Design

Development tooling standards including Deno runtime, JSR package registry, and configuration files. Use when setting up projects, managing dependencies, or configuring build tools.

Transform tool-heavy workflows into MCP code execution patterns for token savings and optimized processing. Triggers: MCP, code execution, tool chain, data pipeline, tool transformation, batch processing, workflow optimization Use when: >3 tools chained sequentially, large datasets (>10k rows), large files (>50KB), context usage >25% DO NOT use when: simple tool calls that don't chain. DO NOT use when: context pressure is low and tools are fast. Use this skill BEFORE building complex tool chains. Optimize proactively.

Evaluate public API surfaces against internal guidelines and external exemplars. Triggers: API review, API design, consistency audit, API documentation, versioning, surface inventory, exemplar research Use when: reviewing API design, auditing consistency, governing documentation, researching API exemplars DO NOT use when: architecture review - use architecture-review. DO NOT use when: implementation bugs - use bug-review. Use this skill for API surface evaluation and design review.

Guide to deciding whether to escalate from a lower model (haiku/sonnet) to a higher model (sonnet/opus). Triggers: model escalation, haiku to sonnet, sonnet to opus, reasoning depth, task complexity, model selection, capability trade-off Use when: evaluating whether to escalate models, facing genuine complexity requiring deeper reasoning, novel patterns with no existing solutions, high-stakes decisions requiring capability investment DO NOT use when: thrashing without investigation - investigate root cause first. DO NOT use when: time pressure alone - urgency doesn't change task complexity. DO NOT use when: "just to be safe" - assess actual complexity instead. NEVER escalate without investigation first. This is the Iron Law.

Python testing with pytest, fixtures, mocking, and TDD workflows. Triggers: pytest, unit tests, test fixtures, mocking, TDD, test suite, coverage, test-driven development, testing patterns, parameterized tests Use when: writing unit tests, setting up test suites, implementing TDD, configuring pytest, creating fixtures, async testing DO NOT use when: evaluating test quality - use pensive:test-review instead. DO NOT use when: infrastructure test config - use leyline:pytest-config. Consult this skill for Python testing implementation and patterns.

Generic weighted scoring and threshold-based decision framework for evaluating artifacts against configurable criteria. Triggers: evaluation, scoring, quality gates, decision framework, rubrics, weighted criteria, threshold decisions, artifact evaluation Use when: implementing evaluation systems, creating quality gates, designing scoring rubrics, building decision frameworks DO NOT use when: simple pass/fail without scoring needs. Consult this skill when building evaluation or scoring systems.

Shared testing quality metrics and standards for cross-plugin use. Referenced by pensive:test-review and parseltongue:python-testing. Triggers: testing standards, quality metrics, coverage thresholds, test quality, anti-patterns, testing best practices, quality gates Use when: evaluating test quality, setting coverage thresholds, identifying testing anti-patterns, establishing quality standards DO NOT use when: simple scripts without quality requirements. Consult this skill when establishing testing quality standards.

Build a minimal, stable core system that loads plug-ins to provide feature variability and extensibility for platform development. Triggers: microkernel, plugin architecture, plugin system, extensibility, platform design, IDE architecture, marketplace, core system, plugin loader Use when: building platforms, IDEs, or marketplaces with third-party extensions, core stability is critical while features vary, plugin isolation is needed DO NOT use when: selecting from multiple paradigms - use architecture-paradigms first. DO NOT use when: no extensibility requirements exist. DO NOT use when: plugin isolation overhead isn't justified. Consult this skill when designing plugin architectures or building platforms.

Employ the Hexagonal (Ports & Adapters) pattern to decouple domain logic from infrastructure, maximizing flexibility and testability. Triggers: hexagonal architecture, ports and adapters, infrastructure independence, dependency inversion, clean architecture, domain isolation, adapter pattern, infrastructure abstraction, database independence, framework independence Use when: designing systems with strong business logic separation, anticipating infrastructure changes, needing easy mocking for tests, building portable domain code DO NOT use when: selecting from multiple paradigms - use architecture-paradigms first. DO NOT use when: building simple CRUD apps without complex domain logic. Consult this skill when implementing hexagonal patterns or migrating to port-based design.

Design skills as modular building blocks for predictable token usage. Triggers: skill design, skill architecture, modularization, token optimization, skill structure, refactoring skills, new skill creation, skill complexity Use when: creating new skills that will be >150 lines, breaking down complex monolithic skills, planning skill architecture, refactoring overlapping skills, reviewing skill maintainability, designing skill module structure DO NOT use when: evaluating existing skill quality - use skills-eval instead. DO NOT use when: writing prose for humans - use writing-clearly-and-concisely. DO NOT use when: need improvement recommendations - use skills-eval. Use this skill BEFORE creating any new skill. Check even if unsure.

Create clear, testable specifications with user stories and acceptance criteria. Triggers: spec writing, feature specification, requirements, user stories Use when: creating new specifications or writing acceptance criteria DO NOT use when: generating implementation tasks - use task-planning.

Design and construct virtual memory palaces for spatial knowledge organization using mnemonic techniques. Triggers: memory palace, spatial organization, mnemonic, knowledge architecture, domain mapping, layout design, memory structure, recall enhancement Use when: creating new memory palace structures, organizing complex domains, designing spatial layouts for knowledge retention DO NOT use when: quick knowledge search - use knowledge-locator instead. DO NOT use when: session-specific context - use session-palace-builder. Consult this skill when designing permanent memory palace structures.

Reusable patterns and templates for Claude Code skill and hook development. Triggers: validation patterns, error handling, testing templates, workflow patterns, shared patterns, reusable templates, DRY patterns, common workflows Use when: creating new skills or hooks that need consistent patterns, implementing validation logic, setting up error handling, creating test scaffolding, referencing standard workflow structures DO NOT use when: pattern is specific to one skill only. DO NOT use when: pattern is still evolving - wait for stability. DO NOT use when: pattern is context-dependent requiring variations. Reference these patterns to validate consistency across the ecosystem.

Compose processing stages using a pipes-and-filters model for ETL, media processing, or compiler-like workloads. Triggers: pipeline architecture, pipes and filters, ETL, data transformation, stream processing, CI/CD pipeline, media processing, batch processing Use when: data flows through fixed sequence of transformations, stages can be independently developed and tested, parallel processing of stages is beneficial DO NOT use when: selecting from multiple paradigms - use architecture-paradigms first. DO NOT use when: data flow isn't sequential or predictable. DO NOT use when: complex branching/merging logic dominates. Consult this skill when designing data pipelines or transformation workflows.

Serverless FaaS for event-driven workloads with minimal infrastructure management. Triggers: serverless, FaaS, Lambda, event-driven, pay-per-use Use when: workloads are event-driven with bursty traffic DO NOT use when: long-running processes or stateful operations required.

System architecture: modules, project structure, ADRs, and testing. Use when designing or reviewing systems.

CQRS and Event Sourcing for auditability, read/write separation, and temporal queries. Triggers: CQRS, event sourcing, audit trail, temporal queries Use when: read/write scaling differs or audit trail required DO NOT use when: simple CRUD - use architecture-paradigms first.

Qwen CLI delegation workflow implementing delegation-core for Alibaba's Qwen models. Triggers: qwen cli, qwen delegation, alibaba qwen, qwen batch, multi-file analysis, qwen summarization, qwen extraction, 100K context Use when: delegation-core selected Qwen, need Qwen's large context capabilities, batch processing or multi-file analysis required DO NOT use when: deciding which model to use - use delegation-core first. DO NOT use when: qwen CLI not installed or configured. Consult this skill when implementing Qwen-specific delegation workflows.

Competence in data analytics and machine learning, enabling developers to build data-driven features and integrate AI/ML capabilities.

The practice of restructuring and simplifying code continuously – reducing complexity, improving design, and keeping codebases clean.