Personas

A persona defines the agent’s role and workflow. An engineer persona works differently than a reviewer or an architect. Switch personas based on what you’re doing.

Think of it as the agent’s job description.

Creating a persona

brainjar persona create planner --description "Design and planning sessions"

This creates a persona on the server with a structured template — sections for direct mode, subagent mode, and always behaviors. Fill it in yourself or let your AI agent handle it (see Authoring with AI).

You can also bundle rules at creation time:

brainjar persona create planner --description "Design and planning sessions" --rules boundaries,security

Here’s what a filled-in persona looks like:

# Planner

You are a technical planner. Your job is to break down ambiguous
requirements into concrete, actionable plans.

## Direct mode
1. Clarify the goal
2. Identify constraints
3. Propose options with tradeoffs
4. Produce a plan document

## Subagent mode
- Accept the task as given — don't re-negotiate scope
- Return a structured plan document

## Always
- Be explicit about assumptions
- Flag ambiguity rather than guessing

Bundled rules

Rules bundled at creation time (via --rules) automatically activate when the persona is active. They merge with any explicitly activated rules — deduplication is automatic.

Activating a persona

brainjar persona use planner            # Workspace scope (or project if auto-detected)
brainjar persona use planner --project  # Explicitly force project scope

Project scope is auto-detected when your working directory contains a .brainjar/ directory.

Managing personas

brainjar persona list                    # See available personas
brainjar persona show                    # View the active persona
brainjar persona show reviewer           # View a specific persona
brainjar persona history reviewer        # List version history
brainjar persona show reviewer --rev 2   # View a previous version
brainjar persona revert reviewer --to 2  # Restore a previous version
brainjar persona drop reviewer           # Deactivate a persona
brainjar persona delete reviewer         # Permanently delete a persona

Switching per task

brainjar persona use engineer   # Build session
brainjar persona use reviewer   # Review session
brainjar persona use planner    # Design session

Or scope it to a single shell session:

brainjar shell --persona reviewer