Rules

Rules are the most fundamental configuration unit. They are instructions that are “always on” or conditionally applied to guide the AI’s behavior, style, and constraints.

Default Rules vs. Custom Rules

Most editors refer to these as “System Prompts” or “Custom Instructions”. aix unifies them under the concept of Rules.

Usage

Define rules in ai.json:

{
   "rules": {
      "conciseness": {
         "activation": "always",
         "content": "Be concise. Do not explain code unless asked."
      },
      "testing": {
         "activation": "glob",
         "globs": ["**/*.test.ts"],
         "content": "Use Vitest. Prefer 'it' over 'test'."
      }
   }
}

Activation Modes

Mode	Description	Editor Support
always	Active for every request.	All editors
glob	Active only when editing files matching the glob pattern.	Cursor, VS Code, Windsurf
auto	The AI decides when to activate the rule based on its description.	Cursor, Windsurf (Cascade)
manual	Must be explicitly referenced by the user.	None (future support)

If an editor doesn’t support a specific activation mode (like glob), aix falls back to always for that editor.

Sources

Rules can be defined:

• Inline: content: "string"
• File: path: "./rules/rule.md"
• Git: git: { url: "...", path: "..." }
• npm: npm: { package: "...", path: "..." }

Common Use Cases

• Code Style: Indentation, naming conventions, preferred libraries.
• Workflow: “Always write tests before code”, “Update documentation when changing APIs”.
• Personality: “Be Socratic”, “Act as a senior engineer”.