Cursor

Cursor Rules, AGENTS.md, and .cursorignore explained

Understand Cursor Rules, AGENTS.md, and .cursorignore for project context, rule inheritance, and index control. Includes setup, examples, and common fixes.

Short answer

Cursor Rules tell Cursor how to work in a project. AGENTS.md is a repository instruction file many coding agents can read. .cursorignore controls which files or directories Cursor should not index or read.

They all relate to project context, but they solve different problems: Rules guide behavior, AGENTS.md gives cross-agent instructions, and .cursorignore excludes content.

Comparison

File / feature	Main role
Cursor Rules	Project, team, or user-level rules for Cursor
`AGENTS.md`	Cross-agent repository instructions and collaboration norms
`.cursorignore`	Files or directories Cursor should ignore
API Key / Base URL	Model request setup, not project rules

Good content for Rules

Project coding style
Framework conventions
Component and directory rules
Test and validation requirements
Cursor editing behavior

Good content for .cursorignore

Large build artifacts
Dependency directories
Generated files
Sensitive directories that should not be indexed
Large files unrelated to current development

Common mistakes

Writing API Keys in Rules or AGENTS.md.
Treating .cursorignore as a complete security system.
Keeping outdated rules that mislead the AI.
Thinking Base URL configuration replaces project rules.
Mixing Cursor Rules with Claude Code CLAUDE.md.

About BetterToken

BetterToken handles model API access and usage visibility. Cursor Rules, AGENTS.md, and .cursorignore handle project context and editing behavior.

API access is only the first step. Long-term output quality depends heavily on clear rules and controlled context.