Lexicon MCP

Lexicon is a professional prompt management system for macOS. Organize your AI prompt library, build reusable templates with variables, and trigger prompts directly from Claude Desktop through the built-in Model Context Protocol (MCP) server.

Lexicon requires an auto-renewable subscription — Lexicon Pro, $1.99/month — to unlock and use the app. All of the features described below are part of the Lexicon Pro subscription; there is no separately purchasable content, and the app has no free tier beyond the subscription paywall shown on first launch.

WHAT LEXICON PRO INCLUDES

ORGANIZE YOUR PROMPT LIBRARY
Build a structured library of prompts organized by category, tags, and difficulty level. Lexicon handles libraries of any size with a high-performance virtualized table view. Use the sidebar to browse categories, or search instantly with real-time filtering.

TEMPLATE SYSTEM WITH VARIABLES
Create reusable prompt templates with {{variable}} placeholders. Define argument types, default values, and validation rules. Preview how your prompt renders with sample values before using it.

MCP INTEGRATION
Lexicon includes a bundled MCP server that connects directly to Claude Desktop and other MCP-compatible AI tools. Access your entire prompt library, trigger prompts with arguments, and manage collections — all from within your AI workflow. No separate server installation required.

SMART COLLECTIONS
Create dynamic collections that auto-update based on criteria you define: frequently used prompts, high-rated templates, recently created items, prompts by category or tag, and more. Manual collections let you curate your own groupings.

SEARCH AND FILTER
Find any prompt instantly. Search by name, description, tags, or content. Use search tokens for precision: tag:python, category:code-review, rating:4, difficulty:advanced. Filter by category, difficulty, author, and usage count.

IMPORT AND EXPORT
Import prompts from JSON files or ZIP archives. Export your entire library or individual prompts for sharing and backup. Supports batch operations for team workflows.

PRIVACY FIRST
All data stays on your Mac. No cloud accounts, no telemetry, no external API calls. Your prompts are stored in a local SQLite database that you fully control.

KEY FEATURES (all included with Lexicon Pro):
- Three-pane interface: categories, prompt table, and detail editor
- Multi-message prompt builder with role selection (system, user, assistant)
- Template variable extraction and preview rendering
- Tag management with inline editing
- Usage statistics and metadata tracking
- JSON import/export with ZIP archive support
- Comprehensive keyboard shortcuts
- Dark mode interface

SUBSCRIPTION DETAILS
Lexicon Pro is an auto-renewable subscription priced at $1.99/month that unlocks all of the app's functionality. Payment will be charged to your Apple ID account at confirmation of purchase. The subscription automatically renews unless it is canceled at least 24 hours before the end of the current period. Your account will be charged for renewal within 24 hours prior to the end of the current period. You can manage or cancel your subscription in your Apple ID account settings at any time after purchase.

Privacy Policy: https://heltonlabs.com/lexicon-privacy.html
Terms of Use: https://heltonlabs.com/lexicon-terms.html