RPKG file format

RPKG is Museris's portable package format for characters and lorebooks. It is intended for sharing or transferring that content without exporting an entire local library.

An RPKG file uses the .rpkg extension and is a ZIP archive. The package MIME type is application/vnd.museris.rpkg.

Package layout

Museris 1.0 exports manifest.json and the mimetype file. Content documents are optional, so a package may contain characters, lorebooks, or both.

mimetype
manifest.json
characters/<character-id>.json
lore/<lorebook-id>.json

mimetype contains exactly this text:

application/vnd.museris.rpkg

Manifest

manifest.json is UTF-8 JSON with this shape:

{
  "version": "1.0",
  "exportedAt": "2026-07-30T12:00:00.000Z"
}

version must use major.minor form. The current format version is 1.0. Museris writes exportedAt as an ISO 8601 timestamp when it creates a package.

Character documents

Each characters/<id>.json document contains:

{
  "id": "example_character",
  "lastUpdate": 1785432000000,
  "name": "Nyx",
  "definition": "Nyx is a resourceful mechanic.",
  "greetings": ["Nyx looks up from the engine."],
  "tagline": "A sharp-tongued mechanic.",
  "avatar": null
}

avatar may be null or a data URL containing the image. greetings is an array; the first greeting is the normal opening greeting and later values are alternatives.

Lorebook documents

Each lore/<id>.json document contains:

{
  "id": "example_lorebook",
  "lastUpdate": 1785432000000,
  "name": "Outpost Kestrel",
  "entries": [
    {
      "id": "kestrel_overview",
      "name": "Overview",
      "content": "A remote repair station at the edge of known space."
    }
  ]
}

Identifier rules

Document and lore-entry IDs must be 8 to 128 characters long and use only letters, numbers, underscores, and hyphens.

Import behavior and limits

Museris validates the manifest and every character or lorebook document it finds under the paths above. Unknown archive files are ignored.

RPKG currently carries characters and lorebooks only. It does not contain roleplay chats, instruct chats, prompt templates, connection presets, summarization settings, or a complete app backup. Use Settings → Export Data when you need a backup of the whole local library.