--- title: Send Events url: https://platform.claude.com/docs/en/api/python/beta/sessions/events/send --- # Send Events `beta.sessions.events.send(session_id, **kwargs) -> BetaManagedAgentsSendSessionEvents` **POST** `/v1/sessions/{session_id}/events` Send Events ## Parameters - `session_id: str` (path parameter) - `events: Iterable[BetaManagedAgentsEventParams]` Events to send to the `session`. - `class BetaManagedAgentsUserMessageEventParams` Parameters for sending a user message to the session. - `type: Literal["user.message"]` - `content: Iterable[Content]` Array of content blocks for the user message. - `class BetaManagedAgentsTextBlock` Regular text content. - `type: Literal["text"]` - `text: str` The text content. minLength: 1 - `class BetaManagedAgentsImageBlock` Image content specified directly as base64 data or as a reference via a URL. - `type: Literal["image"]` - `source: Source` The source of the image data. - `class BetaManagedAgentsBase64ImageSource` Base64-encoded image data. - `type: Literal["base64"]` - `data: str` Base64-encoded image data. minLength: 1 - `media_type: str` MIME type of the image (e.g., "image/png", "image/jpeg", "image/gif", "image/webp"). minLength: 1 - `class BetaManagedAgentsURLImageSource` Image referenced by URL. - `type: Literal["url"]` - `url: str` URL of the image to fetch. minLength: 1 - `class BetaManagedAgentsFileImageSource` Image referenced by file ID. - `type: Literal["file"]` - `file_id: str` ID of a previously uploaded file. minLength: 1 - `class BetaManagedAgentsDocumentBlock` Document content, either specified directly as base64 data, as text, or as a reference via a URL. - `type: Literal["document"]` - `source: Source` The source of the document data. - `class BetaManagedAgentsBase64DocumentSource` Base64-encoded document data. - `type: Literal["base64"]` - `data: str` Base64-encoded document data. minLength: 1 - `media_type: str` MIME type of the document (e.g., "application/pdf"). minLength: 1 - `class BetaManagedAgentsPlainTextDocumentSource` Plain text document content. - `type: Literal["text"]` - `data: str` The plain text content. minLength: 1 - `media_type: Literal["text/plain"]` MIME type of the text content. Must be "text/plain". - `class BetaManagedAgentsURLDocumentSource` Document referenced by URL. - `type: Literal["url"]` - `url: str` URL of the document to fetch. minLength: 1 - `class BetaManagedAgentsFileDocumentSource` Document referenced by file ID. - `type: Literal["file"]` - `file_id: str` ID of a previously uploaded file. minLength: 1 - `context: Optional[str]` Additional context about the document for the model. - `title: Optional[str]` The title of the document. - `class BetaManagedAgentsRedactedBlock` Placeholder for content withheld by Anthropic model policy. - `type: Literal["redacted"]` - `class BetaManagedAgentsUserInterruptEventParams` Parameters for sending an interrupt to pause the agent. - `type: Literal["user.interrupt"]` - `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 BetaManagedAgentsUserToolConfirmationEventParams` Parameters for confirming or denying a tool execution request. - `type: Literal["user.tool_confirmation"]` - `result: Literal["allow", "deny"]` The confirmation result: 'allow' or 'deny'. - `"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?sdk_languages=python#beta_managed_agents_session_requires_action.event_ids) `stop_reason.event_ids` field. minLength: 1, maxLength: 128 - `deny_message: Optional[str]` Optional message providing context for a 'deny' decision. Only allowed when result is 'deny'. maxLength: 10000 - `class BetaManagedAgentsUserCustomToolResultEventParams` Parameters for providing the result of a custom tool execution. - `type: Literal["user.custom_tool_result"]` - `custom_tool_use_id: str` The id of the `agent.custom_tool_use` event this result corresponds to. It is also listed in the last `session.status_idle` [event's](https://platform.claude.com/docs/en/api/beta/sessions/events/list?sdk_languages=python#beta_managed_agents_session_requires_action.event_ids) `stop_reason.event_ids` field. minLength: 1, maxLength: 128 - `content: Optional[Iterable[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. - `type: Literal["search_result"]` - `citations: BetaManagedAgentsSearchResultCitations` Citation settings for this search result. - `enabled: bool` Whether citations are enabled for this search result. - `content: List[BetaManagedAgentsSearchResultContent]` Array of text content blocks from the search result. - `type: Literal["text"]` - `text: str` The text content. minLength: 1 - `source: str` The URL source of the search result. minLength: 1 - `title: str` The title of the search result. minLength: 1 - `is_error: Optional[bool]` Whether the tool execution resulted in an error. - `class BetaManagedAgentsUserDefineOutcomeEventParams` Parameters for defining an outcome the agent should work toward. The agent begins work on receipt. - `type: Literal["user.define_outcome"]` - `description: str` What the agent should produce. This is the task specification. - `rubric: Rubric` How to grade the outcome. Text or file reference. - `class BetaManagedAgentsFileRubricParams` Rubric referenced by a file uploaded via the Files API. - `type: Literal["file"]` - `file_id: str` ID of the rubric file. - `class BetaManagedAgentsTextRubricParams` Rubric content provided inline as text. - `type: Literal["text"]` - `content: str` Rubric content. Plain text or markdown — the grader treats it as freeform text. Maximum 262144 characters. maxLength: 262144 - `max_iterations: Optional[int]` Eval→revision cycles before giving up. Default 3, max 20. format: int32 - `class BetaManagedAgentsUserToolResultEventParams` Parameters for providing the result of an agent-toolset tool execution. Only valid on `self_hosted` environments, where sandbox-routed tools are executed by the client rather than the server. - `type: Literal["user.tool_result"]` - `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?sdk_languages=python#beta_managed_agents_session_requires_action.event_ids) `stop_reason.event_ids` field. minLength: 1, maxLength: 128 - `content: Optional[Iterable[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 BetaManagedAgentsSystemMessageEventParams` Privileged context for the accompanying turn and all subsequent turns, appended to the session's system context as a `role: "system"` turn rather than replacing the top-level system prompt. At most one per request: it must be the final event and immediately follow the `user.message`, `user.tool_result`, or `user.custom_tool_result` it accompanies. Only supported on models that accept mid-conversation system messages. - `type: Literal["system.message"]` - `content: Iterable[BetaManagedAgentsSystemContentBlockParam]` System content blocks to append. Text-only. - `type: Literal["text"]` - `text: str` The text content. minLength: 1 - `betas: Optional[List[AnthropicBetaParam]]` (header parameter) Optional header to specify the beta version(s) you want to use. - `str` - `"message-batches-2024-09-24"` - `"prompt-caching-2024-07-31"` - `"computer-use-2024-10-22"` - `"computer-use-2025-01-24"` - `"pdfs-2024-09-25"` - `"token-counting-2024-11-01"` - `"token-efficient-tools-2025-02-19"` - `"output-128k-2025-02-19"` - `"files-api-2025-04-14"` - `"mcp-client-2025-04-04"` - `"mcp-client-2025-11-20"` - `"dev-full-thinking-2025-05-14"` - `"interleaved-thinking-2025-05-14"` - `"code-execution-2025-05-22"` - `"extended-cache-ttl-2025-04-11"` - `"context-1m-2025-08-07"` - `"context-management-2025-06-27"` - `"model-context-window-exceeded-2025-08-26"` - `"skills-2025-10-02"` - `"fast-mode-2026-02-01"` - `"output-300k-2026-03-24"` - `"user-profiles-2026-03-24"` - `"user-profiles-2026-08-18"` - `"user-profiles-2026-09-04"` - `"advisor-tool-2026-03-01"` - `"managed-agents-2026-04-01"` - `"cache-diagnosis-2026-04-07"` - `"dreaming-2026-04-21"` - `"thinking-token-count-2026-05-13"` - `"server-side-fallback-2026-06-01"` - `"server-side-fallback-2026-07-01"` - `"fallback-credit-2026-06-01"` - `"fallback-credit-2026-07-01"` - `"agent-memory-2026-07-22"` - `"mid-conversation-tool-changes-2026-07-01"` - `"compact-2026-01-12"` - `"computer-use-2025-11-24"` - `"mcp-tunnels-2026-06-22"` - `"structured-outputs-2025-11-13"` - `"task-budgets-2026-03-13"` - `"thinking-display-updates-2026-08-18"` - `"ce-user-management-2026-07-13"` - `"mid-conversation-output-config-2026-07-01"` - `"thinking-binding-controls-2026-08-01"` - `"mid-conversation-system-clear-at-2026-08-21"` - `"compact-2026-09-04"` - `"inline-tools-2026-09-15"` - `"mcp-client-2026-09-15"` - `"ce-plugins-2026-09-01"` - `"spend-limit-reads-2026-09-26"` - `workspace_id: Optional[str]` (header parameter) Optional header to select the Workspace for this request. The value is a Workspace ID (for example, `wrkspc_011CZkZaBF1tNoB5wlCeusgy`). Only needed for credentials that can act on more than one Workspace. A credential that belongs to a specific Workspace may omit it; if sent, it must match that Workspace. ## Returns - `class BetaManagedAgentsSendSessionEvents` Events that were successfully sent to the session. - `data: Optional[List[Data]]` Sent events - `class BetaManagedAgentsUserMessageEvent` A user message event in the session conversation. - `type: Literal["user.message"]` - `id: str` Unique identifier for this event. - `content: List[Content]` Array of content blocks comprising the user message. - `class BetaManagedAgentsTextBlock` Regular text content. - `type: Literal["text"]` - `text: str` The text content. minLength: 1 - `class BetaManagedAgentsImageBlock` Image content specified directly as base64 data or as a reference via a URL. - `type: Literal["image"]` - `source: Source` The source of the image data. - `class BetaManagedAgentsBase64ImageSource` Base64-encoded image data. - `type: Literal["base64"]` - `data: str` Base64-encoded image data. minLength: 1 - `media_type: str` MIME type of the image (e.g., "image/png", "image/jpeg", "image/gif", "image/webp"). minLength: 1 - `class BetaManagedAgentsURLImageSource` Image referenced by URL. - `type: Literal["url"]` - `url: str` URL of the image to fetch. minLength: 1 - `class BetaManagedAgentsFileImageSource` Image referenced by file ID. - `type: Literal["file"]` - `file_id: str` ID of a previously uploaded file. minLength: 1 - `class BetaManagedAgentsDocumentBlock` Document content, either specified directly as base64 data, as text, or as a reference via a URL. - `type: Literal["document"]` - `source: Source` The source of the document data. - `class BetaManagedAgentsBase64DocumentSource` Base64-encoded document data. - `type: Literal["base64"]` - `data: str` Base64-encoded document data. minLength: 1 - `media_type: str` MIME type of the document (e.g., "application/pdf"). minLength: 1 - `class BetaManagedAgentsPlainTextDocumentSource` Plain text document content. - `type: Literal["text"]` - `data: str` The plain text content. minLength: 1 - `media_type: Literal["text/plain"]` MIME type of the text content. Must be "text/plain". - `class BetaManagedAgentsURLDocumentSource` Document referenced by URL. - `type: Literal["url"]` - `url: str` URL of the document to fetch. minLength: 1 - `class BetaManagedAgentsFileDocumentSource` Document referenced by file ID. - `type: Literal["file"]` - `file_id: str` ID of a previously uploaded file. minLength: 1 - `context: Optional[str]` Additional context about the document for the model. - `title: Optional[str]` The title of the document. - `class BetaManagedAgentsRedactedBlock` Placeholder for content withheld by Anthropic model policy. - `type: Literal["redacted"]` - `processed_at: Optional[datetime]` Timestamp when the agent finished processing this message. format: date-time - `class BetaManagedAgentsUserInterruptEvent` An interrupt event that pauses agent execution and returns control to the user. - `type: Literal["user.interrupt"]` - `id: str` Unique identifier for this event. - `processed_at: Optional[datetime]` Timestamp when the interrupt was processed. format: date-time - `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. - `type: Literal["user.tool_confirmation"]` - `id: str` Unique identifier for this event. - `result: Literal["allow", "deny"]` The confirmation result: 'allow' or 'deny'. - `"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?sdk_languages=python#beta_managed_agents_session_requires_action.event_ids) `stop_reason.event_ids` field. - `deny_message: Optional[str]` Optional message providing context for a 'deny' decision. Only allowed when