> This page is for Expression Measurement. > For clean Markdown of any page, append .md to the page URL. > For a complete documentation index, see https://dev.hume.ai/llms.txt. > For AI client integration (Claude Code, Cursor, etc.), connect to the MCP server at https://dev.hume.ai/_mcp/server. # Stream images GET /v1/expression/video/realtime Stream JPEG frames from a camera or a video and receive, for each frame, the faces detected in it and their expression measurements. ## Sending frames Send each frame as one binary message containing a complete JPEG. Every frame gets exactly one reply: a `measurement.result`, or an `error`. - **Configuration:** send `session.update` before your first frame. A `session.update` after your first frame ends the session with `config_invalid`. - **Rejected frames:** a frame that is empty, is not a JPEG, or is over the pixel limit gets `invalid_image_frame`. A frame over 2MB ends the session with `message_too_large`. - **Send rate:** send frames as they are captured or played, up to 3 per second. A frame sent faster can get `rate_limited` and is not measured. From a live camera, drop it and send the next frame; from a recording, wait briefly and resend it. To measure a recorded video faster than it plays, send its frames to the video file endpoint. - **Under load:** replies slow down; a frame within the send rate is never rejected because the server is busy. - **Failures:** a frame whose measurement fails gets `internal_error`; resend it if you need its result. Five failures in a row end the session. ## Matching results to frames Replies arrive in the order you sent the frames, so pair them by position. - Keep a queue of the frames you have sent. Remove the oldest for each `measurement.result`, and for each `error` with code `invalid_image_frame`, `rate_limited` or `internal_error`. - Other errors do not consume a frame: they answer a JSON message you sent, or end the session. - Frames sent before `session.close` receive their replies before `session.closed`. - `frame_id` counts results, not frames. It does not advance for a frame that received an `error`, so do not use it as an index into your own frames. ## Detection and measurement The server detects the faces in each frame and lists them in `faces`. It measures the largest of them, up to the limit below, and lists those first, largest first. - A face is skipped, and is not listed, if its detection confidence is below `face.threshold` or its bounding box is under `face.min_size` pixels on its shorter side. - Each measured face carries its bounding box, its detection confidence, a `face_id`, and two sets of scores: `expressions` for emotional expressions such as amusement or interest, and `descriptions` for visible facial actions such as a smile or a jaw drop. - The faces that were not measured follow, most confident first, up to 32 faces in all. Each carries its bounding box and detection confidence, with `face_id`, `expressions` and `descriptions` null. - A frame with no faces is a normal result: a `measurement.result` with an empty `faces` array. - `face_id` tracks a face across frames in the session. A face normally keeps its ID while it is measured, and can get it back after it leaves the view or is no longer among the largest faces. IDs restart in every session and do not identify a person. ## Limits | Limit | Value | |---|---| | Message size | 2MB | | Pixels per frame | 8,294,400 (the area of a 3840x2160 image) | | Send rate | 3 frames per second | | Faces measured per frame | 2 by default, the largest; contact support to raise it | | Faces listed per frame | 32 | | Consecutive measurement failures | 5, after which the session ends | ## Message flow A session of four frames, the third a PNG sent by mistake. The rejected frame gets no `frame_id`, so the last result is `frame_id` 2. In `session.closed`, `received.frames` counts only the 3 frames accepted for measurement, and `produced.measurements` counts faces, so it is 4. | Direction | Message | |---|---| | receive | `session.created` | | send | `session.update` (if you change the configuration) | | receive | `session.updated` (if you sent `session.update`) | | send | frame | | receive | `measurement.result` (`frame_id` 0, face 0) | | send | frame | | receive | `measurement.result` (`frame_id` 1, faces 0 and 1) | | send | frame (a PNG, not a JPEG) | | receive | `error` (`invalid_image_frame`) | | send | frame | | receive | `measurement.result` (`frame_id` 2, face 1) | | send | `session.close` | | receive | `session.closed` (`received.frames` 3, `produced.measurements` 4) | Reference: https://dev.hume.ai/expression-measurement/reference/video/stream-images ## AsyncAPI Specification ```yaml asyncapi: 2.6.0 info: title: Stream images version: subpackage_video.Stream images description: >- Stream JPEG frames from a camera or a video and receive, for each frame, the faces detected in it and their expression measurements. ## Sending frames Send each frame as one binary message containing a complete JPEG. Every frame gets exactly one reply: a `measurement.result`, or an `error`. - **Configuration:** send `session.update` before