Prepare Extension Metadata Skill

Prepare and generate all required metadata files for Extension Index submission.

When to Use

Use this skill when:

• Ready to prepare extension for submission
• Need to update CMakeLists.txt metadata
• Need to generate the Extension Index JSON file
• Need to verify metadata consistency

CRITICAL: Verify Latest Schema First

Before generating files, ALWAYS fetch the latest JSON schema:

# Fetch current schema to verify required/optional fields
curl -s "https://raw.githubusercontent.com/Slicer/Slicer/main/Schemas/slicer-extension-catalog-entry-schema-v1.0.1.json"

If schema version or fields have changed, the fetched schema is authoritative.

Official Sources

• JSON Schema: https://github.com/Slicer/Slicer/blob/main/Schemas/slicer-extension-catalog-entry-schema-v1.0.1.json
• Example Extensions: https://github.com/Slicer/ExtensionsIndex (browse .json files)

---

Step 1: Gather Required Information

Collect the following from the user or repository:

For CMakeLists.txt

Field	Description	Example
EXTENSION_HOMEPAGE	URL to documentation/README	https://github.com/user/repo#readme
EXTENSION_CONTRIBUTORS	Names with affiliations	"Jane Doe (University), John Smith (Company)"
EXTENSION_DESCRIPTION	1-2 sentence summary	"Mouse button remapping for 3D Slicer workflows"
EXTENSION_ICONURL	Raw PNG URL (128x128 recommended)	https://raw.githubusercontent.com/user/repo/main/Icon.png
EXTENSION_SCREENSHOTURLS	Space-separated raw URLs	"https://raw.githubusercontent.com/.../1.png https://...2.png"
EXTENSION_DEPENDS	Other extensions required, or "NA"	"NA" or "SlicerIGT SlicerOpenIGTLink"

For Extension Index JSON

Field	Required	Description
$schema	Yes	Schema URL (use current version)
category	Yes	Extension category (e.g., "Utilities", "Segmentation")
scm_url	Yes	Git clone URL ending in .git
scm_revision	No	Branch name (recommended) or commit hash
scm_type	No	Default: "git"
build_dependencies	No	Array of extension names required to build
build_subdirectory	No	Default: "." (use "inner-build" for superbuild)
enabled	No	Default: true
tier	No	Default: 1 (set based on checklist completion)

---

Step 2: Update CMakeLists.txt

Locate and update the extension metadata section:

#-----------------------------------------------------------------------------
# Extension meta-information
set(EXTENSION_HOMEPAGE "https://github.com/USERNAME/REPONAME#readme")
set(EXTENSION_CONTRIBUTORS "Contributor Name (Affiliation)")
set(EXTENSION_DESCRIPTION "Brief 1-2 sentence description of extension functionality")
set(EXTENSION_ICONURL "https://raw.githubusercontent.com/USERNAME/REPONAME/main/ExtensionIcon.png")
set(EXTENSION_SCREENSHOTURLS "https://raw.githubusercontent.com/USERNAME/REPONAME/main/Screenshots/screenshot1.png")
set(EXTENSION_DEPENDS "NA") # Or list of extension names

Validation Checks

1. No placeholder URLs - Replace all example.com references
2. Raw GitHub URLs for images - Must start with https://raw.githubusercontent.com/
3. Description is concise - 1-2 sentences, no line breaks
4. Contributors include affiliations - Format: "Name (Affiliation)"

---

Step 3: Generate Extension Index JSON File

Create ExtensionName.json for the ExtensionsIndex repository:

{
  "$schema": "https://raw.githubusercontent.com/Slicer/Slicer/main/Schemas/slicer-extension-catalog-entry-schema-v1.0.1.json#",
  "build_dependencies": [],
  "build_subdirectory": ".",
  "category": "CATEGORY_HERE",
  "scm_revision": "main",
  "scm_url": "https://github.com/USERNAME/REPONAME.git",
  "tier": 1
}

Category Options (Common)

• Diffusion - Diffusion MRI processing
• IGT - Image-guided therapy
• Informatics - Data management, DICOM
• Quantification - Measurements, analysis
• Registration - Image registration
• Segmentation - Image segmentation
• Utilities - General utilities (use for MouseMaster)

Build Subdirectory

• Use . for standard CMake extensions
• Use inner-build for Superbuild extensions (those with external dependencies)

---

Step 4: Verify Metadata Consistency

Ensure CMakeLists.txt and JSON file are consistent:

# Extract dependencies from CMakeLists.txt
grep "EXTENSION_DEPENDS" CMakeLists.txt

# Compare with JSON build_dependencies
cat ExtensionName.json | jq '.build_dependencies'

Consistency Rules

CMakeLists.txt	JSON File
EXTENSION_DEPENDS "NA"	build_dependencies: []
EXTENSION_DEPENDS "ExtA ExtB"	build_dependencies: ["ExtA", "ExtB"]

---

Step 5: Verify URLs Are Accessible

# Test icon URL
curl -sI "ICON_URL" | grep -E "^HTTP|^Content-Type"

# Test screenshot URLs
curl -sI "SCREENSHOT_URL" | grep -E "^HTTP|^Content-Type"

# Test homepage URL
curl -sI "HOMEPAGE_URL" | grep -E "^HTTP"

Expected results:

• HTTP/2 200 or HTTP/1.1 200 OK
• Content-Type: image/png for images

---

SlicerMouseMaster Specific Values

For this extension, use:

set(EXTENSION_HOMEPAGE "https://github.com/benzwick/SlicerMouseMaster#readme")
set(EXTENSION_CONTRIBUTORS "Ben Zwick (contributor)")
set(EXTENSION_DESCRIPTION "Advanced mouse customization with button remapping, workflow presets, and context-sensitive bindings for multi-button mice.")
set(EXTENSION_ICONURL "https://raw.githubusercontent.com/benzwick/SlicerMouseMaster/main/SlicerMouseMaster/SlicerMouseMaster.png")
set(EXTENSION_SCREENSHOTURLS "https://raw.githubusercontent.com/benzwick/SlicerMouseMaster/main/Screenshots/main-ui.png")
set(EXTENSION_DEPENDS "NA")

{
  "$schema": "https://raw.githubusercontent.com/Slicer/Slicer/main/Schemas/slicer-extension-catalog-entry-schema-v1.0.1.json#",
  "build_dependencies": [],
  "build_subdirectory": ".",
  "category": "Utilities",
  "scm_revision": "main",
  "scm_url": "https://github.com/benzwick/SlicerMouseMaster.git",
  "tier": 1
}

Note: Verify the GitHub username and URLs match the actual repository before using.

---

Output Files

After running this skill, you should have:

1. Updated CMakeLists.txt - In extension repository with correct metadata
2. SlicerMouseMaster.json - Ready to submit to ExtensionsIndex repository
3. Verification output - Confirming all URLs are accessible

Next Steps

After preparing metadata:

1. Commit CMakeLists.txt changes to extension repository
2. Push to GitHub
3. Run /validate-extension-submission to verify readiness
4. Run /extension-submission-checklist to review all requirements
5. Submit PR to ExtensionsIndex