRetryStatusRetrying object
        
        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.
        
        BetaManagedAgentsRetryStatusExhausted object
        
        This turn is dead; queued inputs are flushed and the session returns to idle. Client may send a new prompt.
        
        BetaManagedAgentsRetryStatusTerminal object
        
        The session encountered a terminal error and will transition to terminated state.
    - BetaManagedAgentsModelRequestFailedError object
      
      A model request failed for a reason other than overload or rate-limiting.
      - type: "model_request_failed_error"
      - message: string
        
        Human-readable error description.
      - retry_status: BetaManagedAgentsRetryStatusRetrying or BetaManagedAgentsRetryStatusExhausted or BetaManagedAgentsRetryStatusTerminal
        
        What the client should do next in response to this error.
        
        BetaManagedAgentsRetryStatusRetrying object
        
        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.
        
        BetaManagedAgentsRetryStatusExhausted object
        
        This turn is dead; queued inputs are flushed and the session returns to idle. Client may send a new prompt.
        
        BetaManagedAgentsRetryStatusTerminal object
        
        The session encountered a terminal error and will transition to terminated state.
    - BetaManagedAgentsMCPConnectionFailedError object
      
      Failed to connect to an MCP server.
      - type: "mcp_connection_failed_error"
      - mcp_server_name: string
        
        Name of the MCP server that failed to connect.
      - message: string
        
        Human-readable error description.
      - retry_status: BetaManagedAgentsRetryStatusRetrying or BetaManagedAgentsRetryStatusExhausted or BetaManagedAgentsRetryStatusTerminal
        
        What the client should do next in response to this error.
        
        BetaManagedAgentsRetryStatusRetrying object
        
        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.
        
        BetaManagedAgentsRetryStatusExhausted object
        
        This turn is dead; queued inputs are flushed and the session returns to idle. Client may send a new prompt.
        
        BetaManagedAgentsRetryStatusTerminal object
        
        The session encountered a terminal error and will transition to terminated state.
    - BetaManagedAgentsMCPAuthenticationFailedError object
      
      Authentication to an MCP server failed.
      - type: "mcp_authentication_failed_error"
      - mcp_server_name: string
        
        Name of the MCP server that failed authentication.
      - message: string
        
        Human-readable error description.
      - retry_status: BetaManagedAgentsRetryStatusRetrying or BetaManagedAgentsRetryStatusExhausted or BetaManagedAgentsRetryStatusTerminal
        
        What the client should do next in response to this error.
        
        BetaManagedAgentsRetryStatusRetrying object
        
        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.
        
        BetaManagedAgentsRetryStatusExhausted object
        
        This turn is dead; queued inputs are flushed and the session returns to idle. Client may send a new prompt.
        
        BetaManagedAgentsRetryStatusTerminal object
        
        The session encountered a terminal error and will transition to terminated state.
    - BetaManagedAgentsBillingError object
      
      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.
      - type: "billing_error"
      - message: string
        
        Human-readable error description.
      - retry_status: BetaManagedAgentsRetryStatusRetrying or BetaManagedAgentsRetryStatusExhausted or BetaManagedAgentsRetryStatusTerminal
        
        What the client should do next in response to this error.
        
        BetaManagedAgentsRetryStatusRetrying object
        
        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.
        
        BetaManagedAgentsRetryStatusExhausted object
        
        This turn is dead; queued inputs are flushed and the session returns to idle. Client may send a new prompt.
        
        BetaManagedAgentsRetryStatusTerminal object
        
        The session encountered a terminal error and will transition to terminated state.
    - BetaManagedAgentsCredentialHostUnreachableError object
      
      An environment_variable credential's auth.networking.allowed_hosts includes a host the environment's network policy does not permit.
      - type: "credential_host_unreachable_error"
      - credential_id: string
        
        ID of the affected credential.
      - message: string
        
        Human-readable error description.
      - retry_status: BetaManagedAgentsRetryStatusRetrying or BetaManagedAgentsRetryStatusExhausted or BetaManagedAgentsRetryStatusTerminal
        
        What the client should do next in response to this error.
        
        BetaManagedAgentsRetryStatusRetrying object
        
        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.
        
        BetaManagedAgentsRetryStatusExhausted object
        
        This turn is dead; queued inputs are flushed and the session returns to idle. Client may send a new prompt.
        
