Captures learnings, errors, and corrections to enable continuous improvement. Use when: (1) A command or operation fails unexpectedly, (2) User corrects Claude ('No, that's wrong...', 'Actually...'), (3) User requests a capability that doesn't exist, (4) An external API or tool fails, (5) Claude realizes its knowledge is outdated or incorrect, (6) A better approach is discovered for a recurring task. Also review learnings before major tasks. For CI-only/headless learning capture, use self-improvement-ci.

Automatically identify metamorphic properties (symmetry, linearity, additivity, input invariances) from programs or functions. Use when generating metamorphic tests, discovering program properties, validating transformations, or creating test oracles without explicit specifications. Analyzes control flow, data flow, and sample executions to output structured properties for metamorphic test generation and verification.

Perform a refactor pass focused on simplicity after recent changes. Use when the user asks for a refactor/cleanup pass, simplification, or dead-code removal and expects build/tests to verify behavior.

Zapier automation patterns and Enterprise API integration for Granola. Use when building automated workflows, connecting Granola to 8,000+ apps via Zapier, or querying the Enterprise API for notes and transcripts. Trigger: "granola zapier", "granola automation", "granola API", "granola SDK".

Execute comprehensive platform migrations to Databricks from legacy systems. Use when migrating from on-premises Hadoop, other cloud platforms, or legacy data warehouses to Databricks. Trigger with phrases like "migrate to databricks", "hadoop migration", "snowflake to databricks", "legacy migration", "data warehouse migration".

Apply production-ready Customer.io SDK patterns. Use when implementing typed clients, retry logic, event batching, or singleton management for customerio-node. Trigger: "customer.io best practices", "customer.io patterns", "production customer.io", "customer.io architecture", "customer.io singleton".

Fetch Twitter/X post content including long-form Articles with full images and metadata. Use when Claude needs to retrieve tweet/article content, author info, engagement metrics, and embedded media. Supports individual posts and X Articles (long-form content). Automatically downloads all images to local attachments folder and generates complete Markdown with proper image references. Preferred over Jina for X Articles with images.

Fetch Twitter/X post content by URL using jina.ai API to bypass JavaScript restrictions. Use when Claude needs to retrieve tweet content including author, timestamp, post text, images, and thread replies. Supports individual posts or batch fetching from x.com or twitter.com URLs.

This skill enables Claude to validate test suite quality by performing mutation testing. It is triggered when the user asks to run mutation tests, analyze test effectiveness, or improve test coverage. The skill introduces code mutations, runs tests against the mutated code, and reports on the "survival rate" of the mutations, indicating the effectiveness of the test suite. Use this skill when the user requests to assess the quality of their tests using mutation testing techniques. Specific trigger terms include "mutation testing", "test effectiveness", "mutation score", and "surviving mutants".

Automatically handles semantic version updates across plugin.json and marketplace catalog when user mentions version bump, update version, or release. Ensures version consistency in claude-code-plugins repository.

This skill enables Claude to validate test suite quality by performing mutation testing. It is triggered when the user asks to run mutation tests, analyze test effectiveness, or improve test coverage. The skill introduces code mutations, runs tests against the mutated code, and reports on the "survival rate" of the mutations, indicating the effectiveness of the test suite. Use this skill when the user requests to assess the quality of their tests using mutation testing techniques. Specific trigger terms include "mutation testing", "test effectiveness", "mutation score", and "surviving mutants".

This skill uses the pci-dss-validator plugin to assess codebases and infrastructure configurations for compliance with the Payment Card Industry Data Security Standard (PCI DSS). It identifies potential vulnerabilities and deviations from PCI DSS requirements. Use this skill when the user requests to "validate PCI compliance", "check PCI DSS", "assess PCI security", or "review PCI standards" for a given project or configuration. It helps ensure that systems handling cardholder data meet the necessary security controls.

Automatically handles semantic version updates across plugin.json and marketplace catalog when user mentions version bump, update version, or release. Ensures version consistency in claude-code-plugins repository.

Master authentication and authorization patterns including JWT, OAuth2, session management, and RBAC to build secure, scalable access control systems. Use when implementing auth systems, securing APIs, or debugging security issues.

Build read models and projections from event streams. Use when implementing CQRS read sides, building materialized views, or optimizing query performance in event-sourced systems.

Run focused `kit` CLI commands (file-tree, symbols, search, semantic discovery, dependency analysis, and exports) to build high-signal repository context fast. Use when you need to understand an unfamiliar codebase, prep context for Claude, plan refactors, audit dependencies, or answer “where is X implemented?” without manually grepping.

Release workflow for the Stave repository that confirms whether the next release is patch or minor before bumping the version, reviews the actual PR changes and PR description `Changes` sections in the release scope instead of relying on commit titles alone, generates release notes with `conventional-changelog`, and opens a pull request against `main` from a dedicated temporary release worktree so the user's original checkout stays on its original branch. Use when the user asks to cut the next release, ship the current changes as a versioned release, or prepare a release PR. After the PR merges, the repository's GitHub Actions workflow builds and publishes the release artifacts automatically.

Migrate to RevenueCat from raw StoreKit or Google Play Billing, or upgrade the RevenueCat SDK across a major version. Use when the user says migrate to RevenueCat, switch from StoreKit to RC, upgrade RevenueCat SDK, from v4 to v5, observer mode, RevenueCat major version upgrade, or already have in app purchases and want to add RevenueCat on iOS, Android, Kotlin Multiplatform, Flutter, or React Native.

End-to-end RevenueCat integration — sets up the dashboard side via the RevenueCat MCP (project, app, public API key) and installs/configures the Purchases SDK in the app. Use when the user asks to add RevenueCat, integrate Purchases, install the RevenueCat SDK, set up a RevenueCat API key, configure Purchases on launch, or set up a brand new RevenueCat integration on iOS, Android, Kotlin Multiplatform, Flutter, or React Native.