Extension Submission Checklist Skill

Review and track progress against the official 3D Slicer Extension Index submission requirements.

When to Use

Use this skill when:

• •Preparing to submit an extension to the Slicer Extension Index
• •Reviewing submission readiness
• •Creating a pull request for extension submission

CRITICAL: Verify Latest Requirements First

Before using this checklist, ALWAYS fetch the latest official requirements:

# Fetch the current PR template (authoritative checklist)
curl -s "https://raw.githubusercontent.com/Slicer/ExtensionsIndex/main/.github/PULL_REQUEST_TEMPLATE.md"

# Fetch the current JSON schema
curl -s "https://raw.githubusercontent.com/Slicer/Slicer/main/Schemas/slicer-extension-catalog-entry-schema-v1.0.1.json"

Compare fetched content against this skill. If discrepancies exist, the fetched content is authoritative.

Official Sources (Verified 2025-01-26)

• •PR Template: https://github.com/Slicer/ExtensionsIndex/blob/main/.github/PULL_REQUEST_TEMPLATE.md
• •JSON Schema: https://github.com/Slicer/Slicer/blob/main/Schemas/slicer-extension-catalog-entry-schema-v1.0.1.json
• •Documentation: https://slicer.readthedocs.io/en/latest/developer_guide/extensions.html

Extension Tiers

Extensions are classified by quality/maturity level:

Tiers 2 and 4 are reserved for future use.

Tier 1 Requirements (Minimum for Listing)

Naming and Repository

• • Extension name is reasonable - Not too general, not too narrow, suggests what it's for
• • Extension name does NOT start with "Slicer" - Unless it bridges Slicer to external tool/library
• • Repository name follows convention - Slicer + ExtensionName (e.g., SlicerMouseMaster)
• • Repository has 3d-slicer-extension GitHub topic - For discoverability at https://github.com/topics/3d-slicer-extension

Description and Documentation

• • Extension description summarizes functionality - 1-2 sentences understandable by non-experts
• • Any related patents disclosed - Must be mentioned in extension description if applicable

Licensing

• • LICENSE.txt present in repository root
• • License name mentioned on extension homepage
• • Permissive license used - MIT or Apache recommended
• • If restrictive license used - Reason explained and license name in description

URLs and References

• • scm_url correct - Repository checkout URL (e.g., https://github.com/user/repo.git)
• • scm_revision appropriate - Branch name (main, master) preferred over specific git hash
• • Icon URL correct - Raw data URL, not webpage (e.g., https://raw.githubusercontent.com/...)
• • Screenshot URLs correct - At least one screenshot, raw data URLs

Metadata Consistency

• • JSON file consistent with CMakeLists.txt - Dependencies, category, etc. must match

Homepage Requirements

Homepage URL must point to valid webpage containing:

• • Extension name
• • Short description (1-2 sentences)
• • At least one informative image/screenshot
• • Description of each contained module (at least one sentence each)
• • Publication link (if available) - Link to paper or PubMed reference

GitHub Repository Settings

Hide unused features to reduce noise:

• • Settings > Features - Uncheck Wiki, Projects, Discussions (if not used)
• • About section - Uncheck Releases, Packages (if not used)

Safety Requirements

• • No unreliable binaries - Does not include/download binaries from untrusted sources
• • No data transmission without consent - Explicit opt-in required for any data sending

Tier 3 Requirements (Community-Supported)

All Tier 1 requirements PLUS:

Documentation and Testing

• • Documentation provided for most modules
• • Tutorial with step-by-step instructions - At least for most typical use case
• • Tutorial includes screenshots
• • Sample data registered with Sample Data module - For easy user access

Code Quality

• • Follows Slicer programming conventions - GUI/logic separation, etc.
• • Follows Slicer UI conventions - Minimal popups, no unnecessary custom styling

Build and Platform Support

• • Builds successfully on Windows
• • Builds successfully on macOS
• • Builds successfully on Linux

Maintainer Responsiveness

• • Responds to issues on extension repository
• • Responds to pull requests on extension repository
• • Responds to @mentions on Slicer Forum (discourse.slicer.org)

Licensing (Additional)

• • Permissive license for main functions - Apache or MIT recommended
• • Non-permissive optional components require user approval - Pop-up explaining terms

Tier 5 Requirements (Core Extensions)

All Tier 1 and Tier 3 requirements PLUS:

• • Slicer core developer has commit access - For Slicer-related fixes
• • Automated tests for all critical features
• • Maintainers respond to Forum questions - About the extension

Submission Process Steps

1. •Verify latest requirements (see CRITICAL section above)
2. •Complete all Tier 1 requirements (minimum)
3. •Run /validate-extension-submission skill to check readiness
4. •Run /prepare-extension-metadata skill to generate JSON file
5. •Fork https://github.com/Slicer/ExtensionsIndex
6. •Add your JSON file to the forked repository's main branch
7. •Create pull request using the template
8. •Check all applicable boxes in the PR template
9. •Respond to reviewer feedback

Files to Prepare

Example JSON File (Catalog Entry)

{
  "$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/user/SlicerExtensionName.git",
  "tier": 1
}

Validation Commands

# Validate JSON syntax
python -c "import json; json.load(open('ExtensionName.json'))"

# Check CMakeLists.txt metadata
grep -E "^set\(EXTENSION_" CMakeLists.txt

# Verify icon URL is accessible
curl -sI "https://raw.githubusercontent.com/..." | head -1

# Verify screenshot URLs are accessible
curl -sI "https://raw.githubusercontent.com/..." | head -1