        BetaManagedAgentsRetryStatusTerminal object
        
        The session encountered a terminal error and will transition to terminated state.
      - vault_id: string
        
        ID of the vault containing the affected credential.
  - processed_at: string
    
    A timestamp in RFC 3339 format
    
    format: date-time
- BetaManagedAgentsSessionStatusRescheduledEvent object
  
  Indicates the session is recovering from an error state and is rescheduled for execution.
  - type: "session.status_rescheduled"
  - id: string
    
    Unique identifier for this event.
  - processed_at: string
    
    A timestamp in RFC 3339 format
    
    format: date-time
- BetaManagedAgentsSessionStatusRunningEvent object
  
  Indicates the session is actively running and the agent is working.
  - type: "session.status_running"
  - id: string
    
    Unique identifier for this event.
  - processed_at: string
    
    A timestamp in RFC 3339 format
    
    format: date-time
- BetaManagedAgentsSessionStatusIdleEvent object
  
  Indicates the agent has paused and is awaiting user input.
  - type: "session.status_idle"
  - id: string
    
    Unique identifier for this event.
  - processed_at: string
    
    A timestamp in RFC 3339 format
    
    format: date-time
  - stop_reason: BetaManagedAgentsSessionEndTurn or BetaManagedAgentsSessionRequiresAction or BetaManagedAgentsSessionRetriesExhausted or BetaManagedAgentsSessionBudgetReached
    - BetaManagedAgentsSessionEndTurn object
      
      The agent completed its turn naturally and is ready for the next user message.
      - type: "end_turn"
    - BetaManagedAgentsSessionRequiresAction object
      
      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.
      - type: "requires_action"
      - event_ids: array of string
        
        The ids of events the agent is blocked on. Resolving fewer than all re-emits session.status_idle with the remainder.
    - BetaManagedAgentsSessionRetriesExhausted object
      
      The turn ended because repeated errors exhausted the retry budget or an error escalated to retry_status: 'exhausted'.
      - type: "retries_exhausted"
    - BetaManagedAgentsSessionBudgetReached object
      
      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.
      - type: "budget_reached"
- BetaManagedAgentsSessionStatusTerminatedEvent object
  
  Indicates the session has terminated, either due to an error or completion.
  - type: "session.status_terminated"
  - id: string
    
    Unique identifier for this event.
  - processed_at: string
    
    A timestamp in RFC 3339 format
    
    format: date-time
- BetaManagedAgentsSessionThreadCreatedEvent object
  
  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.
  - type: "session.thread_created"
  - id: string
    
    Unique identifier for this event.
  - agent_name: string
    
    Name of the callable agent the thread runs.
  - processed_at: string
    
    A timestamp in RFC 3339 format
    
    format: date-time
  - session_thread_id: string
    
    Public sthr_ ID of the newly created thread.
- BetaManagedAgentsSpanOutcomeEvaluationStartEvent object
  
  Emitted when an outcome evaluation cycle begins.
  - type: "span.outcome_evaluation_start"
  - id: string
    
    Unique identifier for this event.
  - iteration: number
    
    0-indexed revision cycle. 0 is the first evaluation; 1 is the re-evaluation after the first revision; etc.
    
    format: int32
  - outcome_id: string
    
    The outc_ ID of the outcome being evaluated.
  - processed_at: string
    
    A timestamp in RFC 3339 format
    
    format: date-time
- BetaManagedAgentsSpanOutcomeEvaluationEndEvent object
  
  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.
  - type: "span.outcome_evaluation_end"
  - id: string
    
    Unique identifier for this event.
  - explanation: string
    
    Human-readable explanation of the verdict. For needs_revision, describes which criteria failed and why.
  - iteration: number
    
    0-indexed revision cycle, matching the corresponding span.outcome_evaluation_start.
    
    format: int32
  - outcome_evaluation_start_id: string
    
    The id of the corresponding span.outcome_evaluation_start event.
  - outcome_id: string
    
    The outc_ ID of the outcome being evaluated.
  - processed_at: string
    
    A timestamp in RFC 3339 format
    
    format: date-time
  - result: string
    
    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.
  - usage: BetaManagedAgentsSpanModelUsage
    
    Token usage for a single model request.
    - cache_creation_input_tokens: number
      
      Tokens used to create prompt cache in this request.
      
      format: int32
    - cache_read_input_tokens: number
      
      Tokens read from prompt cache in this request.
      
