cff-version: 1.2.0
message: "If you reference this work, please cite it as below."
title: "Claude's Hidden Toolkit: The Definitive Guide to Claude.ai's Undocumented Internal Tools"
type: software
authors:
  - family-names: "Marinoni Moretto"
    given-names: "Francesco"
    orcid: ""
version: "1.4"
date-released: "2026-03-17"
url: "https://github.com/n1-ai/claude-hidden-toolkit"
license: "CC-BY-4.0"
keywords:
  - claude
  - anthropic
  - ai-tools
  - reverse-engineering
  - internal-tools
  - tool-use
  - model-context-protocol
  - claude-ai
  - artifact-api
  - ios-reminders
abstract: >-
  Comprehensive reverse-engineering documentation of 37 undocumented internal
  tools in Claude.ai's consumer interfaces (browser, desktop app, Android, iOS).
  Covers complete parameter schemas, confirmed response formats, platform-specific
  behavior differences, a three-tier tool loading architecture across four client
  surfaces, the artifact execution layer (Claude-inside-Claude API calls, session-scoped
  storage, MCP endpoint access), and MCP connector state as an architectural variable.
  Based on 50+ manual tests with empirical verification across all platforms. Edition 1.4
  includes contributions from two external researchers.