your first frame. A `session.update` after your first frame ends the session with `config_invalid`. - **Rejected frames:** a frame that is empty, is not a JPEG, or is over the pixel limit gets `invalid_image_frame`. A frame over 2MB ends the session with `message_too_large`. - **Send rate:** send frames as they are captured or played, up to 3 per second. A frame sent faster can get `rate_limited` and is not measured. From a live camera, drop it and send the next frame; from a recording, wait briefly and resend it. To measure a recorded video faster than it plays, send its frames to the video file endpoint. - **Under load:** replies slow down; a frame within the send rate is never rejected because the server is busy. - **Failures:** a frame whose measurement fails gets `internal_error`; resend it if you need its result. Five failures in a row end the session. ## Matching results to frames Replies arrive in the order you sent the frames, so pair them by position. - Keep a queue of the frames you have sent. Remove the oldest for each `measurement.result`, and for each `error` with code `invalid_image_frame`, `rate_limited` or `internal_error`. - Other errors do not consume a frame: they answer a JSON message you sent, or end the session. - Frames sent before `session.close` receive their replies before `session.closed`. - `frame_id` counts results, not frames. It does not advance for a frame that received an `error`, so do not use it as an index into your own frames. ## Detection and measurement The server detects the faces in each frame and lists them in `faces`. It measures the largest of them, up to the limit below, and lists those first, largest first. - A face is skipped, and is not listed, if its detection confidence is below `face.threshold` or its bounding box is under `face.min_size` pixels on its shorter side. - Each measured face carries its bounding box, its detection confidence, a `face_id`, and two sets of scores: `expressions` for emotional expressions such as amusement or interest, and `descriptions` for visible facial actions such as a smile or a jaw drop. - The faces that were not measured follow, most confident first, up to 32 faces in all. Each carries its bounding box and detection confidence, with `face_id`, `expressions` and `descriptions` null. - A frame with no faces is a normal result: a `measurement.result` with an empty `faces` array. - `face_id` tracks a face across frames in the session. A face normally keeps its ID while it is measured, and can get it back after it leaves the view or is no longer among the largest faces. IDs restart in every session and do not identify a person. ## Limits | Limit | Value | |---|---| | Message size | 2MB | | Pixels per frame | 8,294,400 (the area of a 3840x2160 image) | | Send rate | 3 frames per second | | Faces measured per frame | 2 by default, the largest; contact support to raise it | | Faces listed per frame | 32 | | Consecutive measurement failures | 5, after which the session ends | ## Message flow A session of four frames, the third a PNG sent by mistake. The rejected frame gets no `frame_id`, so the last result is `frame_id` 2. In `session.closed`, `received.frames` counts only the 3 frames accepted for measurement, and `produced.measurements` counts faces, so it is 4. | Direction | Message | |---|---| | receive | `session.created` | | send | `session.update` (if you change the configuration) | | receive | `session.updated` (if you sent `session.update`) | | send | frame | | receive | `measurement.result` (`frame_id` 0, face 0) | | send | frame | | receive | `measurement.result` (`frame_id` 1, faces 0 and 1) | | send | frame (a PNG, not a JPEG) | | receive | `error` (`invalid_image_frame`) | | send | frame | | receive | `measurement.result` (`frame_id` 2, face 1) | | send | `session.close` | | receive | `session.closed` (`received.frames` 3, `produced.measurements` 4) | channels: /v1/expression/video/realtime: description: >- Stream JPEG frames from a camera or a video and receive, for each frame, the faces detected in it and their expression measurements. ## Sending frames Send each frame as one binary message containing a complete JPEG. Every frame gets exactly one reply: a `measurement.result`, or an `error`. - **Configuration:** send `session.update` before your first frame. A `session.update` after your first frame ends the session with `config_invalid`. - **Rejected frames:** a frame that is empty, is not a JPEG, or is over the pixel limit gets `invalid_image_frame`. A frame over 2MB ends the session with `message_too_large`. - **Send rate:** send frames as they are captured or played, up to 3 per second. A frame sent faster can get `rate_limited` and is not measured. From a live camera, drop it and send the next frame; from a recording, wait briefly and resend it. To measure a recorded video faster than it plays, send its frames to the video file endpoint. - **Under load:** replies slow down; a frame within the send rate is never rejected because the server is busy. - **Failures:** a frame whose measurement fails gets `internal_error`; resend it if you need its result. Five failures