      format: int32
    - input_tokens: number
      
      Input tokens consumed by this request.
      
      format: int32
    - output_tokens: number
      
      Output tokens generated by this request.
      
      format: int32
    - speed: optional "standard" or "fast" or null
      
      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"
      - "fast"
- BetaManagedAgentsSpanModelRequestStartEvent object
  
  Emitted when a model request is initiated by the agent.
  - type: "span.model_request_start"
  - id: string
    
    Unique identifier for this event.
  - processed_at: string
    
    A timestamp in RFC 3339 format
    
    format: date-time
- BetaManagedAgentsSpanModelRequestEndEvent object
  
  Emitted when a model request completes.
  - type: "span.model_request_end"
  - id: string
    
    Unique identifier for this event.
  - is_error: boolean or null
    
    Whether the model request resulted in an error.
  - model_request_start_id: string
    
    The id of the corresponding span.model_request_start event.
  - model_usage: BetaManagedAgentsSpanModelUsage
    
    Token usage for a single model request.
  - processed_at: string
    
    A timestamp in RFC 3339 format
    
    format: date-time
- BetaManagedAgentsSpanOutcomeEvaluationOngoingEvent object
  
  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.
  - type: "span.outcome_evaluation_ongoing"
  - id: string
    
    Unique identifier for this event.
  - iteration: number
    
    0-indexed revision cycle, matching the corresponding span.outcome_evaluation_start.
    
    format: int32
  - outcome_id: string
    
    The outc_ ID of the outcome being evaluated.
  - processed_at: string
    
    A timestamp in RFC 3339 format
    
    format: date-time
- BetaManagedAgentsUserDefineOutcomeEvent object
  
  Echo of a user.define_outcome input event. Carries the server-generated outcome_id that subsequent span.outcome_evaluation_* events reference.
  - type: "user.define_outcome"
  - id: string
    
    Unique identifier for this event.
  - description: string
    
    What the agent should produce. Copied from the input event.
  - max_iterations: number or null
    
    Evaluate-then-revise cycles before giving up. Default 3, max 20.
    
    format: int32
  - outcome_id: string
    
    Server-generated outc_ ID for this outcome. Referenced by span.outcome_evaluation_* events and the session's outcome_evaluations list.
  - processed_at: string
    
    A timestamp in RFC 3339 format
    
    format: date-time
  - rubric: BetaManagedAgentsFileRubric or BetaManagedAgentsTextRubric
    
    Rubric for grading the quality of an outcome.
    - BetaManagedAgentsFileRubric object
      
      Rubric referenced by a file uploaded via the Files API.
      - type: "file"
      - file_id: string
        
        ID of the rubric file.
    - BetaManagedAgentsTextRubric object
      
      Rubric content provided inline as text.
      - type: "text"
      - content: string
        
        Rubric content. Plain text or markdown — the grader treats it as freeform text.
- BetaManagedAgentsSessionDeletedEvent object
  
  Emitted when a session has been deleted. Terminates any active event stream — no further events will be emitted for this session.
  - type: "session.deleted"
  - id: string
    
    Unique identifier for this event.
  - processed_at: string
    
    A timestamp in RFC 3339 format
    
    format: date-time
- BetaManagedAgentsSessionThreadStatusRunningEvent object
  
  A session thread has begun executing. Emitted on the thread's own stream and cross-posted to the primary stream for child threads.
  - type: "session.thread_status_running"
  - id: string
    
    Unique identifier for this event.
  - agent_name: string
    
    Name of the agent the thread runs.
  - processed_at: string
    
    A timestamp in RFC 3339 format
    
    format: date-time
  - session_thread_id: string
    
    Public sthr_ ID of the thread that started running.
- BetaManagedAgentsSessionThreadStatusIdleEvent object
  
  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.
  - type: "session.thread_status_idle"
  - id: string
    
    Unique identifier for this event.
  - agent_name: string
    
    Name of the agent the thread runs.
  - processed_at: string
    
    A timestamp in RFC 3339 format
    
    format: date-time
  - session_thread_id: string
    
    Public sthr_ ID of the thread that went idle.
  - stop_reason: BetaManagedAgentsSessionEndTurn or BetaManagedAgentsSessionRequiresAction or BetaManagedAgentsSessionRetriesExhausted or BetaManagedAgentsSessionBudgetReached
    - BetaManagedAgentsSessionEndTurn object
      
