Install
claude mcp add raven -- npx -y raven-mcp (or add to your MCP client config manually)
Orientation
Install Raven, then let Claude call design audits, token lookups, UI patterns, and taste checks while it builds. Add it in under 2 minutes — pick the path that matches how you use Claude.
claude mcp add raven -- npx -y raven-mcp (or add to your MCP client config manually)
restart your agent — Raven’s 104 tools are now available
ask your agent to audit a page, generate a design system, or check contrast; it calls the right tool automatically.
If you’re in the terminal, this is the fastest path:
claude mcp add raven -- npx -y raven-mcpAsk Claude to build or check UI; Raven gives it callable tools:
"Build me a pricing page with 3 tiers"
"Check this signup form for accessibility issues"
"Use Stripe's design tokens for the checkout flow"Add a .mcp.json to your project root so everyone on the team gets Raven automatically:
{"mcpServers": {"raven": {"command": "npx","args": ["-y", "raven-mcp"]}}}Add this to your config file (macOS: ~/Library/Application Support/Claude/claude_desktop_config.json · Windows: %APPDATA%\Claude\claude_desktop_config.json):
{"mcpServers": {"raven": {"command": "npx","args": ["-y", "raven-mcp"]}}}Requires Node.js 18 or later.
Prefer not to edit JSON? Download the extension and double-click it. Claude Desktop installs Raven automatically — no Node, no terminal.
macOS · Windows · Linux • ~4.7 MB · v1.12.1
.mcpb file above.git clone https://github.com/rhinocap/raven-mcp.git
cd raven-mcp && npm install && npm run buildReference
Raven provides 104 tools across 19 knowledge layers. Claude calls the relevant tool based on the task; the cards below show what each tool returns.
get_principlesGet design principles relevant to a UI context. Returns usability heuristics, laws of UX, Gestalt principles, accessibility requirements, typography rules, and color theory — matched to what you’re designing.
Parameters
contextrequiredcategoryoptionalplatformoptionalformatoptionalevaluate_designEvaluate a design description against UX principles. Returns relevant principles, potential violations, and improvement suggestions.
Parameters
descriptionoptionalbefore_screenshotoptionalafter_screenshotoptionalgoalsoptionalcontextoptionalcompactoptionalget_checklistGet a pre-publish checklist for a specific UI type. Returns actionable yes/no items to verify before shipping.
Parameters
typerequiredplatformoptionalget_d4d_frameworkGet the Design for Delight (D4D) framework templates. Returns customer problem statement, ideal state, hypothesis, LOFA, and experiment templates for structured product thinking.
Parameters
stageoptionalget_patternGet proven UI/UX patterns for a specific design type. Returns do’s, don’ts, evidence, and checklists for signup flows, pricing pages, navigation, forms, landing pages, dashboards, modals, empty states, error states, loading states, CTAs, social proof, and mobile conversion.
Parameters
typerequiredplatformoptionalgoaloptionalget_business_strategyGet business and monetization strategies for digital products. Covers monetization models, retention strategies, onboarding optimization, growth mechanics, and product metrics frameworks.
Parameters
typerequiredstageoptionallist_design_systemsBrowse available design systems for tokens. Filter by category (fintech, productivity, developer, component-library, design-system) or search by name.
Parameters
categoryoptionalsearchoptionalget_design_systemGet design tokens for a specific design system. Returns colors, typography, spacing, radii, elevation, and motion tokens in W3C DTCG, CSS custom properties, or flat format.
Parameters
idrequiredgroupoptionalformatoptionalgenerate_design_systemGenerate a complete, custom design system with full token set. Provide a brand color to auto-generate a harmonious palette, pick a style preset, and export as visual HTML documentation, CSS variables, W3C DTCG JSON, Figma Variables, or SVG palette card. The HTML export is a beautiful, self-contained page suitable for sharing with stakeholders.
Parameters
namerequiredbase_systemoptionalbrand_coloroptionalstyleoptionaldark_modeoptionalformatoptionalcompose_systemMix tokens from different design systems to create a custom composite. Example: Linear’s colors + Stripe’s typography.
