# Threads ## List Session Threads `beta.sessions.threads.list(strsession_id, ThreadListParams**kwargs) -> SyncPageCursor[BetaManagedAgentsSessionThread]` **get** `/v1/sessions/{session_id}/threads` List Session Threads ### Parameters - `session_id: str` - `limit: Optional[int]` Maximum results per page. Defaults to 1000. - `page: Optional[str]` Opaque pagination cursor from a previous response's next_page. Forward-only. - `betas: Optional[List[AnthropicBetaParam]]` Optional header to specify the beta version(s) you want to use. - `str` - `Literal["message-batches-2024-09-24", "prompt-caching-2024-07-31", "computer-use-2024-10-22", 25 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"` - `"advisor-tool-2026-03-01"` - `"managed-agents-2026-04-01"` - `"cache-diagnosis-2026-04-07"` - `"thinking-token-count-2026-05-13"` - `"server-side-fallback-2026-06-01"` - `"fallback-credit-2026-06-01"` ### Returns - `class BetaManagedAgentsSessionThread: …` An execution thread within a `session`. Each session has one primary thread plus zero or more child threads spawned by the coordinator. - `id: str` Unique identifier for this thread. - `agent: BetaManagedAgentsSessionThreadAgent` 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`. - `id: str` - `description: Optional[str]` - `mcp_servers: List[BetaManagedAgentsMCPServerURLDefinition]` - `name: str` - `type: Literal["url"]` - `"url"` - `url: str` - `model: BetaManagedAgentsModelConfig` Model identifier and configuration. - `id: BetaManagedAgentsModel` The model that will power your agent. See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options. - `Literal["claude-fable-5", "claude-opus-4-8", "claude-opus-4-7", 8 more]` The model that will power your agent. See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options. - `claude-fable-5` - Next generation of intelligence for the hardest knowledge work and coding problems - `claude-opus-4-8` - Frontier intelligence for long-running agents and coding - `claude-opus-4-7` - Frontier intelligence for long-running agents and coding - `claude-opus-4-6` - Most intelligent model for building 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` - Premium model combining maximum intelligence with practical performance - `claude-opus-4-5-20251101` - Premium model combining maximum intelligence with practical performance - `claude-sonnet-4-5` - High-performance model for agents and coding - `claude-sonnet-4-5-20250929` - High-performance model for agents and coding - `"claude-fable-5"` Next generation of intelligence for the hardest knowledge work and coding problems - `"claude-opus-4-8"` Frontier intelligence for long-running agents and coding - `"claude-opus-4-7"` Frontier intelligence for long-running agents and coding - `"claude-opus-4-6"` Most intelligent model for building 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"` Premium model combining maximum intelligence with practical performance - `"claude-opus-4-5-20251101"` Premium model combining maximum intelligence with practical performance - `"claude-sonnet-4-5"` High-performance model for agents and coding - `"claude-sonnet-4-5-20250929"` High-performance model for agents and coding - `str` - `speed: Optional[Literal["standard", "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"` - `name: str` - `skills: List[Skill]` - `class BetaManagedAgentsAnthropicSkill: …` A resolved Anthropic-managed skill. - `skill_id: str` - `type: Literal["anthropic"]` - `"anthropic"` - `version: str` - `class BetaManagedAgentsCustomSkill: …` A resolved user-created custom skill. - `skill_id: str` - `type: Literal["custom"]` - `"custom"` - `version: str` - `system: Optional[str]` - `tools: List[Tool]` - `class BetaManagedAgentsAgentToolset20260401: …` - `configs: List[BetaManagedAgentsAgentToolConfig]` - `enabled: bool` - `name: Literal["bash", "edit", "read", 5 more]` Built-in agent tool identifier. - `"bash"` - `"edit"` - `"read"` - `"write"` - `"glob"` - `"grep"` - `"web_fetch"` - `"web_search"` - `permission_policy: PermissionPolicy` Permission policy for tool execution. - `class BetaManagedAgentsAlwaysAllowPolicy: …` Tool calls are automatically approved without user confirmation. - `type: Literal["always_allow"]` - `"always_allow"` - `class BetaManagedAgentsAlwaysAskPolicy: …` Tool calls require user confirmation before execution. - `type: Literal["always_ask"]` - `"always_ask"` - `default_config: BetaManagedAgentsAgentToolsetDefaultConfig` Resolved default configuration for agent tools. - `enabled: bool` - `permission_policy: PermissionPolicy` Permission policy for tool execution. - `class BetaManagedAgentsAlwaysAllowPolicy: …` Tool calls are automatically approved without user confirmation. - `class BetaManagedAgentsAlwaysAskPolicy: …` Tool calls require user confirmation before execution. - `type: Literal["agent_toolset_20260401"]` - `"agent_toolset_20260401"` - `class BetaManagedAgentsMCPToolset: …` - `configs: List[BetaManagedAgentsMCPToolConfig]` - `enabled: bool` - `name: str` - `permission_policy: PermissionPolicy` Permission policy for tool execution. - `class BetaManagedAgentsAlwaysAllowPolicy: …` Tool calls are automatically approved without user confirmation. - `class BetaManagedAgentsAlwaysAskPolicy: …` Tool calls require user confirmation before execution. - `default_config: BetaManagedAgentsMCPToolsetDefaultConfig` Resolved default configuration for all tools from an MCP server. - `enabled: bool` - `permission_policy: PermissionPolicy` Permission policy for tool execution. - `class BetaManagedAgentsAlwaysAllowPolicy: …` Tool calls are automatically approved without user confirmation. - `class BetaManagedAgentsAlwaysAskPolicy: …` Tool calls require user confirmation before execution. - `mcp_server_name: str` - `type: Literal["mcp_toolset"]` - `"mcp_toolset"` - `class BetaManagedAgentsCustomTool: …` A custom tool as returned in API responses. - `description: str` - `input_schema: BetaManagedAgentsCustomToolInputSchema` JSON Schema for custom tool input parameters. - `type: Literal["object"]` - `"object"` - `properties: Optional[Dict[str, object]]` - `required: Optional[List[str]]` - `name: str` - `type: Literal["custom"]` - `"custom"` - `type: Literal["agent"]` - `"agent"` - `version: int` - `archived_at: Optional[datetime]` A timestamp in RFC 3339 format - `created_at: datetime` A timestamp in RFC 3339 format - `parent_thread_id: Optional[str]` Parent thread that spawned this thread. Null for the primary thread. - `session_id: str` The session this thread belongs to. - `stats: Optional[BetaManagedAgentsSessionThreadStats]` Timing statistics for a session thread. - `active_seconds: Optional[float]` Cumulative time in seconds the thread spent actively running. Excludes idle time. - `duration_seconds: Optional[float]` Elapsed time since thread creation in seconds. For archived threads, frozen at the final update. - `startup_seconds: Optional[float]` Time in seconds for the thread to begin running. Zero for child threads, which start immediately. - `status: BetaManagedAgentsSessionThreadStatus` SessionThreadStatus enum - `"running"` - `"idle"` - `"rescheduling"` - `"terminated"` - `type: Literal["session_thread"]` - `"session_thread"` - `updated_at: datetime` A timestamp in RFC 3339 format - `usage: Optional[BetaManagedAgentsSessionThreadUsage]` Cumulative token usage for a session thread across all turns. - `cache_creation: Optional[BetaManagedAgentsCacheCreationUsage]` Prompt-cache creation token usage broken down by cache lifetime. - `ephemeral_1h_input_tokens: Optional[int]` Tokens used to create 1-hour ephemeral cache entries. - `ephemeral_5m_input_tokens: Optional[int]` Tokens used to create 5-minute ephemeral cache entries. - `cache_read_input_tokens: Optional[int]` Total tokens read from prompt cache. - `input_tokens: Optional[int]` Total input tokens consumed across all turns. - `output_tokens: Optional[int]` Total output tokens generated across all turns. ### Example ```python import os from anthropic import Anthropic client = Anthropic( api_key=os.environ.get("ANTHROPIC_API_KEY"), # This is the default and can be omitted ) page = client.beta.sessions.threads.list( session_id="sesn_011CZkZAtmR3yMPDzynEDxu7", ) page = page.data[0] print(page.id) ``` #### Response ```json { "data": [ { "id": "sthr_011CZkZVWa6oIjw0rgXZpnBt", "agent": { "id": "agent_011CZkYqphY8vELVzwCUpqiQ", "description": "A focused research subagent.", "mcp_servers": [ { "name": "example-mcp", "type": "url", "url": "https://example-server.modelcontextprotocol.io/sse" } ], "model": { "id": "claude-sonnet-4-6", "speed": "standard" }, "name": "Researcher", "skills": [ { "skill_id": "xlsx", "type": "anthropic", "version": "1" } ], "system": "You are a research subagent that gathers and summarises sources for the coordinating agent.", "tools": [ { "configs": [ { "enabled": true, "name": "bash", "permission_policy": { "type": "always_allow" } } ], "default_config": { "enabled": true, "permission_policy": { "type": "always_ask" } }, "type": "agent_toolset_20260401" } ], "type": "agent", "version": 1 }, "archived_at": null, "created_at": "2026-03-15T10:00:00Z", "parent_thread_id": null, "session_id": "sesn_011CZkZAtmR3yMPDzynEDxu7", "stats": { "active_seconds": 0, "duration_seconds": 0, "startup_seconds": 0 }, "status": "idle", "type": "session_thread", "updated_at": "2026-03-15T10:00:00Z", "usage": { "cache_creation": { "ephemeral_1h_input_tokens": 0, "ephemeral_5m_input_tokens": 0 }, "cache_read_input_tokens": 0, "input_tokens": 0, "output_tokens": 0 } } ], "next_page": "page_MjAyNS0wNS0xNFQwMDowMDowMFo=" } ``` ## Get Session Thread `beta.sessions.threads.retrieve(strthread_id, ThreadRetrieveParams**kwargs) -> BetaManagedAgentsSessionThread` **get** `/v1/sessions/{session_id}/threads/{thread_id}` Get Session Thread ### Parameters - `session_id: str` - `thread_id: str` - `betas: Optional[List[AnthropicBetaParam]]` Optional header to specify the beta version(s) you want to use. - `str` - `Literal["message-batches-2024-09-24", "prompt-caching-2024-07-31", "computer-use-2024-10-22", 25 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"` - `"advisor-tool-2026-03-01"` - `"managed-agents-2026-04-01"` - `"cache-diagnosis-2026-04-07"` - `"thinking-token-count-2026-05-13"` - `"server-side-fallback-2026-06-01"` - `"fallback-credit-2026-06-01"` ### Returns - `class BetaManagedAgentsSessionThread: …` An execution thread within a `session`. Each session has one primary thread plus zero or more child threads spawned by the coordinator. - `id: str` Unique identifier for this thread. - `agent: BetaManagedAgentsSessionThreadAgent` 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`. - `id: str` - `description: Optional[str]` - `mcp_servers: List[BetaManagedAgentsMCPServerURLDefinition]` - `name: str` - `type: Literal["url"]` - `"url"` - `url: str` - `model: BetaManagedAgentsModelConfig` Model identifier and configuration. - `id: BetaManagedAgentsModel` The model that will power your agent. See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options. - `Literal["claude-fable-5", "claude-opus-4-8", "claude-opus-4-7", 8 more]` The model that will power your agent. See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options. - `claude-fable-5` - Next generation of intelligence for the hardest knowledge work and coding problems - `claude-opus-4-8` - Frontier intelligence for long-running agents and coding - `claude-opus-4-7` - Frontier intelligence for long-running agents and coding - `claude-opus-4-6` - Most intelligent model for building 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` - Premium model combining maximum intelligence with practical performance - `claude-opus-4-5-20251101` - Premium model combining maximum intelligence with practical performance - `claude-sonnet-4-5` - High-performance model for agents and coding - `claude-sonnet-4-5-20250929` - High-performance model for agents and coding - `"claude-fable-5"` Next generation of intelligence for the hardest knowledge work and coding problems - `"claude-opus-4-8"` Frontier intelligence for long-running agents and coding - `"claude-opus-4-7"` Frontier intelligence for long-running agents and coding - `"claude-opus-4-6"` Most intelligent model for building 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"` Premium model combining maximum intelligence with practical performance - `"claude-opus-4-5-20251101"` Premium model combining maximum intelligence with practical performance - `"claude-sonnet-4-5"` High-performance model for agents and coding - `"claude-sonnet-4-5-20250929"` High-performance model for agents and coding - `str` - `speed: Optional[Literal["standard", "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"` - `name: str` - `skills: List[Skill]` - `class BetaManagedAgentsAnthropicSkill: …` A resolved Anthropic-managed skill. - `skill_id: str` - `type: Literal["anthropic"]` - `"anthropic"` - `version: str` - `class BetaManagedAgentsCustomSkill: …` A resolved user-created custom skill. - `skill_id: str` - `type: Literal["custom"]` - `"custom"` - `version: str` - `system: Optional[str]` - `tools: List[Tool]` - `class BetaManagedAgentsAgentToolset20260401: …` - `configs: List[BetaManagedAgentsAgentToolConfig]` - `enabled: bool` - `name: Literal["bash", "edit", "read", 5 more]` Built-in agent tool identifier. - `"bash"` - `"edit"` - `"read"` - `"write"` - `"glob"` - `"grep"` - `"web_fetch"` - `"web_search"` - `permission_policy: PermissionPolicy` Permission policy for tool execution. - `class BetaManagedAgentsAlwaysAllowPolicy: …` Tool calls are automatically approved without user confirmation. - `type: Literal["always_allow"]` - `"always_allow"` - `class BetaManagedAgentsAlwaysAskPolicy: …` Tool calls require user confirmation before execution. - `type: Literal["always_ask"]` - `"always_ask"` - `default_config: BetaManagedAgentsAgentToolsetDefaultConfig` Resolved default configuration for agent tools. - `enabled: bool` - `permission_policy: PermissionPolicy` Permission policy for tool execution. - `class BetaManagedAgentsAlwaysAllowPolicy: …` Tool calls are automatically approved without user confirmation. - `class BetaManagedAgentsAlwaysAskPolicy: …` Tool calls require user confirmation before execution. - `type: Literal["agent_toolset_20260401"]` - `"agent_toolset_20260401"` - `class BetaManagedAgentsMCPToolset: …` - `configs: List[BetaManagedAgentsMCPToolConfig]` - `enabled: bool` - `name: str` - `permission_policy: PermissionPolicy` Permission policy for tool execution. - `class BetaManagedAgentsAlwaysAllowPolicy: …` Tool calls are automatically approved without user confirmation. - `class BetaManagedAgentsAlwaysAskPolicy: …` Tool calls require user confirmation before execution. - `default_config: BetaManagedAgentsMCPToolsetDefaultConfig` Resolved default configuration for all tools from an MCP server. - `enabled: bool` - `permission_policy: PermissionPolicy` Permission policy for tool execution. - `class BetaManagedAgentsAlwaysAllowPolicy: …` Tool calls are automatically approved without user confirmation. - `class BetaManagedAgentsAlwaysAskPolicy: …` Tool calls require user confirmation before execution. - `mcp_server_name: str` - `type: Literal["mcp_toolset"]` - `"mcp_toolset"` - `class BetaManagedAgentsCustomTool: …` A custom tool as returned in API responses. - `description: str` - `input_schema: BetaManagedAgentsCustomToolInputSchema` JSON Schema for custom tool input parameters. - `type: Literal["object"]` - `"object"` - `properties: Optional[Dict[str, object]]` - `required: Optional[List[str]]` - `name: str` - `type: Literal["custom"]` - `"custom"` - `type: Literal["agent"]` - `"agent"` - `version: int` - `archived_at: Optional[datetime]` A timestamp in RFC 3339 format - `created_at: datetime` A timestamp in RFC 3339 format - `parent_thread_id: Optional[str]` Parent thread that spawned this thread. Null for the primary thread. - `session_id: str` The session this thread belongs to. - `stats: Optional[BetaManagedAgentsSessionThreadStats]` Timing statistics for a session thread. - `active_seconds: Optional[float]` Cumulative time in seconds the thread spent actively running. Excludes idle time. - `duration_seconds: Optional[float]` Elapsed time since thread creation in seconds. For archived threads, frozen at the final update. - `startup_seconds: Optional[float]` Time in seconds for the thread to begin running. Zero for child threads, which start immediately. - `status: BetaManagedAgentsSessionThreadStatus` SessionThreadStatus enum - `"running"` - `"idle"` - `"rescheduling"` - `"terminated"` - `type: Literal["session_thread"]` - `"session_thread"` - `updated_at: datetime` A timestamp in RFC 3339 format - `usage: Optional[BetaManagedAgentsSessionThreadUsage]` Cumulative token usage for a session thread across all turns. - `cache_creation: Optional[BetaManagedAgentsCacheCreationUsage]` Prompt-cache creation token usage broken down by cache lifetime. - `ephemeral_1h_input_tokens: Optional[int]` Tokens used to create 1-hour ephemeral cache entries. - `ephemeral_5m_input_tokens: Optional[int]` Tokens used to create 5-minute ephemeral cache entries. - `cache_read_input_tokens: Optional[int]` Total tokens read from prompt cache. - `input_tokens: Optional[int]` Total input tokens consumed across all turns. - `output_tokens: Optional[int]` Total output tokens generated across all turns. ### Example ```python import os from anthropic import Anthropic client = Anthropic( api_key=os.environ.get("ANTHROPIC_API_KEY"), # This is the default and can be omitted ) beta_managed_agents_session_thread = client.beta.sessions.threads.retrieve( thread_id="sthr_011CZkZVWa6oIjw0rgXZpnBt", session_id="sesn_011CZkZAtmR3yMPDzynEDxu7", ) print(beta_managed_agents_session_thread.id) ``` #### Response ```json { "id": "sthr_011CZkZVWa6oIjw0rgXZpnBt", "agent": { "id": "agent_011CZkYqphY8vELVzwCUpqiQ", "description": "A focused research subagent.", "mcp_servers": [ { "name": "example-mcp", "type": "url", "url": "https://example-server.modelcontextprotocol.io/sse" } ], "model": { "id": "claude-sonnet-4-6", "speed": "standard" }, "name": "Researcher", "skills": [ { "skill_id": "xlsx", "type": "anthropic", "version": "1" } ], "system": "You are a research subagent that gathers and summarises sources for the coordinating agent.", "tools": [ { "configs": [ { "enabled": true, "name": "bash", "permission_policy": { "type": "always_allow" } } ], "default_config": { "enabled": true, "permission_policy": { "type": "always_ask" } }, "type": "agent_toolset_20260401" } ], "type": "agent", "version": 1 }, "archived_at": null, "created_at": "2026-03-15T10:00:00Z", "parent_thread_id": null, "session_id": "sesn_011CZkZAtmR3yMPDzynEDxu7", "stats": { "active_seconds": 0, "duration_seconds": 0, "startup_seconds": 0 }, "status": "idle", "type": "session_thread", "updated_at": "2026-03-15T10:00:00Z", "usage": { "cache_creation": { "ephemeral_1h_input_tokens": 0, "ephemeral_5m_input_tokens": 0 }, "cache_read_input_tokens": 0, "input_tokens": 0, "output_tokens": 0 } } ``` ## Archive Session Thread `beta.sessions.threads.archive(strthread_id, ThreadArchiveParams**kwargs) -> BetaManagedAgentsSessionThread` **post** `/v1/sessions/{session_id}/threads/{thread_id}/archive` Archive Session Thread ### Parameters - `session_id: str` - `thread_id: str` - `betas: Optional[List[AnthropicBetaParam]]` Optional header to specify the beta version(s) you want to use. - `str` - `Literal["message-batches-2024-09-24", "prompt-caching-2024-07-31", "computer-use-2024-10-22", 25 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"` - `"advisor-tool-2026-03-01"` - `"managed-agents-2026-04-01"` - `"cache-diagnosis-2026-04-07"` - `"thinking-token-count-2026-05-13"` - `"server-side-fallback-2026-06-01"` - `"fallback-credit-2026-06-01"` ### Returns - `class BetaManagedAgentsSessionThread: …` An execution thread within a `session`. Each session has one primary thread plus zero or more child threads spawned by the coordinator. - `id: str` Unique identifier for this thread. - `agent: BetaManagedAgentsSessionThreadAgent` 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`. - `id: str` - `description: Optional[str]` - `mcp_servers: List[BetaManagedAgentsMCPServerURLDefinition]` - `name: str` - `type: Literal["url"]` - `"url"` - `url: str` - `model: BetaManagedAgentsModelConfig` Model identifier and configuration. - `id: BetaManagedAgentsModel` The model that will power your agent. See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options. - `Literal["claude-fable-5", "claude-opus-4-8", "claude-opus-4-7", 8 more]` The model that will power your agent. See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options. - `claude-fable-5` - Next generation of intelligence for the hardest knowledge work and coding problems - `claude-opus-4-8` - Frontier intelligence for long-running agents and coding - `claude-opus-4-7` - Frontier intelligence for long-running agents and coding - `claude-opus-4-6` - Most intelligent model for building 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` - Premium model combining maximum intelligence with practical performance - `claude-opus-4-5-20251101` - Premium model combining maximum intelligence with practical performance - `claude-sonnet-4-5` - High-performance model for agents and coding - `claude-sonnet-4-5-20250929` - High-performance model for agents and coding - `"claude-fable-5"` Next generation of intelligence for the hardest knowledge work and coding problems - `"claude-opus-4-8"` Frontier intelligence for long-running agents and coding - `"claude-opus-4-7"` Frontier intelligence for long-running agents and coding - `"claude-opus-4-6"` Most intelligent model for building 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"` Premium model combining maximum intelligence with practical performance - `"claude-opus-4-5-20251101"` Premium model combining maximum intelligence with practical performance - `"claude-sonnet-4-5"` High-performance model for agents and coding - `"claude-sonnet-4-5-20250929"` High-performance model for agents and coding - `str` - `speed: Optional[Literal["standard", "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"` - `name: str` - `skills: List[Skill]` - `class BetaManagedAgentsAnthropicSkill: …` A resolved Anthropic-managed skill. - `skill_id: str` - `type: Literal["anthropic"]` - `"anthropic"` - `version: str` - `class BetaManagedAgentsCustomSkill: …` A resolved user-created custom skill. - `skill_id: str` - `type: Literal["custom"]` - `"custom"` - `version: str` - `system: Optional[str]` - `tools: List[Tool]` - `class BetaManagedAgentsAgentToolset20260401: …` - `configs: List[BetaManagedAgentsAgentToolConfig]` - `enabled: bool` - `name: Literal["bash", "edit", "read", 5 more]` Built-in agent tool identifier. - `"bash"` - `"edit"` - `"read"` - `"write"` - `"glob"` - `"grep"` - `"web_fetch"` - `"web_search"` - `permission_policy: PermissionPolicy` Permission policy for tool execution. - `class BetaManagedAgentsAlwaysAllowPolicy: …` Tool calls are automatically approved without user confirmation. - `type: Literal["always_allow"]` - `"always_allow"` - `class BetaManagedAgentsAlwaysAskPolicy: …` Tool calls require user confirmation before execution. - `type: Literal["always_ask"]` - `"always_ask"` - `default_config: BetaManagedAgentsAgentToolsetDefaultConfig` Resolved default configuration for agent tools. - `enabled: bool` - `permission_policy: PermissionPolicy` Permission policy for tool execution. - `class BetaManagedAgentsAlwaysAllowPolicy: …` Tool calls are automatically approved without user confirmation. - `class BetaManagedAgentsAlwaysAskPolicy: …` Tool calls require user confirmation before execution. - `type: Literal["agent_toolset_20260401"]` - `"agent_toolset_20260401"` - `class BetaManagedAgentsMCPToolset: …` - `configs: List[BetaManagedAgentsMCPToolConfig]` - `enabled: bool` - `name: str` - `permission_policy: PermissionPolicy` Permission policy for tool execution. - `class BetaManagedAgentsAlwaysAllowPolicy: …` Tool calls are automatically approved without user confirmation. - `class BetaManagedAgentsAlwaysAskPolicy: …` Tool calls require user confirmation before execution. - `default_config: BetaManagedAgentsMCPToolsetDefaultConfig` Resolved default configuration for all tools from an MCP server. - `enabled: bool` - `permission_policy: PermissionPolicy` Permission policy for tool execution. - `class BetaManagedAgentsAlwaysAllowPolicy: …` Tool calls are automatically approved without user confirmation. - `class BetaManagedAgentsAlwaysAskPolicy: …` Tool calls require user confirmation before execution. - `mcp_server_name: str` - `type: Literal["mcp_toolset"]` - `"mcp_toolset"` - `class BetaManagedAgentsCustomTool: …` A custom tool as returned in API responses. - `description: str` - `input_schema: BetaManagedAgentsCustomToolInputSchema` JSON Schema for custom tool input parameters. - `type: Literal["object"]` - `"object"` - `properties: Optional[Dict[str, object]]` - `required: Optional[List[str]]` - `name: str` - `type: Literal["custom"]` - `"custom"` - `type: Literal["agent"]` - `"agent"` - `version: int` - `archived_at: Optional[datetime]` A timestamp in RFC 3339 format - `created_at: datetime` A timestamp in RFC 3339 format - `parent_thread_id: Optional[str]` Parent thread that spawned this thread. Null for the primary thread. - `session_id: str` The session this thread belongs to. - `stats: Optional[BetaManagedAgentsSessionThreadStats]` Timing statistics for a session thread. - `active_seconds: Optional[float]` Cumulative time in seconds the thread spent actively running. Excludes idle time. - `duration_seconds: Optional[float]` Elapsed time since thread creation in seconds. For archived threads, frozen at the final update. - `startup_seconds: Optional[float]` Time in seconds for the thread to begin running. Zero for child threads, which start immediately. - `status: BetaManagedAgentsSessionThreadStatus` SessionThreadStatus enum - `"running"` - `"idle"` - `"rescheduling"` - `"terminated"` - `type: Literal["session_thread"]` - `"session_thread"` - `updated_at: datetime` A timestamp in RFC 3339 format - `usage: Optional[BetaManagedAgentsSessionThreadUsage]` Cumulative token usage for a session thread across all turns. - `cache_creation: Optional[BetaManagedAgentsCacheCreationUsage]` Prompt-cache creation token usage broken down by cache lifetime. - `ephemeral_1h_input_tokens: Optional[int]` Tokens used to create 1-hour ephemeral cache entries. - `ephemeral_5m_input_tokens: Optional[int]` Tokens used to create 5-minute ephemeral cache entries. - `cache_read_input_tokens: Optional[int]` Total tokens read from prompt cache. - `input_tokens: Optional[int]` Total input tokens consumed across all turns. - `output_tokens: Optional[int]` Total output tokens generated across all turns. ### Example ```python import os from anthropic import Anthropic client = Anthropic( api_key=os.environ.get("ANTHROPIC_API_KEY"), # This is the default and can be omitted ) beta_managed_agents_session_thread = client.beta.sessions.threads.archive( thread_id="sthr_011CZkZVWa6oIjw0rgXZpnBt", session_id="sesn_011CZkZAtmR3yMPDzynEDxu7", ) print(beta_managed_agents_session_thread.id) ``` #### Response ```json { "id": "sthr_011CZkZVWa6oIjw0rgXZpnBt", "agent": { "id": "agent_011CZkYqphY8vELVzwCUpqiQ", "description": "A focused research subagent.", "mcp_servers": [ { "name": "example-mcp", "type": "url", "url": "https://example-server.modelcontextprotocol.io/sse" } ], "model": { "id": "claude-sonnet-4-6", "speed": "standard" }, "name": "Researcher", "skills": [ { "skill_id": "xlsx", "type": "anthropic", "version": "1" } ], "system": "You are a research subagent that gathers and summarises sources for the coordinating agent.", "tools": [ { "configs": [ { "enabled": true, "name": "bash", "permission_policy": { "type": "always_allow" } } ], "default_config": { "enabled": true, "permission_policy": { "type": "always_ask" } }, "type": "agent_toolset_20260401" } ], "type": "agent", "version": 1 }, "archived_at": null, "created_at": "2026-03-15T10:00:00Z", "parent_thread_id": null, "session_id": "sesn_011CZkZAtmR3yMPDzynEDxu7", "stats": { "active_seconds": 0, "duration_seconds": 0, "startup_seconds": 0 }, "status": "idle", "type": "session_thread", "updated_at": "2026-03-15T10:00:00Z", "usage": { "cache_creation": { "ephemeral_1h_input_tokens": 0, "ephemeral_5m_input_tokens": 0 }, "cache_read_input_tokens": 0, "input_tokens": 0, "output_tokens": 0 } } ``` ## Domain Types ### Beta Managed Agents Session Thread - `class BetaManagedAgentsSessionThread: …` An execution thread within a `session`. Each session has one primary thread plus zero or more child threads spawned by the coordinator. - `id: str` Unique identifier for this thread. - `agent: BetaManagedAgentsSessionThreadAgent` 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`. - `id: str` - `description: Optional[str]` - `mcp_servers: List[BetaManagedAgentsMCPServerURLDefinition]` - `name: str` - `type: Literal["url"]` - `"url"` - `url: str` - `model: BetaManagedAgentsModelConfig` Model identifier and configuration. - `id: BetaManagedAgentsModel` The model that will power your agent. See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options. - `Literal["claude-fable-5", "claude-opus-4-8", "claude-opus-4-7", 8 more]` The model that will power your agent. See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options. - `claude-fable-5` - Next generation of intelligence for the hardest knowledge work and coding problems - `claude-opus-4-8` - Frontier intelligence for long-running agents and coding - `claude-opus-4-7` - Frontier intelligence for long-running agents and coding - `claude-opus-4-6` - Most intelligent model for building 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` - Premium model combining maximum intelligence with practical performance - `claude-opus-4-5-20251101` - Premium model combining maximum intelligence with practical performance - `claude-sonnet-4-5` - High-performance model for agents and coding - `claude-sonnet-4-5-20250929` - High-performance model for agents and coding - `"claude-fable-5"` Next generation of intelligence for the hardest knowledge work and coding problems - `"claude-opus-4-8"` Frontier intelligence for long-running agents and coding - `"claude-opus-4-7"` Frontier intelligence for long-running agents and coding - `"claude-opus-4-6"` Most intelligent model for building 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"` Premium model combining maximum intelligence with practical performance - `"claude-opus-4-5-20251101"` Premium model combining maximum intelligence with practical performance - `"claude-sonnet-4-5"` High-performance model for agents and coding - `"claude-sonnet-4-5-20250929"` High-performance model for agents and coding - `str` - `speed: Optional[Literal["standard", "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"` - `name: str` - `skills: List[Skill]` - `class BetaManagedAgentsAnthropicSkill: …` A resolved Anthropic-managed skill. - `skill_id: str` - `type: Literal["anthropic"]` - `"anthropic"` - `version: str` - `class BetaManagedAgentsCustomSkill: …` A resolved user-created custom skill. - `skill_id: str` - `type: Literal["custom"]` - `"custom"` - `version: str` - `system: Optional[str]` - `tools: List[Tool]` - `class BetaManagedAgentsAgentToolset20260401: …` - `configs: List[BetaManagedAgentsAgentToolConfig]` - `enabled: bool` - `name: Literal["bash", "edit", "read", 5 more]` Built-in agent tool identifier. - `"bash"` - `"edit"` - `"read"` - `"write"` - `"glob"` - `"grep"` - `"web_fetch"` - `"web_search"` - `permission_policy: PermissionPolicy` Permission policy for tool execution. - `class BetaManagedAgentsAlwaysAllowPolicy: …` Tool calls are automatically approved without user confirmation. - `type: Literal["always_allow"]` - `"always_allow"` - `class BetaManagedAgentsAlwaysAskPolicy: …` Tool calls require user confirmation before execution. - `type: Literal["always_ask"]` - `"always_ask"` - `default_config: BetaManagedAgentsAgentToolsetDefaultConfig` Resolved default configuration for agent tools. - `enabled: bool` - `permission_policy: PermissionPolicy` Permission policy for tool execution. - `class BetaManagedAgentsAlwaysAllowPolicy: …` Tool calls are automatically approved without user confirmation. - `class BetaManagedAgentsAlwaysAskPolicy: …` Tool calls require user confirmation before execution. - `type: Literal["agent_toolset_20260401"]` - `"agent_toolset_20260401"` - `class BetaManagedAgentsMCPToolset: …` - `configs: List[BetaManagedAgentsMCPToolConfig]` - `enabled: bool` - `name: str` - `permission_policy: PermissionPolicy` Permission policy for tool execution. - `class BetaManagedAgentsAlwaysAllowPolicy: …` Tool calls are automatically approved without user confirmation. - `class BetaManagedAgentsAlwaysAskPolicy: …` Tool calls require user confirmation before execution. - `default_config: BetaManagedAgentsMCPToolsetDefaultConfig` Resolved default configuration for all tools from an MCP server. - `enabled: bool` - `permission_policy: PermissionPolicy` Permission policy for tool execution. - `class BetaManagedAgentsAlwaysAllowPolicy: …` Tool calls are automatically approved without user confirmation. - `class BetaManagedAgentsAlwaysAskPolicy: …` Tool calls require user confirmation before execution. - `mcp_server_name: str` - `type: Literal["mcp_toolset"]` - `"mcp_toolset"` - `class BetaManagedAgentsCustomTool: …` A custom tool as returned in API responses. - `description: str` - `input_schema: BetaManagedAgentsCustomToolInputSchema` JSON Schema for custom tool input parameters. - `type: Literal["object"]` - `"object"` - `properties: Optional[Dict[str, object]]` - `required: Optional[List[str]]` - `name: str` - `type: Literal["custom"]` - `"custom"` - `type: Literal["agent"]` - `"agent"` - `version: int` - `archived_at: Optional[datetime]` A timestamp in RFC 3339 format - `created_at: datetime` A timestamp in RFC 3339 format - `parent_thread_id: Optional[str]` Parent thread that spawned this thread. Null for the primary thread. - `session_id: str` The session this thread belongs to. - `stats: Optional[BetaManagedAgentsSessionThreadStats]` Timing statistics for a session thread. - `active_seconds: Optional[float]` Cumulative time in seconds the thread spent actively running. Excludes idle time. - `duration_seconds: Optional[float]` Elapsed time since thread creation in seconds. For archived threads, frozen at the final update. - `startup_seconds: Optional[float]` Time in seconds for the thread to begin running. Zero for child threads, which start immediately. - `status: BetaManagedAgentsSessionThreadStatus` SessionThreadStatus enum - `"running"` - `"idle"` - `"rescheduling"` - `"terminated"` - `type: Literal["session_thread"]` - `"session_thread"` - `updated_at: datetime` A timestamp in RFC 3339 format - `usage: Optional[BetaManagedAgentsSessionThreadUsage]` Cumulative token usage for a session thread across all turns. - `cache_creation: Optional[BetaManagedAgentsCacheCreationUsage]` Prompt-cache creation token usage broken down by cache lifetime. - `ephemeral_1h_input_tokens: Optional[int]` Tokens used to create 1-hour ephemeral cache entries. - `ephemeral_5m_input_tokens: Optional[int]` Tokens used to create 5-minute ephemeral cache entries. - `cache_read_input_tokens: Optional[int]` Total tokens read from prompt cache. - `input_tokens: Optional[int]` Total input tokens consumed across all turns. - `output_tokens: Optional[int]` Total output tokens generated across all turns. ### Beta Managed Agents Session Thread Stats - `class BetaManagedAgentsSessionThreadStats: …` Timing statistics for a session thread. - `active_seconds: Optional[float]` Cumulative time in seconds the thread spent actively running. Excludes idle time. - `duration_seconds: Optional[float]` Elapsed time since thread creation in seconds. For archived threads, frozen at the final update. - `startup_seconds: Optional[float]` Time in seconds for the thread to begin running. Zero for child threads, which start immediately. ### Beta Managed Agents Session Thread Status - `Literal["running", "idle", "rescheduling", "terminated"]` SessionThreadStatus enum - `"running"` - `"idle"` - `"rescheduling"` - `"terminated"` ### Beta Managed Agents Session Thread Usage - `class BetaManagedAgentsSessionThreadUsage: …` Cumulative token usage for a session thread across all turns. - `cache_creation: Optional[BetaManagedAgentsCacheCreationUsage]` Prompt-cache creation token usage broken down by cache lifetime. - `ephemeral_1h_input_tokens: Optional[int]` Tokens used to create 1-hour ephemeral cache entries. - `ephemeral_5m_input_tokens: Optional[int]` Tokens used to create 5-minute ephemeral cache entries. - `cache_read_input_tokens: Optional[int]` Total tokens read from prompt cache. - `input_tokens: Optional[int]` Total input tokens consumed across all turns. - `output_tokens: Optional[int]` Total output tokens generated across all turns. ### Beta Managed Agents Stream Session Thread Events - `BetaManagedAgentsStreamSessionThreadEvents` Server-sent event in a single thread's stream. - `class BetaManagedAgentsUserMessageEvent: …` A user message event in the session conversation. - `id: str` Unique identifier for this event. - `content: List[Content]` Array of content blocks comprising the user message. - `class BetaManagedAgentsTextBlock: …` Regular text content. - `text: str` The text content. - `type: Literal["text"]` - `"text"` - `class BetaManagedAgentsImageBlock: …` Image content specified directly as base64 data or as a reference via a URL. - `source: Source` Union type for image source variants. - `class BetaManagedAgentsBase64ImageSource: …` Base64-encoded image data. - `data: str` Base64-encoded image data. - `media_type: str` MIME type of the image (e.g., "image/png", "image/jpeg", "image/gif", "image/webp"). - `type: Literal["base64"]` - `"base64"` - `class BetaManagedAgentsURLImageSource: …` Image referenced by URL. - `type: Literal["url"]` - `"url"` - `url: str` URL of the image to fetch. - `class BetaManagedAgentsFileImageSource: …` Image referenced by file ID. - `file_id: str` ID of a previously uploaded file. - `type: Literal["file"]` - `"file"` - `type: Literal["image"]` - `"image"` - `class BetaManagedAgentsDocumentBlock: …` Document content, either specified directly as base64 data, as text, or as a reference via a URL. - `source: Source` Union type for document source variants. - `class BetaManagedAgentsBase64DocumentSource: …` Base64-encoded document data. - `data: str` Base64-encoded document data. - `media_type: str` MIME type of the document (e.g., "application/pdf"). - `type: Literal["base64"]` - `"base64"` - `class BetaManagedAgentsPlainTextDocumentSource: …` Plain text document content. - `data: str` The plain text content. - `media_type: Literal["text/plain"]` MIME type of the text content. Must be "text/plain". - `"text/plain"` - `type: Literal["text"]` - `"text"` - `class BetaManagedAgentsURLDocumentSource: …` Document referenced by URL. - `type: Literal["url"]` - `"url"` - `url: str` URL of the document to fetch. - `class BetaManagedAgentsFileDocumentSource: …` Document referenced by file ID. - `file_id: str` ID of a previously uploaded file. - `type: Literal["file"]` - `"file"` - `type: Literal["document"]` - `"document"` - `context: Optional[str]` Additional context about the document for the model. - `title: Optional[str]` The title of the document. - `type: Literal["user.message"]` - `"user.message"` - `processed_at: Optional[datetime]` A timestamp in RFC 3339 format - `class BetaManagedAgentsUserInterruptEvent: …` An interrupt event that pauses agent execution and returns control to the user. - `id: str` Unique identifier for this event. - `type: Literal["user.interrupt"]` - `"user.interrupt"` - `processed_at: Optional[datetime]` A timestamp in RFC 3339 format - `session_thread_id: Optional[str]` If absent, interrupts every non-archived thread in a multiagent session (or the primary alone in a single-agent session). If present, interrupts only the named thread. - `class BetaManagedAgentsUserToolConfirmationEvent: …` A tool confirmation event that approves or denies a pending tool execution. - `id: str` Unique identifier for this event. - `result: Literal["allow", "deny"]` UserToolConfirmationResult enum - `"allow"` - `"deny"` - `tool_use_id: str` 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. - `type: Literal["user.tool_confirmation"]` - `"user.tool_confirmation"` - `deny_message: Optional[str]` Optional message providing context for a 'deny' decision. Only allowed when result is 'deny'. - `processed_at: Optional[datetime]` A timestamp in RFC 3339 format - `session_thread_id: Optional[str]` When set, the confirmation routes to this subagent's thread rather than the primary. Echo this from the `session_thread_id` on the `agent.tool_use` or `agent.mcp_tool_use` event that prompted the approval. - `class BetaManagedAgentsUserCustomToolResultEvent: …` Event sent by the client providing the result of a custom tool execution. - `id: str` Unique identifier for this event. - `custom_tool_use_id: str` 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. - `type: Literal["user.custom_tool_result"]` - `"user.custom_tool_result"` - `content: Optional[List[Content]]` The result content returned by the tool. - `class BetaManagedAgentsTextBlock: …` Regular text content. - `class BetaManagedAgentsImageBlock: …` Image content specified directly as base64 data or as a reference via a URL. - `class BetaManagedAgentsDocumentBlock: …` Document content, either specified directly as base64 data, as text, or as a reference via a URL. - `class BetaManagedAgentsSearchResultBlock: …` A block containing a web search result. - `citations: BetaManagedAgentsSearchResultCitations` Citation settings for a search result. - `enabled: bool` Whether citations are enabled for this search result. - `content: List[BetaManagedAgentsSearchResultContent]` Array of text content blocks from the search result. - `text: str` The text content. - `type: Literal["text"]` - `"text"` - `source: str` The URL source of the search result. - `title: str` The title of the search result. - `type: Literal["search_result"]` - `"search_result"` - `is_error: Optional[bool]` Whether the tool execution resulted in an error. - `processed_at: Optional[datetime]` A timestamp in RFC 3339 format - `session_thread_id: Optional[str]` Routes this result to a subagent thread. Copy from the `agent.custom_tool_use` event's `session_thread_id`. - `class BetaManagedAgentsAgentCustomToolUseEvent: …` Event emitted when the agent calls a custom tool. The session goes idle until the client sends a `user.custom_tool_result` event with the result. - `id: str` Unique identifier for this event. - `input: Dict[str, object]` Input parameters for the tool call. - `name: str` Name of the custom tool being called. - `processed_at: datetime` A timestamp in RFC 3339 format - `type: Literal["agent.custom_tool_use"]` - `"agent.custom_tool_use"` - `session_thread_id: Optional[str]` When set, this event was cross-posted from a subagent's thread to surface its custom tool use on the primary thread's stream. Empty on the thread's own events. Echo this on a `user.custom_tool_result` event to route the result back. - `class BetaManagedAgentsAgentMessageEvent: …` An agent response event in the session conversation. - `id: str` Unique identifier for this event. - `content: List[BetaManagedAgentsTextBlock]` Array of text blocks comprising the agent response. - `text: str` The text content. - `type: Literal["text"]` - `processed_at: datetime` A timestamp in RFC 3339 format - `type: Literal["agent.message"]` - `"agent.message"` - `class BetaManagedAgentsAgentThinkingEvent: …` Indicates the agent is making forward progress via extended thinking. A progress signal, not a content carrier. - `id: str` Unique identifier for this event. - `processed_at: datetime` A timestamp in RFC 3339 format - `type: Literal["agent.thinking"]` - `"agent.thinking"` - `class BetaManagedAgentsAgentMCPToolUseEvent: …` Event emitted when the agent invokes a tool provided by an MCP server. - `id: str` Unique identifier for this event. - `input: Dict[str, object]` Input parameters for the tool call. - `mcp_server_name: str` Name of the MCP server providing the tool. - `name: str` Name of the MCP tool being used. - `processed_at: datetime` A timestamp in RFC 3339 format - `type: Literal["agent.mcp_tool_use"]` - `"agent.mcp_tool_use"` - `evaluated_permission: Optional[Literal["allow", "ask", "deny"]]` AgentEvaluatedPermission enum - `"allow"` - `"ask"` - `"deny"` - `session_thread_id: Optional[str]` When set, this event was cross-posted from a subagent's thread to surface its permission request on the primary thread's stream. Empty on the thread's own events. Echo this on a `user.tool_confirmation` event to route the approval back. - `class BetaManagedAgentsAgentMCPToolResultEvent: …` Event representing the result of an MCP tool execution. - `id: str` Unique identifier for this event. - `mcp_tool_use_id: str` The id of the `agent.mcp_tool_use` event this result corresponds to. - `processed_at: datetime` A timestamp in RFC 3339 format - `type: Literal["agent.mcp_tool_result"]` - `"agent.mcp_tool_result"` - `content: Optional[List[Content]]` The result content returned by the tool. - `class BetaManagedAgentsTextBlock: …` Regular text content. - `class BetaManagedAgentsImageBlock: …` Image content specified directly as base64 data or as a reference via a URL. - `class BetaManagedAgentsDocumentBlock: …` Document content, either specified directly as base64 data, as text, or as a reference via a URL. - `class BetaManagedAgentsSearchResultBlock: …` A block containing a web search result. - `is_error: Optional[bool]` Whether the tool execution resulted in an error. - `class BetaManagedAgentsAgentToolUseEvent: …` Event emitted when the agent invokes a built-in agent tool. - `id: str` Unique identifier for this event. - `input: Dict[str, object]` Input parameters for the tool call. - `name: str` Name of the agent tool being used. - `processed_at: datetime` A timestamp in RFC 3339 format - `type: Literal["agent.tool_use"]` - `"agent.tool_use"` - `evaluated_permission: Optional[Literal["allow", "ask", "deny"]]` AgentEvaluatedPermission enum - `"allow"` - `"ask"` - `"deny"` - `session_thread_id: Optional[str]` When set, this event was cross-posted from a subagent's thread to surface its permission request on the primary thread's stream. Empty on the thread's own events. Echo this on a `user.tool_confirmation` event to route the approval back. - `class BetaManagedAgentsAgentToolResultEvent: …` Event representing the result of an agent tool execution. - `id: str` Unique identifier for this event. - `processed_at: datetime` A timestamp in RFC 3339 format - `tool_use_id: str` The id of the `agent.tool_use` event this result corresponds to. - `type: Literal["agent.tool_result"]` - `"agent.tool_result"` - `content: Optional[List[Content]]` The result content returned by the tool. - `class BetaManagedAgentsTextBlock: …` Regular text content. - `class BetaManagedAgentsImageBlock: …` Image content specified directly as base64 data or as a reference via a URL. - `class BetaManagedAgentsDocumentBlock: …` Document content, either specified directly as base64 data, as text, or as a reference via a URL. - `class BetaManagedAgentsSearchResultBlock: …` A block containing a web search result. - `is_error: Optional[bool]` Whether the tool execution resulted in an error. - `class BetaManagedAgentsAgentThreadMessageReceivedEvent: …` Delivery event written to the target thread's input stream when an agent-to-agent message arrives. - `id: str` Unique identifier for this event. - `content: List[Content]` Message content blocks. - `class BetaManagedAgentsTextBlock: …` Regular text content. - `class BetaManagedAgentsImageBlock: …` Image content specified directly as base64 data or as a reference via a URL. - `class BetaManagedAgentsDocumentBlock: …` Document content, either specified directly as base64 data, as text, or as a reference via a URL. - `from_session_thread_id: str` Public `sthr_` ID of the thread that sent the message. - `processed_at: datetime` A timestamp in RFC 3339 format - `type: Literal["agent.thread_message_received"]` - `"agent.thread_message_received"` - `from_agent_name: Optional[str]` Name of the callable agent this message came from. Absent when received from the primary agent. - `class BetaManagedAgentsAgentThreadMessageSentEvent: …` Observability event emitted to the sender's output stream when an agent-to-agent message is sent. - `id: str` Unique identifier for this event. - `content: List[Content]` Message content blocks. - `class BetaManagedAgentsTextBlock: …` Regular text content. - `class BetaManagedAgentsImageBlock: …` Image content specified directly as base64 data or as a reference via a URL. - `class BetaManagedAgentsDocumentBlock: …` Document content, either specified directly as base64 data, as text, or as a reference via a URL. - `processed_at: datetime` A timestamp in RFC 3339 format - `to_session_thread_id: str` Public `sthr_` ID of the thread the message was sent to. - `type: Literal["agent.thread_message_sent"]` - `"agent.thread_message_sent"` - `to_agent_name: Optional[str]` Name of the callable agent this message was sent to. Absent when sent to the primary agent. - `class BetaManagedAgentsAgentThreadContextCompactedEvent: …` Indicates that context compaction (summarization) occurred during the session. - `id: str` Unique identifier for this event. - `processed_at: datetime` A timestamp in RFC 3339 format - `type: Literal["agent.thread_context_compacted"]` - `"agent.thread_context_compacted"` - `class BetaManagedAgentsSessionErrorEvent: …` An error event indicating a problem occurred during session execution. - `id: str` Unique identifier for this event. - `error: Error` An unknown or unexpected error occurred during session execution. A fallback variant; clients that don't recognize a new error code can match on `retry_status` and `message` alone. - `class BetaManagedAgentsUnknownError: …` An unknown or unexpected error occurred during session execution. A fallback variant; clients that don't recognize a new error code can match on `retry_status` and `message` alone. - `message: str` Human-readable error description. - `retry_status: RetryStatus` What the client should do next in response to this error. - `class BetaManagedAgentsRetryStatusRetrying: …` The server is retrying automatically. Client should wait; the same error type may fire again as retrying, then once as exhausted when the retry budget runs out. - `type: Literal["retrying"]` - `"retrying"` - `class BetaManagedAgentsRetryStatusExhausted: …` This turn is dead; queued inputs are flushed and the session returns to idle. Client may send a new prompt. - `type: Literal["exhausted"]` - `"exhausted"` - `class BetaManagedAgentsRetryStatusTerminal: …` The session encountered a terminal error and will transition to `terminated` state. - `type: Literal["terminal"]` - `"terminal"` - `type: Literal["unknown_error"]` - `"unknown_error"` - `class BetaManagedAgentsModelOverloadedError: …` The model is currently overloaded. Emitted after automatic retries are exhausted. - `message: str` Human-readable error description. - `retry_status: RetryStatus` What the client should do next in response to this error. - `class BetaManagedAgentsRetryStatusRetrying: …` The server is retrying automatically. Client should wait; the same error type may fire again as retrying, then once as exhausted when the retry budget runs out. - `class BetaManagedAgentsRetryStatusExhausted: …` This turn is dead; queued inputs are flushed and the session returns to idle. Client may send a new prompt. - `class BetaManagedAgentsRetryStatusTerminal: …` The session encountered a terminal error and will transition to `terminated` state. - `type: Literal["model_overloaded_error"]` - `"model_overloaded_error"` - `class BetaManagedAgentsModelRateLimitedError: …` The model request was rate-limited. - `message: str` Human-readable error description. - `retry_status: RetryStatus` What the client should do next in response to this error. - `class BetaManagedAgentsRetryStatusRetrying: …` The server is retrying automatically. Client should wait; the same error type may fire again as retrying, then once as exhausted when the retry budget runs out. - `class BetaManagedAgentsRetryStatusExhausted: …` This turn is dead; queued inputs are flushed and the session returns to idle. Client may send a new prompt. - `class BetaManagedAgentsRetryStatusTerminal: …` The session encountered a terminal error and will transition to `terminated` state. - `type: Literal["model_rate_limited_error"]` - `"model_rate_limited_error"` - `class BetaManagedAgentsModelRequestFailedError: …` A model request failed for a reason other than overload or rate-limiting. - `message: str` Human-readable error description. - `retry_status: RetryStatus` What the client should do next in response to this error. - `class BetaManagedAgentsRetryStatusRetrying: …` The server is retrying automatically. Client should wait; the same error type may fire again as retrying, then once as exhausted when the retry budget runs out. - `class BetaManagedAgentsRetryStatusExhausted: …` This turn is dead; queued inputs are flushed and the session returns to idle. Client may send a new prompt. - `class BetaManagedAgentsRetryStatusTerminal: …` The session encountered a terminal error and will transition to `terminated` state. - `type: Literal["model_request_failed_error"]` - `"model_request_failed_error"` - `class BetaManagedAgentsMCPConnectionFailedError: …` Failed to connect to an MCP server. - `mcp_server_name: str` Name of the MCP server that failed to connect. - `message: str` Human-readable error description. - `retry_status: RetryStatus` What the client should do next in response to this error. - `class BetaManagedAgentsRetryStatusRetrying: …` The server is retrying automatically. Client should wait; the same error type may fire again as retrying, then once as exhausted when the retry budget runs out. - `class BetaManagedAgentsRetryStatusExhausted: …` This turn is dead; queued inputs are flushed and the session returns to idle. Client may send a new prompt. - `class BetaManagedAgentsRetryStatusTerminal: …` The session encountered a terminal error and will transition to `terminated` state. - `type: Literal["mcp_connection_failed_error"]` - `"mcp_connection_failed_error"` - `class BetaManagedAgentsMCPAuthenticationFailedError: …` Authentication to an MCP server failed. - `mcp_server_name: str` Name of the MCP server that failed authentication. - `message: str` Human-readable error description. - `retry_status: RetryStatus` What the client should do next in response to this error. - `class BetaManagedAgentsRetryStatusRetrying: …` The server is retrying automatically. Client should wait; the same error type may fire again as retrying, then once as exhausted when the retry budget runs out. - `class BetaManagedAgentsRetryStatusExhausted: …` This turn is dead; queued inputs are flushed and the session returns to idle. Client may send a new prompt. - `class BetaManagedAgentsRetryStatusTerminal: …` The session encountered a terminal error and will transition to `terminated` state. - `type: Literal["mcp_authentication_failed_error"]` - `"mcp_authentication_failed_error"` - `class BetaManagedAgentsBillingError: …` The caller's organization or workspace cannot make model requests — out of credits or spend limit reached. Retrying with the same credentials will not succeed; the caller must resolve the billing state. - `message: str` Human-readable error description. - `retry_status: RetryStatus` What the client should do next in response to this error. - `class BetaManagedAgentsRetryStatusRetrying: …` The server is retrying automatically. Client should wait; the same error type may fire again as retrying, then once as exhausted when the retry budget runs out. - `class BetaManagedAgentsRetryStatusExhausted: …` This turn is dead; queued inputs are flushed and the session returns to idle. Client may send a new prompt. - `class BetaManagedAgentsRetryStatusTerminal: …` The session encountered a terminal error and will transition to `terminated` state. - `type: Literal["billing_error"]` - `"billing_error"` - `class BetaManagedAgentsCredentialHostUnreachableError: …` An `environment_variable` credential's `auth.networking.allowed_hosts` includes a host the environment's network policy does not permit. - `credential_id: str` ID of the affected credential. - `message: str` Human-readable error description. - `retry_status: RetryStatus` What the client should do next in response to this error. - `class BetaManagedAgentsRetryStatusRetrying: …` The server is retrying automatically. Client should wait; the same error type may fire again as retrying, then once as exhausted when the retry budget runs out. - `class BetaManagedAgentsRetryStatusExhausted: …` This turn is dead; queued inputs are flushed and the session returns to idle. Client may send a new prompt. - `class BetaManagedAgentsRetryStatusTerminal: …` The session encountered a terminal error and will transition to `terminated` state. - `type: Literal["credential_host_unreachable_error"]` - `"credential_host_unreachable_error"` - `vault_id: str` ID of the vault containing the affected credential. - `processed_at: datetime` A timestamp in RFC 3339 format - `type: Literal["session.error"]` - `"session.error"` - `class BetaManagedAgentsSessionStatusRescheduledEvent: …` Indicates the session is recovering from an error state and is rescheduled for execution. - `id: str` Unique identifier for this event. - `processed_at: datetime` A timestamp in RFC 3339 format - `type: Literal["session.status_rescheduled"]` - `"session.status_rescheduled"` - `class BetaManagedAgentsSessionStatusRunningEvent: …` Indicates the session is actively running and the agent is working. - `id: str` Unique identifier for this event. - `processed_at: datetime` A timestamp in RFC 3339 format - `type: Literal["session.status_running"]` - `"session.status_running"` - `class BetaManagedAgentsSessionStatusIdleEvent: …` Indicates the agent has paused and is awaiting user input. - `id: str` Unique identifier for this event. - `processed_at: datetime` A timestamp in RFC 3339 format - `stop_reason: StopReason` The agent completed its turn naturally and is ready for the next user message. - `class BetaManagedAgentsSessionEndTurn: …` The agent completed its turn naturally and is ready for the next user message. - `type: Literal["end_turn"]` - `"end_turn"` - `class BetaManagedAgentsSessionRequiresAction: …` The agent is idle waiting on one or more blocking user-input events (tool confirmation, custom tool result, etc.). Resolving all of them transitions the session back to running. - `event_ids: List[str]` The ids of events the agent is blocked on. Resolving fewer than all re-emits `session.status_idle` with the remainder. - `type: Literal["requires_action"]` - `"requires_action"` - `class BetaManagedAgentsSessionRetriesExhausted: …` The turn ended because the retry budget was exhausted (`max_iterations` hit or an error escalated to `retry_status: 'exhausted'`). - `type: Literal["retries_exhausted"]` - `"retries_exhausted"` - `type: Literal["session.status_idle"]` - `"session.status_idle"` - `class BetaManagedAgentsSessionStatusTerminatedEvent: …` Indicates the session has terminated, either due to an error or completion. - `id: str` Unique identifier for this event. - `processed_at: datetime` A timestamp in RFC 3339 format - `type: Literal["session.status_terminated"]` - `"session.status_terminated"` - `class BetaManagedAgentsSessionThreadCreatedEvent: …` Emitted when a subagent is spawned as a new thread. Written to the parent thread's output stream so clients observing the session see child creation. - `id: str` Unique identifier for this event. - `agent_name: str` Name of the callable agent the thread runs. - `processed_at: datetime` A timestamp in RFC 3339 format - `session_thread_id: str` Public `sthr_` ID of the newly created thread. - `type: Literal["session.thread_created"]` - `"session.thread_created"` - `class BetaManagedAgentsSpanOutcomeEvaluationStartEvent: …` Emitted when an outcome evaluation cycle begins. - `id: str` Unique identifier for this event. - `iteration: int` 0-indexed revision cycle. 