      The agent completed its turn naturally and is ready for the next user message.
    - BetaManagedAgentsSessionRequiresAction object
      
      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.
    - BetaManagedAgentsSessionRetriesExhausted object
      
      The turn ended because repeated errors exhausted the retry budget or an error escalated to retry_status: 'exhausted'.
    - BetaManagedAgentsSessionBudgetReached object
      
      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.
- BetaManagedAgentsSessionThreadStatusTerminatedEvent object
  
  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.
  - type: "session.thread_status_terminated"
  - id: string
    
    Unique identifier for this event.
  - agent_name: string
    
    Name of the agent the thread runs.
  - processed_at: string
    
    A timestamp in RFC 3339 format
    
    format: date-time
  - session_thread_id: string
    
    Public sthr_ ID of the thread that terminated.
- BetaManagedAgentsUserToolResultEvent object
  
  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.
  - type: "user.tool_result"
  - id: string
    
    Unique identifier for this event.
  - tool_use_id: string
    
    The id of the agent.tool_use event this result corresponds to, which can be found in the last session.status_idle event's stop_reason.event_ids field.
  - content: optional array of BetaManagedAgentsTextBlock or BetaManagedAgentsImageBlock or BetaManagedAgentsDocumentBlock or BetaManagedAgentsSearchResultBlock
    
    The result content returned by the tool.
    - BetaManagedAgentsTextBlock object
      
      Regular text content.
    - BetaManagedAgentsImageBlock object
      
      Image content specified directly as base64 data or as a reference via a URL.
    - BetaManagedAgentsDocumentBlock object
      
      Document content, either specified directly as base64 data, as text, or as a reference via a URL.
    - BetaManagedAgentsSearchResultBlock object
      
      A block containing a web search result.
  - is_error: optional boolean or null
    
    Whether the tool execution resulted in an error.
  - processed_at: optional string or null
    
    A timestamp in RFC 3339 format
    
    format: date-time
  - session_thread_id: optional string or null
    
    Set by the server to the subagent thread this result was routed to. Omitted when it was routed to the primary thread.
- BetaManagedAgentsSessionThreadStatusRescheduledEvent object
  
  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.
  - type: "session.thread_status_rescheduled"
  - id: string
    
    Unique identifier for this event.
  - agent_name: string
    
    Name of the agent the thread runs.
  - processed_at: string
    
    A timestamp in RFC 3339 format
    
    format: date-time
  - session_thread_id: string
    
    Public sthr_ ID of the thread that is retrying.
- BetaManagedAgentsSessionUpdatedEvent object
  
  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.
  - type: "session.updated"
  - id: string
    
    Unique identifier for this event.
  - processed_at: string
    
    A timestamp in RFC 3339 format
    
    format: date-time
  - agent: optional BetaManagedAgentsSessionAgent or null
    
    Resolved agent definition for a session. Snapshot of the agent at session creation time.
    - type: "agent"
    - id: string
    - description: string or null
    - mcp_servers: array of BetaManagedAgentsMCPServerURLDefinition
      - type: "url"
      - name: string
      - url: string
    - model: BetaManagedAgentsModelConfig
      
      Model identifier and configuration.
      - id: BetaManagedAgentsModel
        
        The model that will power your agent.
        
        See models for additional details and options.
        
        "claude-fable-5-1" or "claude-sonnet-5" or "claude-fable-5" or 11 more
        
        The model that will power your agent.
        
        See models for additional details and options.
        
        "claude-fable-5-1"
        
        Frontier intelligence for ambitious tasks across coding, scientific discovery, and enterprise workflows
        
        "claude-sonnet-5"
        
        High-performance model for coding and agents
        
        "claude-fable-5"
        
        Next generation of intelligence for the hardest knowledge work and coding problems
        
        "claude-opus-5"
        
        Powerful intelligence for long-running agents and coding
        
        "claude-opus-4-8"
        
        Powerful intelligence for long-running agents and coding
        
        "claude-opus-4-7"
        
        Powerful intelligence for long-running agents and coding
        
        "claude-opus-4-6"
        
        Powerful intelligence for long-running agents and coding
        
        "claude-sonnet-4-6"
        
        Best combination of speed and intelligence
        
        "claude-haiku-4-5"
        
        Fastest model with near-frontier intelligence
        
        "claude-haiku-4-5-20251001"
        
        Fastest model with near-frontier intelligence
        
        "claude-opus-4-5"
        
        Powerful intelligence for long-running agents and coding
        
        "claude-opus-4-5-20251101"
        
        Powerful intelligence for long-running agents and coding
        
        "claude-sonnet-4-5"
        
        High-performance model for agents and coding
        
        "claude-sonnet-4-5-20250929"
        
        High-performance model for agents and coding
        
        string
      - effort: optional BetaManagedAgentsEffortLow or BetaManagedAgentsEffortMedium or BetaManagedAgentsEffortHigh or 2 more
        
        How hard Claude works on each turn. Sets output_config.effort on every Messages call the session makes.
        