Parameters
compositionsrequiredformatoptionalconfigure_design_system_sourceSave which local DESIGN.md file Raven should use for design-system inventory and comparison.
Parameters
project_dirrequiredsource_kindrequireddesign_file_pathoptionalplatformoptionalaliasesoptionalinventory_design_systemRead component declarations and tokens from a local DESIGN.md file.
Parameters
project_diroptionaldesign_file_pathoptionallist_design_system_componentsList the components and provenance in the Raven canonical baseline.
Parameters
baselineoptionaldiff_design_systemDiff a project’s declared design system (DESIGN.md) against the Raven canonical baseline: reports missing components, missing interaction/accessibility states, missing variants, and raw-literal token drift, as a scored report with fix priorities.
Parameters
project_diroptionaldesign_file_pathoptionalbaselineoptionalplatformoptionallist_content_systemsBrowse available content design systems — brand voice and tone guides from real companies (Mailchimp, GOV.UK, Shopify Polaris, Atlassian). Filter by category or search by name.
Parameters
categoryoptionalsearchoptionalget_content_systemGet a brand’s content design system — voice attributes, tone shifts by context, vocabulary (use/avoid/never), grammar rules, content patterns for errors/empty-states/buttons/etc., and inclusive language guidance.
Parameters
idrequiredsectionoptionalget_content_principlesGet UX-writing principles — clarity over cleverness, active voice, error-message anatomy, inclusive language, voice vs tone, and more. Filter by the writing context (e.g. ’error messages’, ’notifications’, ’form labels’).
Parameters
contextoptionalformatoptionalget_content_patternGet content design patterns — copy recipes for error messages, empty-state copy, notifications, and form validation. Returns do’s, don’ts, good/bad examples, evidence, and a checklist.
Parameters
typerequiredaudit_contentEvaluate an array of content items (headings, prose, CTAs, labels, captions, metrics, outcomes) against UX-writing principles and deterministic heuristics. Returns a per-item verdict (pass/warn/fail) with matched principle ids, concrete issues grounded in principle text, a before→after rewrite suggestion, and an aggregate summary. Heuristics: metric items must carry a number+unit; cta/label must be action-led and ≤4 words; prose flags passive voice, jargon, and hedging; headings flag filler openers and buzzwords; captions flag duplication of any heading in the batch. Pure offline — no network or browser. Use this instead of evaluate_design when you need per-item content verdicts rather than the principle library.
Parameters
itemsrequiredsystemoptionalgoalsoptionalget_research_methodGet research method details — qualitative (interviews, contextual inquiry, diary, field, intercept), quantitative (surveys, analytics, A/B tests, benchmarking, clickstream), or usability (moderated, unmoderated, 5-second, card sort, tree test, heuristic eval). Returns specific protocols, do/don’t guidance, evidence, and a checklist. Use when the user is designing a study or asking how to measure something.
Parameters
categoryoptionalsearchoptionalget_metrics_frameworkGet a product-metrics framework — HEART (Google), AARRR/Pirate (Dave McClure), North Star Metric, Conversion Funnel, RICE Scoring, or OKRs. Returns structure, when-to-use, pitfalls, and examples. Use when the user asks ’how should we measure success?’ or ’what metrics should we track?’
Parameters
idoptionalsearchoptionalget_service_patternGet a service design pattern — service blueprinting, human handoff, signup-as-service, omnichannel continuity, or moments of truth / recovery. Returns patterns, do/don’t guidance, evidence, and a checklist. Use when the user is designing a service flow, escalation, cross-channel experience, or moment of truth.
Parameters
typerequiredget_service_standardGet the GOV.UK Service Standard — 14 points the UK government uses to assess whether a public service is ready to launch. Widely applicable as a rigorous service-quality checklist beyond government. Use when the user asks how to evaluate a whole service.
