Answer in brief
A component API is everything a component accepts and gives back: its props or attributes, the values each one allows, its defaults, its events and the places it takes content. It is the contract between the design system and whoever uses the component. An agent can only use a component correctly when that contract is written down where it can read it, ideally as types.
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.
Why it matters to an agent
A person who uses a component wrongly sees the result and fixes it. An agent often does not look. If the API says a button’s variant takes primary or secondary, the agent can stay inside it; if the API is only implied by examples, it may invent a danger variant that renders as nothing. The clearer the contract, the fewer of those quiet failures.
How the ranked systems write it
The 12 document their components for people in different ways, and differ more in how a program can read them: TypeScript types in most, with a manifest of custom elements beside them in Material Web, options tables for a template language in GOV.UK, and HTML blueprints with documented base components in Salesforce Lightning. The typed props term covers the machine-readable part, and the best AI-ready design systems, ranked list each system’s rating for it in its directory entry.
Questions & answers
In the best case, 3 places agree: the type declarations in the package, a props table on the docs page, and a server or manifest it can query. React Spectrum, for one, puts a table of each prop’s type, default and description on every component page, also as Markdown.
Sources for this entry
- React Spectrum, Button as Markdown (opens in a new tab)
A component page with an API table of each prop’s type, default and description.
- Material Web, button docs (opens in a new tab)
A web component’s API section, listing its properties.
- GOV.UK button, Nunjucks options (opens in a new tab)
A component API written as a table of macro options, with no code types.
Continue this reading path
Tokens and data
Quality and checks
Selection and fit
Selection and fit
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 (opens in a new tab)The flagship: 12 public design systems compared, each rating linked to its proof
- Best AI Design System (opens in a new tab)A buyer’s guide to picking the one design system your agents follow
- Simbolik (opens in a new tab)Simon Martin’s studio: the AI Systems service, design and brand systems, advisory
- Simbolik Design System (opens in a new tab)The free design system Simbolik builds on, with its rules for agents
Cite this entry
Best AI-Ready Design Systems. “Component API.” Reviewed . https://bestaireadydesignsystems.com/glossary/component-api/