        BetaManagedAgentsEffortLow object
        
        Low effort. Favors latency over reasoning depth.
        
        type: "low"
        
        BetaManagedAgentsEffortMedium object
        
        Medium effort. Balances latency and reasoning depth.
        
        type: "medium"
        
        BetaManagedAgentsEffortHigh object
        
        High effort. Favors reasoning depth.
        
        type: "high"
        
        BetaManagedAgentsEffortXhigh object
        
        Extra-high effort. Not all models accept this level.
        
        type: "xhigh"
        
        BetaManagedAgentsEffortMax object
        
        Maximum effort. Favors reasoning depth over latency.
        
        type: "max"
      - inference_geo: optional string
        
        Geographic region for model inference. When unset, requests fall through to the workspace's default_inference_geo.
      - speed: optional "standard" or "fast"
        
        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"
        
        "fast"
    - multiagent: BetaManagedAgentsSessionMultiagentCoordinator or null
      
      Resolved coordinator topology with full agent definitions for each roster member.
      - type: "coordinator"
      - agents: array of BetaManagedAgentsSessionThreadAgent or BetaManagedAgentsAdvisor
        
        Full agent definitions the coordinator may spawn as session threads.
        
        BetaManagedAgentsSessionThreadAgent object
        
        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.
        
        type: "agent"
        
        id: string
        
        description: string or null
        
        mcp_servers: array of BetaManagedAgentsMCPServerURLDefinition
        
        type: "url"
        
        name: string
        
        url: string
        
        model: BetaManagedAgentsModelConfig
        
        Model identifier and configuration.
        
        name: string
        
        skills: array of BetaManagedAgentsAnthropicSkill or BetaManagedAgentsCustomSkill
        
        BetaManagedAgentsAnthropicSkill object
        
        A resolved Anthropic-managed skill.
        
        type: "anthropic"
        
        skill_id: string
        
        version: string
        
        BetaManagedAgentsCustomSkill object
        
        A resolved user-created custom skill.
        
        type: "custom"
        
        skill_id: string
        
        version: string
        
        system: string or null
        
        tools: array of BetaManagedAgentsAgentToolset20260401 or BetaManagedAgentsMCPToolset or BetaManagedAgentsCustomTool
        
        BetaManagedAgentsAgentToolset20260401 object
        
        type: "agent_toolset_20260401"
        
        configs: array of BetaManagedAgentsAgentToolConfig
        
        BetaManagedAgentsBashToolConfig object
        
        Configuration for the bash tool.
        
        type: "bash"
        
        enabled: boolean
        
        name: "bash"
        
        permission_policy: BetaManagedAgentsAlwaysAllowPolicy or BetaManagedAgentsAlwaysAskPolicy or BetaManagedAgentsAutoPolicy
        
        Permission policy for tool execution.
        
        BetaManagedAgentsAlwaysAllowPolicy object
        
        Tool calls are automatically approved without user confirmation.
        
        type: "always_allow"
        
        BetaManagedAgentsAlwaysAskPolicy object
        
        Tool calls require user confirmation before execution.
        
        type: "always_ask"
        
        BetaManagedAgentsAutoPolicy object
        
        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.
        
        type: "auto"
        
        BetaManagedAgentsEditToolConfig object
        
        Configuration for the edit tool.
        
        type: "edit"
        
        enabled: boolean
        
        name: "edit"
        
        permission_policy: BetaManagedAgentsAlwaysAllowPolicy or BetaManagedAgentsAlwaysAskPolicy or BetaManagedAgentsAutoPolicy
        
        Permission policy for tool execution.
        
        BetaManagedAgentsAlwaysAllowPolicy object
        
        Tool calls are automatically approved without user confirmation.
        