No parameters
generate_service_blueprintRender a service blueprint as a self-contained HTML page. Supports two modes: (1) classic Shostack single-actor blueprint — user action, frontstage, backstage, support, evidence, pain/delight; (2) two-actor HI-loop blueprint — when `actors` is supplied, renders two swim lanes with a line of interaction between them (e.g. customer ↔ lawyer, patient ↔ doctor, buyer ↔ agent). Each actor gets their own actions, frontstage (what they see), and evidence. Optionally accepts an ideal-state to render side-by-side with the current state.
Parameters
service_namerequiredsubtitleoptionalactorsoptionalcurrentrequiredidealoptionalget_brand_systemGet a complete design system for building an app with branding like a specific company. Say ’Make me an app with branding like Spotify’ and get the full token set, style guide, and implementation instructions. Matches against 12 known design systems and provides closest match with ready-to-use CSS.
Parameters
companyrequiredformatoptionalmodeoptionalget_brand_principlesGet brand and visual-design principles — logo usage (clear space, min sizes, variants, placement, restraint), gradient usage (hierarchy, palette, contrast, trend vs signature), imagery (consistency, representation, purpose), visual hierarchy, and brand-as-system thinking. Use when the user asks about branding, logos, gradients, imagery, visual consistency, or how to treat a brand across surfaces.
Parameters
topicoptionalformatoptionalget_brand_trendsGet current brand and visual-design trends — what’s working in 2026 and where each trend fits or fails. Includes bento grids, monospace type, neon-on-dark-glass, generative patterns, brutalism rebound, AI-generated imagery, lowercase/mixed case. Each trend is time-stamped — treat as a calibration signal, not a prescription.
No parameters
audit_swiftuiAudit SwiftUI source against Apple’s Human Interface Guidelines. Flags hardcoded .font(.system(size:)) below ~13pt and tiny semantic fonts (.caption/.caption2), hardcoded Color(red:green:blue:)/hex instead of asset-catalog or semantic system colors, an empty/undefined AccentColor, interactive frames below 44×44pt, and ad-hoc spacing off the 4/8-pt grid. Rewards semantic Dynamic Type fonts, semantic system colors, SF Symbols, and flexible frames. iOS-native checks only — no web/CSS rules. Returns pass/fail per check with fix instructions.
Parameters
sourcerequiredaccent_color_contentsoptionalstrictoptionalprojectoptionalprofileoptionalaudit_rnAudit React Native / Expo source (JSX/TSX + StyleSheet) against the iOS HIG + Android Material conventions RN must satisfy. Flags touchables missing accessibilityLabel/accessibilityRole, touchables below 44pt without hitSlop, allowFontScaling={false}, fontSize below ~13, screens without SafeAreaView, and (for multi-mode apps) hardcoded colors with no useColorScheme/Appearance dark-mode handling. Rewards SafeAreaView, hitSlop, Platform-aware code, and a theme. RN-native checks only — no web/CSS or SwiftUI rules. Same return shape as audit_page. (RN renders to native widgets, so audit_ios_screen scores the rendered screen.)
Parameters
sourcerequiredcolor_schemeoptionalstrictoptionalprojectoptionalprofileoptionalaudit_ios_screenAudit a rendered iOS screen from a view-hierarchy/accessibility snapshot (and optional screenshot). Alias of audit_screen with platform:"ios". Call with no arguments for the expected snapshot shape. Call with {elements:[{label,rect:{x,y,w,h},role,fontPt,fgColor,bgColor}],viewport:{w,h}} to score 44×44pt touch targets, contrast (with iOS secondaryLabel/tertiaryLabel treated as platform-standard — warn not fail), and visual rhythm (alignment, gap consistency, optical balance) in points. Same return shape as audit_page.
Parameters
projectoptionalprofileoptionalelementsoptionalviewportoptionalscreenshotoptionalaudit_ios_privacyAudit an iOS or React Native/Expo app’s privacy posture for App Review and user trust. Reads a native Info.plist XML OR an Expo app.json (managed Expo apps have no Info.plist) — plus optional PRIVACY.md, entitlements, and source. Flags: NS*UsageDescription strings that are vague/missing or contradict the code (e.g. a HealthKit write claim the code never fulfills), entitlements/permissions and Android permissions the app doesn’t use, ATS cleartext exceptions and non-HTTPS endpoints, secrets/keys shipped in the bundle or app.json, and default data-egress paths not disclosed at the point of choice (a pre-selected ’Recommended’ option that silently sends personal data to a server). Same return shape as audit_page.