in a row end the session. ## Matching results to frames Replies arrive in the order you sent the frames, so pair them by position. - Keep a queue of the frames you have sent. Remove the oldest for each `measurement.result`, and for each `error` with code `invalid_image_frame`, `rate_limited` or `internal_error`. - Other errors do not consume a frame: they answer a JSON message you sent, or end the session. - Frames sent before `session.close` receive their replies before `session.closed`. - `frame_id` counts results, not frames. It does not advance for a frame that received an `error`, so do not use it as an index into your own frames. ## Detection and measurement The server detects the faces in each frame and lists them in `faces`. It measures the largest of them, up to the limit below, and lists those first, largest first. - A face is skipped, and is not listed, if its detection confidence is below `face.threshold` or its bounding box is under `face.min_size` pixels on its shorter side. - Each measured face carries its bounding box, its detection confidence, a `face_id`, and two sets of scores: `expressions` for emotional expressions such as amusement or interest, and `descriptions` for visible facial actions such as a smile or a jaw drop. - The faces that were not measured follow, most confident first, up to 32 faces in all. Each carries its bounding box and detection confidence, with `face_id`, `expressions` and `descriptions` null. - A frame with no faces is a normal result: a `measurement.result` with an empty `faces` array. - `face_id` tracks a face across frames in the session. A face normally keeps its ID while it is measured, and can get it back after it leaves the view or is no longer among the largest faces. IDs restart in every session and do not identify a person. ## Limits | Limit | Value | |---|---| | Message size | 2MB | | Pixels per frame | 8,294,400 (the area of a 3840x2160 image) | | Send rate | 3 frames per second | | Faces measured per frame | 2 by default, the largest; contact support to raise it | | Faces listed per frame | 32 | | Consecutive measurement failures | 5, after which the session ends | ## Message flow A session of four frames, the third a PNG sent by mistake. The rejected frame gets no `frame_id`, so the last result is `frame_id` 2. In `session.closed`, `received.frames` counts only the 3 frames accepted for measurement, and `produced.measurements` counts faces, so it is 4. | Direction | Message | |---|---| | receive | `session.created` | | send | `session.update` (if you change the configuration) | | receive | `session.updated` (if you sent `session.update`) | | send | frame | | receive | `measurement.result` (`frame_id` 0, face 0) | | send | frame | | receive | `measurement.result` (`frame_id` 1, faces 0 and 1) | | send | frame (a PNG, not a JPEG) | | receive | `error` (`invalid_image_frame`) | | send | frame | | receive | `measurement.result` (`frame_id` 2, face 1) | | send | `session.close` | | receive | `session.closed` (`received.frames` 3, `produced.measurements` 4) | publish: operationId: subpackage_video.Stream images-publish summary: Server messages message: oneOf: - $ref: >- #/components/messages/subpackage_video.Stream images-server-0-videoReceiveSessionCreated - $ref: >- #/components/messages/subpackage_video.Stream images-server-1-videoReceiveSessionUpdated - $ref: >- #/components/messages/subpackage_video.Stream images-server-2-videoReceiveMeasurementResult - $ref: >- #/components/messages/subpackage_video.Stream images-server-3-videoReceiveError - $ref: >- #/components/messages/subpackage_video.Stream images-server-4-videoReceiveSessionClosed subscribe: operationId: subpackage_video.Stream images-subscribe summary: Client messages message: oneOf: - $ref: >- #/components/messages/subpackage_video.Stream images-client-0-videoSendSessionUpdate - $ref: >- #/components/messages/subpackage_video.Stream images-client-1-videoSendSessionClose - $ref: >- #/components/messages/subpackage_video.Stream images-client-2-videoSendImageFrame servers: Production: url: wss://api.cloud.hume.ai/ protocol: wss x-default: true components: messages: subpackage_video.Stream images-server-0-videoReceiveSessionCreated: name: videoReceiveSessionCreated title: session.created description: >- Sent when the connection opens, before you send anything. Carries the session ID and the default configuration, which stays in effect unless you change it with `session.update`. payload: $ref: '#/components/schemas/video_sessionCreated' subpackage_video.Stream images-server-1-videoReceiveSessionUpdated: name: videoReceiveSessionUpdated title: session.updated description: >- Sent when a `session.update` is accepted. Carries the full configuration now in effect, including defaults for any fields you omitted. payload: $ref: '#/components/schemas/video_sessionUpdated' subpackage_video.Stream images-server-2-videoReceiveMeasurementResult: name: videoReceiveMeasurementResult title: measurement.result description: >- Sent once for every frame that was measured, in the order you sent the frames, including frames in which no face was found. payload: $ref: '#/components/schemas/video_measurementResult' subpackage_video.Stream images-server-3-videoReceiveError: name: videoReceiveError title: error description: >- Sent when a message you sent is rejected or the server fails to process it. For a recoverable error the message is rejected and the session continues; for a session-ending error, `session.closed` with `reason` `error` follows. `ErrorCode` lists each code, its class, and what to do. payload: $ref: '#/components/schemas/video_error' subpackage_video.Stream images-server-4-videoReceiveSessionClosed: name: videoReceiveSessionClosed title: session.closed description: >- Sent as the last message of the session. Carries the reason the session ended and totals of what was received and produced. The connection closes immediately after it, with the close code for the `reason`. payload: $ref: '#/components/schemas/video_sessionClosed' subpackage_video.Stream images-client-0-videoSendSessionUpdate: name: videoSendSessionUpdate title: session.update description: >- Replaces the whole configuration; any field you omit returns to its default. Send it before your first frame, because once a frame has passed the rate check, whether or not it decoded, a `session.update` ends the session with `config_invalid`. The server confirms with `session.updated`, or ends the session with `config_invalid` if the message contains an unrecognized field or an unsupported value. payload: $ref: '#/components/schemas/video_sessionUpdate' subpackage_video.Stream images-client-1-videoSendSessionClose: name: videoSendSessionClose title: session.close description: >- Ends the session. The server sends any final results, then `session.closed`, and closes the connection with code 1000; on the audio endpoint, if the final measurement fails, `error` and `session.closed` with `reason` `error` follow instead. Prefer this to closing the WebSocket yourself, which ends the session immediately and discards any final results and the totals. payload: $ref: '#/components/schemas/video_sessionClose' subpackage_video.Stream images-client-2-videoSendImageFrame: name: videoSendImageFrame title: image frame description: >- A binary message containing one complete JPEG image. The server detects the faces in it and answers with one `measurement.result`, or with an `error` if the frame is rejected or its measurement fails. Frames rejected with `invalid_image_frame` or `rate_limited` are skipped and the session continues; a message over the size limit ends the session with `message_too_large`. payload: $ref: '#/components/schemas/video_imageFrame' schemas: SessionId: type: string format: uuid description: >- Unique identifier for the session. It is also the `run_id` of the run the session is recorded as. Include it when contacting support about a session. title: SessionId ImageConfig: type: object properties: type: type: string enum: - image/jpeg required: - type description: The image format. title: ImageConfig FaceConfig: type: object properties: threshold: type: number format: double minimum: 0 maximum: 1 description: >- Minimum detection confidence for a face to be measured. Lower values include more faces at the risk of false detections. This scale is specific to this API; thresholds tuned for other face detection APIs do not carry over. Reported rounded to four decimal places. min_size: type: integer minimum: 1 maximum: 4294967295 description: >- Minimum face size to measure, as the shorter side of the face's bounding box in pixels of the submitted image. required: - threshold - min_size description: The face detection settings. title: FaceConfig video_sessionCreated: type: object properties: type: type: string enum: - session.created session_id: $ref: '#/components/schemas/SessionId' image: $ref: '#/components/schemas/ImageConfig' face: $ref: '#/components/schemas/FaceConfig' required: - type - session_id - image - face description: >- The session ID and the configuration in effect when the connection opened. title: video_sessionCreated video_sessionUpdated: type: object properties: type: type: string enum: - session.updated image: $ref: '#/components/schemas/ImageConfig' face: $ref: '#/components/schemas/FaceConfig' required: - type - image - face description: >- The full configuration in effect after a `session.update`, including defaults for any fields you omitted. title: video_sessionUpdated BoundingBox: type: array items: type: number format: double description: >- The location of the face in the submitted image, as `[x0, y0, x1, y1]`: the top-left and bottom-right corners in pixels, with the origin at the top-left of the image. Coordinates are in the pixels as stored in the file: EXIF orientation is not applied. title: BoundingBox VideoExpressionName: type: string description: >- The name of an expression that can be detected on a face, from a vocabulary that differs from that of audio expressions; see the [full list of video expressions](/expression-measurement/docs/video/measurements#expressions). Names are lowercase and may contain spaces and punctuation. New names may be added over time; treat a name you do not recognize as a new prediction. title: VideoExpressionName VideoExpressionScore: type: object properties: name: $ref: '#/components/schemas/VideoExpressionName' probability: type: number format: double minimum: 0 maximum: 1 description: >- The probability that this expression is present, rounded to four decimal places. required: - name - probability description: A scored expression detected on the face. title: VideoExpressionScore VideoDescriptionName: type: string description: >- The name of a visible facial action; see the [full list of video descriptions](/expression-measurement/docs/video/measurements#descriptions). Names are lowercase and may contain spaces and punctuation. New names may be added over time; treat a name you do not recognize as a new prediction. title: VideoDescriptionName VideoDescriptionScore: type: object properties: name: $ref: '#/components/schemas/VideoDescriptionName' probability: type: number format: double minimum: 0 maximum: 1 description: >- The probability that this action is present, rounded to four decimal places. required: - name - probability description: A scored facial action. title: VideoDescriptionScore Face: type: object properties: face_id: type: - integer - 'null' minimum: 0 description: >- Tracks this face across the images of a realtime session or a file request. IDs are assigned from 0 in the order faces are first measured, largest first within an image. A face normally keeps its ID while it is measured, and can get it back after it leaves the view or is no longer among the largest faces. The server remembers up to 32 faces, so a face that returns after many others have been measured may receive a new ID. IDs restart in every session and every file request, unless a file request continues them with a `face_state`, and do not identify a person. Null for a face that was not measured. bbox: $ref: '#/components/schemas/BoundingBox' confidence: type: number format: double minimum: 0 maximum: 1 description: >- Confidence that the bounding box contains a face. Always at or above the configured `threshold`. Unrelated to the expression scores. expressions: type: - array - 'null' items: $ref: '#/components/schemas/VideoExpressionScore' description: >- Expressions detected on the face, such as `amusement`, `interest` and `surprise (positive)`, in descending order of probability, then by name. Only scores above 0.1 are included, so the array may be empty. `probability` is the chance a human rater would name the expression for this face, independently for each expression. Null for a face that was not measured. descriptions: type: - array - 'null' items: $ref: '#/components/schemas/VideoDescriptionScore' description: >- Visible facial actions, such as `smile`, `jaw drop` and `wide-eyed`, in descending order of probability, then by name. Only scores above 0.1 are included, so the array may be empty. Null for a face that was not measured. required: - face_id - bbox - confidence - expressions - descriptions description: >- A face detected in the image, with its expression measurements if it was measured. Only the largest faces in an image are measured; the others carry their bounding box and detection confidence, with `face_id`, `expressions` and `descriptions` null. title: Face video_measurementResult: type: object properties: type: type: string enum: - measurement.result frame_id: type: integer minimum: 0 description: >- Sequential identifier of the frame within the session, starting at 0. Only frames answered with a `measurement.result` receive an ID, so the Nth result is for the Nth frame that was not answered with an `error`. faces: type: array items: $ref: '#/components/schemas/Face' description: >- The faces detected in the frame: the measured faces first, largest first, then the faces that were not measured, in descending order of confidence. required: - type - frame_id - faces description: >- Expression measurements for every face in one frame. `faces` is empty when no face was detected; this is a normal result, not an error. title: video_measurementResult ErrorCode: type: string enum: - invalid_audio_frame - invalid_image_frame - message_invalid - rate_limited - config_invalid - message_too_large - internal_error description: >- Identifies what went wrong and whether the session continues. **Recoverable.** The message is rejected and the session continues. - `invalid_audio_frame`: the audio frame was empty, had an odd number of bytes, or held more than 10 seconds of audio. Check how you slice audio and keep sending. Audio only. - `invalid_image_frame`: the frame was empty, was not a JPEG, or exceeded the pixel limit. Check the image and keep sending. Video only. - `message_invalid`: a text message was not valid JSON, had no `type`, or had an unrecognized `type`. Correct the message and keep sending. - `rate_limited`: media arrived faster than the send rate and was not processed. Audio: wait briefly and send the same frame again, so that the stream stays continuous. Video: from a live camera, drop the frame and send the next; from a recording, wait briefly and send the same frame again. **Depends on the endpoint.