        BetaManagedAgentsAlwaysAskPolicy object
        
        Tool calls require user confirmation before execution.
        
        BetaManagedAgentsAutoPolicy object
        
        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.
        
        BetaManagedAgentsReadToolConfig object
        
        Configuration for the read tool.
        
        type: "read"
        
        enabled: boolean
        
        name: "read"
        
        permission_policy: BetaManagedAgentsAlwaysAllowPolicy or BetaManagedAgentsAlwaysAskPolicy or BetaManagedAgentsAutoPolicy
        
        Permission policy for tool execution.
        
        BetaManagedAgentsAlwaysAllowPolicy object
        
        Tool calls are automatically approved without user confirmation.
        
        BetaManagedAgentsAlwaysAskPolicy object
        
        Tool calls require user confirmation before execution.
        
        BetaManagedAgentsAutoPolicy object
        
        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.
        
        BetaManagedAgentsWriteToolConfig object
        
        Configuration for the write tool.
        
        type: "write"
        
        enabled: boolean
        
        name: "write"
        
        permission_policy: BetaManagedAgentsAlwaysAllowPolicy or BetaManagedAgentsAlwaysAskPolicy or BetaManagedAgentsAutoPolicy
        
        Permission policy for tool execution.
        
        BetaManagedAgentsAlwaysAllowPolicy object
        
        Tool calls are automatically approved without user confirmation.
        
        BetaManagedAgentsAlwaysAskPolicy object
        
        Tool calls require user confirmation before execution.
        
        BetaManagedAgentsAutoPolicy object
        
        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.
        
        BetaManagedAgentsGlobToolConfig object
        
        Configuration for the glob tool.
        
        type: "glob"
        
        enabled: boolean
        
        name: "glob"
        
        permission_policy: BetaManagedAgentsAlwaysAllowPolicy or BetaManagedAgentsAlwaysAskPolicy or BetaManagedAgentsAutoPolicy
        
        Permission policy for tool execution.
        
        BetaManagedAgentsAlwaysAllowPolicy object
        
        Tool calls are automatically approved without user confirmation.
        
        BetaManagedAgentsAlwaysAskPolicy object
        
        Tool calls require user confirmation before execution.
        
        BetaManagedAgentsAutoPolicy object
        
        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.
        
        BetaManagedAgentsGrepToolConfig object
        
        Configuration for the grep tool.
        
        type: "grep"
        
        enabled: boolean
        
        name: "grep"
        
        permission_policy: BetaManagedAgentsAlwaysAllowPolicy or BetaManagedAgentsAlwaysAskPolicy or BetaManagedAgentsAutoPolicy
        
        Permission policy for tool execution.
        
        BetaManagedAgentsAlwaysAllowPolicy object
        
        Tool calls are automatically approved without user confirmation.
        
        BetaManagedAgentsAlwaysAskPolicy object
        
        Tool calls require user confirmation before execution.
        
        BetaManagedAgentsAutoPolicy object
        
        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.
        
        BetaManagedAgentsWebFetchToolConfig object
        
        Configuration for the web_fetch tool.
        
        type: "web_fetch"
        
        enabled: boolean
        
        name: "web_fetch"
        
        permission_policy: BetaManagedAgentsAlwaysAllowPolicy or BetaManagedAgentsAlwaysAskPolicy or BetaManagedAgentsAutoPolicy
        
        Permission policy for tool execution.
        
        BetaManagedAgentsAlwaysAllowPolicy object
        
        Tool calls are automatically approved without user confirmation.
        
        BetaManagedAgentsAlwaysAskPolicy object
        
        Tool calls require user confirmation before execution.
        
        BetaManagedAgentsAutoPolicy object
        
        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.
        
        allowed_domains: optional array of string
        
        blocked_domains: optional array of string
        
        max_content_tokens: optional number or null
        
        format: int32
        
        BetaManagedAgentsWebSearchToolConfig object
        
        Configuration for the web_search tool.
        
        type: "web_search"
        
        enabled: boolean
        
        name: "web_search"
        
        permission_policy: BetaManagedAgentsAlwaysAllowPolicy or BetaManagedAgentsAlwaysAskPolicy or BetaManagedAgentsAutoPolicy
        
        Permission policy for tool execution.
        
        BetaManagedAgentsAlwaysAllowPolicy object
        
        Tool calls are automatically approved without user confirmation.
        