result is 'deny'. maxLength: 10000 - `processed_at: Optional[datetime]` Timestamp when the confirmation was processed. format: date-time - `session_thread_id: Optional[str]` Set by the server to the subagent thread this confirmation was routed to. Omitted when it was routed to the primary thread. - `class BetaManagedAgentsUserCustomToolResultEvent` Event sent by the client providing the result of a custom tool execution. - `type: Literal["user.custom_tool_result"]` - `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. It is also listed in the last `session.status_idle` [event's](https://platform.claude.com/docs/en/api/beta/sessions/events/list?sdk_languages=python#beta_managed_agents_session_requires_action.event_ids) `stop_reason.event_ids` field. - `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. - `type: Literal["search_result"]` - `citations: BetaManagedAgentsSearchResultCitations` Citation settings for this search result. - `enabled: bool` Whether citations are enabled for this search result. - `content: List[BetaManagedAgentsSearchResultContent]` Array of text content blocks from the search result. - `type: Literal["text"]` - `text: str` The text content. minLength: 1 - `source: str` The URL source of the search result. minLength: 1 - `title: str` The title of the search result. minLength: 1 - `is_error: Optional[bool]` Whether the tool execution resulted in an error. - `processed_at: Optional[datetime]` Timestamp when this result was processed. format: date-time - `session_thread_id: Optional[str]` Set by the server to the subagent thread this result was routed to. Omitted when it was routed to the primary thread. - `class BetaManagedAgentsUserDefineOutcomeEvent` Echo of a `user.define_outcome` input event. Carries the server-generated `outcome_id` that subsequent `span.outcome_evaluation_*` events reference. - `type: Literal["user.define_outcome"]` - `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. format: int32 - `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` Timestamp when the outcome was accepted. format: date-time - `rubric: Rubric` How to grade the outcome. File rubrics are currently resolved to their text content; clients should handle both variants. - `class BetaManagedAgentsFileRubric` Rubric referenced by a file uploaded via the Files API. - `type: Literal["file"]` - `file_id: str` ID of the rubric file. - `class BetaManagedAgentsTextRubric` Rubric content provided inline as text. - `type: Literal["text"]` - `content: str` Rubric content. Plain text or markdown — the grader treats it as freeform text. - `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. - `type: Literal["user.tool_result"]` - `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?sdk_languages=python#beta_managed_agents_session_requires_action.event_ids) `stop_reason.event_ids` field. - `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]` Timestamp when this result was processed. format: date-time - `session_thread_id: Optional[str]` Set by the server to the subagent thread this result was routed to. Omitted when it was routed to the primary thread. - `class BetaManagedAgentsSystemMessageEvent` A mid-conversation system message event. Carries system-role content that is appended to the session as a `role: "system"` turn. - `type: Literal["system.message"]` - `id: str` Unique identifier for this event. - `content: List[BetaManagedAgentsSystemContentBlock]` System content blocks. Text-only. - `type: Literal["text"]` - `text: str` The text content. minLength: 1 - `processed_at: Optional[datetime]` Timestamp when this system message was processed. format: date-time ## 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_send_session_events = client.beta.sessions.events.send( session_id="sesn_011CZkZAtmR3yMPDzynEDxu7", events=[ { "content": [ { "text": "Where is my order #1234?", "type": "text", } ], "type": "user.message", } ], ) print(beta_managed_agents_send_session_events.data) ``` ### Response (200) ```json { "data": [ { "id": "sevt_011CZkZGPp1iBcp4kaQSihUm", "content": [ { "text": "Where is my order #1234?", "type": "text" } ], "type": "user.message", "processed_at": "2026-03-15T10:00:00Z" } ] } ```