Skill UI

A portable discipline for type safety at the network edge of React apps. It establishes a single typed API client as the fetch boundary, enforcing parse-don't-validate rules to transform wire JSON into trusted domain types. This approach normalizes errors and uses branded identifiers to prevent silent bugs, ensuring untyped data never escapes the boundary.

GraphQL enables clients to request precise data structures through a single endpoint with a typed schema. This skill covers schema design, resolvers, DataLoader optimization, federation for microservices, and client integration tools like Apollo. It emphasizes treating the schema as a contract and understanding when to use GraphQL versus REST for complex data relationships.

A comprehensive guide for designing and implementing production-grade microservices using gRPC in Go. Covers best practices for API contract standardization with Protobuf and Buf, securing service-to-service communication via mTLS, and integrating deep observability using OpenTelemetry interceptors. Ideal for building high-performance, reliable internal APIs.

This skill provides comprehensive patterns for creating, maintaining, and validating OpenAPI 3.1 specifications for RESTful APIs. Use it for design-first API contract definition, generating specs from existing code, creating detailed API documentation, validating implementation conformance against the contract, and generating client SDKs. It ensures consistency across the entire API lifecycle.

This skill assists developers in creating Pydantic models following a multi-model pattern for clean API contracts. It supports defining Base, Create, Update, Response, and InDB models with camelCase aliases and optional fields. Ideal for Python backend development, ensuring type safety and seamless integration with TypeScript types.

A critical discipline for managing expenses when integrating paid AI or inference APIs. This guard treats dollar cost as a third complexity dimension, mandating the definition of cost contracts (max calls per run, max budget per run, max budget per day). It enforces best practices for bounding loops, retries, and fan-out, ensuring that code bugs cannot lead to unexpected overspending. Best practice requires configuring hard caps both in the code and at the provider dashboard for defense in depth.

This guide provides a systematic, safe workflow for refactoring rapidly developed or AI-generated fullstack applications. It focuses on identifying and removing dead code, fixing broken imports, and consolidating repetitive logic while strictly maintaining existing API contracts, routes, and core functionality. Use this before launch to ensure a stable, maintainable production baseline, following a 'surgery, not demolition' philosophy.

Generates a draft 2020-12 JSON Schema from an already confirmed field list, defining property names, types and only user-confirmed required or enum values. Use it for API contracts, import/export validation, form generation and schema docs.

Perform evidence-backed impact analysis before changing code, data, interfaces, or governance documents, and compare planned impact with actual diff after implementation. Covers call paths, data/schema, API contracts, tests, docs, ADRs, deployment, migration, and rollback. Use for cross-module or high-risk changes, database migrations, authentication, public interfaces, blast-radius questions, pre-change checks, and post-implementation alignment.

This skill helps design and review API contract tests between providers and consumers. It focuses on verifying wire-level behavior during schema changes, compatibility regressions, and client integration failures. By using local fixtures and existing tools, it ensures type assertions alone are not validation. It classifies changes as breaking or compatible, builds test matrices for various scenarios, and verifies boundaries without provisioning new services.