        BetaManagedAgentsAlwaysAskPolicy object
        
        Tool calls require user confirmation before execution.
        
        BetaManagedAgentsAutoPolicy object
        
        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.
        
        allowed_domains: optional array of string
        
        blocked_domains: optional array of string
        
        user_location: optional BetaManagedAgentsUserLocation or null
        
        Approximate user location for search result localization.
        
        type: "approximate"
        
        Location precision. Only "approximate" is supported.
        
        city: optional string or null
        
        City name.
        
        minLength: 1, maxLength: 255
        
        country: optional string or null
        
        Two-letter ISO 3166-1 country code, uppercase.
        
        region: optional string or null
        
        Region or state name.
        
        minLength: 1, maxLength: 255
        
        timezone: optional string or null
        
        IANA timezone identifier, e.g. "America/Los_Angeles".
        
        minLength: 1, maxLength: 255
        
        default_config: BetaManagedAgentsAgentToolsetDefaultConfig
        
        Resolved default configuration for agent tools.
        
        enabled: boolean
        
        permission_policy: BetaManagedAgentsAlwaysAllowPolicy or BetaManagedAgentsAlwaysAskPolicy or BetaManagedAgentsAutoPolicy
        
        Permission policy for tool execution.
        
        BetaManagedAgentsAlwaysAllowPolicy object
        
        Tool calls are automatically approved without user confirmation.
        
        BetaManagedAgentsAlwaysAskPolicy object
        
        Tool calls require user confirmation before execution.
        
        BetaManagedAgentsAutoPolicy object
        
        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.
        
        BetaManagedAgentsMCPToolset object
        
        type: "mcp_toolset"
        
        configs: array of BetaManagedAgentsMCPToolConfig
        
        enabled: boolean
        
        name: string
        
        permission_policy: BetaManagedAgentsAlwaysAllowPolicy or BetaManagedAgentsAlwaysAskPolicy or BetaManagedAgentsAutoPolicy
        
        Permission policy for tool execution.
        
        BetaManagedAgentsAlwaysAllowPolicy object
        
        Tool calls are automatically approved without user confirmation.
        
        BetaManagedAgentsAlwaysAskPolicy object
        
        Tool calls require user confirmation before execution.
        
        BetaManagedAgentsAutoPolicy object
        
        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.
        
        default_config: BetaManagedAgentsMCPToolsetDefaultConfig
        
        Resolved default configuration for all tools from an MCP server.
        
        enabled: boolean
        
        permission_policy: BetaManagedAgentsAlwaysAllowPolicy or BetaManagedAgentsAlwaysAskPolicy or BetaManagedAgentsAutoPolicy
        
        Permission policy for tool execution.
        
        BetaManagedAgentsAlwaysAllowPolicy object
        
        Tool calls are automatically approved without user confirmation.
        
        BetaManagedAgentsAlwaysAskPolicy object
        
        Tool calls require user confirmation before execution.
        
        BetaManagedAgentsAutoPolicy object
        
        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.
        
        mcp_server_name: string
        
        BetaManagedAgentsCustomTool object
        
        A custom tool as returned in API responses.
        
        type: "custom"
        
        description: string
        
        input_schema: BetaManagedAgentsCustomToolInputSchema
        
        JSON Schema for custom tool input parameters.
        
        type: "object"
        
        properties: optional map[unknown] or null
        
        required: optional array of string or null
        
        name: string
        
        version: number
        
        format: int32
        
        BetaManagedAgentsAdvisor object
        
        Platform advisor roster entry: a model the session's primary thread may consult mid-turn.
        
        type: "advisor"
        
        model: string
        
        The advisor model id.
    - name: string
    - skills: array of BetaManagedAgentsAnthropicSkill or BetaManagedAgentsCustomSkill
      - BetaManagedAgentsAnthropicSkill object
        
        A resolved Anthropic-managed skill.
      - BetaManagedAgentsCustomSkill object
        
        A resolved user-created custom skill.
    - system: string or null
    - tools: array of BetaManagedAgentsAgentToolset20260401 or BetaManagedAgentsMCPToolset or BetaManagedAgentsCustomTool
      - BetaManagedAgentsAgentToolset20260401 object
      - BetaManagedAgentsMCPToolset object
      - BetaManagedAgentsCustomTool object
        
