Initial release: Edition 1.3 — 28 tools, 3 platforms, fully verified

Claude's Hidden Toolkit documents 28 undocumented internal tools across
Claude.ai's browser, desktop app, and mobile app interfaces. All parameter
schemas and response formats are empirically confirmed through cross-platform
testing.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

.github/ISSUE_TEMPLATE/correction.yml

@@ -0,0 +1,47 @@
+name: "🐛 Correction"
+description: Report an error or outdated information in the book
+title: "[Correction] "
+labels: ["correction"]
+body:
+  - type: input
+    id: location
+    attributes:
+      label: Location in Book
+      description: Which chapter, tool card, or section?
+      placeholder: "e.g., Tool Card 5 (message_compose_v1), Chapter 7"
+    validations:
+      required: true
+  - type: textarea
+    id: current
+    attributes:
+      label: What the Book Currently Says
+      description: Quote or paraphrase the incorrect/outdated content
+    validations:
+      required: true
+  - type: textarea
+    id: observed
+    attributes:
+      label: What You Observed Instead
+      description: Describe the correct behavior with evidence
+    validations:
+      required: true
+  - type: dropdown
+    id: platform
+    attributes:
+      label: Platform Tested On
+      multiple: true
+      options:
+        - Browser (claude.ai)
+        - Desktop App (macOS)
+        - Desktop App (Windows)
+        - Mobile App (Android)
+        - Mobile App (iOS)
+    validations:
+      required: true
+  - type: input
+    id: date
+    attributes:
+      label: Date of Observation
+      placeholder: "2026-02-16"
+    validations:
+      required: true

.github/ISSUE_TEMPLATE/discovery.yml

@@ -0,0 +1,65 @@
+name: "🔍 New Tool Discovery"
+description: Report a newly discovered tool or capability
+title: "[Discovery] "
+labels: ["discovery"]
+body:
+  - type: input
+    id: tool-name
+    attributes:
+      label: Tool Name
+      description: The internal tool name (e.g., `reminder_create_v0`)
+      placeholder: tool_name_v0
+    validations:
+      required: true
+  - type: dropdown
+    id: platform
+    attributes:
+      label: Platform
+      description: Where did you discover this?
+      multiple: true
+      options:
+        - Browser (claude.ai)
+        - Desktop App (macOS)
+        - Desktop App (Windows)
+        - Mobile App (Android)
+        - Mobile App (iOS)
+    validations:
+      required: true
+  - type: dropdown
+    id: discovery-method
+    attributes:
+      label: Discovery Method
+      options:
+        - tool_search query
+        - System prompt extraction
+        - Behavioral observation
+        - Error message / stack trace
+        - Other
+    validations:
+      required: true
+  - type: textarea
+    id: schema
+    attributes:
+      label: Parameter Schema
+      description: JSON schema if available (from tool_search results or system prompt)
+      render: json
+  - type: textarea
+    id: response
+    attributes:
+      label: Response Example
+      description: A real response from calling the tool
+      render: json
+  - type: textarea
+    id: behavior
+    attributes:
+      label: Observed Behavior
+      description: What does the tool do? Any gotchas, edge cases, or platform differences?
+    validations:
+      required: true
+  - type: input
+    id: date
+    attributes:
+      label: Date of Discovery
+      placeholder: "2026-02-16"
+    validations:
+      required: true

.github/ISSUE_TEMPLATE/screenshot.yml

@@ -0,0 +1,48 @@
+name: "📸 Screenshot Contribution"
+description: Submit a screenshot for one of the 22 [Upcoming] figures
+title: "[Screenshot] fig_XX — "
+labels: ["screenshot"]
+body:
+  - type: input
+    id: figure
+    attributes:
+      label: Figure Number
+      description: Which figure are you providing? (fig_01 through fig_22)
+      placeholder: "fig_07"
+    validations:
+      required: true
+  - type: dropdown
+    id: platform
+    attributes:
+      label: Platform Captured On
+      options:
+        - Browser (claude.ai)
+        - Desktop App (macOS)
+        - Desktop App (Windows)
+        - Mobile App (Android)
+        - Mobile App (iOS)
+    validations:
+      required: true
+  - type: textarea
+    id: description
+    attributes:
+      label: What's Shown
+      description: Brief description of what the screenshot captures
+    validations:
+      required: true
+  - type: textarea
+    id: screenshot
+    attributes:
+      label: Screenshot
+      description: Drag and drop your screenshot here. Please blur any personal information.
+    validations:
+      required: true
+  - type: checkboxes
+    id: privacy
+    attributes:
+      label: Privacy Check
+      options:
+        - label: I have blurred or removed all personal information from this screenshot
+          required: true
+        - label: I consent to this image being used in the book under CC BY 4.0
+          required: true