Claude Code Custom Output Styles: Create Markdown Files That Modify the System Prompt for Domain-Specific Roles — Diagrams-First, Data Analyst, Writing Assistant

Claude Code Docs·medium signal

Claude Code now supports custom output styles via Markdown files with frontmatter at ~/.claude/output-styles/ (user-level) or .claude/output-styles/ (project-level). Set `keep-coding-instructions: true` in frontmatter to retain coding behavior while changing communication style, or omit it to repurpose Claude as a non-engineering assistant. Built-in presets include Proactive (execute immediately, make assumptions), Explanatory (educational insights between code), and Learning (TODO(human) markers for collaborative coding). Configure via /config → Output style or set `outputStyle` in settings.json. Plugins can also ship output styles that auto-apply via `force-for-plugin: true`.