        A custom tool as returned in API responses.
    - version: number
      
      format: int32
  - budget: optional BetaManagedAgentsBudgetLimit or null
    
    A hard spend ceiling. The session stops issuing new model requests once the tracked list cost reaches max_list_cost.
    - type: "limit"
    - max_list_cost: BetaMonetaryAmount
      
      A monetary amount in a specific currency.
      - amount: string
        
        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.
      - currency: BetaCurrency
        
        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.
  - metadata: optional map[string]
    
    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.
  - title: optional string or null
    
    The session's new title. Present only when the update changed it.
- BetaManagedAgentsStartEvent object
  
  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.
  - type: "event_start"
  - event: BetaManagedAgentsStartEventPreview
    
    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.
    - BetaManagedAgentsAgentMessagePreview object
      - type: "agent.message"
      - id: string
        
        The id the buffered agent.message will carry if it is emitted. Matches the event_id on this preview's event_delta events.
    - BetaManagedAgentsAgentThinkingPreview object
      - type: "agent.thinking"
      - id: string
        
        The id the buffered agent.thinking will carry if it is emitted. Start-only — no event_delta events follow.
- BetaManagedAgentsDeltaEvent object
  
  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.
  - type: "event_delta"
  - delta: BetaManagedAgentsDeltaContent
    
    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.
    - type: "content_delta"
    - content: BetaManagedAgentsTextBlock
      
      Regular text content.
    - index: optional number
      
      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.
      
      format: uint32
  - event_id: string
    
    The id of the event being previewed. Matches event.id on the corresponding event_start and the buffered event that reconciles the preview.
- BetaManagedAgentsSystemMessageEvent object
  
  A mid-conversation system message event. Carries system-role content that is appended to the session as a role: "system" turn.
  - type: "system.message"
  - id: string
    
    Unique identifier for this event.
  - content: array of BetaManagedAgentsSystemContentBlock
    
    System content blocks. Text-only.
    - type: "text"
    - text: string
      
      The text content.
      
      minLength: 1
  - processed_at: optional string or null
    
    A timestamp in RFC 3339 format
    
    format: date-time
- BetaManagedAgentsSessionUsageEvent object
  
  Periodic snapshot of the session's cumulative usage and tracked list cost.
  - type: "session.usage"
  - id: string
    
    Unique identifier for this event.
  - processed_at: string
    
    A timestamp in RFC 3339 format
    
    format: date-time
  - usage: BetaManagedAgentsSessionUsageSnapshot
    
    Point-in-time snapshot of a session's cumulative usage.
    - active_seconds: optional number
      
      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.
      
      format: double
    - cache_creation: optional BetaManagedAgentsCacheCreationUsage
      
      Prompt-cache creation token usage broken down by cache lifetime.
      - ephemeral_1h_input_tokens: optional number
        
        Tokens used to create 1-hour ephemeral cache entries.
        
        format: int32
      - ephemeral_5m_input_tokens: optional number
        
        Tokens used to create 5-minute ephemeral cache entries.
        
        format: int32
    - cache_read_input_tokens: optional number
      
      Total tokens read from prompt cache.
      
      format: int32
    - input_tokens: optional number
      
      Total input tokens consumed across all turns.
      
      format: int32
    - list_cost: optional BetaMonetaryAmount
      
      A monetary amount in a specific currency.
    - output_tokens: optional number
      
      Total output tokens generated across all turns.
      
      format: int32
    - server_tool_use: optional BetaManagedAgentsServerToolUsage
      
      Cumulative count of server-executed tool invocations, broken down by tool.
      - web_fetch_requests: optional number
        
        Number of server-executed web fetch requests.
        
        format: int32
      - web_search_requests: optional number
        
        Number of server-executed web search requests.
        
        format: int32
  - budget: optional BetaManagedAgentsBudgetLimit or null
    
    A hard spend ceiling. The session stops issuing new model requests once the tracked list cost reaches max_list_cost.

# Example

bash

curl https://api.anthropic.com/v1/sessions/$SESSION_ID/events/stream \
    -H 'anthropic-version: 2023-06-01' \
    -H 'anthropic-beta: managed-agents-2026-04-01' \
    -H "X-Api-Key: $ANTHROPIC_API_KEY"

# Response (200)

json

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

spb doc-api

# title: Stream Events url: https://platform.claude.com/docs/en/api/beta/sessions/events/stream

# Stream Events

# Path parameters

# Query parameters

# Headers

# Returns

# Example

# Response (200)

Theme