0 is the first evaluation; 1 is the re-evaluation after the first revision; etc. - `outcome_id: str` The `outc_` ID of the outcome being evaluated. - `processed_at: datetime` A timestamp in RFC 3339 format - `type: Literal["span.outcome_evaluation_start"]` - `"span.outcome_evaluation_start"` - `class BetaManagedAgentsSpanOutcomeEvaluationEndEvent: …` Emitted when an outcome evaluation cycle completes. Carries the verdict and aggregate token usage. A verdict of `needs_revision` means another evaluation cycle follows; `satisfied`, `max_iterations_reached`, `failed`, or `interrupted` are terminal — no further evaluation cycles follow. - `id: str` Unique identifier for this event. - `explanation: str` Human-readable explanation of the verdict. For `needs_revision`, describes which criteria failed and why. - `iteration: int` 0-indexed revision cycle, matching the corresponding `span.outcome_evaluation_start`. - `outcome_evaluation_start_id: str` The id of the corresponding `span.outcome_evaluation_start` event. - `outcome_id: str` The `outc_` ID of the outcome being evaluated. - `processed_at: datetime` A timestamp in RFC 3339 format - `result: str` 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. - `type: Literal["span.outcome_evaluation_end"]` - `"span.outcome_evaluation_end"` - `usage: BetaManagedAgentsSpanModelUsage` Token usage for a single model request. - `cache_creation_input_tokens: int` Tokens used to create prompt cache in this request. - `cache_read_input_tokens: int` Tokens read from prompt cache in this request. - `input_tokens: int` Input tokens consumed by this request. - `output_tokens: int` Output tokens generated by this request. - `speed: Optional[Literal["standard", "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"` - `class BetaManagedAgentsSpanModelRequestStartEvent: …` Emitted when a model request is initiated by the agent. - `id: str` Unique identifier for this event. - `processed_at: datetime` A timestamp in RFC 3339 format - `type: Literal["span.model_request_start"]` - `"span.model_request_start"` - `class BetaManagedAgentsSpanModelRequestEndEvent: …` Emitted when a model request completes. - `id: str` Unique identifier for this event. - `is_error: Optional[bool]` Whether the model request resulted in an error. - `model_request_start_id: str` The id of the corresponding `span.model_request_start` event. - `model_usage: BetaManagedAgentsSpanModelUsage` Token usage for a single model request. - `processed_at: datetime` A timestamp in RFC 3339 format - `type: Literal["span.model_request_end"]` - `"span.model_request_end"` - `class BetaManagedAgentsSpanOutcomeEvaluationOngoingEvent: …` Periodic heartbeat emitted while an outcome evaluation cycle is in progress. Distinguishes 'evaluation is actively running' from 'evaluation is stuck' between the corresponding `span.outcome_evaluation_start` and `span.outcome_evaluation_end` events. - `id: str` Unique identifier for this event. - `iteration: int` 0-indexed revision cycle, matching the corresponding `span.outcome_evaluation_start`. - `outcome_id: str` The `outc_` ID of the outcome being evaluated. - `processed_at: datetime` A timestamp in RFC 3339 format - `type: Literal["span.outcome_evaluation_ongoing"]` - `"span.outcome_evaluation_ongoing"` - `class BetaManagedAgentsUserDefineOutcomeEvent: …` Echo of a `user.define_outcome` input event. Carries the server-generated `outcome_id` that subsequent `span.outcome_evaluation_*` events reference. - `id: str` Unique identifier for this event. - `description: str` What the agent should produce. Copied from the input event. - `max_iterations: Optional[int]` Evaluate-then-revise cycles before giving up. Default 3, max 20. - `outcome_id: str` Server-generated `outc_` ID for this outcome. Referenced by `span.outcome_evaluation_*` events and the session's `outcome_evaluations` list. - `processed_at: datetime` A timestamp in RFC 3339 format - `rubric: Rubric` Rubric for grading the quality of an outcome. - `class BetaManagedAgentsFileRubric: …` Rubric referenced by a file uploaded via the Files API. - `file_id: str` ID of the rubric file. - `type: Literal["file"]` - `"file"` - `class BetaManagedAgentsTextRubric: …` Rubric content provided inline as text. - `content: str` Rubric content. Plain text or markdown — the grader treats it as freeform text. - `type: Literal["text"]` - `"text"` - `type: Literal["user.define_outcome"]` - `"user.define_outcome"` - `class BetaManagedAgentsSessionDeletedEvent: …` Emitted when a session has been deleted. Terminates any active event stream — no further events will be emitted for this session. - `id: str` Unique identifier for this event. - `processed_at: datetime` A timestamp in RFC 3339 format - `type: Literal["session.deleted"]` - `"session.deleted"` - `class BetaManagedAgentsSessionThreadStatusRunningEvent: …` A session thread has begun executing. Emitted on the thread's own stream and cross-posted to the primary stream for child threads. - `id: str` Unique identifier for this event. - `agent_name: str` Name of the agent the thread runs. - `processed_at: datetime` A timestamp in RFC 3339 format - `session_thread_id: str` Public sthr_ ID of the thread that started running. - `type: Literal["session.thread_status_running"]` - `"session.thread_status_running"` - `class BetaManagedAgentsSessionThreadStatusIdleEvent: …` A session thread has yielded and is awaiting input. Emitted on the thread's own stream and cross-posted to the primary stream for child threads. - `id: str` Unique identifier for this event. - `agent_name: str` Name of the agent the thread runs. - `processed_at: datetime` A timestamp in RFC 3339 format - `session_thread_id: str` Public sthr_ ID of the thread that went idle. - `stop_reason: StopReason` The agent completed its turn naturally and is ready for the next user message. - `class BetaManagedAgentsSessionEndTurn: …` The agent completed its turn naturally and is ready for the next user message. - `class BetaManagedAgentsSessionRequiresAction: …` The agent is idle waiting on one or more blocking user-input events (tool confirmation, custom tool result, etc.). Resolving all of them transitions the session back to running. - `class BetaManagedAgentsSessionRetriesExhausted: …` The turn ended because the retry budget was exhausted (`max_iterations` hit or an error escalated to `retry_status: 'exhausted'`). - `type: Literal["session.thread_status_idle"]` - `"session.thread_status_idle"` - `class BetaManagedAgentsSessionThreadStatusTerminatedEvent: …` A session thread has terminated and will accept no further input. Emitted on the thread's own stream and cross-posted to the primary stream for child threads. - `id: str` Unique identifier for this event. - `agent_name: str` Name of the agent the thread runs. - `processed_at: datetime` A timestamp in RFC 3339 format - `session_thread_id: str` Public sthr_ ID of the thread that terminated. - `type: Literal["session.thread_status_terminated"]` - `"session.thread_status_terminated"` - `class BetaManagedAgentsUserToolResultEvent: …` Event sent by the client providing the result of an agent-toolset tool execution. Only valid on `self_hosted` environments, where sandbox-routed tools are executed by the client rather than the server. - `id: str` Unique identifier for this event. - `tool_use_id: str` 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. - `type: Literal["user.tool_result"]` - `"user.tool_result"` - `content: Optional[List[Content]]` The result content returned by the tool. - `class BetaManagedAgentsTextBlock: …` Regular text content. - `class BetaManagedAgentsImageBlock: …` Image content specified directly as base64 data or as a reference via a URL. - `class BetaManagedAgentsDocumentBlock: …` Document content, either specified directly as base64 data, as text, or as a reference via a URL. - `class BetaManagedAgentsSearchResultBlock: …` A block containing a web search result. - `is_error: Optional[bool]` Whether the tool execution resulted in an error. - `processed_at: Optional[datetime]` A timestamp in RFC 3339 format - `session_thread_id: Optional[str]` Routes this result to a subagent thread. Copy from the `agent.tool_use` event's `session_thread_id`. - `class BetaManagedAgentsSessionThreadStatusRescheduledEvent: …` A session thread hit a transient error and is retrying automatically. Emitted on the thread's own stream and cross-posted to the primary stream for child threads. - `id: str` Unique identifier for this event. - `agent_name: str` Name of the agent the thread runs. - `processed_at: datetime` A timestamp in RFC 3339 format - `session_thread_id: str` Public sthr_ ID of the thread that is retrying. - `type: Literal["session.thread_status_rescheduled"]` - `"session.thread_status_rescheduled"` - `class BetaManagedAgentsSessionUpdatedEvent: …` Emitted when an UpdateSession request changed at least one field. Carries only the fields that changed; absent fields were not part of the update. The new configuration applies from the next turn. - `id: str` Unique identifier for this event. - `processed_at: datetime` A timestamp in RFC 3339 format - `type: Literal["session.updated"]` - `"session.updated"` - `agent: Optional[BetaManagedAgentsSessionAgent]` Resolved `agent` definition for a `session`. Snapshot of the `agent` at `session` creation time. - `id: str` - `description: Optional[str]` - `mcp_servers: List[BetaManagedAgentsMCPServerURLDefinition]` - `name: str` - `type: Literal["url"]` - `"url"` - `url: str` - `model: BetaManagedAgentsModelConfig` Model identifier and configuration. - `id: BetaManagedAgentsModel` The model that will power your agent. See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options. - `Literal["claude-fable-5", "claude-opus-4-8", "claude-opus-4-7", 8 more]` The model that will power your agent. See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options. - `claude-fable-5` - Next generation of intelligence for the hardest knowledge work and coding problems - `claude-opus-4-8` - Frontier intelligence for long-running agents and coding - `claude-opus-4-7` - Frontier intelligence for long-running agents and coding - `claude-opus-4-6` - Most intelligent model for building 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` - Premium model combining maximum intelligence with practical performance - `claude-opus-4-5-20251101` - Premium model combining maximum intelligence with practical performance - `claude-sonnet-4-5` - High-performance model for agents and coding - `claude-sonnet-4-5-20250929` - High-performance model for agents and coding - `"claude-fable-5"` Next generation of intelligence for the hardest knowledge work and coding problems - `"claude-opus-4-8"` Frontier intelligence for long-running agents and coding - `"claude-opus-4-7"` Frontier intelligence for long-running agents and coding - `"claude-opus-4-6"` Most intelligent model for building 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"` Premium model combining maximum intelligence with practical performance - `"claude-opus-4-5-20251101"` Premium model combining maximum intelligence with practical performance - `"claude-sonnet-4-5"` High-performance model for agents and coding - `"claude-sonnet-4-5-20250929"` High-performance model for agents and coding - `str` - `speed: Optional[Literal["standard", "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: Optional[BetaManagedAgentsSessionMultiagentCoordinator]` Resolved coordinator topology with full agent definitions for each roster member. - `agents: List[BetaManagedAgentsSessionThreadAgent]` Full `agent` definitions the coordinator may spawn as session threads. - `id: str` - `description: Optional[str]` - `mcp_servers: List[BetaManagedAgentsMCPServerURLDefinition]` - `name: str` - `type: Literal["url"]` - `url: str` - `model: BetaManagedAgentsModelConfig` Model identifier and configuration. - `name: str` - `skills: List[Skill]` - `class BetaManagedAgentsAnthropicSkill: …` A resolved Anthropic-managed skill. - `skill_id: str` - `type: Literal["anthropic"]` - `"anthropic"` - `version: str` - `class BetaManagedAgentsCustomSkill: …` A resolved user-created custom skill. - `skill_id: str` - `type: Literal["custom"]` - `"custom"` - `version: str` - `system: Optional[str]` - `tools: List[Tool]` - `class BetaManagedAgentsAgentToolset20260401: …` - `configs: List[BetaManagedAgentsAgentToolConfig]` - `enabled: bool` - `name: Literal["bash", "edit", "read", 5 more]` Built-in agent tool identifier. - `"bash"` - `"edit"` - `"read"` - `"write"` - `"glob"` - `"grep"` - `"web_fetch"` - `"web_search"` - `permission_policy: PermissionPolicy` Permission policy for tool execution. - `class BetaManagedAgentsAlwaysAllowPolicy: …` Tool calls are automatically approved without user confirmation. - `type: Literal["always_allow"]` - `"always_allow"` - `class BetaManagedAgentsAlwaysAskPolicy: …` Tool calls require user confirmation before execution. - `type: Literal["always_ask"]` - `"always_ask"` - `default_config: BetaManagedAgentsAgentToolsetDefaultConfig` Resolved default configuration for agent tools. - `enabled: bool` - `permission_policy: PermissionPolicy` Permission policy for tool execution. - `class BetaManagedAgentsAlwaysAllowPolicy: …` Tool calls are automatically approved without user confirmation. - `class BetaManagedAgentsAlwaysAskPolicy: …` Tool calls require user confirmation before execution. - `type: Literal["agent_toolset_20260401"]` - `"agent_toolset_20260401"` - `class BetaManagedAgentsMCPToolset: …` - `configs: List[BetaManagedAgentsMCPToolConfig]` - `enabled: bool` - `name: str` - `permission_policy: PermissionPolicy` Permission policy for tool execution. - `class BetaManagedAgentsAlwaysAllowPolicy: …` Tool calls are automatically approved without user confirmation. - `class BetaManagedAgentsAlwaysAskPolicy: …` Tool calls require user confirmation before execution. - `default_config: BetaManagedAgentsMCPToolsetDefaultConfig` Resolved default configuration for all tools from an MCP server. - `enabled: bool` - `permission_policy: PermissionPolicy` Permission policy for tool execution. - `class BetaManagedAgentsAlwaysAllowPolicy: …` Tool calls are automatically approved without user confirmation. - `class BetaManagedAgentsAlwaysAskPolicy: …` Tool calls require user confirmation before execution. - `mcp_server_name: str` - `type: Literal["mcp_toolset"]` - `"mcp_toolset"` - `class BetaManagedAgentsCustomTool: …` A custom tool as returned in API responses. - `description: str` - `input_schema: BetaManagedAgentsCustomToolInputSchema` JSON Schema for custom tool input parameters. - `type: Literal["object"]` - `"object"` - `properties: Optional[Dict[str, object]]` - `required: Optional[List[str]]` - `name: str` - `type: Literal["custom"]` - `"custom"` - `type: Literal["agent"]` - `"agent"` - `version: int` - `type: Literal["coordinator"]` - `"coordinator"` - `name: str` - `skills: List[Skill]` - `class BetaManagedAgentsAnthropicSkill: …` A resolved Anthropic-managed skill. - `class BetaManagedAgentsCustomSkill: …` A resolved user-created custom skill. - `system: Optional[str]` - `tools: List[Tool]` - `class BetaManagedAgentsAgentToolset20260401: …` - `class BetaManagedAgentsMCPToolset: …` - `class BetaManagedAgentsCustomTool: …` A custom tool as returned in API responses. - `type: Literal["agent"]` - `"agent"` - `version: int` - `metadata: Optional[Dict[str, str]]` 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[str]` The session's new title. Present only when the update changed it. - `class BetaManagedAgentsSystemMessageEvent: …` A mid-conversation system message event. Carries system-role content that is appended to the session as a `role: "system"` turn. - `id: str` Unique identifier for this event. - `content: List[BetaManagedAgentsSystemContentBlock]` System content blocks. Text-only. - `text: str` The text content. - `type: Literal["text"]` - `"text"` - `type: Literal["system.message"]` - `"system.message"` - `processed_at: Optional[datetime]` A timestamp in RFC 3339 format # Events ## List Session Thread Events `beta.sessions.threads.events.list(strthread_id, EventListParams**kwargs) -> SyncPageCursor[BetaManagedAgentsSessionEvent]` **get** `/v1/sessions/{session_id}/threads/{thread_id}/events` List Session Thread Events ### Parameters - `session_id: str` - `thread_id: str` - `limit: Optional[int]` Query parameter for limit - `page: Optional[str]` Query parameter for page - `betas: Optional[List[AnthropicBetaParam]]` Optional header to specify the beta version(s) you want to use. - `str` - `Literal["message-batches-2024-09-24", "prompt-caching-2024-07-31", "computer-use-2024-10-22", 25 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"` - `"advisor-tool-2026-03-01"` - `"managed-agents-2026-04-01"` - `"cache-diagnosis-2026-04-07"` - `"thinking-token-count-2026-05-13"` - `"server-side-fallback-2026-06-01"` - `"fallback-credit-2026-06-01"` ### Returns - `BetaManagedAgentsSessionEvent` Union type for all event types in a session. - `class BetaManagedAgentsUserMessageEvent: …` A user message event in the session conversation. - `id: str` Unique identifier for this event. - `content: List[Content]` Array of content blocks comprising the user message. - `class BetaManagedAgentsTextBlock: …` Regular text content. - `text: str` The text content. - `type: Literal["text"]` - `"text"` - `class BetaManagedAgentsImageBlock: …` Image content specified directly as base64 data or as a reference via a URL. - `source: Source` Union type for image source variants. - `class BetaManagedAgentsBase64ImageSource: …` Base64-encoded image data. - `data: str` Base64-encoded image data. - `media_type: str` MIME type of the image (e.g., "image/png", "image/jpeg", "image/gif", "image/webp"). - `type: Literal["base64"]` - `"base64"` - `class BetaManagedAgentsURLImageSource: …` Image referenced by URL. - `type: Literal["url"]` - `"url"` - `url: str` URL of the image to fetch. - `class BetaManagedAgentsFileImageSource: …` Image referenced by file ID. - `file_id: str` ID of a previously uploaded file. - `type: Literal["file"]` - `"file"` - `type: Literal["image"]` - `"image"` - `class BetaManagedAgentsDocumentBlock: …` Document content, either specified directly as base64 data, as text, or as a reference via a URL. - `source: Source` Union type for document source variants. - `class BetaManagedAgentsBase64DocumentSource: …` Base64-encoded document data. - `data: str` Base64-encoded document data. - `media_type: str` MIME type of the document (e.g., "application/pdf"). - `type: Literal["base64"]` - `"base64"` - `class BetaManagedAgentsPlainTextDocumentSource: …` Plain text document content. - `data: str` The plain text content. - `media_type: Literal["text/plain"]` MIME type of the text content. Must be "text/plain". - `"text/plain"` - `type: Literal["text"]` - `"text"` - `class BetaManagedAgentsURLDocumentSource: …` Document referenced by URL. - `type: Literal["url"]` - `"url"` - `url: str` URL of the document to fetch. - `class BetaManagedAgentsFileDocumentSource: …` Document referenced by file ID. - `file_id: str` ID of a previously uploaded file. - `type: Literal["file"]` - `"file"` - `type: Literal["document"]` - `"document"` - `context: Optional[str]` Additional context about the document for the model. - `title: Optional[str]` The title of the document. - `type: Literal["user.message"]` - `"user.message"` - `processed_at: Optional[datetime]` A timestamp in RFC 3339 format - `class BetaManagedAgentsUserInterruptEvent: …` An interrupt event that pauses agent execution and returns control to the user. - `id: str` Unique identifier for this event. - `type: Literal["user.interrupt"]` - `"user.interrupt"` - `processed_at: Optional[datetime]` A timestamp in RFC 3339 format - `session_thread_id: Optional[str]` If absent, interrupts every non-archived thread in a multiagent session (or the primary alone in a single-agent session). If present, interrupts only the named thread. - `class BetaManagedAgentsUserToolConfirmationEvent: …` A tool confirmation event that approves or denies a pending tool execution. - `id: str` Unique identifier for this event. - `result: Literal["allow", "deny"]` UserToolConfirmationResult enum - `"allow"` - `"deny"` - `tool_use_id: str` 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. - `type: Literal["user.tool_confirmation"]` - `"user.tool_confirmation"` - `deny_message: Optional[str]` Optional message providing context for a 'deny' decision. Only allowed when result is 'deny'. - `processed_at: Optional[datetime]` A timestamp in RFC 3339 format - `session_thread_id: Optional[str]` When set, the confirmation routes to this subagent's thread rather than the primary. Echo this from the `session_thread_id` on the `agent.tool_use` or `agent.mcp_tool_use` event that prompted the approval. - `class BetaManagedAgentsUserCustomToolResultEvent: …` Event sent by the client providing the result of a custom tool execution. - `id: str` Unique identifier for this event. - `custom_tool_use_id: str` 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. - `type: Literal["user.custom_tool_result"]` - `"user.custom_tool_result"` - `content: Optional[List[Content]]` The result content returned by the tool. - `class BetaManagedAgentsTextBlock: …` Regular text content. - `class BetaManagedAgentsImageBlock: …` Image content specified directly as base64 data or as a reference via a URL. - `class BetaManagedAgentsDocumentBlock: …` Document content, either specified directly as base64 data, as text, or as a reference via a URL. - `class BetaManagedAgentsSearchResultBlock: …` A block containing a web search result. - `citations: BetaManagedAgentsSearchResultCitations` Citation settings for a search result. - `enabled: bool` Whether citations are enabled for this search result. - `content: List[BetaManagedAgentsSearchResultContent]` Array of text content blocks from the search result. - `text: str` The text content. - `type: Literal["text"]` - `"text"` - `source: str` The URL source of the search result. - `title: str` The title of the search result. - `type: Literal["search_result"]` - `"search_result"` - `is_error: Optional[bool]` Whether the tool execution resulted in an error. - `processed_at: Optional[datetime]` A timestamp in RFC 3339 format - `session_thread_id: Optional[str]` Routes this result to a subagent thread. Copy from the `agent.custom_tool_use` event's `session_thread_id`. - `class BetaManagedAgentsAgentCustomToolUseEvent: …` Event emitted when the agent calls a custom tool. The session goes idle until the client sends a `user.custom_tool_result` event with the result. - `id: str` Unique identifier for this event. - `input: Dict[str, object]` Input parameters for the tool call. - `name: str` Name of the custom tool being called. - `processed_at: datetime` A timestamp in RFC 3339 format - `type: Literal["agent.custom_tool_use"]` - `"agent.custom_tool_use"` - `session_thread_id: Optional[str]` When set, this event was cross-posted from a subagent's thread to surface its custom tool use on the primary thread's stream. Empty on the thread's own events. Echo this on a `user.custom_tool_result` event to route the result back. - `class BetaManagedAgentsAgentMessageEvent: …` An agent response event in the session conversation. - `id: str` Unique identifier for this event. - `content: List[BetaManagedAgentsTextBlock]` Array of text blocks comprising the agent response. - `text: str` The text content. - `type: Literal["text"]` - `processed_at: datetime` A timestamp in RFC 3339 format - `type: Literal["agent.message"]` - `"agent.message"` - `class BetaManagedAgentsAgentThinkingEvent: …` Indicates the agent is making forward progress via extended thinking. A progress signal, not a content carrier. - `id: str` Unique identifier for this event. - `processed_at: datetime` A timestamp in RFC 3339 format - `type: Literal["agent.thinking"]` - `"agent.thinking"` - `class BetaManagedAgentsAgentMCPToolUseEvent: …` Event emitted when the agent invokes a tool provided by an MCP server. - `id: str` Unique identifier for this event. - `input: Dict[str, object]` Input parameters for the tool call. - `mcp_server_name: str` Name of the MCP server providing the tool. - `name: str` Name of the MCP tool being used. - `processed_at: datetime` A timestamp in RFC 3339 format - `type: Literal["agent.mcp_tool_use"]` - `"agent.mcp_tool_use"` - `evaluated_permission: Optional[Literal["allow", "ask", "deny"]]` AgentEvaluatedPermission enum - `"allow"` - `"ask"` - `"deny"` - `session_thread_id: Optional[str]` When set, this event was cross-posted from a subagent's thread to surface its permission request on the primary thread's stream. Empty on the thread's own events. Echo this on a `user.tool_confirmation` event to route the approval back. - `class BetaManagedAgentsAgentMCPToolResultEvent: …` Event representing the result of an MCP tool execution. - `id: str` Unique identifier for this event. - `mcp_tool_use_id: str` The id of the `agent.mcp_tool_use` event this result corresponds to. - `processed_at: datetime` A timestamp in RFC 3339 format - `type: Literal["agent.mcp_tool_result"]` - `"agent.mcp_tool_result"` - `content: Optional[List[Content]]` The result content returned by the tool. - `class BetaManagedAgentsTextBlock: …` Regular text content. - `class BetaManagedAgentsImageBlock: …` Image content specified directly as base64 data or as a reference via a URL. - `class BetaManagedAgentsDocumentBlock: …` Document content, either specified directly as base64 data, as text, or as a reference via a URL. - `class BetaManagedAgentsSearchResultBlock: …` A block containing a web search result. - `is_error: Optional[bool]` Whether the tool execution resulted in an error. - `class BetaManagedAgentsAgentToolUseEvent: …` Event emitted when the agent invokes a built-in agent tool. - `id: str` Unique identifier for this event. - `input: Dict[str, object]` Input parameters for the tool call. - `name: str` Name of the agent tool being used. - `processed_at: datetime` A timestamp in RFC 3339 format - `type: Literal["agent.tool_use"]` - `"agent.tool_use"` - `evaluated_permission: Optional[Literal["allow", "ask", "deny"]]` AgentEvaluatedPermission enum - `"allow"` - `"ask"` - `"deny"` - `session_thread_id: Optional[str]` When set, this event was cross-posted from a subagent's thread to surface its permission request on the primary thread's stream. Empty on the thread's own events. Echo this on a `user.tool_confirmation` event to route the approval back. - `class BetaManagedAgentsAgentToolResultEvent: …` Event representing the result of an agent tool execution. - `id: str` Unique identifier for this event. - `processed_at: datetime` A timestamp in RFC 3339 format - `tool_use_id: str` The id of the `agent.tool_use` event this result corresponds to. - `type: Literal["agent.tool_result"]` - `"agent.tool_result"` - `content: Optional[List[Content]]` The result content returned by the tool. - `class BetaManagedAgentsTextBlock: …` Regular text content. - `class BetaManagedAgentsImageBlock: …` Image content specified directly as base64 data or as a reference via a URL. - `class BetaManagedAgentsDocumentBlock: …` Document content, either specified directly as base64 data, as text, or as a reference via a URL. - `class BetaManagedAgentsSearchResultBlock: …` A block containing a web search result. - `is_error: Optional[bool]` Whether the tool execution resulted in an error. - `class BetaManagedAgentsAgentThreadMessageReceivedEvent: …` Delivery event written to the target thread's input stream when an agent-to-agent message arrives. - `id: str` Unique identifier for this event. - `content: List[Content]` Message content blocks. - `class BetaManagedAgentsTextBlock: …` Regular text content. - `class BetaManagedAgentsImageBlock: …` Image content specified directly as base64 data or as a reference via a URL. - `class BetaManagedAgentsDocumentBlock: …` Document content, either specified directly as base64 data, as text, or as a reference via a URL. - `from_session_thread_id: str` Public `sthr_` ID of the thread that sent the message. - `processed_at: datetime` A timestamp in RFC 3339 format - `type: Literal["agent.thread_message_received"]` - `"agent.thread_message_received"` - `from_agent_name: Optional[str]` Name of the callable agent this message came from. Absent when received from the primary agent. - `class BetaManagedAgentsAgentThreadMessageSentEvent: …` Observability event emitted to the sender's output stream when an agent-to-agent message is sent. - `id: str` Unique identifier for this event. - `content: List[Content]` Message content blocks. - `class BetaManagedAgentsTextBlock: …` Regular text content. - `class BetaManagedAgentsImageBlock: …` Image content specified directly as base64 data or as a reference via a URL. - `class BetaManagedAgentsDocumentBlock: …` Document content, either specified directly as base64 data, as text, or as a reference via a URL. - `processed_at: datetime` A timestamp in RFC 3339 format - `to_session_thread_id: str` Public `sthr_` ID of the thread the message was sent to. - `type: Literal["agent.thread_message_sent"]` - `"agent.thread_message_sent"` - `to_agent_name: Optional[str]` Name of the callable agent this message was sent to. Absent when sent to the primary agent. - `class BetaManagedAgentsAgentThreadContextCompactedEvent: …` Indicates that context compaction (summarization) occurred during the session. - `id: str` Unique identifier for this event. - `processed_at: datetime` A timestamp in RFC 3339 format - `type: Literal["agent.thread_context_compacted"]` - `"agent.thread_context_compacted"` - `class BetaManagedAgentsSessionErrorEvent: …` An error event indicating a problem occurred during session execution. - `id: str` Unique identifier for this event. - `error: Error` An unknown or unexpected error occurred during session execution. A fallback variant; clients that don't recognize a new error code can match on `retry_status` and `message` alone. - `class BetaManagedAgentsUnknownError: …` An unknown or unexpected error occurred during session execution. A fallback variant; clients that don't recognize a new error code can match on `retry_status` and `message` alone. - `message: str` Human-readable error description. - `retry_status: RetryStatus` What the client should do next in response to this error. - `class BetaManagedAgentsRetryStatusRetrying: …` The server is retrying automatically. Client should wait; the same error type may fire again as retrying, then once as exhausted when the retry budget runs out. - `type: Literal["retrying"]` - `"retrying"` - `class BetaManagedAgentsRetryStatusExhausted: …` This turn is dead; queued inputs are flushed and the session returns to idle. Client may send a new prompt. - `type: Literal["exhausted"]` - `"exhausted"` - `class BetaManagedAgentsRetryStatusTerminal: …` The session encountered a terminal error and will transition to `terminated` state. - `type: Literal["terminal"]` - `"terminal"` - `type: Literal["unknown_error"]` - `"unknown_error"` - `class BetaManagedAgentsModelOverloadedError: …` The model is currently overloaded. Emitted after automatic retries are exhausted. - `message: str` Human-readable error description. - `retry_status: RetryStatus` What the client should do next in response to this error. - `class BetaManagedAgentsRetryStatusRetrying: …` The server is retrying automatically. Client should wait; the same error type may fire again as retrying, then once as exhausted when the retry budget runs out. - `class BetaManagedAgentsRetryStatusExhausted: …` This turn is dead; queued inputs are flushed and the session returns to idle. Client may send a new prompt. - `class BetaManagedAgentsRetryStatusTerminal: …` The session encountered a terminal error and will transition to `terminated` state. - `type: Literal["model_overloaded_error"]` - `"model_overloaded_error"` - `class BetaManagedAgentsModelRateLimitedError: …` The model request was rate-limited. - `message: str` Human-readable error description. - `retry_status: RetryStatus` What the client should do next in response to this error. - `class BetaManagedAgentsRetryStatusRetrying: …` The server is retrying automatically. Client should wait; the same error type may fire again as retrying, then once as exhausted when the retry budget runs out. - `class BetaManagedAgentsRetryStatusExhausted: …` This turn is dead; queued inputs are flushed and the session returns to idle. Client may send a new prompt. - `class BetaManagedAgentsRetryStatusTerminal: …` The session encountered a terminal error and will transition to `terminated` state. - `type: Literal["model_rate_limited_error"]` - `"model_rate_limited_error"` - `class BetaManagedAgentsModelRequestFailedError: …` A model request failed for a reason other than overload or rate-limiting. - `message: str` Human-readable error description. - `retry_status: RetryStatus` What the client should do next in response to this error. - `class BetaManagedAgentsRetryStatusRetrying: …` The server is retrying automatically. Client should wait; the same error type may fire again as retrying, then once as exhausted when the retry budget runs out. - `class BetaManagedAgentsRetryStatusExhausted: …` This turn is dead; queued inputs are flushed and the session returns to idle. Client may send a new prompt. - `class BetaManagedAgentsRetryStatusTerminal: …` The session encountered a terminal error and will transition to `terminated` state. - `type: Literal["model_request_failed_error"]` - `"model_request_failed_error"` - `class BetaManagedAgentsMCPConnectionFailedError: …` Failed to connect to an MCP server. - `mcp_server_name: str` Name of the MCP server that failed to connect. - `message: str` Human-readable error description. - `retry_status: RetryStatus` What the client should do next in response to this error. - `class BetaManagedAgentsRetryStatusRetrying: …` The server is retrying automatically. Client should wait; the same error type may fire again as retrying, then once as exhausted when the retry budget runs out. - `class BetaManagedAgentsRetryStatusExhausted: …` This turn is dead; queued inputs are flushed and the session returns to idle. Client may send a new prompt. - `class BetaManagedAgentsRetryStatusTerminal: …` The session encountered a terminal error and will transition to `terminated` state. - `type: Literal["mcp_connection_failed_error"]` - `"mcp_connection_failed_error"` - `class BetaManagedAgentsMCPAuthenticationFailedError: …` Authentication to an MCP server failed. - `mcp_server_name: str` Name of the MCP server that failed authentication. - `message: str` Human-readable error description. - `retry_status: RetryStatus` What the client should do next in response to this error. - `class BetaManagedAgentsRetryStatusRetrying: …` The server is retrying automatically. Client should wait; the same error type may fire again as retrying, then once as exhausted when the retry budget runs out. - `class BetaManagedAgentsRetryStatusExhausted: …` This turn is dead; queued inputs are flushed and the session returns to idle. Client may send a new prompt. - `class BetaManagedAgentsRetryStatusTerminal: …` The session encountered a terminal error and will transition to `terminated` state. - `type: Literal["mcp_authentication_failed_error"]` - `"mcp_authentication_failed_error"` - `class BetaManagedAgentsBillingError: …` The caller's organization or workspace cannot make model requests — out of credits or spend limit reached. Retrying with the same credentials will not succeed; the caller must resolve the billing state. - `message: str` Human-readable error description. - `retry_status: RetryStatus` What the client should do next in response to this error. - `class BetaManagedAgentsRetryStatusRetrying: …` The server is retrying automatically. Client should wait; the same error type may fire again as retrying, then once as exhausted when the retry budget runs out. - `class BetaManagedAgentsRetryStatusExhausted: …` This turn is dead; queued inputs are flushed and the session returns to idle. Client may send a new prompt. - `class BetaManagedAgentsRetryStatusTerminal: …` The session encountered a terminal error and will transition to `terminated` state. - `type: Literal["billing_error"]` - `"billing_error"` - `class BetaManagedAgentsCredentialHostUnreachableError: …` An `environment_variable` credential's `auth.networking.allowed_hosts` includes a host the environment's network policy does not permit. - `credential_id: str` ID of the affected credential. - `message: str` Human-readable error description. - `retry_status: RetryStatus` What the client should do next in response to this error. - `class BetaManagedAgentsRetryStatusRetrying: …` The server is retrying automatically. Client should wait; the same error type may fire again as retrying, then once as exhausted when the retry budget runs out. - `class BetaManagedAgentsRetryStatusExhausted: …` This turn is dead; queued inputs are flushed and the session returns to idle. Client may send a new prompt. - `class BetaManagedAgentsRetryStatusTerminal: …` The session encountered a terminal error and will transition to `terminated` state. - `type: Literal["credential_host_unreachable_error"]` - `"credential_host_unreachable_error"` - `vault_id: str` ID of the vault containing the affected credential. - `processed_at: datetime` A timestamp in RFC 3339 format - `type: Literal["session.error"]` - `"session.error"` - `class BetaManagedAgentsSessionStatusRescheduledEvent: …` Indicates the session is recovering from an error state and is rescheduled for execution. - `id: str` Unique identifier for this event. - `processed_at: datetime` A timestamp in RFC 3339 format - `type: Literal["session.status_rescheduled"]` - `"session.status_rescheduled"` - `class BetaManagedAgentsSessionStatusRunningEvent: …` Indicates the session is actively running and the agent is working. - `id: str` Unique identifier for this event. - `processed_at: datetime` A timestamp in RFC 3339 format - `type: Literal["session.status_running"]` - `"session.status_running"` - `class BetaManagedAgentsSessionStatusIdleEvent: …` Indicates the agent has paused and is awaiting user input. - `id: str` Unique identifier for this event. - `processed_at: datetime` A timestamp in RFC 3339 format - `stop_reason: StopReason` The agent completed its turn naturally and is ready for the next user message. - `class BetaManagedAgentsSessionEndTurn: …` The agent completed its turn naturally and is ready for the next user message. - `type: Literal["end_turn"]` - `"end_turn"` - `class BetaManagedAgentsSessionRequiresAction: …` The agent is idle waiting on one or more blocking user-input events (tool confirmation, custom tool result, etc.). Resolving all of them transitions the session back to running. - `event_ids: List[str]` The ids of events the agent is blocked on. Resolving fewer than all re-emits `session.status_idle` with the remainder. - `type: Literal["requires_action"]` - `"requires_action"` - `class BetaManagedAgentsSessionRetriesExhausted: …` The turn ended because the retry budget was exhausted (`max_iterations` hit or an error escalated to `retry_status: 'exhausted'`). - `type: Literal["retries_exhausted"]` - `"retries_exhausted"` - `type: Literal["session.status_idle"]` - `"session.status_idle"` - `class BetaManagedAgentsSessionStatusTerminatedEvent: …` Indicates the session has terminated, either due to an error or completion. - `id: str` Unique identifier for this event. - `processed_at: datetime` A timestamp in RFC 3339 format - `type: Literal["session.status_terminated"]` - `"session.status_terminated"` - `class BetaManagedAgentsSessionThreadCreatedEvent: …` Emitted when a subagent is spawned as a new thread. Written to the parent thread's output stream so clients observing the session see child creation. - `id: str` Unique identifier for this event. - `agent_name: str` Name of the callable agent the thread runs. - `processed_at: datetime` A timestamp in RFC 3339 format - `session_thread_id: str` Public `sthr_` ID of the newly created thread. - `type: Literal["session.thread_created"]` - `"session.thread_created"` - `class BetaManagedAgentsSpanOutcomeEvaluationStartEvent: …` Emitted when an outcome evaluation cycle begins. - `id: str` Unique identifier for this event. - `iteration: int` 0-indexed revision cycle. 