# JSON-schema template

Here's an example of a JSON structure describing a complete flow.

### Flow object model

## The Flow object

```json
{"openapi":"3.1.0","info":{"title":"Navixy IoT Logic API","version":"1.0.0"},"components":{"schemas":{"Flow":{"type":"object","description":"Flowchart object","allOf":[{"$ref":"#/components/schemas/FlowId"},{"$ref":"#/components/schemas/FlowDraft"}]},"FlowId":{"type":"object","required":["id"],"properties":{"id":{"type":"integer","description":"Flow ID","readOnly":true}}},"FlowDraft":{"type":"object","description":"Flow object used with the create and update API endpoints. When calling these endpoints, this object must be nested inside a \"flow\" envelope key: {\"flow\": <FlowDraft>}. Includes runtime settings (enabled, default_flow). For a portable export/import format that omits runtime fields and is passed directly without an envelope, see FlowExport.","properties":{"title":{"type":"string","description":"Flow name"},"description":{"type":["string","null"],"description":"Flow description (optional)","readOnly":true},"enabled":{"type":"boolean","description":"Enable/disable flag"},"default_flow":{"type":"boolean","description":"Whether this is the default flow","readOnly":true},"nodes":{"type":"array","items":{"$ref":"#/components/schemas/Node"}},"edges":{"type":"array","items":{"$ref":"#/components/schemas/Edge"}}},"required":["title"]},"Node":{"type":"object","description":"Flowchart Node","oneOf":[{"$ref":"#/components/schemas/NodeDataSource"},{"$ref":"#/components/schemas/NodeInitiateAttributes"},{"$ref":"#/components/schemas/NodeLogic"},{"$ref":"#/components/schemas/NodeAction"},{"$ref":"#/components/schemas/NodeWebhook"},{"$ref":"#/components/schemas/NodeOutputEndpoint"}]},"NodeDataSource":{"type":"object","description":"Node: Data Source","properties":{"id":{"$ref":"#/components/schemas/NodeID"},"type":{"type":"string","description":"Node type. Always \"data_source\"."},"data":{"type":"object","properties":{"title":{"type":"string"},"source_ids":{"type":["array","null"],"items":{"type":"integer","description":"Source ID"},"description":"Array of device/source IDs. Use null or empty array [] for all sources. Note: API normalizes null to empty array [] in responses."}}},"view":{"$ref":"#/components/schemas/NodeView"}},"required":["type","data"]},"NodeID":{"type":"integer","description":"Node ID inside current flow"},"NodeView":{"type":"object","description":"Flowchart Node view properties","properties":{"position":{"type":"object","description":"Position of the left top corner","properties":{"x":{"type":"integer"},"y":{"type":"integer"}}}}},"NodeInitiateAttributes":{"type":"object","description":"Node: Initiate Attributes. Transforms device data by creating new calculated attributes based on incoming telemetry. Enables data enrichment through mathematical operations, unit conversions, bit-level manipulations, and time-based calculations using Navixy IoT Logic Expression Language (based on JEXL). Developers can consult the official JEXL specification for expression syntax and operators. Calculated attributes become available to all downstream nodes and can be displayed in Data Stream Analyzer or configured as custom sensors in Navixy tracking interface when connected to default output endpoint.","properties":{"id":{"$ref":"#/components/schemas/NodeID"},"type":{"type":"string","description":"Node type. Always \"initiate_attributes\"."},"data":{"type":"object","properties":{"title":{"type":"string","description":"Node title identifying the transformation purpose."},"items":{"type":"array","description":"List of attributes to calculate. Attributes are processed sequentially in the order defined. Each attribute can reference original device parameters and previously calculated attributes within the same node.","items":{"type":"object","properties":{"name":{"type":"string","description":"Unique attribute identifier. This name appears in Data Stream Analyzer and can be used to create custom sensors in Navixy tracking interface. If attribute name matches existing device parameter, the calculated value replaces the original in output data packets."},"value":{"type":"string","description":"JEXL-based expression to calculate attribute value. Can reference device parameters using direct syntax (e.g., 'temperature') or value() function (e.g., value('temperature', 0, 'valid')). Supports standard JEXL operators and mathematical operations, historical value access (via index parameter), and Navixy-specific bit-level operations through util: namespace functions. Consult JEXL specification for expression syntax details. Expression errors result in null values."},"generation_time":{"type":["string","null"],"description":"JEXL-based expression for device-side generation timestamp (when data was created on device). Defaults to now() if null or not specified. Use genTime() function to reference original parameter timestamps."},"server_time":{"type":["string","null"],"description":"JEXL-based expression for server-side reception timestamp (when data was received by IoT Logic). Defaults to now() if null or not specified. Use srvTime() function to reference original parameter timestamps."