> ## Documentation Index > Fetch the complete documentation index at: https://docs.opensink.com/llms.txt > Use this file to discover all available pages before exploring further. # Create Agent Session Activity > Create a new activity for a session Required scope: `agent_session_activities:write`, `agent_session_activities:all`, or `all:all` ## OpenAPI ````yaml api-reference/openapi.json post /api/v1/agent-session-activities openapi: 3.0.0 info: title: OpenSink API description: API documentation for OpenSink version: 1.0.0 servers: - url: https://api.opensink.com description: Production Server security: - bearerAuth: [] tags: - name: Sink description: Sink management endpoints - name: Sink Item description: Sink item endpoints - name: Cron Job description: Cron job scheduling endpoints - name: Cron Job Run description: Cron job execution history - name: Agent description: Agent management endpoints - name: Agent Config description: Agent configuration endpoints - name: Agent Session description: Agent session endpoints - name: Agent Session Input Request description: Agent session input request endpoints - name: Agent Session Activity description: Agent session activity log endpoints paths: /api/v1/agent-session-activities: post: tags: - Agent Session Activity summary: Create Agent Session Activity description: >- Create a new activity for a session Required scope: `agent_session_activities:write`, `agent_session_activities:all`, or `all:all` operationId: createAgentSessionActivity requestBody: content: application/json: schema: type: object properties: session_id: type: string format: uuid description: Parent session ID agent_id: type: string format: uuid description: Parent agent ID type: type: string enum: - session_started - session_ended - message - input_request_created - input_request_resolved - sink_item_created - state_updated description: Activity type source: type: string enum: - system - agent - user description: Activity source related_entity_id: type: string format: uuid nullable: true description: Related entity ID (e.g., input request ID, sink item ID) message: type: string nullable: true description: Human-readable message payload: type: object additionalProperties: true nullable: true description: Additional activity data links: type: array items: type: object properties: text: type: string description: Link text href: type: string format: uri description: Link URL required: - text - href description: Associated links required: - session_id - agent_id - type - source required: true responses: '200': description: An activity log entry for an agent session content: application/json: schema: type: object description: An activity log entry for an agent session properties: id: type: string format: uuid description: Unique identifier session_id: type: string format: uuid description: Parent session ID agent_id: type: string format: uuid description: Parent agent ID workspace_id: type: string format: uuid description: Workspace ID type: type: string enum: - session_started - session_ended - message - input_request_created - input_request_resolved - sink_item_created - state_updated description: Activity type source: type: string enum: - system - agent - user description: Activity source related_entity_id: type: string format: uuid nullable: true description: Related entity ID (e.g., input request ID, sink item ID) message: type: string nullable: true description: Human-readable message payload: type: object additionalProperties: true nullable: true description: Additional activity data links: type: array items: type: object properties: text: type: string description: Link text href: type: string format: uri description: Link URL required: - text - href description: Associated links created_at: type: string format: date-time description: Creation timestamp updated_at: type: string format: date-time description: Last update timestamp '201': description: An activity log entry for an agent session content: application/json: schema: type: object description: An activity log entry for an agent session properties: id: type: string format: uuid description: Unique identifier session_id: type: string format: uuid description: Parent session ID agent_id: type: string format: uuid description: Parent agent ID workspace_id: type: string format: uuid description: Workspace ID type: type: string enum: - session_started - session_ended - message - input_request_created - input_request_resolved - sink_item_created - state_updated description: Activity type source: type: string enum: - system - agent - user description: Activity source related_entity_id: type: string format: uuid nullable: true description: Related entity ID (e.g., input request ID, sink item ID) message: type: string nullable: true description: Human-readable message payload: type: object additionalProperties: true nullable: true description: Additional activity data links: type: array items: type: object properties: text: type: string description: Link text href: type: string format: uri description: Link URL required: - text - href description: Associated links created_at: type: string format: date-time description: Creation timestamp updated_at: type: string format: date-time description: Last update timestamp '400': description: Default Response content: application/json: schema: type: object properties: error: type: string example: Bad request '401': description: Default Response content: application/json: schema: type: object properties: error: type: string example: Unauthorized '403': description: Default Response content: application/json: schema: type: object properties: error: type: string example: Insufficient permissions components: securitySchemes: bearerAuth: type: http scheme: bearer description: API key authentication ````