PrePrompt

Underspecified prompts get mediocre answers. PrePrompt rewrites the vague ones — adding the missing context, constraints, and output format — before the model ever sees them.

Get PrePrompt

Most people want the Chrome extension. It rewrites your prompts right where you already work — ChatGPT, Claude, Gemini, and Perplexity — with nothing to install locally.

👉 Add PrePrompt to Chrome → preprompt.org — free, 30 rewrites/month.

This package (pip install preprompt) brings the same service to your IDE and terminal: a hook and MCP server for Claude Code, Cursor, Windsurf, and Zed, plus a small CLI. It uses the same PrePrompt account and the same monthly credits as the extension.

What it does

Most prompts sent to an LLM are underspecified — they're missing context, output format expectations, or technical constraints that the developer has in their head but didn't type. PrePrompt scores every prompt and rewrites the complex ones. Simple prompts ("what is jwt") pass through untouched.

BEFORE  write a function that handles youtube oauth token refresh
        and manages expired credentials with error handling

AFTER   Write a Python function for FastAPI that handles YouTube OAuth 2.0
        token refresh. The function should: (1) detect expired credentials
        by checking the expiry timestamp, (2) use the refresh token to
        obtain a new access token via the YouTube API, (3) update and
        persist the new credentials (consider using a database or file
        storage), and (4) include comprehensive error handling for invalid
        refresh tokens, network failures, and API errors with appropriate
        logging and exception types.

In Claude Code, a rewritten prompt shows up as an annotation box:

╔═ PrePrompt +58 ════════════════════════════════════════════╗
║ The rewritten prompt specifies the technical               ║
║ implementation details, clarifies the complete workflow,   ║
║ and adds concrete error scenarios and storage              ║
║ considerations relevant to FastAPI applications.           ║
╠════════════════════════════════════════════════════════════╣
║ ORIGINAL  write a function that handles youtube oauth t... ║
║ OPTIMIZED Write a Python function for FastAPI that handles ║
║           YouTube OAuth 2.0 token refresh. The function    ║
║           should: (1) detect expired credentials by        ║
║           checking the expiry timestamp...                 ║
╚════════════════════════════════════════════════════════════╝

Install

pip install preprompt
preprompt-install        # registers the hook + MCP server (Claude Code, and Cursor if installed)
preprompt-login          # paste a token from preprompt.org/dashboard/tokens
# Restart Claude Code or Cursor

A PrePrompt account is required — the free plan works. PrePrompt never asks for, stores, or uses an Anthropic API key.

Upgrading from 0.1.x

0.2.0 requires a PrePrompt account and no longer uses your own Anthropic key. Upgrade, re-run preprompt-install (it replaces the old hook and Cursor entry, which held your key), then sign in:

pip install --upgrade preprompt
preprompt-install
preprompt-login

0.1.x also saved the key in ~/.preprompt/.env. 0.2.0 ignores it; delete that line.

How it works

Classification runs on your machine: a pure-heuristic scorer, no network call, under 1ms per prompt.

• Clear prompts pass through untouched — nothing is sent anywhere.
• Prompts that look like they contain a secret (API keys, tokens, private keys) are never sent — they pass through unchanged.
• Prompts that need work are sent to PrePrompt's hosted engine, rewritten, and returned. Each delivered rewrite uses one credit.

SCORE  REWRITE  PROMPT
   48  YES      write me a middleware that validates tokens and handles refresh
  -35  no       what is jwt
  -45  no       thanks
   65  YES      refactor this to handle edge cases and manage errors properly
  -20  no       add tests
   70  YES      implement a rate limiter that tracks requests, manages quotas...

Credits

Rewrites draw from your PrePrompt account's monthly credits — the same pool as the Chrome extension. The free plan includes 30 rewrites/month; paid plans add more. See preprompt.org/pricing.

You are not charged when a prompt passes through, when a secret is detected, when you're signed out or out of credits, or when a rewrite fails.

CLI

preprompt-install          # register the hook + MCP server (Claude Code, Cursor)
preprompt-uninstall        # remove everything preprompt-install added
preprompt-login            # sign in with a PrePrompt access token
preprompt-usage            # credits used / remaining this month
preprompt-history          # recent prompt events across all sessions
preprompt-stats            # rewrite stats (total, intercepted, avg score)
preprompt-test-classifier  # see how sample prompts are scored (runs locally)
preprompt-feedback         # rate recent rewrites
preprompt-watch            # live feed of rewrites in a second terminal
preprompt-clip             # rewrite the prompt on your clipboard
preprompt-optimize "..."   # rewrite a prompt from the command line

MCP tools

Requirements

• Python 3.11+
• A PrePrompt account (preprompt.org)
• Claude Code, Cursor, Windsurf, or Zed

Local history is kept at ~/.preprompt/history.db. See what's collected and why.

License

Proprietary — © 2026 PrePrompt. All rights reserved. See LICENSE.

Working on PrePrompt itself? Start with AGENTS.md in the repository.