Sketches

Sketches are the lowest-fidelity artifact in the design toolkit — quick, disposable drawings of an interface, screen, data model, or API interaction meant to explore an idea in minutes rather than hours. They sit at the front of the fidelity spectrum, well before wireframes, mockups, and prototypes, and their whole value is that they are cheap enough to throw away. A sketch is a thinking tool, not a deliverable.

• Low fidelity by design - Rough enough that nobody mistakes them for a finished decision, which keeps feedback focused on ideas.
• Fast and disposable - Made in minutes on paper or a whiteboard, so many alternatives can be tried and discarded.
• Shared vocabulary - A common visual reference that lets designers, engineers, and stakeholders align before code exists.
• Front of the design lifecycle - The first pass that later hardens into a wireframe, mockup, or an API contract.

In API design, sketching is where a resource model or an interaction flow first gets externalized — a napkin diagram of endpoints and relationships that later firms up into an OpenAPI definition or an AsyncAPI contract. Design-first teams often start here precisely because the cost of changing a sketch is near zero while the cost of changing shipped code is high. As more API design moves into agent-assisted tooling, these early rough passes remain the human step where intent is set before it is formalized into machine-readable artifacts.