Data types and encoding standards

JSON type mapping, timestamp formatting, binary encoding, and value constraints used in NGP messages.

Navixy Generic Protocol messages use standard JSON with a defined set of field types. This page specifies how each type maps to JSON, how timestamps must be formatted, and how binary payloads should be encoded before transmission. Knowing these constraints helps you construct valid messages and avoid silent discard due to type mismatches or encoding errors.

Data types

Type	JSON	Description	Examples	Limitations
Integer	Number	Whole numeric values, no decimals	Bitmasks, counters, impulse counts, passenger counts, RPM	Signed or unsigned, 1–8 bytes
Float	Number	Numeric values with decimal precision	Coordinates, speed, altitude, mileage, voltage	IEEE 754 signed float, up to 8 bytes
String	String	UTF-8 encoded text	Driver name, registration plate, driver ID	Up to 10 KB
Boolean	Boolean	true or false	Ignition state, door state, presence of movement	true or false only
Timestamp	String	ISO 8601 date-time in UTC	Message time, GNSS fix time	Must be valid ISO 8601 UTC
Blob	String	Binary data, Base64-encoded	Photos, raw sensor data, BLE payloads, audio	Up to 1 MB encoded
Mixed	Any	Value of any JSON type	Custom attributes where type varies by attribute	Follows the type constraints of the specific attribute
Array	Array	Ordered list of objects of the same structure	mobile_cells, wifi_points	No size limit
Object	Object	Named set of attributes grouped under a single key	location, individual mobile cell, individual Wi-Fi point	No size limit

Timestamps

All timestamps must use ISO 8601 UTC format.

"message_time": "2024-09-02T23:59:59Z"

The trailing Z indicates UTC. Timezone offsets are not supported. Always convert to UTC before sending.

Binary data

For raw payloads such as sensor data, tachograph logs, images, or audio, binary content must be Base64-encoded and sent as a string value.

{
  "my_sensor_data": "SGVsbG8gd29ybGQh",
  "tachograph_log": "U29tZSB0YWNoZW9nIGxvZw==",
  "photo": "/9j/4AAQSkZJRgABAQEAYABgAAD...",
  "audio": "UklGRjIAAABXRUJQVlA4WAoAAAAQAAAA..."
}

NGP is not optimized for large binary payloads. The 1 MB limit per encoded blob applies per attribute. Avoid sending multiple large blobs in a single message.

Continue reading to learn about Message structure and attributes in Navixy Generic Protocol.