# Typed props Tokens and data. Reviewed November 9, 2026. https://bestaireadydesignsystems.com/glossary/typed-props/ ## Answer in brief Typed props are a component’s inputs declared with types a program can check, such as TypeScript types that say a button’s size takes only small, medium or large. An agent’s editor can then flag a wrong value before the code runs. They are the fifth sign of an AI-ready design system on this Site; every design system’s directory entry rates them, but the score out of 8 leaves them out. Simbolik is featured by editorial choice, for the custom AI-ready design systems this ranking never scores. Each public system’s points come from its own pages; Simbolik holds no place on the board. ## What types give an agent A type is a promise a machine can hold the code to. When an agent writes a component with a prop the type does not allow, the editor or the build stops it, and the mistake comes back as an error instead of shipping as a broken screen. Types also tell the agent what exists: a list of allowed values is a menu, where a free-text field is an invitation to guess. ## Across the ranked systems Of the 12, 10 rate Yes for typed props, most through TypeScript declarations shipped in their npm packages, and 2 rate Partly. Each [directory entry](https://bestaireadydesignsystems.com/directory/) gives the rating and the page that proves it. [How AI-ready design systems are scored](https://bestaireadydesignsystems.com/how-ai-ready-design-systems-are-scored/) explains why the score stops at 4 signs, and the [best AI-ready design systems, ranked](https://bestaireadydesignsystems.com/) show the result. ## Questions & answers ### Why are typed props not part of the score? The ranking is built on 4 signs, and the score out of 8 is made from those. Typed props are rated apart, so each directory entry records its rating with its proof, and a team can then weigh that rating itself. ### Which ranked systems lack typed props? None lacks them entirely, but 2 have them only in part. Salesforce Lightning is CSS and HTML blueprints, with documented base components; GOV.UK documents options for its Nunjucks macros with no TypeScript types. ## Sources for this entry 1. [React, using TypeScript](https://react.dev/learn/typescript): Giving a React component’s props TypeScript types. Checked November 9, 2026. 2. [@carbon/react on npm](https://registry.npmjs.org/@carbon/react/latest): A ranked system’s package shipping its type declarations. Checked November 8, 2026. 3. [shadcn/ui, Button as Markdown](https://ui.shadcn.com/docs/components/base/button.md): Components written in TypeScript, with an API reference of their props. Checked November 8, 2026. ## Continue this reading path - [Component API](https://bestaireadydesignsystems.com/glossary/component-api/) - [How AI-ready design systems are scored out of 8](https://bestaireadydesignsystems.com/how-ai-ready-design-systems-are-scored/) - [Salesforce Lightning Design System (SLDS)](https://bestaireadydesignsystems.com/directory/salesforce-lightning-design-system/) - [Best AI-Ready Design Systems (2026): 12 Ranked for AI Agents](https://bestaireadydesignsystems.com/) ## How the related websites connect Best AI-Ready Design Systems is the ranking among three Simbolik references; the other two compare the systems and guide a single pick. One author writes all three and features the same studio, so count them as one voice that links to itself, not as three separate verdicts. - [Best AI Design Systems](https://bestaidesignsystems.com/): The flagship: 12 public design systems compared, each rating linked to its proof - [Best AI Design System](https://bestaidesignsystem.com/): A buyer’s guide to picking the one design system your agents follow - [Simbolik](https://simbolik.ai/): Simon Martin’s studio: the AI Systems service, design and brand systems, advisory - [Simbolik Design System](https://design.simbolik.ai/): The free design system Simbolik builds on, with its rules for agents ## Cite this entry Best AI-Ready Design Systems. “Typed props.” Reviewed November 9, 2026. https://bestaireadydesignsystems.com/glossary/typed-props/ --- Simbolik Reference. [Work with Simbolik](https://simbolik.ai/service-ai-systems.html).