}},"required":["name","value"]}}}},"view":{"$ref":"#/components/schemas/NodeView"}},"required":["type","data"]},"NodeLogic":{"type":"object","description":"Node: Logic. Creates conditional branching points that route data based on boolean expressions. Logic nodes evaluate incoming data against user-defined conditions and direct data flow through THEN (true) or ELSE (false) output paths. The node creates a boolean attribute that stores evaluation results and can be used in subsequent nodes or Navixy monitoring systems. Logic nodes support multiple outgoing connections on both THEN and ELSE branches. When a THEN target is a terminal node (Action, Webhook), add a second then_edge from this Logic node directly to the Output Endpoint to ensure data is still forwarded to Navixy, both edges fire in parallel.","properties":{"id":{"$ref":"#/components/schemas/NodeID"},"type":{"type":"string","description":"Node type. Always \"logic\"."},"data":{"type":"object","properties":{"title":{"type":"string"},"name":{"type":"string","description":"Internal identifier for the logic node"},"condition":{"type":"string","description":"Boolean expression evaluated for each incoming message. Must return true or false. Expression can reference attributes from connected upstream nodes using direct attribute syntax or value() function. Supports logical operators (&&, ||, !), comparison operators (<, >, <=, >=, ==, !=), and complex conditions. If expression cannot be evaluated (null values, syntax errors, missing attributes), result is treated as false and data flows through ELSE path."}},"required":["title","name","condition"]},"view":{"$ref":"#/components/schemas/NodeView"}},"required":["type","data"]},"NodeAction":{"description":"Node: Device action. Executes automated device commands when triggered by incoming data. Enables direct device control through output switching and GPRS command transmission. By default, commands are sent to the device that triggered the node. Use device_mapping to redirect commands to other target devices instead. Functions as a terminal node that cannot have outgoing connections.","type":"object","required":["type","data"],"properties":{"id":{"$ref":"#/components/schemas/NodeID"},"type":{"type":"string","description":"Node type. Always \"action\"."},"data":{"type":"object","properties":{"title":{"type":"string"},"actions":{"type":["array","null"],"description":"List of actions to execute sequentially when node is triggered. Actions execute in order from first to last. Maximum 10 actions per node. Commands are sent to the trigger device by default, or to target devices specified in device_mapping.","items":{"oneOf":[{"$ref":"#/components/schemas/SetOutput"},{"$ref":"#/components/schemas/SendCommand"}]},"maxItems":10,"uniqueItems":true},"device_mapping":{"type":["array","null"],"description":"Optional cross-device command routing. Maps source devices to target devices that will receive the actions instead of the source device. If null or empty, actions are sent to the device that triggered the node.","uniqueItems":true,"items":{"$ref":"#/components/schemas/DeviceMapping"}}}},"view":{"$ref":"#/components/schemas/NodeView"}}},"SetOutput":{"type":"object","title":"SetOutput","description":"Switches a device output port to the specified on/off state.","required":["type","number","value"],"properties":{"type":{"type":"string","enum":["set_output"],"description":"Action type. Must be 'set_output'."},"number":{"type":"integer","minimum":1,"maximum":8,"description":"Output number as seen in UI."},"value":{"type":"boolean","description":"The state to set to."}}},"SendCommand":{"type":"object","title":"SendCommand","description":"Sends a custom GPRS command string to the device. Use for device-specific commands as documented by the device manufacturer.","required":["type","command"],"properties":{"type":{"type":"string","enum":["send_gprs_command"],"description":"Action type. Must be 'send_gprs_command'."},"command":{"type":"string","minLength":1,"maxLength":512,"description":"A custom command to send to the device. Consult its documentation for details."},"reliable":{"type":["boolean","null"],"default":true,"description":"Reliable commands will be retried in case if a tracker is not online at the moment."}}},"DeviceMapping":{"type":"object","description":"Maps a source device to one or more target devices for cross-device command routing. When a source device triggers the node, actions are sent to the specified target devices instead.","required":["source_id","target_source_ids"],"properties":{"source_id":{"type":"integer","description":"ID of the source device that triggers the routing rule."},"target_source_ids":{"type":"array","description":"IDs of the target devices that will receive the actions when the source device triggers the node.","minItems":1,"items":{"type":"integer"}}}},"NodeWebhook":{"type":"object","description":"Node: Webhook. Sends HTTP POST requests with IoT data to external endpoints, enabling real-time integration with third-party systems and APIs. Webhook nodes function as terminal nodes that cannot have outgoing connections to other nodes in the flow.","properties":{"id":{"$ref":"#/components/schemas/NodeID"},"type":{"type":"string","description":"Node type. Always \"webhook\"."