Run mutant, read mutation reports, fix alive mutations, and verify coverage. Use when running mutation testing, responding to alive mutations, or improving test quality. Triggers: "mutation testing", "mutant", "alive mutation", "mutation coverage". WHEN NOT: Writing tests from scratch (use rspec-agent), fixing failing tests, or general code review.
Multi-axis adversarial review using friction engineering. Routes a spec, plan, ADR, service design, schema, or any design artifact through 5 specialized reviewers with explicit prohibitions. Each reviewer tags positions as [sound], [contestable], [blind_spot], or [refuted]. Returns a consolidated friction report for human arbitration before implementation begins. Use when reviewing feature specs, architecture decisions, service designs, database schemas, or any artifact where hidden assumptions must be surfaced. WHEN NOT: code already written (use code-review), routine CRUD with no design decisions, quick one-off questions, or post-implementation reviews.
Reviews Dependabot gem upgrade PRs for breaking changes, codebase impact, and merge readiness. Use when user pastes a Dependabot PR URL, asks about a gem version bump, or wants to audit open dependency PRs ("which dep PRs are safe to merge", "audit our deps", "check dependabot"). WHEN NOT: Non-Dependabot PRs, npm/yarn upgrades, or general code review.
PostgreSQL database patterns for query optimization, schema design, indexing, and security.
Behavioral guidelines to reduce common LLM coding mistakes. Use when writing, reviewing, or refactoring code to avoid overcomplication, make surgical changes, surface assumptions, and define verifiable success criteria.
Audits Rails application accessibility against WCAG 2.2 Level AA, detects violations with axe-core / Lighthouse / Pa11y, and reports remediation guidance for ERB views, ViewComponents, Stimulus controllers, and Turbo-powered interactions. Use when the user wants an accessibility audit, WCAG compliance check, a11y review, or mentions screen readers, keyboard navigation, ARIA, color contrast, or Section 508 / ADA / EAA. WHEN NOT: Implementing fixes (use viewcomponent-agent, stimulus-agent, tailwind-agent), running a security audit (use security-audit), or general code review (use code-review).
Get an independent second opinion from OpenAI Codex CLI on a plan, diff, spec, or Claude's last response. Use when the user asks to "get a second opinion", "have codex review", "cross-check with codex", or wants adversarial review of Claude's output. Argument is one of plan|diff|spec|last-response (default last-response).
Implements real-time features with Action Cable and WebSockets. Use when adding live updates, chat features, notifications, real-time dashboards, or when user mentions Action Cable, WebSockets, channels, or real-time. WHEN NOT: Simple HTTP request/response flows, REST APIs, static content, or features that don't need real-time updates.