Overview
Every plugin in the Tons of Skills marketplace is assigned exactly one category. Categories drive the primary navigation on the Explore page, power filtered search results, and help developers find plugins relevant to their workflow. Choosing the right category directly affects your plugin’s discoverability.
Categories are defined in marketplace.extended.json (the marketplace source of truth), not in plugin.json. The plugin manifest handles identity and keywords; the marketplace catalog handles categorization and display metadata. This separation means you can update a plugin’s category without modifying the plugin itself.
Allowed Categories
The marketplace schema enforces a fixed set of 17 categories. CI validation rejects any plugin listing with a category not in this list.
Category Reference Table
| Category | Slug | Description | Example Plugins |
|---|---|---|---|
| Automation | automation | Workflow automation, task scheduling, process orchestration, and repetitive task elimination. | CI pipeline generators, cron job managers, file watchers |
| Business Tools | business-tools | Business process tools, project management integrations, invoicing, CRM workflows, and operational utilities. | Invoice generators, project trackers, reporting tools |
| DevOps | devops | Infrastructure management, CI/CD pipelines, container orchestration, deployment automation, and monitoring. | Terraform helpers, Docker compose generators, Kubernetes auditors |
| Code Analysis | code-analysis | Static analysis, code quality metrics, complexity scoring, dependency auditing, and architectural review. | Linters, complexity analyzers, dead code detectors |
| Debugging | debugging | Bug diagnosis, error analysis, log parsing, stack trace interpretation, and runtime debugging assistance. | Error tracers, log parsers, memory leak detectors |
| AI/ML Assistance | ai-ml-assistance | Machine learning workflows, model training, prompt engineering, data science pipelines, and AI integration. | Model evaluators, prompt optimizers, dataset validators |
| Frontend Development | frontend-development | UI component generation, CSS tooling, responsive design, accessibility testing, and frontend framework utilities. | React scaffolders, CSS generators, design system builders |
| Security | security | Vulnerability scanning, secret detection, compliance checking, penetration testing assistance, and security auditing. | Secret scanners, dependency auditors, OWASP checkers |
| Testing | testing | Test generation, test coverage analysis, mutation testing, E2E test scaffolding, and test quality auditing. | Unit test generators, coverage reporters, test data factories |
| Documentation | documentation | API documentation generation, README scaffolding, changelog management, and technical writing assistance. | API doc generators, changelog builders, JSDoc helpers |
| Performance | performance | Performance profiling, bundle analysis, load testing, optimization recommendations, and runtime benchmarking. | Bundle analyzers, lighthouse auditors, query optimizers |
| Database | database | Database schema management, query optimization, migration generation, and data modeling. | Schema designers, migration generators, query explainers |
| Cloud Infrastructure | cloud-infrastructure | Cloud provider integrations, serverless deployment, infrastructure-as-code, and multi-cloud management. | AWS CDK helpers, GCP deployers, serverless scaffolders |
| Accessibility | accessibility | WCAG compliance checking, screen reader testing, color contrast analysis, and inclusive design tooling. | WCAG auditors, contrast checkers, ARIA validators |
| Mobile | mobile | Mobile app development, React Native tooling, Flutter utilities, and cross-platform mobile workflows. | React Native scaffolders, Flutter generators, app store helpers |
| Skill Enhancers | skill-enhancers | Meta-plugins that enhance Claude Code’s own capabilities, extend the plugin system, or provide cross-cutting utilities. | Plugin validators, skill composers, workflow orchestrators |
| Other | other | Plugins that do not fit neatly into any other category. Use sparingly and only when no other category is a reasonable fit. | Miscellaneous utilities, experimental tools |
Category Distribution
The Tons of Skills marketplace tracks category distribution to ensure balanced coverage. As of the current release, the most populated categories are devops, automation, code-analysis, and testing. Categories like accessibility and mobile have fewer plugins, representing opportunities for new contributions.
How Categories Are Used
Explore Page Filtering
The Explore page displays category chips that allow users to filter the full plugin list. Each chip shows the category name and the count of plugins in that category. Selecting a category filters the grid to show only matching plugins.
Search Integration
The ccpi search command and the marketplace search bar both index categories. Searching for “devops” returns all plugins in the devops category, even if “devops” does not appear in the plugin name or description.
Plugin Detail Pages
Each plugin’s detail page displays its category as a clickable badge. Clicking the badge navigates to the Explore page filtered to that category, helping users discover related plugins.
Marketplace Catalog
The marketplace.extended.json file associates each plugin with its category. During the build pipeline, sync-catalog.mjs copies this data into catalog.json, which powers the Explore page and search index.
Choosing the Right Category
Follow these guidelines to select the most appropriate category for your plugin.
Primary Function Rule
Choose the category that matches the plugin’s primary function, not its implementation technology. A plugin that generates Terraform configurations is devops or cloud-infrastructure, not code-analysis, even though it may analyze existing configs to generate new ones.