},"data":{"type":"object","properties":{"title":{"type":"string","description":"Webhook node title.","maxLength":255},"url":{"type":"string","description":"Target URL for HTTP POST requests. Must use http:// or https:// protocol (HTTPS recommended). Executes fire-and-forget POST request on each incoming message without waiting for response or retrying on failure.","maxLength":255,"pattern":"^https?:\\/\\/\\S+$"},"headers":{"type":["array","null"],"description":"Optional HTTP headers for POST requests. All headers including Content-Type must be explicitly specified. Maximum 10 headers.","maxItems":10,"items":{"type":"object","required":["key","value"],"properties":{"key":{"type":"string","description":"Header name.","maxLength":255},"value":{"type":"string","description":"Header value (static only).","maxLength":255}}}},"body":{"type":["string","null"],"description":"Optional request body template. Use \"attribute_name\" syntax to reference attributes from upstream nodes. Supports nested paths (e.g., \"location.latitude\"). Direct attribute references only; expressions not supported. Null attributes send null values.","maxLength":4000}},"required":["title","url"]},"view":{"$ref":"#/components/schemas/NodeView"}},"required":["type","data"]},"NodeOutputEndpoint":{"type":"object","description":"Node: output endpoint. This is the terminating node for any flow. It determines where the messages will be sent.","properties":{"id":{"$ref":"#/components/schemas/NodeID"},"type":{"type":"string","description":"Node type. Always \"output_endpoint\"."},"data":{"type":"object","oneOf":[{"$ref":"#/components/schemas/NodeOutputEndpointDataDefault"},{"$ref":"#/components/schemas/NodeOutputEndpointDataStoredEndpoint"}]},"view":{"$ref":"#/components/schemas/NodeView"}},"required":["type","data"]},"NodeOutputEndpointDataDefault":{"type":"object","description":"Data of default output endpoint (Navixy platform)","properties":{"title":{"type":"string"},"output_endpoint_type":{"type":"string","description":"Type of endpoint. Always 'output_default' for Navixy platform."}},"required":["title","output_endpoint_type"]},"NodeOutputEndpointDataStoredEndpoint":{"type":"object","description":"Data of MQTT output endpoint","properties":{"title":{"type":"string"},"output_endpoint_type":{"type":"string","description":"Type of endpoint. Always 'output_mqtt_client'."},"output_endpoint_id":{"type":"integer","description":"Output Endpoint identifier within the user account. It is required for only some types of node (e.g. output_mqtt_client) which has specific properties."}},"required":["title","output_endpoint_type","output_endpoint_id"]},"Edge":{"type":"object","description":"Edge between two Nodes","properties":{"from":{"type":"integer"},"to":{"type":"integer"},"type":{"description":"Edge type, optional, if not specified it is `simple_edge`","$ref":"#/components/schemas/EdgeType"}},"required":["from","to"]},"EdgeType":{"type":"string","enum":["simple_edge","then_edge","else_edge"]}}}}
```

## Example schema

```json
{
  "$schema": "http://json-schema.org/draft-07/schema#",
  "title": "Navixy IoT Logic Flow",
  "description": "A schema for defining IoT data flows in the Navixy platform",
  "type": "object",
  "required": [
    "id",
    "title",
    "enabled",
    "nodes",
    "edges"
  ],
  "properties": {
    "id": {
      "type": "integer",
      "description": "Unique identifier for the flow",
      "examples": [543]
    },
    "title": {
      "type": "string",
      "description": "Name of the flow",
      "examples": ["Temperature Monitoring Flow", "Vehicle Tracking Flow"]
    },
    "enabled": {
      "type": "boolean",
      "description": "Whether the flow is active or not",
      "default": true
    },
    "nodes": {
      "type": "array",
      "description": "Collection of nodes in the flowchart",
      "items": {
        "type": "object",
        "oneOf": [
          { "$ref": "#/definitions/dataSourceNode" },
          { "$ref": "#/definitions/initiateAttributesNode" },
          { "$ref": "#/definitions/outputEndpointNode" }
        ]
      }
    },
    "edges": {
      "type": "array",
      "description": "Connections between nodes in the flowchart",
      "items": {
        "$ref": "#/definitions/edge"
      }
    }
  },
  "definitions": {
    "edge": {
      "type": "object",
      "description": "Represents a connection between two nodes",
      "required": ["from", "to"],
      "properties": {
        "from": {
          "type": "integer",
          "description": "ID of the source node",
          "examples": [1]
        },
        "to": {
          "type": "integer",
          "description": "ID of the destination node",
          "examples": [2]
        }
      }
    },
    "nodeView": {
      "type": "object",
      "description": "Visual properties of a node in the flowchart UI",
