Personas

Personas define how Xavier's reviewer agents think. Each persona is a markdown file containing a system prompt that shapes the reviewer's lens — what it looks for, what it prioritizes, and how it frames findings.

Default personas

Xavier ships with three:

Persona	File	Focus
Correctness	`correctness.md`	Logic errors, edge cases, missing validations, broken contracts
Security	`security.md`	Vulnerabilities, auth issues, injection risks, data exposure
Performance	`performance.md`	Unnecessary computation, memory leaks, render cycles, query efficiency

These live in ~/.xavier/personas/ and are installed during /xavier setup.

Persona file format

A persona is a markdown file with a system prompt:

---
name: Security Reviewer
type: persona
focus: [vulnerabilities, auth, injection, data-exposure]
---

# Security Reviewer

You are a security-focused code reviewer. Your job is to find
vulnerabilities, authentication issues, injection risks, and
data exposure problems.

## What to look for

- SQL injection, XSS, command injection
- Authentication and authorization gaps
- Secrets or tokens in code or logs
- Insecure data storage or transmission
- Missing input validation at trust boundaries

## How to report

Rate each finding by severity (critical, high, medium, low).
Focus on actionable findings — skip theoretical concerns that
don't apply to this specific code.

The frontmatter fields:

Field	Description
`name`	Display name for the reviewer
`type`	Always `persona`
`focus`	List of focus areas — used for categorizing findings

The body is the system prompt injected into the reviewer agent.

Creating custom personas

Add a markdown file to ~/.xavier/personas/:

---
name: Accessibility Reviewer
type: persona
focus: [a11y, aria, keyboard-nav, screen-readers]
---

# Accessibility Reviewer

You are an accessibility-focused code reviewer. Your job is to
find issues that would prevent users with disabilities from
using this application effectively.

## What to look for

- Missing or incorrect ARIA attributes
- Keyboard navigation gaps
- Color contrast issues in style changes
- Missing alt text on images
- Focus management problems in dynamic UI
- Screen reader compatibility issues

## How to report

Reference WCAG 2.1 guidelines where applicable. Distinguish
between Level A (must fix), Level AA (should fix), and
Level AAA (nice to have).

The new persona is automatically included in the review panel next time you run /xavier review.

Repo-level overrides

Place persona files in <your-repo>/.xavier/personas/ to override globals for that repo:

my-app/
└── .xavier/
    └── personas/
        ├── correctness.md    # overrides the global correctness persona
        └── data-integrity.md # additional persona for this repo only

Override rules:

A repo persona with the same filename as a global persona replaces it
A repo persona with a new filename adds to the panel
Global personas not overridden remain active

Adjusting the panel size

The number of reviewers equals the number of persona files. To run a 5-reviewer panel, have 5 persona files. To run a focused 1-reviewer review, keep only the persona you care about.

For most codebases, 3-4 personas hits the sweet spot between thoroughness and speed.

Last updated: 4/8/26, 10:45 PM

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