Decision Framework
Ask these questions in order:
- What problem does this plugin solve? Map the problem domain to a category.
- Who is the primary user? A plugin for DevOps engineers belongs in
devops; a plugin for frontend developers belongs infrontend-development. - What is the primary output? Test generation belongs in
testing; documentation generation belongs indocumentation. - Does it fit multiple categories? Choose the one that best describes the primary use case. Use
keywordsinplugin.jsonto capture secondary concerns.
Category Selection Examples
| Plugin | Primary Function | Category | Reasoning |
|---|---|---|---|
| Terraform Plan Analyzer | Analyzes Terraform plans for issues | devops | Primary audience is DevOps; primary action is infrastructure review |
| React Component Scaffolder | Generates React components with tests | frontend-development | Primary output is frontend code |
| SQL Query Optimizer | Suggests query performance improvements | database | Primary domain is database operations |
| OWASP Dependency Checker | Scans dependencies for known CVEs | security | Primary function is vulnerability detection |
| API Documentation Generator | Creates OpenAPI docs from source code | documentation | Primary output is documentation |
| Plugin Validator | Validates plugin.json and SKILL.md files | skill-enhancers | Enhances the plugin system itself |
When to Use “other”
The other category is a catch-all for plugins that genuinely do not fit any specific category. Use it sparingly. Before defaulting to other, consider whether the plugin might fit into automation (general-purpose tools) or skill-enhancers (meta-tools).
Plugins in other receive less category-based discovery traffic because users rarely filter by “other.” If possible, choose a more specific category.
Tags and Keywords
While categories provide broad classification, tags and keywords enable fine-grained discovery. Tags are defined in two places:
| Location | Field | Purpose |
|---|---|---|
plugin.json | keywords | Plugin-level discovery terms, indexed by ccpi search |
SKILL.md frontmatter | tags | Skill-level discovery terms, indexed by the marketplace search |
Tagging Best Practices
Be specific. Generic tags like code or tool do not differentiate your plugin. Use technology names, problem domains, and specific frameworks:
// Good
"keywords": ["terraform", "drift-detection", "aws", "infrastructure-as-code"]
// Poor
"keywords": ["code", "tool", "devops", "useful"]Cover the technology stack. Include the primary language, framework, and platform:
"keywords": ["react", "typescript", "storybook", "component-library", "design-system"]Include problem-domain terms. Users search for problems, not solutions:
"keywords": ["memory-leak", "performance-profiling", "heap-analysis", "garbage-collection"]Use synonyms and abbreviations. Users may search for either form:
"keywords": ["kubernetes", "k8s", "container-orchestration", "helm"]Limit to 3-8 keywords. Each keyword should add discovery value. Beyond 8, the marginal benefit drops significantly.
Tag Hierarchy
The marketplace search system indexes keywords in this priority order:
- Plugin
name(highest weight) - Plugin
description - Plugin
keywordsarray - Skill
tagsarrays - Plugin category name
This means keywords do not need to duplicate words already present in the name or description.
Where Categories Are Defined
Categories are set in marketplace.extended.json, the marketplace source of truth. Each plugin entry includes a category field:
{
"name": "terraform-drift-detector",
"category": "devops",
"description": "Detect Terraform configuration drift",
...
}After editing marketplace.extended.json, run pnpm run sync-marketplace to regenerate the CLI-compatible marketplace.json. The marketplace build pipeline then copies catalog data into the Astro site’s data files.
Do not add category to plugin.json. The CI pipeline rejects any plugin.json containing fields outside the eight-field allowlist. See the plugin.json Schema Reference for the complete list of permitted fields.
Category Validation
The Astro content collection schema (marketplace/src/content/config.ts) enforces a Zod enum for categories. If a plugin listing contains an invalid category string, the build fails with a schema validation error.
category: z.enum([
'automation',
'business-tools',
'devops',
'code-analysis',
'debugging',
'ai-ml-assistance',
'frontend-development',
'security',
'testing',
'documentation',
'performance',
'database',
'cloud-infrastructure',
'accessibility',
'mobile',
'skill-enhancers',
'other'
])New categories cannot be added without updating this enum, the validate-plugins.yml CI workflow, and the Explore page filter UI. Category additions are rare and require a pull request to the core repository.
SaaS Packs and Categories
SaaS skill packs (located at plugins/saas-packs/*-pack) follow the same categorization rules but tend to cluster in business-tools, automation, and cloud-infrastructure. Each SaaS pack is a standalone plugin with its own plugin.json and marketplace entry. The category should reflect what the pack helps users accomplish, not the SaaS platform itself.
For example, a Stripe integration pack that helps manage billing workflows belongs in business-tools, while a Datadog integration pack that helps with monitoring belongs in devops.