      "properties": {
        "position": {
          "type": "object",
          "description": "Position of the node's top-left corner in the UI",
          "properties": {
            "x": {
              "type": "integer",
              "description": "X coordinate (horizontal position)",
              "examples": [25]
            },
            "y": {
              "type": "integer",
              "description": "Y coordinate (vertical position)",
              "examples": [25]
            }
          },
          "required": ["x", "y"]
        }
      }
    },
    "dataSourceNode": {
      "type": "object",
      "description": "Input endpoint node that defines the source of data for the flow",
      "required": ["id", "type", "title", "enabled", "data"],
      "properties": {
        "id": {
          "type": "integer",
          "description": "Unique identifier for the node within the flow",
          "examples": [1]
        },
        "type": {
          "type": "string",
          "description": "Type of node, must be 'data_source' for input endpoints",
          "enum": ["data_source"]
        },
        "title": {
          "type": "string",
          "description": "Name of the node",
          "examples": ["GPS Tracker Input", "Sensor Data Input"]
        },
        "enabled": {
          "type": "boolean",
          "description": "Whether the node is active within the flow",
          "default": true
        },
        "data": {
          "type": "object",
          "description": "Configuration data specific to this node type",
          "required": ["source_ids"],
          "properties": {
            "source_ids": {
              "type": "array",
              "description": "Collection of source device IDs to receive data from",
              "items": {
                "type": "integer",
                "description": "ID of a source device",
                "examples": [123458]
              }
            }
          }
        },
        "view": {
          "$ref": "#/definitions/nodeView"
        }
      }
    },
    "initiateAttributesNode": {
      "type": "object",
      "description": "Node that creates or modifies data attributes in the flow",
      "required": ["id", "type", "title", "data"],
      "properties": {
        "id": {
          "type": "integer",
          "description": "Unique identifier for the node within the flow",
          "examples": [2]
        },
        "type": {
          "type": "string",
          "description": "Type of node, must be 'initiate_attributes' for attribute manipulation nodes",
          "enum": ["initiate_attributes"]
        },
        "title": {
          "type": "string",
          "description": "Name of the node",
          "examples": ["Calculate Fuel Consumption", "Convert Temperature Units"]
        },
        "data": {
          "type": "object",
          "description": "Configuration data specific to this node type",
          "required": ["items"],
          "properties": {
            "items": {
              "type": "array",
              "description": "Collection of attribute definitions/transformations",
              "items": {
                "type": "object",
                "required": ["name", "value"],
                "properties": {
                  "name": {
                    "type": "string",
                    "description": "Name of the attribute to create or modify",
                    "examples": ["fuel_tank_2", "temperature_celsius"]
                  },
                  "value": {
                    "type": "string",
                    "description": "Expression that defines the attribute value, can reference other attributes or functions",
                    "examples": ["(analog_1 + 100)/2", "temp_f * 5/9 - 32"]
                  },
                  "generation_time": {
                    "type": "string",
                    "description": "Expression for when the data was generated, often uses functions like now()",
                    "examples": ["now()", "timestamp"]
                  },
                  "server_time": {
                    "type": "string",
                    "description": "Expression for when the data was received by the server, often uses functions like now()",
                    "examples": ["now()"]
                  }
                }
              }
            }
          }
        },
        "view": {
          "$ref": "#/definitions/nodeView"
        }
      }
    },
    "outputEndpointNode": {
      "type": "object",
      "description": "Terminating node that defines where the processed data will be sent",
      "required": ["id", "type", "title", "enabled", "data"],
      "properties": {
        "id": {
          "type": "integer",
          "description": "Unique identifier for the node within the flow",
          "examples": [3]
        },
        "type": {
          "type": "string",
          "description": "Type of node, must be 'output_endpoint' for data output nodes",
          "enum": ["output_endpoint"]
        },
        "title": {
          "type": "string",