0 is the first evaluation; 1 is the re-evaluation after the first revision; etc. - `outcome_id: str` The `outc_` ID of the outcome being evaluated. - `processed_at: datetime` A timestamp in RFC 3339 format - `type: Literal["span.outcome_evaluation_start"]` - `"span.outcome_evaluation_start"` - `class BetaManagedAgentsSpanOutcomeEvaluationEndEvent: …` Emitted when an outcome evaluation cycle completes. Carries the verdict and aggregate token usage. A verdict of `needs_revision` means another evaluation cycle follows; `satisfied`, `max_iterations_reached`, `failed`, or `interrupted` are terminal — no further evaluation cycles follow. - `id: str` Unique identifier for this event. - `explanation: str` Human-readable explanation of the verdict. For `needs_revision`, describes which criteria failed and why. - `iteration: int` 0-indexed revision cycle, matching the corresponding `span.outcome_evaluation_start`. - `outcome_evaluation_start_id: str` The id of the corresponding `span.outcome_evaluation_start` event. - `outcome_id: str` The `outc_` ID of the outcome being evaluated. - `processed_at: datetime` A timestamp in RFC 3339 format - `result: str` 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. - `type: Literal["span.outcome_evaluation_end"]` - `"span.outcome_evaluation_end"` - `usage: BetaManagedAgentsSpanModelUsage` Token usage for a single model request. - `cache_creation_input_tokens: int` Tokens used to create prompt cache in this request. - `cache_read_input_tokens: int` Tokens read from prompt cache in this request. - `input_tokens: int` Input tokens consumed by this request. - `output_tokens: int` Output tokens generated by this request. - `speed: Optional[Literal["standard", "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"` - `class BetaManagedAgentsSpanModelRequestStartEvent: …` Emitted when a model request is initiated by the agent. - `id: str` Unique identifier for this event. - `processed_at: datetime` A timestamp in RFC 3339 format - `type: Literal["span.model_request_start"]` - `"span.model_request_start"` - `class BetaManagedAgentsSpanModelRequestEndEvent: …` Emitted when a model request completes. - `id: str` Unique identifier for this event. - `is_error: Optional[bool]` Whether the model request resulted in an error. - `model_request_start_id: str` The id of the corresponding `span.model_request_start` event. - `model_usage: BetaManagedAgentsSpanModelUsage` Token usage for a single model request. - `processed_at: datetime` A timestamp in RFC 3339 format - `type: Literal["span.model_request_end"]` - `"span.model_request_end"` - `class BetaManagedAgentsSpanOutcomeEvaluationOngoingEvent: …` Periodic heartbeat emitted while an outcome evaluation cycle is in progress. Distinguishes 'evaluation is actively running' from 'evaluation is stuck' between the corresponding `span.outcome_evaluation_start` and `span.outcome_evaluation_end` events. - `id: str` Unique identifier for this event. - `iteration: int` 0-indexed revision cycle, matching the corresponding `span.outcome_evaluation_start`. - `outcome_id: str` The `outc_` ID of the outcome being evaluated. - `processed_at: datetime` A timestamp in RFC 3339 format - `type: Literal["span.outcome_evaluation_ongoing"]` - `"span.outcome_evaluation_ongoing"` - `class BetaManagedAgentsUserDefineOutcomeEvent: …` Echo of a `user.define_outcome` input event. Carries the server-generated `outcome_id` that subsequent `span.outcome_evaluation_*` events reference. - `id: str` Unique identifier for this event. - `description: str` What the agent should produce. Copied from the input event. - `max_iterations: Optional[int]` Evaluate-then-revise cycles before giving up. Default 3, max 20. - `outcome_id: str` Server-generated `outc_` ID for this outcome. Referenced by `span.outcome_evaluation_*` events and the session's `outcome_evaluations` list. - `processed_at: datetime` A timestamp in RFC 3339 format - `rubric: Rubric` Rubric for grading the quality of an outcome. - `class BetaManagedAgentsFileRubric: …` Rubric referenced by a file uploaded via the Files API. - `file_id: str` ID of the rubric file. - `type: Literal["file"]` - `"file"` - `class BetaManagedAgentsTextRubric: …` Rubric content provided inline as text. - `content: str` Rubric content. Plain text or markdown — the grader treats it as freeform text. - `type: Literal["text"]` - `"text"` - `type: Literal["user.define_outcome"]` - `"user.define_outcome"` - `class BetaManagedAgentsSessionDeletedEvent: …` Emitted when a session has been deleted. Terminates any active event stream — no further events will be emitted for this session. - `id: str` Unique identifier for this event. - `processed_at: datetime` A timestamp in RFC 3339 format - `type: Literal["session.deleted"]` - `"session.deleted"` - `class BetaManagedAgentsSessionThreadStatusRunningEvent: …` A session thread has begun executing. Emitted on the thread's own stream and cross-posted to the primary stream for child threads. - `id: str` Unique identifier for this event. - `agent_name: str` Name of the agent the thread runs. - `processed_at: datetime` A timestamp in RFC 3339 format - `session_thread_id: str` Public sthr_ ID of the thread that started running. - `type: Literal["session.thread_status_running"]` - `"session.thread_status_running"` - `class BetaManagedAgentsSessionThreadStatusIdleEvent: …` A session thread has yielded and is awaiting input. Emitted on the thread's own stream and cross-posted to the primary stream for child threads. - `id: str` Unique identifier for this event. - `agent_name: str` Name of the agent the thread runs. - `processed_at: datetime` A timestamp in RFC 3339 format - `session_thread_id: str` Public sthr_ ID of the thread that went idle. - `stop_reason: StopReason` The agent completed its turn naturally and is ready for the next user message. - `class BetaManagedAgentsSessionEndTurn: …` The agent completed its turn naturally and is ready for the next user message. - `class BetaManagedAgentsSessionRequiresAction: …` The agent is idle waiting on one or more blocking user-input events (tool confirmation, custom tool result, etc.). Resolving all of them transitions the session back to running. - `class BetaManagedAgentsSessionRetriesExhausted: …` The turn ended because the retry budget was exhausted (`max_iterations` hit or an error escalated to `retry_status: 'exhausted'`). - `type: Literal["session.thread_status_idle"]` - `"session.thread_status_idle"` - `class BetaManagedAgentsSessionThreadStatusTerminatedEvent: …` A session thread has terminated and will accept no further input. Emitted on the thread's own stream and cross-posted to the primary stream for child threads. - `id: str` Unique identifier for this event. - `agent_name: str` Name of the agent the thread runs. - `processed_at: datetime` A timestamp in RFC 3339 format - `session_thread_id: str` Public sthr_ ID of the thread that terminated. - `type: Literal["session.thread_status_terminated"]` - `"session.thread_status_terminated"` - `class BetaManagedAgentsUserToolResultEvent: …` Event sent by the client providing the result of an agent-toolset tool execution. Only valid on `self_hosted` environments, where sandbox-routed tools are executed by the client rather than the server. - `id: str` Unique identifier for this event. - `tool_use_id: str` 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. - `type: Literal["user.tool_result"]` - `"user.tool_result"` - `content: Optional[List[Content]]` The result content returned by the tool. - `class BetaManagedAgentsTextBlock: …` Regular text content. - `class BetaManagedAgentsImageBlock: …` Image content specified directly as base64 data or as a reference via a URL. - `class BetaManagedAgentsDocumentBlock: …` Document content, either specified directly as base64 data, as text, or as a reference via a URL. - `class BetaManagedAgentsSearchResultBlock: …` A block containing a web search result. - `is_error: Optional[bool]` Whether the tool execution resulted in an error. - `processed_at: Optional[datetime]` A timestamp in RFC 3339 format - `session_thread_id: Optional[str]` Routes this result to a subagent thread. Copy from the `agent.tool_use` event's `session_thread_id`. - `class BetaManagedAgentsSessionThreadStatusRescheduledEvent: …` A session thread hit a transient error and is retrying automatically. Emitted on the thread's own stream and cross-posted to the primary stream for child threads. - `id: str` Unique identifier for this event. - `agent_name: str` Name of the agent the thread runs. - `processed_at: datetime` A timestamp in RFC 3339 format - `session_thread_id: str` Public sthr_ ID of the thread that is retrying. - `type: Literal["session.thread_status_rescheduled"]` - `"session.thread_status_rescheduled"` - `class BetaManagedAgentsSessionUpdatedEvent: …` Emitted when an UpdateSession request changed at least one field. Carries only the fields that changed; absent fields were not part of the update. The new configuration applies from the next turn. - `id: str` Unique identifier for this event. - `processed_at: datetime` A timestamp in RFC 3339 format - `type: Literal["session.updated"]` - `"session.updated"` - `agent: Optional[BetaManagedAgentsSessionAgent]` Resolved `agent` definition for a `session`. Snapshot of the `agent` at `session` creation time. - `id: str` - `description: Optional[str]` - `mcp_servers: List[BetaManagedAgentsMCPServerURLDefinition]` - `name: str` - `type: Literal["url"]` - `"url"` - `url: str` - `model: BetaManagedAgentsModelConfig` Model identifier and configuration. - `id: BetaManagedAgentsModel` The model that will power your agent. See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options. - `Literal["claude-fable-5", "claude-opus-4-8", "claude-opus-4-7", 8 more]` The model that will power your agent. See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options. - `claude-fable-5` - Next generation of intelligence for the hardest knowledge work and coding problems - `claude-opus-4-8` - Frontier intelligence for long-running agents and coding - `claude-opus-4-7` - Frontier intelligence for long-running agents and coding - `claude-opus-4-6` - Most intelligent model for building 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` - Premium model combining maximum intelligence with practical performance - `claude-opus-4-5-20251101` - Premium model combining maximum intelligence with practical performance - `claude-sonnet-4-5` - High-performance model for agents and coding - `claude-sonnet-4-5-20250929` - High-performance model for agents and coding - `"claude-fable-5"` Next generation of intelligence for the hardest knowledge work and coding problems - `"claude-opus-4-8"` Frontier intelligence for long-running agents and coding - `"claude-opus-4-7"` Frontier intelligence for long-running agents and coding - `"claude-opus-4-6"` Most intelligent model for building 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"` Premium model combining maximum intelligence with practical performance - `"claude-opus-4-5-20251101"` Premium model combining maximum intelligence with practical performance - `"claude-sonnet-4-5"` High-performance model for agents and coding - `"claude-sonnet-4-5-20250929"` High-performance model for agents and coding - `str` - `speed: Optional[Literal["standard", "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: Optional[BetaManagedAgentsSessionMultiagentCoordinator]` Resolved coordinator topology with full agent definitions for each roster member. - `agents: List[BetaManagedAgentsSessionThreadAgent]` Full `agent` definitions the coordinator may spawn as session threads. - `id: str` - `description: Optional[str]` - `mcp_servers: List[BetaManagedAgentsMCPServerURLDefinition]` - `name: str` - `type: Literal["url"]` - `url: str` - `model: BetaManagedAgentsModelConfig` Model identifier and configuration. - `name: str` - `skills: List[Skill]` - `class BetaManagedAgentsAnthropicSkill: …` A resolved Anthropic-managed skill. - `skill_id: str` - `type: Literal["anthropic"]` - `"anthropic"` - `version: str` - `class BetaManagedAgentsCustomSkill: …` A resolved user-created custom skill. - `skill_id: str` - `type: Literal["custom"]` - `"custom"` - `version: str` - `system: Optional[str]` - `tools: List[Tool]` - `class BetaManagedAgentsAgentToolset20260401: …` - `configs: List[BetaManagedAgentsAgentToolConfig]` - `enabled: bool` - `name: Literal["bash", "edit", "read", 5 more]` Built-in agent tool identifier. - `"bash"` - `"edit"` - `"read"` - `"write"` - `"glob"` - `"grep"` - `"web_fetch"` - `"web_search"` - `permission_policy: PermissionPolicy` Permission policy for tool execution. - `class BetaManagedAgentsAlwaysAllowPolicy: …` Tool calls are automatically approved without user confirmation. - `type: Literal["always_allow"]` - `"always_allow"` - `class BetaManagedAgentsAlwaysAskPolicy: …` Tool calls require user confirmation before execution. - `type: Literal["always_ask"]` - `"always_ask"` - `default_config: BetaManagedAgentsAgentToolsetDefaultConfig` Resolved default configuration for agent tools. - `enabled: bool` - `permission_policy: PermissionPolicy` Permission policy for tool execution. - `class BetaManagedAgentsAlwaysAllowPolicy: …` Tool calls are automatically approved without user confirmation. - `class BetaManagedAgentsAlwaysAskPolicy: …` Tool calls require user confirmation before execution. - `type: Literal["agent_toolset_20260401"]` - `"agent_toolset_20260401"` - `class BetaManagedAgentsMCPToolset: …` - `configs: List[BetaManagedAgentsMCPToolConfig]` - `enabled: bool` - `name: str` - `permission_policy: PermissionPolicy` Permission policy for tool execution. - `class BetaManagedAgentsAlwaysAllowPolicy: …` Tool calls are automatically approved without user confirmation. - `class BetaManagedAgentsAlwaysAskPolicy: …` Tool calls require user confirmation before execution. - `default_config: BetaManagedAgentsMCPToolsetDefaultConfig` Resolved default configuration for all tools from an MCP server. - `enabled: bool` - `permission_policy: PermissionPolicy` Permission policy for tool execution. - `class BetaManagedAgentsAlwaysAllowPolicy: …` Tool calls are automatically approved without user confirmation. - `class BetaManagedAgentsAlwaysAskPolicy: …` Tool calls require user confirmation before execution. - `mcp_server_name: str` - `type: Literal["mcp_toolset"]` - `"mcp_toolset"` - `class BetaManagedAgentsCustomTool: …` A custom tool as returned in API responses. - `description: str` - `input_schema: BetaManagedAgentsCustomToolInputSchema` JSON Schema for custom tool input parameters. - `type: Literal["object"]` - `"object"` - `properties: Optional[Dict[str, object]]` - `required: Optional[List[str]]` - `name: str` - `type: Literal["custom"]` - `"custom"` - `type: Literal["agent"]` - `"agent"` - `version: int` - `type: Literal["coordinator"]` - `"coordinator"` - `name: str` - `skills: List[Skill]` - `class BetaManagedAgentsAnthropicSkill: …` A resolved Anthropic-managed skill. - `class BetaManagedAgentsCustomSkill: …` A resolved user-created custom skill. - `system: Optional[str]` - `tools: List[Tool]` - `class BetaManagedAgentsAgentToolset20260401: …` - `class BetaManagedAgentsMCPToolset: …` - `class BetaManagedAgentsCustomTool: …` A custom tool as returned in API responses. - `type: Literal["agent"]` - `"agent"` - `version: int` - `metadata: Optional[Dict[str, str]]` 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[str]` The session's new title. Present only when the update changed it. - `class BetaManagedAgentsSystemMessageEvent: …` A mid-conversation system message event. Carries system-role content that is appended to the session as a `role: "system"` turn. - `id: str` Unique identifier for this event. - `content: List[BetaManagedAgentsSystemContentBlock]` System content blocks. Text-only. - `text: str` The text content. - `type: Literal["text"]` - `"text"` - `type: Literal["system.message"]` - `"system.message"` - `processed_at: Optional[datetime]` A timestamp in RFC 3339 format ### Example ```python import os from anthropic import Anthropic client = Anthropic( api_key=os.environ.get("ANTHROPIC_API_KEY"), # This is the default and can be omitted ) page = client.beta.sessions.threads.events.list( thread_id="sthr_011CZkZVWa6oIjw0rgXZpnBt", session_id="sesn_011CZkZAtmR3yMPDzynEDxu7", ) page = page.data[0] print(page) ``` #### Response ```json { "data": [ { "id": "sevt_011CZkZGOp0iBcp4kaQSihUmy", "content": [ { "text": "Where is my order #1234?", "type": "text" } ], "type": "user.message", "processed_at": "2026-03-15T10:00:00Z" } ], "next_page": "next_page" } ``` ## Stream Session Thread Events `beta.sessions.threads.events.stream(strthread_id, EventStreamParams**kwargs) -> BetaManagedAgentsStreamSessionThreadEvents` **get** `/v1/sessions/{session_id}/threads/{thread_id}/stream` Stream Session Thread Events ### Parameters - `session_id: str` - `thread_id: str` - `betas: Optional[List[AnthropicBetaParam]]` Optional header to specify the beta version(s) you want to use. - `str` - `Literal["message-batches-2024-09-24", "prompt-caching-2024-07-31", "computer-use-2024-10-22", 25 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"` - `"advisor-tool-2026-03-01"` - `"managed-agents-2026-04-01"` - `"cache-diagnosis-2026-04-07"` - `"thinking-token-count-2026-05-13"` - `"server-side-fallback-2026-06-01"` - `"fallback-credit-2026-06-01"` ### Returns - `BetaManagedAgentsStreamSessionThreadEvents` Server-sent event in a single thread's stream. - `class BetaManagedAgentsUserMessageEvent: …` A user message event in the session conversation. - `id: str` Unique identifier for this event. - `content: List[Content]` Array of content blocks comprising the user message. - `class BetaManagedAgentsTextBlock: …` Regular text content. - `text: str` The text content. - `type: Literal["text"]` - `"text"` - `class