Get one UX/UI principle by slug: title, code, part, difficulty, summary, the bibliographic citations behind it (author, title, year, url) and the link to the full guide on uxuiprinciples.com. With UXUI_API_KEY set (pro mode) the full guide body comes back in content. Use it to identify, summarize or cite a specific principle; use search_principles first when you only have a topic.

Search the 195 UX/UI principles by free text, part, difficulty or tags. Returns the matching principles with slug, title, code, part name and summary, plus the total count. Use it to find which principles apply to a design question before calling get_principle.

List the 195 UX/UI principles, optionally one part at a time. Returns principle summaries (slug, title, code, part name, summary), the total count and the list of part ids. Use it to browse the catalogue or to learn the part ids for search_principles.

Get the ready-to-use AI prompts attached to one principle (prompts to apply, audit or refactor an interface against it). With UXUI_API_KEY set (pro mode) the prompt texts come back in prompts; without it the prompts belong to the paid Principles Library and the tool returns the count and the URL of the guide. Call get_principle first if you only need the summary.

Get one UX smell (interface anti-pattern) by id: name, tagline, symptoms, the Nielsen heuristic it breaks, a step-by-step fix recipe with a time estimate, the related principles and an audit prompt plus a refactoring prompt. Use it once you know the smell id, from list_smells or detect_smell.

List the 12 UX smells (interface anti-patterns such as overloaded screens, form graveyards, silent errors or the AI-aesthetic cliches), optionally filtered by category. Returns id, name, short name, tagline, category and Nielsen heuristic for each. Use it to browse the catalogue before get_smell.

Detect which UX smells match a plain-language description of an interface problem or a user complaint, in English or Spanish. Returns the matched smells with a confidence level and the suggested fix for each. Use it as the first step when a UI "feels off" and the cause is not named yet; runs offline.

Get a fix for a described UX issue: detects the most likely smell (or uses the one you pass), then returns its step-by-step fix recipe, the principles to apply and a refactoring prompt you can hand to a coding agent. Use it when you want an actionable remedy rather than a diagnosis; runs offline.

Get one user flow (onboarding, forms, pricing, dashboard, checkout, search, authentication and more) with its target metrics, the pre-flight checklist to run before designing it and the post-flight checklist to run before shipping it. Use it before designing or shipping a known flow.

List the 12 user flows covered by the checklists (onboarding, forms, pricing, dashboard, empty states, checkout, settings, navigation, search, authentication, notifications, data tables) with the target metric of each. Returns id, name, description, metric target and the number of checklist items per phase. Use it to pick the id for get_flow, generate_checklist or get_flow_principles.

Generate the pre-flight (before design) or post-flight (before ship) checklist for one user flow. Returns the checklist as structured items (each tied to a principle) and as ready-to-paste markdown. Use it to review a design or a pull request against the flow it implements.

Get the key principles that govern one user flow and the UX smells that most often break it. Returns the principle slugs and the smell ids so you can read them with get_principle and get_smell. Use it to ground a flow review in evidence.

Audit a described screen or flow: returns findings mapped to principles and UX smells, each with severity, remediation and business impact, plus a score, the detected interface type, strengths and the three priority fixes. Pro mode only (UXUI_API_KEY set): the audit runs on the uxuiprinciples.com API. Without a key use detect_smell then suggest_fix, which run offline.

Check a screen you built or designed against eight experience requirements: confirmation before consequential actions, error state, empty state, loading state, undo or edit, sources on AI output, recovery after an AI error, consent before automation. Describe the screen as data (flow, components, actions with flags, states implemented) and get pass, fail or not_applicable per rule, each with the principle it comes from and its citations, plus a markdown summary. Call it after generating or changing a screen and fix every fail. Pro mode only (UXUI_API_KEY set); without a key use generate_checklist for the unevaluated checklist.