# How to Use Ponytail with Cursor: Complete Setup Guide

> Learn how to use Ponytail with Cursor effortlessly. Follow our complete setup guide to integrate Ponytail into your project in minutes for enhanced coding.

- Repository: [DietrichGebert/ponytail](https://github.com/DietrichGebert/ponytail)
- Tags: how-to-guide
- Published: 2026-09-07

---

**Copy the `ponytail.mdc` rule file to your project's `.cursor/rules` directory and Cursor automatically loads Ponytail's instructions on startup—no runtime activation required.**

Ponytail provides an "always‑on" integration for the Cursor editor through a simple rule file mechanism. This lets you invoke Ponytail commands with `@` prefixes or benefit from context‑aware suggestions transparently within your workflow. According to the DietrichGebert/ponytail source code, the integration requires only a file copy operation with no additional configuration.

## How the Cursor Integration Works

Cursor recognizes **`.mdc` files** placed in the `.cursor/rules` directory as permanent project rules. When you open a project, Cursor automatically loads every `*.mdc` file it finds there and applies those instructions to all AI interactions.

The Ponytail repository provides a pre‑configured rule file at `.cursor/rules/ponytail.mdc` that encodes the complete instruction set. This file implements what the repository calls "instruction‑only" mode—functionality that works without a separate skill host.

## Step‑by‑Step Setup

### 1. Copy the Rule File

Create the rules directory in your project and copy the `ponytail.mdc` file from the Ponytail repository:

```bash
mkdir -p .cursor/rules
cp path/to/ponytail/.cursor/rules/ponytail.mdc .cursor/rules/

```

The source path depends on where you cloned or extracted the Ponytail repository. The repository structure places the file at `.cursor/rules/ponytail.mdc` relative to the project root.

### 2. Verify Cursor Loaded the Rules

Open your project in Cursor and inspect the **Rules** view. You should see `ponytail.mdc` listed among the active project rules. Cursor reads these files on startup, so a restart may be needed if the file was added while Cursor was already running.

### 3. Use Ponytail Features

Once loaded, Ponytail operates in one of two modes depending on your environment:

- **With a skill‑capable host** (Claude Code, Codex, OpenCode, Gemini, π, etc.): Invoke commands directly using `@` prefixes:

```bash
@ponytail-review   # reviews the current file or selection

```

- **Cursor‑only mode**: The rule file provides the instruction set automatically. Write prompts normally and Ponytail's context‑aware suggestions apply transparently.

## Key Files in the Ponytail Repository

| File | Purpose |
|------|---------|
| `.cursor/rules/ponytail.mdc` | Core rule set that Cursor loads on project start |
| [`README.md`](https://github.com/DietrichGebert/ponytail/blob/main/README.md) (Cursor section) | Documents the copy‑and‑paste workflow |
| [`AGENTS.md`](https://github.com/DietrichGebert/ponytail/blob/main/AGENTS.md) | Lists supported agents and explains the "always‑on" rule concept |
| [`hooks/ponytail-instructions.js`](https://github.com/DietrichGebert/ponytail/blob/main/hooks/ponytail-instructions.js) | Implementation of instruction loading logic used by adapters |

The `ponytail.mdc` file is version‑controlled alongside Ponytail itself. Keep it current by pulling the latest changes from the repository and re‑copying when updates are released.

## Why This Approach Works

The integration leverages Cursor's native rule system rather than requiring a plugin or extension. As implemented in DietrichGebert/ponytail, the [`hooks/ponytail-instructions.js`](https://github.com/DietrichGebert/ponytail/blob/main/hooks/ponytail-instructions.js) module provides the underlying instruction loading logic that adapters like Cursor consume. The `.mdc` file format is Cursor's standard for persistent, project‑scoped AI instructions.

This architecture separates concerns: the repository maintains the instruction logic, while Cursor handles the runtime integration. You benefit from updates to Ponytail by refreshing a single file rather than managing complex package dependencies.

## Summary

- **Primary requirement**: Copy `.cursor/rules/ponytail.mdc` from the Ponytail repository to your project's `.cursor/rules` directory
- **Activation**: Automatic on Cursor startup—no commands or runtime steps needed
- **Usage modes**: `@` command prefixes with skill hosts, or transparent "instruction‑only" mode in Cursor alone
- **Maintenance**: Update by re‑copying the file when the repository changes

## Frequently Asked Questions

### Where does the `ponytail.mdc` file come from?

The file is located in the Ponytail repository at `.cursor/rules/ponytail.mdc`. Clone or download the DietrichGebert/ponytail repository, then copy this file into your own project's `.cursor/rules` directory.

### Do I need to install anything else for Ponytail to work in Cursor?

No additional installation is required. Cursor's native rule system loads `.mdc` files automatically. The only dependency is the rule file itself, which contains all necessary instructions.

### Can I use Ponytail commands without a skill host like Claude Code?

Yes. While `@` commands require a skill‑capable host, the rule file activates Ponytail's "instruction‑only" mode automatically. This provides context‑aware suggestions within Cursor's normal chat interface without special command syntax.

### How do I update Ponytail when the repository changes?

Pull the latest changes from the DietrichGebert/ponytail repository, then replace your local copy of `.cursor/rules/ponytail.mdc` with the updated version. Restart Cursor to load the new rules.