Backend

Use when debugging Rails issues - provides Rails-specific debugging tools (logs, console, byebug, SQL logging) integrated with systematic debugging process

Use when setting up background jobs, caching, or WebSockets - SolidQueue, SolidCache, SolidCable (TEAM RULE

Python Test-Driven Development expertise with pytest, strict red-green-refactor methodology, FastAPI testing patterns, and Pydantic model testing. Use when implementing Python features with TDD, writing pytest tests, testing FastAPI endpoints, developing with test-first approach, or when user mentions 'Python TDD', 'pytest', 'FastAPI testing', 'red-green-refactor', 'Python unit tests', 'test-driven Python', or 'Python test coverage'.

Use when building Rails controllers - RESTful actions, nested resources, skinny controllers, concerns, strong parameters

Comprehensive knowledge base for go-zero microservices framework. Use this skill when working with go-zero to understand correct patterns for REST APIs (Handler/Logic/Context architecture), RPC services (service discovery, load balancing), database operations (sqlx, MongoDB, caching), resilience patterns (circuit breaker, rate limiting), and troubleshooting common issues. Essential for generating production-ready go-zero code that follows framework conventions.

Use when designing Rails models - ActiveRecord patterns, validations, callbacks, scopes, associations, concerns, query objects, form objects

Setting up and configuring Rails 8+ projects - Gemfile dependencies, environment config, credentials, initializers, Docker, RuboCop, project validation

Systematic methodology for constructing compact (<150 lines), expressive, Claude Code-integrated subagent prompts using lambda contracts and symbolic logic. Use when creating new specialized subagents for Claude Code with agent composition, MCP tool integration, or skill references. Validated with phase-planner-executor (V_instance=0.895).

Apply Grey Haven Studio's TypeScript/React and Python/FastAPI coding standards from production templates. Use when writing code, reviewing PRs, fixing linting errors, formatting files, or when the user mentions 'code standards', 'Grey Haven style', 'linting', 'Prettier', 'ESLint', 'Ruff', 'formatting rules', or 'coding conventions'. Includes exact Prettier/ESLint/Ruff configs, naming conventions, project structure, and multi-tenant database patterns.

CRITICAL - Use when securing Rails applications - XSS, SQL injection, CSRF, file uploads, command injection prevention

Use when building Rails view structure - partials, helpers, forms, nested forms, accessibility (WCAG 2.1 AA)

Use when testing Rails applications - TDD, Minitest, fixtures, model testing, mocking, test helpers

Use when sending emails - ActionMailer with async delivery via SolidQueue, templates, previews, and testing

Wrap JSON-backed database columns with ActiveModel-like classes using store_model. Use when creating configuration objects, managing nested JSON attributes, or adding validations to JSON data. Triggers on JSON columns, store_model, typed JSON, configuration objects, or nested attributes.

Gemini image coder - Generate and edit images using Google's Gemini API. Supports text-to-image, image editing, multi-turn refinement, and composition from multiple reference images. Use when user asks to generate images, create images, edit images, or mentions "gemini image coder".

Build FastAPI applications with async patterns, Pydantic validation, dependency injection, and modern Python API practices.

Write Ruby and Rails code in DHH's distinctive 37signals style. Use this skill when writing Ruby code, Rails applications, creating models, controllers, or any Ruby file. Triggers on Ruby/Rails code generation, refactoring requests, or when the user mentions DHH, 37signals, Basecamp, HEY, Fizzy, or Campfire style.

Router skill for DiPeO runtime Python code (execution handlers, service architecture, domain models, LLM infrastructure). Use when task mentions node handlers, EventBus, ServiceRegistry, Envelope pattern, or domain logic. For simple tasks, handle directly; for complex work, escalate to dipeo-package-maintainer agent.

Use proactively for authorization with ActionPolicy. Creates policies, scopes, and integrates with GraphQL/ActionCable. Preferred over Pundit for composable, cacheable authorization.

Read project config from .agents.yml and .agents.local.yml with local overrides. Supports dot notation for nested fields. Invoke with args "<field> <default>".