WHEN deciding whether a PR, branch, diff, or current implementation satisfies an authoritative issue, specification, or decision contract; NOT for improving the written artifact, reconstructing meetings, general code review, or implementing fixes. Returns a read-only criterion-by-criterion proof and acceptance verdict.
Stable consumer-facing API and interface design patterns. Use when designing REST endpoints, cross-team boundaries, or any externally consumed or versioned service contract. Covers contract-first development, error semantics (RFC 9457), REST conventions, pagination, idempotency, rate limiting, and backward…
Decide whether a system needs a backend-for-frontend, how many, and what each one may own: adoption signals and honest costs, one-experience-one-BFF granularity with frontend-team ownership, the shape-don't-decide rule, upstream aggregation with partial-failure and resilience budgets, identity-keyed BFF caching…
Design and protect browser-facing BFF and backend HTTP entry points: an explicit public/protected access classification for every production route, a composition-prepared endpoint registrar that installs session, Origin, Fetch Metadata, CSRF, and content-type policy by construction, provider-free authorization inside…
Use when modifying existing code that lacks tests and you need to document its actual current behavior before making changes -- the legacy code dilemma where you need tests to refactor safely but the code was not written for testability. Specifically for understanding and pinning down what code currently does, not…
Systematic CI/CD failure diagnosis using hypothesis-first investigation, local reproduction, and environment delta analysis. Use when a CI pipeline, GitHub Actions workflow, or build job fails; when tests pass locally but fail in CI; when diagnosing flaky tests, timeouts, or red pipelines; or when the user says "CI is…
Design and evaluate deep modules: cohesive responsibility behind a small, stable caller-facing contract, with information hiding, justified seams, explicit effects, dependency strategy, and behavior-focused tests. Use when designing or changing an in-process module or package contract, consolidating shallow…
WHEN diagnosing a reproducible or observable software failure outside a CI-pipeline-specific workflow; NOT for speculative cleanup, general code review, or speculative behavior changes presented as fixes. Preserves evidence, tests one causal hypothesis at a time, and fixes the owning boundary only when requested…
Create or audit maintainable diagrams when relationships, sequence, state, hierarchy, or quantitative comparisons are materially clearer visually than in prose. Selects a format the destination actually renders, preserves source authority, validates output, and includes an accessible text explanation.
Domain-Driven Design patterns for TypeScript. Use when implementing ubiquitous language, value objects, entities, aggregates, domain events, domain services, or bounded contexts. Only applies to projects that explicitly use DDD. Do NOT use for simple CRUD or projects without domain modeling.
Get a rigorous read-only second opinion on finished work through the host's available reviewer capabilities, preferably from a different model provider. Falls back to a fresh same-provider agent only when necessary and labels the reduced independence. Every review includes a mandatory scope-fidelity check against the…
Research and compare established libraries, open-source tools and applications, managed services, and standard, framework, or platform primitives against an explicit bespoke baseline before committing to a material generic mechanism. Use for library/tool recommendations, build-versus-adopt questions, custom-mechanism…
Event sourcing patterns for functional TypeScript — persist state as an append-only log of past events and rebuild it by folding them. Use when implementing a Decider write model, an event store, projections and read models, event versioning, or snapshots. Builds on the Decider from domain-driven-design and the…
Decide where a learning, gotcha, or decision should live so it is not lost, and capture it there while context is fresh. Use when the user says they just discovered, learned, or found out something non-obvious, asks where a fact should be recorded, written down, or go, wants a setup gotcha, workaround, or decision…
Adversarially review an existing written artifact — stories, plans, acceptance criteria, specs, or design mocks — to surface missing states, unhandled edge cases, unstated assumptions, unverifiable criteria, and slices still too broad or horizontal. Works interactively, one question at a time, writing each answer back…
Discover and, with authorization, install agent skills from the open skills ecosystem. Use when the user explicitly asks to find or install a skill from the external skills ecosystem, asks whether an installable agent skill exists for a task, or wants to extend agent capabilities through skills.sh or a skill…
Use when existing code has untestable dependencies that prevent writing tests -- direct construction of collaborators, static or global function calls, tight coupling to external systems, or singleton access patterns. Specifically for identifying substitution points (seams) that make legacy or tightly-coupled code…
Deprecated compatibility alias for structure-codebase. Activate only for the exact legacy name folder-structure or an explicit $folder-structure invocation. Contains no independent architecture guidance and must delegate to the canonical sibling skill.
Behavior-driven UI testing patterns across Vitest Browser Mode, Playwright E2E evidence boundaries, and DOM Testing Library. Use when testing any front-end application, writing UI or end-to-end tests, querying DOM elements, simulating user interactions, or choosing the lightest harness that proves a browser-observable…
Functional programming patterns with immutable data. Use when writing logic, data transformations, or encountering mutation bugs — including any feature request that builds, merges, filters, sorts, prices or otherwise reshapes records, lists, carts, orders or invoices, even when it never mentions immutability; load it…
Compose installed agent skills into one orchestrated multi-agent run: an agent graph where each node is a sub-agent that loads exactly one skill, edges carry structured data, and stages fan work out, adversarially verify it, and synthesize one deliverable. Claude Code calls the executable form a dynamic workflow; the…
Use when the user or project explicitly adopts hexagonal (ports and adapters) architecture — a README, CLAUDE.md, or ADR that says so is the opt-in. Once a project has opted in, load this for every code change in it, not only architecture work — a new feature, a transport or SDK swap, a bug fix, or a small…
Audit an existing repository or multi-module subsystem for evidence-backed architecture improvements, rank bounded candidates, and present them in a visual HTML report with before-and-after diagrams and a top recommendation. Use when the user asks where architecture investment would pay off across a codebase, wants…
★not rated 728▲
+1 yesterdayA148 tokens
At most 3 mods per repository are shown here, and a mod shipped inside a plugin is left to that plugin's page — the rest are on their repository pages: