v2.0 — Open Standard

JAK File Format Specification

The .jak file is a portable AI identity format. Your personality, context, and preferences in one file that works with any AI tool — LM Studio, Open WebUI, Ollama, and more.

Your data. Your file. No lock-in.

Create Your .jak File JSON Schema

Why .jak?

Every AI tool today is a walled garden. Your ChatGPT memory lives in ChatGPT. Your Claude Projects live in Claude. There's no way to take your AI identity with you.

The .jak file changes that. It's a portable format that stores who you are — your personality, your context, your preferences — in a file YOU own. Use it with any AI tool. Switch tools without starting over. Your identity travels with you.

Overview

A .jak file is a UTF-8 encoded JSON document with the extension .jak. It contains structured information about a person that AI systems can use to personalize interactions.

The format is designed to be:

Human-readable — Plain JSON, open it in any text editor
Portable — Works with LM Studio, Open WebUI, Ollama, and any LLM
User-owned — Lives on your machine, never uploaded anywhere
Extensible — Add custom sections without breaking compatibility
Open — MIT licensed, community-driven

File Structure

{
  "jak_version": "2.0",          // Required: Format version
  "created_at": "2026-03-18T...",  // ISO 8601 timestamp
  "source": "chatgpt_extraction",  // How profile was created

  "identity": { ... },              // Required: Core identity info
  "personality": { ... },           // Traits and values
  "working_style": { ... },         // Work preferences
  "communication": { ... },         // Communication preferences
  "expertise": [ ... ],             // Skills array
  "focus": { ... },                 // Current priorities
  "relationships": { ... },         // Social context
  "emotional": { ... },             // Emotional patterns
  "health": { ... },                // Lifestyle info
  "technology": { ... },            // Tech environment
  "financial": { ... },             // Business context
  "memories": { ... },              // Key facts/people/places
  "gaps": [ ... ],                  // Areas to learn more

  "verified_by_user": true,         // User reviewed profile
  "verified_at": "2026-03-18T..."   // When verified
}

Required Fields

Field	Type	Description
`jak_version`	string	Format version. Must be `"2.0"` for this spec.
`identity`	object	Core identity information. See Identity section.
`identity.display_name`	string	User's full name or display name. REQUIRED

Identity Section

The identity object contains core information about who the person is.

Field	Type	Description
`display_name`	string	Full name or display name REQUIRED
`preferred_name`	string	How user prefers to be addressed (first name, nickname)
`roles`	string[]	Professional roles or occupations
`languages`	string[]	Languages spoken
`nationality`	string	Nationality or cultural context
`one_liner`	string	Short self-description or tagline
`bio`	string	Longer biography
`location`	object	Contains `city` and `country` strings

Extraction from ChatGPT

When extracting a .jak profile from ChatGPT, the following prompt format is used to generate structured output that maps to the .jak schema:

## IDENTITY
Name: [full name]
Preferred name: [how to address]
Location: [city, country]
Nationality / cultural context: [context]
Languages: [comma-separated]
Roles: [comma-separated]
One-liner: [short description]
Bio: [longer description]

## PERSONALITY
Core traits:
- [trait] - [notes]
Thinking style: [description]
Decision making: [description]
...

The parser handles markdown formatting that ChatGPT may add (bold, bullets, etc.) and extracts key-value pairs to build the .jak structure.

Compatibility

The .jak format is designed to work with any AI tool that accepts system prompts or persona configuration. Your .jak file is portable — use it anywhere.

Tool	Status	How to Use
LM Studio	Verified	Paste .jak content into System Prompt field
Open WebUI	Verified	Create Model persona with .jak content as system prompt
Ollama	Compatible	Include in Modelfile SYSTEM section
Jan	Compatible	Add to thread system prompt settings
GPT4All	Compatible	Paste into system prompt in chat settings
LibreChat	Compatible	Set as conversation system prompt
Any LLM API	Compatible	Include .jak content as system message in API calls

Verified = tested and confirmed working. Compatible = uses standard system prompt pattern.

Version History

Version	Date	Changes
`2.0`	March 2026	Current version. Added markdown parsing, field aliases, verification flags.
`1.0`	February 2026	Initial release.

Validation

A valid .jak file must:

Be valid JSON (UTF-8 encoded)
Have jak_version set to "2.0"
Have an identity object with at least display_name
Use the file extension .jak

Optional sections may be omitted entirely. Empty arrays and empty strings are allowed.