BetaManagedAgentsImageBlock: …` Image content specified directly as base64 data or as a reference via a URL. - `source: Source` Union type for image source variants. - `class BetaManagedAgentsBase64ImageSource: …` Base64-encoded image data. - `data: str` Base64-encoded image data. - `media_type: str` MIME type of the image (e.g., "image/png", "image/jpeg", "image/gif", "image/webp"). - `type: Literal["base64"]` - `"base64"` - `class BetaManagedAgentsURLImageSource: …` Image referenced by URL. - `type: Literal["url"]` - `"url"` - `url: str` URL of the image to fetch. - `class BetaManagedAgentsFileImageSource: …` Image referenced by file ID. - `file_id: str` ID of a previously uploaded file. - `type: Literal["file"]` - `"file"` - `type: Literal["image"]` - `"image"` - `class BetaManagedAgentsDocumentBlock: …` Document content, either specified directly as base64 data, as text, or as a reference via a URL. - `source: Source` Union type for document source variants. - `class BetaManagedAgentsBase64DocumentSource: …` Base64-encoded document data. - `data: str` Base64-encoded document data. - `media_type: str` MIME type of the document (e.g., "application/pdf"). - `type: Literal["base64"]` - `"base64"` - `class BetaManagedAgentsPlainTextDocumentSource: …` Plain text document content. - `data: str` The plain text content. - `media_type: Literal["text/plain"]` MIME type of the text content. Must be "text/plain". - `"text/plain"` - `type: Literal["text"]` - `"text"` - `class BetaManagedAgentsURLDocumentSource: …` Document referenced by URL. - `type: Literal["url"]` - `"url"` - `url: str` URL of the document to fetch. - `class BetaManagedAgentsFileDocumentSource: …` Document referenced by file ID. - `file_id: str` ID of a previously uploaded file. - `type: Literal["file"]` - `"file"` - `type: Literal["document"]` - `"document"` - `context: Optional[str]` Additional context about the document for the model. - `title: Optional[str]` The title of the document. - `type: Literal["user.message"]` - `"user.message"` - `processed_at: Optional[datetime]` A timestamp in RFC 3339 format - `class BetaManagedAgentsUserInterruptEvent: …` An interrupt event that pauses agent execution and returns control to the user. - `id: str` Unique identifier for this event. - `type: Literal["user.interrupt"]` - `"user.interrupt"` - `processed_at: Optional[datetime]` A timestamp in RFC 3339 format - `session_thread_id: Optional[str]` If absent, interrupts every non-archived thread in a multiagent session (or the primary alone in a single-agent session). If present, interrupts only the named thread. - `class BetaManagedAgentsUserToolConfirmationEvent: …` A tool confirmation event that approves or denies a pending tool execution. - `id: str` Unique identifier for this event. - `result: Literal["allow", "deny"]` UserToolConfirmationResult enum - `"allow"` - `"deny"` - `tool_use_id: str` 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. - `type: Literal["user.tool_confirmation"]` - `"user.tool_confirmation"` - `deny_message: Optional[str]` Optional message providing context for a 'deny' decision. Only allowed when result is 'deny'. - `processed_at: Optional[datetime]` A timestamp in RFC 3339 format - `session_thread_id: Optional[str]` When set, the confirmation routes to this subagent's thread rather than the primary. Echo this from the `session_thread_id` on the `agent.tool_use` or `agent.mcp_tool_use` event that prompted the approval. - `class BetaManagedAgentsUserCustomToolResultEvent: …` Event sent by the client providing the result of a custom tool execution. - `id: str` Unique identifier for this event. - `custom_tool_use_id: str` 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. - `type: Literal["user.custom_tool_result"]` - `"user.custom_tool_result"` - `content: Optional[List[Content]]` The result content returned by the tool. - `class BetaManagedAgentsTextBlock: …` Regular text content. - `class BetaManagedAgentsImageBlock: …` Image content specified directly as base64 data or as a reference via a URL. - `class BetaManagedAgentsDocumentBlock: …` Document content, either specified directly as base64 data, as text, or as a reference via a URL. - `class BetaManagedAgentsSearchResultBlock: …` A block containing a web search result. - `citations: BetaManagedAgentsSearchResultCitations` Citation settings for a search result. - `enabled: bool` Whether citations are enabled for this search result. - `content: List[BetaManagedAgentsSearchResultContent]` Array of text content blocks from the search result. - `text: str` The text content. - `type: Literal["text"]` - `"text"` - `source: str` The URL source of the search result. - `title: str` The title of the search result. - `type: Literal["search_result"]` - `"search_result"` - `is_error: Optional[bool]` Whether the tool execution resulted in an error. - `processed_at: Optional[datetime]` A timestamp in RFC 3339 format - `session_thread_id: Optional[str]` Routes this result to a subagent thread. Copy from the `agent.custom_tool_use` event's `session_thread_id`. - `class BetaManagedAgentsAgentCustomToolUseEvent: …` Event emitted when the agent calls a custom tool. The session goes idle until the client sends a `user.custom_tool_result` event with the result. - `id: str` Unique identifier for this event. - `input: Dict[str, object]` Input parameters for the tool call. - `name: str` Name of the custom tool being called. - `processed_at: datetime` A timestamp in RFC 3339 format - `type: Literal["agent.custom_tool_use"]` - `"agent.custom_tool_use"` - `session_thread_id: Optional[str]` When set, this event was cross-posted from a subagent's thread to surface its custom tool use on the primary thread's stream. Empty on the thread's own events. Echo this on a `user.custom_tool_result` event to route the result back. - `class BetaManagedAgentsAgentMessageEvent: …` An agent response event in the session conversation. - `id: str` Unique identifier for this event. - `content: List[BetaManagedAgentsTextBlock]` Array of text blocks comprising the agent response. - `text: str` The text content. - `type: Literal["text"]` - `processed_at: datetime` A timestamp in RFC 3339 format - `type: Literal["agent.message"]` - `"agent.message"` - `class BetaManagedAgentsAgentThinkingEvent: …` Indicates the agent is making forward progress via extended thinking. A progress signal, not a content carrier. - `id: str` Unique identifier for this event. - `processed_at: datetime` A timestamp in RFC 3339 format - `type: Literal["agent.thinking"]` - `"agent.thinking"` - `class BetaManagedAgentsAgentMCPToolUseEvent: …` Event emitted when the agent invokes a tool provided by an MCP server. - `id: str` Unique identifier for this event. - `input: Dict[str, object]` Input parameters for the tool call. - `mcp_server_name: str` Name of the MCP server providing the tool. - `name: str` Name of the MCP tool being used. - `processed_at: datetime` A timestamp in RFC 3339 format - `type: Literal["agent.mcp_tool_use"]` - `"agent.mcp_tool_use"` - `evaluated_permission: Optional[Literal["allow", "ask", "deny"]]` AgentEvaluatedPermission enum - `"allow"` - `"ask"` - `"deny"` - `session_thread_id: Optional[str]` When set, this event was cross-posted from a subagent's thread to surface its permission request on the primary thread's stream. Empty on the thread's own events. Echo this on a `user.tool_confirmation` event to route the approval back. - `class BetaManagedAgentsAgentMCPToolResultEvent: …` Event representing the result of an MCP tool execution. - `id: str` Unique identifier for this event. - `mcp_tool_use_id: str` The id of the `agent.mcp_tool_use` event this result corresponds to. - `processed_at: datetime` A timestamp in RFC 3339 format - `type: Literal["agent.mcp_tool_result"]` - `"agent.mcp_tool_result"` - `content: Optional[List[Content]]` The result content returned by the tool. - `class BetaManagedAgentsTextBlock: …` Regular text content. - `class BetaManagedAgentsImageBlock: …` Image content specified directly as base64 data or as a reference via a URL. - `class BetaManagedAgentsDocumentBlock: …` Document content, either specified directly as base64 data, as text, or as a reference via a URL. - `class BetaManagedAgentsSearchResultBlock: …` A block containing a web search result. - `is_error: Optional[bool]` Whether the tool execution resulted in an error. - `class BetaManagedAgentsAgentToolUseEvent: …` Event emitted when the agent invokes a built-in agent tool. - `id: str` Unique identifier for this event. - `input: Dict[str, object]` Input parameters for the tool call. - `name: str` Name of the agent tool being used. - `processed_at: datetime` A timestamp in RFC 3339 format - `type: Literal["agent.tool_use"]` - `"agent.tool_use"` - `evaluated_permission: Optional[Literal["allow", "ask", "deny"]]` AgentEvaluatedPermission enum - `"allow"` - `"ask"` - `"deny"` - `session_thread_id: Optional[str]` When set, this event was cross-posted from a subagent's thread to surface its permission request on the primary thread's stream. Empty on the thread's own events. Echo this on a `user.tool_confirmation` event to route the approval back. - `class BetaManagedAgentsAgentToolResultEvent: …` Event representing the result of an agent tool execution. - `id: str` Unique identifier for this event. - `processed_at: datetime` A timestamp in RFC 3339 format - `tool_use_id: str` The id of the `agent.tool_use` event this result corresponds to. - `type: Literal["agent.tool_result"]` - `"agent.tool_result"` - `content: Optional[List[Content]]` The result content returned by the tool. - `class BetaManagedAgentsTextBlock: …` Regular text content. - `class BetaManagedAgentsImageBlock: …` Image content specified directly as base64 data or as a reference via a URL. - `class BetaManagedAgentsDocumentBlock: …` Document content, either specified directly as base64 data, as text, or as a reference via a URL. - `class BetaManagedAgentsSearchResultBlock: …` A block containing a web search result. - `is_error: Optional[bool]` Whether the tool execution resulted in an error. - `class BetaManagedAgentsAgentThreadMessageReceivedEvent: …` Delivery event written to the target thread's input stream when an agent-to-agent message arrives. - `id: str` Unique identifier for this event. - `content: List[Content]` Message content blocks. - `class BetaManagedAgentsTextBlock: …` Regular text content. - `class BetaManagedAgentsImageBlock: …` Image content specified directly as base64 data or as a reference via a URL. - `class BetaManagedAgentsDocumentBlock: …` Document content, either specified directly as base64 data, as text, or as a reference via a URL. - `from_session_thread_id: str` Public `sthr_` ID of the thread that sent the message. - `processed_at: datetime` A timestamp in RFC 3339 format - `type: Literal["agent.thread_message_received"]` - `"agent.thread_message_received"` - `from_agent_name: Optional[str]` Name of the callable agent this message came from. Absent when received from the primary agent. - `class BetaManagedAgentsAgentThreadMessageSentEvent: …` Observability event emitted to the sender's output stream when an agent-to-agent message is sent. - `id: str` Unique identifier for this event. - `content: List[Content]` Message content blocks. - `class BetaManagedAgentsTextBlock: …` Regular text content. - `class BetaManagedAgentsImageBlock: …` Image content specified directly as base64 data or as a reference via a URL. - `class BetaManagedAgentsDocumentBlock: …` Document content, either specified directly as base64 data, as text, or as a reference via a URL. - `processed_at: datetime` A timestamp in RFC 3339 format - `to_session_thread_id: str` Public `sthr_` ID of the thread the message was sent to. - `type: Literal["agent.thread_message_sent"]` - `"agent.thread_message_sent"` - `to_agent_name: Optional[str]` Name of the callable agent this message was sent to. Absent when sent to the primary agent. - `class BetaManagedAgentsAgentThreadContextCompactedEvent: …` Indicates that context compaction (summarization) occurred during the session. - `id: str` Unique identifier for this event. - `processed_at: datetime` A timestamp in RFC 3339 format - `type: Literal["agent.thread_context_compacted"]` - `"agent.thread_context_compacted"` - `class BetaManagedAgentsSessionErrorEvent: …` An error event indicating a problem occurred during session execution. - `id: str` Unique identifier for this event. - `error: Error` An unknown or unexpected error occurred during session execution. A fallback variant; clients that don't recognize a new error code can match on `retry_status` and `message` alone. - `class BetaManagedAgentsUnknownError: …` An unknown or unexpected error occurred during session execution. A fallback variant; clients that don't recognize a new error code can match on `retry_status` and `message` alone. - `message: str` Human-readable error description. - `retry_status: RetryStatus` What the client should do next in response to this error. - `class BetaManagedAgentsRetryStatusRetrying: …` The server is retrying automatically. Client should wait; the same error type may fire again as retrying, then once as exhausted when the retry budget runs out. - `type: Literal["retrying"]` - `"retrying"` - `class BetaManagedAgentsRetryStatusExhausted: …` This turn is dead; queued inputs are flushed and the session returns to idle. Client may send a new prompt. - `type: Literal["exhausted"]` - `"exhausted"` - `class BetaManagedAgentsRetryStatusTerminal: …` The session encountered a terminal error and will transition to `terminated` state. - `type: Literal["terminal"]` - `"terminal"` - `type: Literal["unknown_error"]` - `"unknown_error"` - `class BetaManagedAgentsModelOverloadedError: …` The model is currently overloaded. Emitted after automatic retries are exhausted. - `message: str` Human-readable error description. - `retry_status: RetryStatus` What the client should do next in response to this error. - `class BetaManagedAgentsRetryStatusRetrying: …` The server is retrying automatically. Client should wait; the same error type may fire again as retrying, then once as exhausted when the retry budget runs out. - `class BetaManagedAgentsRetryStatusExhausted: …` This turn is dead; queued inputs are flushed and the session returns to idle. Client may send a new prompt. - `class BetaManagedAgentsRetryStatusTerminal: …` The session encountered a terminal error and will transition to `terminated` state. - `type: Literal["model_overloaded_error"]` - `"model_overloaded_error"` - `class BetaManagedAgentsModelRateLimitedError: …` The model request was rate-limited. - `message: str` Human-readable error description. - `retry_status: RetryStatus` What the client should do next in response to this error. - `class BetaManagedAgentsRetryStatusRetrying: …` The server is retrying automatically. Client should wait; the same error type may fire again as retrying, then once as exhausted when the retry budget runs out. - `class BetaManagedAgentsRetryStatusExhausted: …` This turn is dead; queued inputs are flushed and the session returns to idle. Client may send a new prompt. - `class BetaManagedAgentsRetryStatusTerminal: …` The session encountered a terminal error and will transition to `terminated` state. - `type: Literal["model_rate_limited_error"]` - `"model_rate_limited_error"` - `class BetaManagedAgentsModelRequestFailedError: …` A model request failed for a reason other than overload or rate-limiting. - `message: str` Human-readable error description. - `retry_status: RetryStatus` What the client should do next in response to this error. - `class BetaManagedAgentsRetryStatusRetrying: …` The server is retrying automatically. Client should wait; the same error type may fire again as retrying, then once as exhausted when the retry budget runs out. - `class BetaManagedAgentsRetryStatusExhausted: …` This turn is dead; queued inputs are flushed and the session returns to idle. Client may send a new prompt. - `class BetaManagedAgentsRetryStatusTerminal: …` The session encountered a terminal error and will transition to `terminated` state. - `type: Literal["model_request_failed_error"]` - `"model_request_failed_error"` - `class BetaManagedAgentsMCPConnectionFailedError: …` Failed to connect to an MCP server. - `mcp_server_name: str` Name of the MCP server that failed to connect. - `message: str` Human-readable error description. - `retry_status: RetryStatus` What the client should do next in response to this error. - `class BetaManagedAgentsRetryStatusRetrying: …` The server is retrying automatically. Client should wait; the same error type may fire again as retrying, then once as exhausted when the retry budget runs out. - `class BetaManagedAgentsRetryStatusExhausted: …` This turn is dead; queued inputs are flushed and the session returns to idle. Client may send a new prompt. - `class BetaManagedAgentsRetryStatusTerminal: …` The session encountered a terminal error and will transition to `terminated` state. - `type: Literal["mcp_connection_failed_error"]` - `"mcp_connection_failed_error"` - `class BetaManagedAgentsMCPAuthenticationFailedError: …` Authentication to an MCP server failed. - `mcp_server_name: str` Name of the MCP server that failed authentication. - `message: str` Human-readable error description. - `retry_status: RetryStatus` What the client should do next in response to this error. - `class BetaManagedAgentsRetryStatusRetrying: …` The server is retrying automatically. Client should wait; the same error type may fire again as retrying, then once as exhausted when the retry budget runs out. - `class BetaManagedAgentsRetryStatusExhausted: …` This turn is dead; queued inputs are flushed and the session returns to idle. Client may send a new prompt. - `class BetaManagedAgentsRetryStatusTerminal: …` The session encountered a terminal error and will transition to `terminated` state. - `type: Literal["mcp_authentication_failed_error"]` - `"mcp_authentication_failed_error"` - `class BetaManagedAgentsBillingError: …` The caller's organization or workspace cannot make model requests — out of credits or spend limit reached. Retrying with the same credentials will not succeed; the caller must resolve the billing state. - `message: str` Human-readable error description. - `retry_status: RetryStatus` What the client should do next in response to this error. - `class BetaManagedAgentsRetryStatusRetrying: …` The server is retrying automatically. Client should wait; the same error type may fire again as retrying, then once as exhausted when the retry budget runs out. - `class BetaManagedAgentsRetryStatusExhausted: …` This turn is dead; queued inputs are flushed and the session returns to idle. Client may send a new prompt. - `class BetaManagedAgentsRetryStatusTerminal: …` The session encountered a terminal error and will transition to `terminated` state. - `type: Literal["billing_error"]` - `"billing_error"` - `class BetaManagedAgentsCredentialHostUnreachableError: …` An `environment_variable` credential's `auth.networking.allowed_hosts` includes a host the environment's network policy does not permit. - `credential_id: str` ID of the affected credential. - `message: str` Human-readable error description. - `retry_status: RetryStatus` What the client should do next in response to this error. - `class BetaManagedAgentsRetryStatusRetrying: …` The server is retrying automatically. Client should wait; the same error type may fire again as retrying, then once as exhausted when the retry budget runs out. - `class BetaManagedAgentsRetryStatusExhausted: …` This turn is dead; queued inputs are flushed and the session returns to idle. Client may send a new prompt. - `class BetaManagedAgentsRetryStatusTerminal: …` The session encountered a terminal