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Streaming/Unary Data Management

This documentation describes how to interact with robot streams for real-time data retrieval or command transmission. These APIs allow users to manage streaming data and send commands to robots when they are online. All streaming operations are rate-limited to 1 second.

Get All Streams​

Endpoint​

GET /robot/{robotId}/streams

Description​

Retrieves a list of all available streams for a specific robot. This includes the component name, stream name, type, direction (input/output), and source type.

Response Fields​

  • ComponentName: The name of the robot component providing the stream.
  • StreamName: The name of the stream.
  • StreamType: The data type of the stream, such as pose, laser scan, or marker.
  • Direction: Indicates whether the stream is an input or output.
  • StreamSourceType: The type of the stream source.

Example Response​

{
    "RobotStreams": [
        {
            "ComponentName": "nimbus/realsense-d435",
            "StreamName": "tf_base_link_to_camera_depth_optical_frame",
            "StreamType": "Nimbus.Messages.geometry_msgs.Pose",
            "Direction": "output",
            "StreamSourceType": 1
        },
        {
            "ComponentName": "nimbus/ros2-legs-detector",
            "StreamName": "scan",
            "StreamType": "Nimbus.Messages.sensor_msgs.LaserScan",
            "Direction": "input",
            "StreamSourceType": 1
        },
        {
            "ComponentName": "nimbus/ros2-legs-detector",
            "StreamName": "legs_visualization_marker",
            "StreamType": "Nimbus.Messages.visualization_msgs.Marker",
            "Direction": "output",
            "StreamSourceType": 1
        }
    ]
}

Get Data from a Specific Stream​

Endpoint​

GET /robot/{robotId}/stream?componentName={ComponentName}&streamName={StreamName}&source={StreamSourceType}

Description​

Fetches data published on a specific stream for a robot. Only streams with an output direction can be accessed.

warning

Before calling this endpoint, use Get All Streams (GET /robot/{robotId}/streams) to retrieve the available streams for your robot. Use the ComponentName and StreamName values from that response as the query parameters here.

Query Parameters​

  • componentName: The name of the component providing the stream (obtained from Get All Streams).
  • streamName: The name of the stream (obtained from Get All Streams).
  • source: The type of the stream source.

Get Message Definition​

Endpoint​

GET /streams/{streamType}/stream

Description​

Retrieves the structure (schema) of the desired message based on its type. This is useful for understanding the expected format of data.

Example Response​


{
    "EmptyMessage": {
        "header": {
            "seq": 0,
            "stamp": "0",
            "frameId": "map"
        },
        "childFrameId": "base_link",
        "pose": {
            "pose": {
                "position": {
                    "x": 0,
                    "y": 0,
                    "z": 0.0
                },
                "orientation": {
                    "x": 0,
                    "y": 0,
                    "z": 0,
                    "w": 1
                }
            },
            "covariance": [
                0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
            ]
        },
        "twist": {
            "twist": {
                "linear": {
                    "x": 0,
                    "y": 0,
                    "z": 0
                },
                "angular": {
                    "x": 0,
                    "y": 0,
                    "z": 0
                }
            },
            "covariance": [
                0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
            ]
        }
    }
}

Post Data to a Specific Stream​

Endpoint​


POST /robot/{robotId}/streams/upload-stream

Description​

Posts JSON data to a specific stream. The stream must be active, and the operation has a timeout of 1 second.

Request Body​

  • componentname: The name of the component receiving the data.
  • streamname: The name of the target stream.
  • source: The type of the stream source.
  • streamjson: The JSON payload containing the data to be sent.
  • datatype: The data type of the stream (e.g., geometry_msgs.Point).

Example Request Body


{
    "componentname": "data-publisher",
    "streamname": "gps",
    "source": "1",
    "streamjson": {
        "x": "1",
        "y": "2",
        "z": "3"
    },
    "datatype": "Nimbus.Messages.geometry_msgs.Point"
}