** - `internal_error`: the server failed while processing media. Audio: the session ends as for a session-ending error; open a new connection. Video: the frame is skipped and the session continues; resend it if you need a result for it. Five consecutive failures end the session; frames that are rejected or have no faces to measure do not reset the count. **Session-ending.** `error` is followed by `session.closed` with `reason` `error`, and the connection closes with code 1008. - `config_invalid`: a `session.update` contained an unrecognized field or an unsupported value, or arrived after you started sending media. Correct the message and open a new connection. - `message_too_large`: a message exceeded the size limit. Reduce the frame size and open a new connection. title: ErrorCode video_error: type: object properties: type: type: string enum: - error code: $ref: '#/components/schemas/ErrorCode' message: type: string description: >- A human-readable description of the error, intended for logging and debugging. The wording may change; use `code` for programmatic handling. retryable: type: boolean description: >- `false` for every error that ends the session. `true` for every error the session survives, except `internal_error` on the video endpoint, where it reports whether the failure was temporary and the frame is worth resending. required: - type - code - message - retryable description: >- A rejected message or a processing failure. `code` says what happened and whether the session continues. title: video_error CloseReason: type: string enum: - client_request - server_shutdown - idle_timeout - error description: >- Why the session ended. `session.closed` is the last message, and the WebSocket close code that follows it depends on the reason. - `client_request`: you sent `session.close`. Close code 1000. - `server_shutdown`: the server is restarting; reconnect at once to start a new session. Close code 1012. - `idle_timeout`: the server received no media frame it could use for 30 seconds; open a new session to continue. Close code 1000. - `error`: a session-ending error, reported in the preceding `error` message. Close code 1008. title: CloseReason VideoReceived: type: object properties: frames: type: integer minimum: 0 description: >- Number of frames accepted for measurement. Frames rejected before detection are not counted, so comparing this with the number you sent tells you how many were rejected. A frame whose measurement then failed with `internal_error` is counted although it produced no result, so this can exceed the number of results you received. required: - frames description: What the server received during the session. title: VideoReceived VideoProduced: type: object properties: measurements: type: integer minimum: 0 description: >- Number of faces measured across all frames: a frame with two measured faces counts as two, and a frame with none counts as zero. A face listed without measurements is not counted. This counts faces; the audio endpoint's field of the same name counts messages. required: - measurements description: What the server produced during the session. title: VideoProduced video_sessionClosed: type: object properties: type: type: string enum: - session.closed session_id: $ref: '#/components/schemas/SessionId' reason: $ref: '#/components/schemas/CloseReason' received: $ref: '#/components/schemas/VideoReceived' produced: $ref: '#/components/schemas/VideoProduced' required: - type - session_id - reason - received - produced description: Why the session ended, and totals of what was received and produced. title: video_sessionClosed ImageConfigUpdate: type: object properties: type: type: string enum: - image/jpeg default: image/jpeg description: >- The format of the frames you send. Only one format is supported; any other value is rejected with `config_invalid`. title: ImageConfigUpdate FaceConfigUpdate: type: object properties: threshold: type: number format: double minimum: 0 maximum: 1 default: 0.9 description: >- Minimum detection confidence for a face to be measured. Lower values include more faces at the risk of false detections. This scale is specific to this API; thresholds tuned for other face detection APIs do not carry over. min_size: type: integer minimum: 1 maximum: 4294967295 default: 60 description: >- Minimum face size to measure, as the shorter side of the face's bounding box in pixels of the submitted image. description: The face detection settings to apply. title: FaceConfigUpdate video_sessionUpdate: type: object properties: type: type: string enum: - session.update image: $ref: '#/components/schemas/ImageConfigUpdate' face: $ref: '#/components/schemas/FaceConfigUpdate' required: - type description: >- The configuration to apply to the session. Omitted fields are reset to their defaults. title: video_sessionUpdate video_sessionClose: type: object properties: type: type: string enum: - session.close required: - type description: A request to end the session. title: video_sessionClose video_imageFrame: type: string format: binary description: >- One complete JPEG image, within the size and pixel limits given in the channel description. title: video_imageFrame ```