.trix File Format v2.0

The .trix file format is a generic and flexible binary container for storing an arbitrary data payload alongside structured metadata.

Structure

The file is structured as follows:

Field	Size (bytes)	Description
Magic Number	4	A constant value, TRIX, to identify the file as a .trix file.
Version	1	The version of the .trix file format (currently 2).
Header Length	4	A 32-bit unsigned integer specifying the length of the JSON Header in bytes. This allows for flexible and extensible metadata.
JSON Header	Header Length	A UTF-8 encoded JSON object containing metadata about the payload. Common keys include content_type, encryption_algorithm, nonce, tag, and created_at.
Payload	variable	The raw binary data. This can be plaintext, ciphertext, or any other data. The interpretation of this data is guided by the metadata in the JSON Header.

Example JSON Header

Here is an example of what the JSON header might look like for a file encrypted with ChaCha20-Poly1305:

{
  "content_type": "application/octet-stream",
  "encryption_algorithm": "chacha20poly1305",
  "nonce": "AAECAwQFBgcICQoLDA0ODxAREhMUFRY=",
  "created_at": "2025-10-30T12:00:00Z"
}

This decoupled design ensures that the .trix container is not tied to any specific encryption scheme, allowing for greater flexibility and future-proofing.