Claude Code Prompt Optimizer

Claude Code Prompt Optimizer

A Claude Code hook that transforms simple prompts into detailed, structured instructions. Add  to any prompt and it'll expand your request into something Claude can really sink its teeth into.

What It Does

When you tag a prompt with , this hook intercepts it and sends it to the same model your session is running, with a rewrite-only system prompt and no tools. The result is a fleshed-out version of your original request with:

- Specific implementation steps
- Error handling considerations
- Testing requirements
- Edge cases to watch for

Basically, it does the prompt engineering for you.

Requirements

- Claude Code CLI installed and logged in (claude login)
- Node.js 18+

API-credit users can use ANTHROPIC_API_KEY instead; see Authentication.

Quick Install

Plugin marketplace (recommended)

In Claude Code:

Then restart Claude Code. The plugin registers the hook for you and installs its
dependencies the first time you use  (about 200 MB, kept across plugin
updates). If you are logged into Claude Code, auth already works.

Keep the plugin updated

Claude Code can update this plugin automatically. Auto-update is off by default for third-party marketplaces, so turn it on once:

1. Run /plugin.
2. Open the Marketplaces tab and select 0-to-1-labs.
3. Choose Enable auto-update.

Claude Code then checks for new versions after each session start and installs them. Restart Claude Code to load an update.

To update by hand:

Alternative: standalone install (no marketplace)

The installer installs dependencies, links the repo into ~/.claude/hooks, registers
the hook in ~/.claude/settings.json with the right timeout, and verifies the fast path.

Use one method, not both. The installer refuses to run when the plugin is already
installed, and the…