> ## Documentation Index > Fetch the complete documentation index at: https://lemonslice.com/docs/llms.txt > Use this file to discover all available pages before exploring further. # Control self-managed session > Send a control event to an active session. ## OpenAPI ````yaml /openapi.json post /liveai/sessions/{session_id}/control openapi: 3.1.0 info: title: LemonSlice description: An API that gives access to a LemonSlice agent via a Daily room. license: name: MIT identifier: MIT version: 1.0.0 servers: - url: https://lemonslice.com/api security: - apiKeyAuth: [] paths: /liveai/sessions/{session_id}/control: post: summary: Control self-managed session description: Send a control event to an active session. operationId: controlSession parameters: - name: session_id in: path description: The ID of the session to control. required: true schema: type: string requestBody: required: true content: application/json: schema: oneOf: - $ref: '#/components/schemas/TerminateEvent' title: Terminate description: >- Immediately shuts down the LemonSlice avatar and removes it from the WebRTC room. - $ref: '#/components/schemas/UpdateImageEvent' title: Update Image description: >- Update the avatar's reference image. When possible, send this event while the avatar is not speaking (any audio currently playing will be cut off). The image changes takes <1 second. See our [Real-time Updates guide](/reference/realtime-updates) for more details. - $ref: '#/components/schemas/UpdateAgentPromptEvent' title: Update Agent Prompt description: >- A high-level system prompt that subtly influences the avatar's expressions while speaking. This prompt is best used to suggest general demeanor (for example, 'feel excited' or 'look sad') rather than precise or deterministic actions. - $ref: '#/components/schemas/UpdateIdlePromptEvent' title: Update Idle Prompt description: >- A high-level system prompt that subtly influences the avatar's expressions during the idle state. - $ref: '#/components/schemas/PoseTriggerEvent' title: Action Trigger description: Trigger a specific action sequence on the active avatar. - $ref: '#/components/schemas/ResetIdleTimeoutEvent' title: Reset Idle Timeout description: >- Resets the idle timeout timer on the session. Useful to keep the session alive when the user is still engaged but the avatar is not currently speaking. discriminator: propertyName: event mapping: update-image: $ref: '#/components/schemas/UpdateImageEvent' terminate: $ref: '#/components/schemas/TerminateEvent' update-agent-prompt: $ref: '#/components/schemas/UpdateAgentPromptEvent' update-idle-prompt: $ref: '#/components/schemas/UpdateIdlePromptEvent' pose-trigger: $ref: '#/components/schemas/PoseTriggerEvent' reset-idle-timeout: $ref: '#/components/schemas/ResetIdleTimeoutEvent' examples: terminate: summary: Terminate session value: event: terminate update_image: summary: Change the avatar image (URL) description: >- Update the avatar's reference image with an image hosted at a public URL. value: event: update-image image_url: https://example.com/avatar.jpg update_image_base64: summary: Change the avatar image (inline base64) description: >- Update the avatar's reference image by sending the new image bytes inline as base64. The decoded image must be under 900 KB. value: event: update-image image_base64: iVBORw0KGgoAAAANSUhEUgAA... update_agent_prompt: summary: Update the agent prompt (for speaking periods) description: Replace the agent prompt used when the avatar is speaking. value: event: update-agent-prompt agent_prompt: a person talking update_idle_prompt: summary: Update the idle prompt (for idle periods) description: Replace the idle prompt used when the avatar is idle. value: event: update-idle-prompt idle_prompt: a serious person pose_trigger: summary: Trigger an action description: Trigger the requested action. value: event: pose-trigger pose_trigger: name: reset_idle_timeout: summary: Reset the idle timeout description: Reset the idle timeout timer to keep the session alive. value: event: reset-idle-timeout responses: '200': description: Control event accepted. content: application/json: schema: type: object properties: success: type: boolean example: success: true '400': description: Invalid event or missing required fields content: application/json: schema: $ref: '#/components/schemas/Error' example: detail: image_url or image_base64 required for update-image event '404': description: Session not found content: application/json: schema: $ref: '#/components/schemas/Error' example: detail: Session not found '413': description: >- Inline image too large. The decoded `image_base64` payload must be under 900 KB; host larger images and pass `image_url` instead. content: application/json: schema: $ref: '#/components/schemas/Error' example: detail: >- image_base64 decodes to 1048576 bytes; inline images must be under 921600 bytes. Host larger images and pass image_url instead. '500': description: Unexpected error content: application/json: schema: $ref: '#/components/schemas/ServerError' security: [] components: schemas: TerminateEvent: type: object required: - event properties: event: type: string const: terminate default: terminate description: terminate UpdateImageEvent: type: object required: - event properties: event: type: string const: update-image default: update-image description: update-image image_url: type: string format: uri description: >- URL of the new avatar image. Must be publicly accessible. Provide exactly one of `image_url` or `image_base64`. example: https://example.com/avatar.jpg image_base64: type: string description: >- Base64-encoded bytes of the new avatar image. A data URL prefix (e.g. `data:image/png;base64,`) is also accepted. The decoded image must be under 900 KB — host larger images and pass `image_url` instead. Provide exactly one of `image_url` or `image_base64`. example: iVBORw0KGgoAAAANSUhEUgAA... UpdateAgentPromptEvent: type: object required: - event - agent_prompt properties: event: type: string const: update-agent-prompt default: update-agent-prompt description: update-agent-prompt agent_prompt: type: string description: >- A high-level system prompt that subtly influences the avatar's expressions while speaking. example: a person talking UpdateIdlePromptEvent: type: object required: - event - idle_prompt properties: event: type: string const: update-idle-prompt default: update-idle-prompt description: update-idle-prompt idle_prompt: type: string description: >- A high-level system prompt that subtly influences the avatar's expressions during the idle state. example: a serious person PoseTriggerEvent: type: object required: - event - pose_trigger properties: event: type: string const: pose-trigger default: pose-trigger description: pose-trigger pose_trigger: type: object required: - name properties: name: type: string description: Name of action to trigger. example: wave ResetIdleTimeoutEvent: type: object required: - event properties: event: type: string const: reset-idle-timeout default: reset-idle-timeout description: reset-idle-timeout Error: type: object properties: detail: type: string ServerError: type: object properties: detail: type: string securitySchemes: apiKeyAuth: type: apiKey in: header name: X-API-Key description: Your LemonSlice API token. ````