error and will transition to `terminated` state. - `type: Literal["credential_host_unreachable_error"]` - `"credential_host_unreachable_error"` - `vault_id: str` ID of the vault containing the affected credential. - `processed_at: datetime` A timestamp in RFC 3339 format - `type: Literal["session.error"]` - `"session.error"` - `class BetaManagedAgentsSessionStatusRescheduledEvent: …` Indicates the session is recovering from an error state and is rescheduled for execution. - `id: str` Unique identifier for this event. - `processed_at: datetime` A timestamp in RFC 3339 format - `type: Literal["session.status_rescheduled"]` - `"session.status_rescheduled"` - `class BetaManagedAgentsSessionStatusRunningEvent: …` Indicates the session is actively running and the agent is working. - `id: str` Unique identifier for this event. - `processed_at: datetime` A timestamp in RFC 3339 format - `type: Literal["session.status_running"]` - `"session.status_running"` - `class BetaManagedAgentsSessionStatusIdleEvent: …` Indicates the agent has paused and is awaiting user input. - `id: str` Unique identifier for this event. - `processed_at: datetime` A timestamp in RFC 3339 format - `stop_reason: StopReason` The agent completed its turn naturally and is ready for the next user message. - `class BetaManagedAgentsSessionEndTurn: …` The agent completed its turn naturally and is ready for the next user message. - `type: Literal["end_turn"]` - `"end_turn"` - `class BetaManagedAgentsSessionRequiresAction: …` The agent is idle waiting on one or more blocking user-input events (tool confirmation, custom tool result, etc.). Resolving all of them transitions the session back to running. - `event_ids: List[str]` The ids of events the agent is blocked on. Resolving fewer than all re-emits `session.status_idle` with the remainder. - `type: Literal["requires_action"]` - `"requires_action"` - `class BetaManagedAgentsSessionRetriesExhausted: …` The turn ended because the retry budget was exhausted (`max_iterations` hit or an error escalated to `retry_status: 'exhausted'`). - `type: Literal["retries_exhausted"]` - `"retries_exhausted"` - `type: Literal["session.status_idle"]` - `"session.status_idle"` - `class BetaManagedAgentsSessionStatusTerminatedEvent: …` Indicates the session has terminated, either due to an error or completion. - `id: str` Unique identifier for this event. - `processed_at: datetime` A timestamp in RFC 3339 format - `type: Literal["session.status_terminated"]` - `"session.status_terminated"` - `class BetaManagedAgentsSessionThreadCreatedEvent: …` Emitted when a subagent is spawned as a new thread. Written to the parent thread's output stream so clients observing the session see child creation. - `id: str` Unique identifier for this event. - `agent_name: str` Name of the callable agent the thread runs. - `processed_at: datetime` A timestamp in RFC 3339 format - `session_thread_id: str` Public `sthr_` ID of the newly created thread. - `type: Literal["session.thread_created"]` - `"session.thread_created"` - `class BetaManagedAgentsSpanOutcomeEvaluationStartEvent: …` Emitted when an outcome evaluation cycle begins. - `id: str` Unique identifier for this event. - `iteration: int` 0-indexed revision cycle. 0 is the first evaluation; 1 is the re-evaluation after the first revision; etc. - `outcome_id: str` The `outc_` ID of the outcome being evaluated. - `processed_at: datetime` A timestamp in RFC 3339 format - `type: Literal["span.outcome_evaluation_start"]` - `"span.outcome_evaluation_start"` - `class BetaManagedAgentsSpanOutcomeEvaluationEndEvent: …` Emitted when an outcome evaluation cycle completes. Carries the verdict and aggregate token usage. A verdict of `needs_revision` means another evaluation cycle follows; `satisfied`, `max_iterations_reached`, `failed`, or `interrupted` are terminal — no further evaluation cycles follow. - `id: str` Unique identifier for this event. - `explanation: str` Human-readable explanation of the verdict. For `needs_revision`, describes which criteria failed and why. - `iteration: int` 0-indexed revision cycle, matching the corresponding `span.outcome_evaluation_start`. - `outcome_evaluation_start_id: str` The id of the corresponding `span.outcome_evaluation_start` event. - `outcome_id: str` The `outc_` ID of the outcome being evaluated. - `processed_at: datetime` A timestamp in RFC 3339 format - `result: str` 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. - `type: Literal["span.outcome_evaluation_end"]` - `"span.outcome_evaluation_end"` - `usage: BetaManagedAgentsSpanModelUsage` Token usage for a single model request. - `cache_creation_input_tokens: int` Tokens used to create prompt cache in this request. - `cache_read_input_tokens: int` Tokens read from prompt cache in this request. - `input_tokens: int` Input tokens consumed by this request. - `output_tokens: int` Output tokens generated by this request. - `speed: Optional[Literal["standard", "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"` - `class BetaManagedAgentsSpanModelRequestStartEvent: …` Emitted when a model request is initiated by the agent. - `id: str` Unique identifier for this event. - `processed_at: datetime` A timestamp in RFC 3339 format - `type: Literal["span.model_request_start"]` - `"span.model_request_start"` - `class BetaManagedAgentsSpanModelRequestEndEvent: …` Emitted when a model request completes. - `id: str` Unique identifier for this event. - `is_error: Optional[bool]` Whether the model request resulted in an error. - `model_request_start_id: str` The id of the corresponding `span.model_request_start` event. - `model_usage: BetaManagedAgentsSpanModelUsage` Token usage for a single model request. - `processed_at: datetime` A timestamp in RFC 3339 format - `type: Literal["span.model_request_end"]` - `"span.model_request_end"` - `class BetaManagedAgentsSpanOutcomeEvaluationOngoingEvent: …` Periodic heartbeat emitted while an outcome evaluation cycle is in progress. Distinguishes 'evaluation is actively running' from 'evaluation is stuck' between the corresponding `span.outcome_evaluation_start` and `span.outcome_evaluation_end` events. - `id: str` Unique identifier for this event. - `iteration: int` 0-indexed revision cycle, matching the corresponding `span.outcome_evaluation_start`. - `outcome_id: str` The `outc_` ID of the outcome being evaluated. - `processed_at: datetime` A timestamp in RFC 3339 format - `type: Literal["span.outcome_evaluation_ongoing"]` - `"span.outcome_evaluation_ongoing"` - `class BetaManagedAgentsUserDefineOutcomeEvent: …` Echo of a `user.define_outcome` input event. Carries the server-generated `outcome_id` that subsequent `span.outcome_evaluation_*` events reference. - `id: str` Unique identifier for this event. - `description: str` What the agent should produce. Copied from the input event. - `max_iterations: Optional[int]` Evaluate-then-revise cycles before giving up. Default 3, max 20. - `outcome_id: str` Server-generated `outc_` ID for this outcome. Referenced by `span.outcome_evaluation_*` events and the session's `outcome_evaluations` list. - `processed_at: datetime` A timestamp in RFC 3339 format - `rubric: Rubric` Rubric for grading the quality of an outcome. - `class BetaManagedAgentsFileRubric: …` Rubric referenced by a file uploaded via the Files API. - `file_id: str` ID of the rubric file. - `type: Literal["file"]` - `"file"` - `class BetaManagedAgentsTextRubric: …` Rubric content provided inline as text. - `content: str` Rubric content. Plain text or markdown — the grader treats it as freeform text. - `type: Literal["text"]` - `"text"` - `type: Literal["user.define_outcome"]` - `"user.define_outcome"` - `class BetaManagedAgentsSessionDeletedEvent: …` Emitted when a session has been deleted. Terminates any active event stream — no further events will be emitted for this session. - `id: str` Unique identifier for this event. - `processed_at: datetime` A timestamp in RFC 3339 format - `type: Literal["session.deleted"]` - `"session.deleted"` - `class BetaManagedAgentsSessionThreadStatusRunningEvent: …` A session thread has begun executing. Emitted on the thread's own stream and cross-posted to the primary stream for child threads. - `id: str` Unique identifier for this event. - `agent_name: str` Name of the agent the thread runs. - `processed_at: datetime` A timestamp in RFC 3339 format - `session_thread_id: str` Public sthr_ ID of the thread that started running. - `type: Literal["session.thread_status_running"]` - `"session.thread_status_running"` - `class BetaManagedAgentsSessionThreadStatusIdleEvent: …` A session thread has yielded and is awaiting input. Emitted on the thread's own stream and cross-posted to the primary stream for child threads. - `id: str` Unique identifier for this event. - `agent_name: str` Name of the agent the thread runs. - `processed_at: datetime` A timestamp in RFC 3339 format - `session_thread_id: str` Public sthr_ ID of the thread that went idle. - `stop_reason: StopReason` The agent completed its turn naturally and is ready for the next user message. - `class BetaManagedAgentsSessionEndTurn: …` The agent completed its turn naturally and is ready for the next user message. - `class BetaManagedAgentsSessionRequiresAction: …` The agent is idle waiting on one or more blocking user-input events (tool confirmation, custom tool result, etc.). Resolving all of them transitions the session back to running. - `class BetaManagedAgentsSessionRetriesExhausted: …` The turn ended because the retry budget was exhausted (`max_iterations` hit or an error escalated to `retry_status: 'exhausted'`). - `type: Literal["session.thread_status_idle"]` - `"session.thread_status_idle"` - `class BetaManagedAgentsSessionThreadStatusTerminatedEvent: …` A session thread has terminated and will accept no further input. Emitted on the thread's own stream and cross-posted to the primary stream for child threads. - `id: str` Unique identifier for this event. - `agent_name: str` Name of the agent the thread runs. - `processed_at: datetime` A timestamp in RFC 3339 format - `session_thread_id: str` Public sthr_ ID of the thread that terminated. - `type: Literal["session.thread_status_terminated"]` - `"session.thread_status_terminated"` - `class BetaManagedAgentsUserToolResultEvent: …` Event sent by the client providing the result of an agent-toolset tool execution. Only valid on `self_hosted` environments, where sandbox-routed tools are executed by the client rather than the server. - `id: str` Unique identifier for this event. - `tool_use_id: str` 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. - `type: Literal["user.tool_result"]` - `"user.tool_result"` - `content: Optional[List[Content]]` The result content returned by the tool. - `class BetaManagedAgentsTextBlock: …` Regular text content. - `class BetaManagedAgentsImageBlock: …` Image content specified directly as base64 data or as a reference via a URL. - `class BetaManagedAgentsDocumentBlock: …` Document content, either specified directly as base64 data, as text, or as a reference via a URL. - `class BetaManagedAgentsSearchResultBlock: …` A block containing a web search result. - `is_error: Optional[bool]` Whether the tool execution resulted in an error. - `processed_at: Optional[datetime]` A timestamp in RFC 3339 format - `session_thread_id: Optional[str]` Routes this result to a subagent thread. Copy from the `agent.tool_use` event's `session_thread_id`. - `class BetaManagedAgentsSessionThreadStatusRescheduledEvent: …` A session thread hit a transient error and is retrying automatically. Emitted on the thread's own stream and cross-posted to the primary stream for child threads. - `id: str` Unique identifier for this event. - `agent_name: str` Name of the agent the thread runs. - `processed_at: datetime` A timestamp in RFC 3339 format - `session_thread_id: str` Public sthr_ ID of the thread that is retrying. - `type: Literal["session.thread_status_rescheduled"]` - `"session.thread_status_rescheduled"` - `class BetaManagedAgentsSessionUpdatedEvent: …` Emitted when an UpdateSession request changed at least one field. Carries only the fields that changed; absent fields were not part of the update. The new configuration applies from the next turn. - `id: str` Unique identifier for this event. - `processed_at: datetime` A timestamp in RFC 3339 format - `type: Literal["session.updated"]` - `"session.updated"` - `agent: Optional[BetaManagedAgentsSessionAgent]` Resolved `agent` definition for a `session`. Snapshot of the `agent` at `session` creation time. - `id: str` - `description: Optional[str]` - `mcp_servers: List[BetaManagedAgentsMCPServerURLDefinition]` - `name: str` - `type: Literal["url"]` - `"url"` - `url: str` - `model: BetaManagedAgentsModelConfig` Model identifier and configuration. - `id: BetaManagedAgentsModel` The model that will power your agent. See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options. - `Literal["claude-fable-5", "claude-opus-4-8", "claude-opus-4-7", 8 more]` The model that will power your agent. See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options. - `claude-fable-5` - Next generation of intelligence for the hardest knowledge work and coding problems - `claude-opus-4-8` - Frontier intelligence for long-running agents and coding - `claude-opus-4-7` - Frontier intelligence for long-running agents and coding - `claude-opus-4-6` - Most intelligent model for building 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` - Premium model combining maximum intelligence with practical performance - `claude-opus-4-5-20251101` - Premium model combining maximum intelligence with practical performance - `claude-sonnet-4-5` - High-performance model for agents and coding - `claude-sonnet-4-5-20250929` - High-performance model for agents and coding - `"claude-fable-5"` Next generation of intelligence for the hardest knowledge work and coding problems - `"claude-opus-4-8"` Frontier intelligence for long-running agents and coding - `"claude-opus-4-7"` Frontier intelligence for long-running agents and coding - `"claude-opus-4-6"` Most intelligent model for building 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"` Premium model combining maximum intelligence with practical performance - `"claude-opus-4-5-20251101"` Premium model combining maximum intelligence with practical performance - `"claude-sonnet-4-5"` High-performance model for agents and coding - `"claude-sonnet-4-5-20250929"` High-performance model for agents and coding - `str` - `speed: Optional[Literal["standard", "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: Optional[BetaManagedAgentsSessionMultiagentCoordinator]` Resolved coordinator topology with full agent definitions for each roster member. - `agents: List[BetaManagedAgentsSessionThreadAgent]` Full `agent` definitions the coordinator may spawn as session threads. - `id: str` - `description: Optional[str]` - `mcp_servers: List[BetaManagedAgentsMCPServerURLDefinition]` - `name: str` - `type: Literal["url"]` - `url: str` - `model: BetaManagedAgentsModelConfig` Model identifier and configuration. - `name: str` - `skills: List[Skill]` - `class BetaManagedAgentsAnthropicSkill: …` A resolved Anthropic-managed skill. - `skill_id: str` - `type: Literal["anthropic"]` - `"anthropic"` - `version: str` - `class BetaManagedAgentsCustomSkill: …` A resolved user-created custom skill. - `skill_id: str` - `type: Literal["custom"]` - `"custom"` - `version: str` - `system: Optional[str]` - `tools: List[Tool]` - `class BetaManagedAgentsAgentToolset20260401: …` - `configs: List[BetaManagedAgentsAgentToolConfig]` - `enabled: bool` - `name: Literal["bash", "edit", "read", 5 more]` Built-in agent tool identifier. - `"bash"` - `"edit"` - `"read"` - `"write"` - `"glob"` - `"grep"` - `"web_fetch"` - `"web_search"` - `permission_policy: PermissionPolicy` Permission policy for tool execution. - `class BetaManagedAgentsAlwaysAllowPolicy: …` Tool calls are automatically approved without user confirmation. - `type: Literal["always_allow"]` - `"always_allow"` - `class BetaManagedAgentsAlwaysAskPolicy: …` Tool calls require user confirmation before execution. - `type: Literal["always_ask"]` - `"always_ask"` - `default_config: BetaManagedAgentsAgentToolsetDefaultConfig` Resolved default configuration for agent tools. - `enabled: bool` - `permission_policy: PermissionPolicy` Permission policy for tool execution. - `class BetaManagedAgentsAlwaysAllowPolicy: …` Tool calls are automatically approved without user confirmation. - `class BetaManagedAgentsAlwaysAskPolicy: …` Tool calls require user confirmation before execution. - `type: Literal["agent_toolset_20260401"]` - `"agent_toolset_20260401"` - `class BetaManagedAgentsMCPToolset: …` - `configs: List[BetaManagedAgentsMCPToolConfig]` - `enabled: bool` - `name: str` - `permission_policy: PermissionPolicy` Permission policy for tool execution. - `class BetaManagedAgentsAlwaysAllowPolicy: …` Tool calls are automatically approved without user confirmation. - `class BetaManagedAgentsAlwaysAskPolicy: …` Tool calls require user confirmation before execution. - `default_config: BetaManagedAgentsMCPToolsetDefaultConfig` Resolved default configuration for all tools from an MCP server. - `enabled: bool` - `permission_policy: PermissionPolicy` Permission policy for tool execution. - `class BetaManagedAgentsAlwaysAllowPolicy: …` Tool calls are automatically approved without user confirmation. - `class BetaManagedAgentsAlwaysAskPolicy: …` Tool calls require user confirmation before execution. - `mcp_server_name: str` - `type: Literal["mcp_toolset"]` - `"mcp_toolset"` - `class BetaManagedAgentsCustomTool: …` A custom tool as returned in API responses. - `description: str` - `input_schema: BetaManagedAgentsCustomToolInputSchema` JSON Schema for custom tool input parameters. - `type: Literal["object"]` - `"object"` - `properties: Optional[Dict[str, object]]` - `required: Optional[List[str]]` - `name: str` - `type: Literal["custom"]` - `"custom"` - `type: Literal["agent"]` - `"agent"` - `version: int` - `type: Literal["coordinator"]` - `"coordinator"` - `name: str` - `skills: List[Skill]` - `class BetaManagedAgentsAnthropicSkill: …` A resolved Anthropic-managed skill. - `class BetaManagedAgentsCustomSkill: …` A resolved user-created custom skill. - `system: Optional[str]` - `tools: List[Tool]` - `class BetaManagedAgentsAgentToolset20260401: …` - `class BetaManagedAgentsMCPToolset: …` - `class BetaManagedAgentsCustomTool: …` A custom tool as returned in API responses. - `type: Literal["agent"]` - `"agent"` - `version: int` - `metadata: Optional[Dict[str, str]]` 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[str]` The session's new title. Present only when the update changed it. - `class BetaManagedAgentsSystemMessageEvent: …` A mid-conversation system message event. Carries system-role content that is appended to the session as a `role: "system"` turn. - `id: str` Unique identifier for this event. - `content: List[BetaManagedAgentsSystemContentBlock]` System content blocks. Text-only. - `text: str` The text content. - `type: Literal["text"]` - `"text"` - `type: Literal["system.message"]` - `"system.message"` - `processed_at: Optional[datetime]` A timestamp in RFC 3339 format ### Example ```python import os from anthropic import Anthropic client = Anthropic( api_key=os.environ.get("ANTHROPIC_API_KEY"), # This is the default and can be omitted ) for event in client.beta.sessions.threads.events.stream( thread_id="sthr_011CZkZVWa6oIjw0rgXZpnBt", session_id="sesn_011CZkZAtmR3yMPDzynEDxu7", ): print(event) ``` #### Response ```json { "id": "sevt_011CZkZGOp0iBcp4kaQSihUmy", "content": [ { "text": "Where is my order #1234?", "type": "text" } ], "type": "user.message", "processed_at": "2026-03-15T10:00:00Z" } ```