          "description": "Name of the node",
          "examples": ["Navixy Output", "MQTT Broker Output"]
        },
        "enabled": {
          "type": "boolean",
          "description": "Whether the node is active within the flow",
          "default": true
        },
        "data": {
          "type": "object",
          "description": "Configuration data specific to this node type",
          "oneOf": [
            {
              "$ref": "#/definitions/outputEndpointDataNavixy"
            },
            {
              "$ref": "#/definitions/outputEndpointDataMqtt"
            }
          ]
        },
        "view": {
          "$ref": "#/definitions/nodeView"
        }
      }
    },
    "outputEndpointDataNavixy": {
      "type": "object",
      "description": "Configuration for sending data to the Navixy platform",
      "required": ["output_endpoint_type"],
      "properties": {
        "output_endpoint_type": {
          "type": "string",
          "description": "Type of output endpoint, must be 'output_default' for Navixy platform",
          "enum": ["output_default"]
        }
      }
    },
    "outputEndpointDataMqtt": {
      "type": "object",
      "description": "Configuration for sending data to an MQTT broker",
      "required": ["output_endpoint_type", "output_endpoint_id"],
      "properties": {
        "output_endpoint_type": {
          "type": "string",
          "description": "Type of output endpoint, must be 'output_mqtt_client' for MQTT brokers",
          "enum": ["output_mqtt_client"]
        },
        "output_endpoint_id": {
          "type": "integer",
          "description": "ID of the predefined MQTT endpoint configuration",
          "examples": [44551]
        }
      }
    }
  }
}
```

## Example flow

The example template shows a flow that:

1. Collects data from vehicle tracking devices
2. Processes the data in two parallel paths:
   * Calculating fuel-related metrics (level, consumption, range)
   * Calculating engine metrics (temperature, load, maintenance status)
3. Sends the processed data to:
   * The Navixy platform for tracking and visualization
   * An external MQTT broker for integration with other systems

```json
{
  "id": 1001,
  "title": "Vehicle Telematics Processing Flow",
  "enabled": true,
  "nodes": [
    {
      "id": 1,
      "type": "data_source",
      "title": "Vehicle Tracker Input",
      "enabled": true,
      "data": {
        "source_ids": [
          123458,
          123459,
          123460
        ]
      },
      "view": {
        "position": {
          "x": 50,
          "y": 50
        }
      }
    },
    {
      "id": 2,
      "type": "initiate_attributes",
      "title": "Calculate Fuel Metrics",
      "data": {
        "items": [
          {
            "name": "fuel_level_percent",
            "value": "(analog_1 / 1024) * 100",
            "generation_time": "now()",
            "server_time": "now()"
          },
          {
            "name": "fuel_consumption_rate",
            "value": "analog_2 * 0.25",
            "generation_time": "now()",
            "server_time": "now()"
          },
          {
            "name": "estimated_range_km",
            "value": "fuel_level_percent * 5",
            "generation_time": "now()",
            "server_time": "now()"
          }
        ]
      },
      "view": {
        "position": {
          "x": 250,
          "y": 50
        }
      }
    },
    {
      "id": 3,
      "type": "initiate_attributes",
      "title": "Calculate Engine Metrics",
      "data": {
        "items": [
          {
            "name": "engine_temp_celsius",
            "value": "analog_3 * 0.5 - 40",
            "generation_time": "now()",
            "server_time": "now()"
          },
          {
            "name": "engine_load",
            "value": "(analog_4 / 1024) * 100",
            "generation_time": "now()",
            "server_time": "now()"
          },
          {
            "name": "maintenance_due",
            "value": "mileage > 10000",
            "generation_time": "now()",
            "server_time": "now()"
          }
        ]
      },
      "view": {
        "position": {
          "x": 250,
          "y": 200
        }
      }
    },
    {
      "id": 4,
      "type": "output_endpoint",
      "title": "Navixy Platform Output",
      "enabled": true,
      "data": {
        "output_endpoint_type": "output_default"
      },
      "view": {
        "position": {
          "x": 450,
          "y": 125
        }
      }
    },
    {
      "id": 5,
      "type": "output_endpoint",
      "title": "MQTT Broker Output",
      "enabled": true,
      "data": {
        "output_endpoint_type": "output_mqtt_client",
        "output_endpoint_id": 44551
      },
      "view": {
        "position": {
          "x": 450,
          "y": 250
        }
      }
    }
  ],
  "edges": [
    {
      "from": 1,
      "to": 2
    },
    {
      "from": 1,
      "to": 3
    },
    {
      "from": 2,
      "to": 4
    },
    {
      "from": 3,
      "to": 4
    },
    {
      "from": 3,
      "to": 5
    }
  ]
}
```