API Contract Designer

What it does

The API Contract Designer is a specialized architect for your AI agent that ensures your APIs are consistent, scalable, and developer-friendly before a single line of code is written. It shifts focus from "endpoints" to "resource modeling," helping you define the nouns, relationships, and lifecycles of your domain. It handles the heavy lifting of cross-cutting concerns like idempotency, error envelopes, and pagination strategies.

Why use this skill

Generic AI prompts often produce brittle, inconsistent APIs that lack cohesive naming or proper error handling. This skill enforces "consistency by construction" by forcing high-level design decisions—such as auth patterns and versioning strategies—across the entire contract. It proactively flags non-idempotent operations and designs retry logic to prevent distributed systems failures.

Supported Standards & Outputs

• REST and GraphQL architectural styles
• OpenAPI Spec (OAS) skeleton generation
• Resource lifecycle modeling and relationship mapping
• Webhook and event-driven architecture design
• Standardized error envelopes and pagination (Cursor/Offset)

The output is a production-ready blueprint, ranging from structured audit reports to copy-paste OpenAPI templates tailored to your specific tech stack and team constraints.