Parameters
info_plistoptionalapp_jsonoptionalprivacy_mdoptionalentitlementsoptionalsourceoptionalaudit_ios_a11yScore an accessibility-enriched iOS element snapshot — missing accessibilityLabel/value/traits, sub-44pt tap targets, per-text WCAG contrast, Dynamic Type clipping, and VoiceOver reading order. Provide {elements:[{label,value,hint,traits,role,rect,fontPt,fgColor,bgColor,dynamicTypeClipped}],viewport}. Capture via the AccessibilitySnapshot XCUITest / ios-capture harness.
Parameters
elementsrequiredviewportrequiredoptionsoptionalaudit_screenAudit a rendered mobile screen (iOS or Android) from a view-hierarchy/accessibility snapshot. Call with no arguments for the expected snapshot shape and how to capture it. Pass platform:"android" to score against the 48dp Material touch minimum and Material muted roles (onSurfaceVariant/outline = warn not fail); default platform:"ios" scores 44pt and treats secondaryLabel/tertiaryLabel as platform-standard. Both score touch targets, contrast, and visual rhythm (alignment, gap consistency, optical balance). Same return shape as audit_page.
Parameters
platformoptionalscroll_settleoptionalprojectoptionalprofileoptionalelementsoptionalviewportoptionalscreenshotoptionalaudit_device_frameDetect cropped content in device-mockup frames (phone/MacBook screenshots, app-preview clips). Three checks: (1) GEOMETRY — call with `frames` (container box + intrinsic media size + object-fit/position; call with NO args for a DevTools snippet) to flag object-fit:cover crop loss when the frame’s aspect ratio ≠ the media’s; (2) MOTION — pass `clips` (first/last frame PNG paths) to detect baked-in pan/zoom (Ken Burns) that drifts the composition; (3) EDGE — pass `edge_frames` (PNG paths) to flag content truncated at a frame edge. Catches the exact failure where a 16:9 clip in a 1.82-AR screen cutout silently slices the bottom, or a Ken-Burns-zoomed source crops content.
Parameters
framesoptionalclipsoptionaledge_framesoptionalaudit_parityCompare iOS vs Android element snapshots against a checklist of named spatial relationships (vertical centering, baseline/left alignment, equal gap/size, presence, truncation) and flag per-relation match/mismatch/uncertain — catches cross-platform layout drift like status text centered on one platform but top-aligned on the other. Provide ios+android {elements,viewport} snapshots and a checklist[].
Parameters
iosrequiredandroidrequiredchecklistrequiredaudit_video_playbackRender a page in headless Chromium and observe whether each <video> actually advances (samples currentTime before/after a play attempt), classifying every clip into playing|paused|stalled|empty|error with a reason. Catches black/non-playing videos that static audits miss — the most common real-world defect on marketing sites with video backgrounds. Pass url to render + observe, or dom_snapshot to classify pre-collected observations without a browser.
Parameters
urloptionaldom_snapshotoptionalobserveMsoptionalauditRun all applicable Raven audits for a target. Detects the surface (web page / iOS screen / React Native / code diff / video) and fans out to the right checks — contrast, tap targets, typography, layout, responsive, and taste for web; the iOS or RN set for native; parity/contract for diffs. Use this instead of choosing individual audit_* tools. Pass `project` to judge against bound taste.
Parameters
urloptionalhtmloptionalnodesoptionalsourceoptionalscreenshotoptionaldiffoptionalsurfaceoptionalintentoptionalprojectoptionalprofileoptionalaudit_pageAudit HTML/CSS against Raven’s design quality standards. Checks typography (min 13px, weight 400+, modular-scale heading ratios, line-height consistency), accessibility (WCAG touch targets, alt text, contrast), responsive patterns (flexbox over grid, clamp sizing, max-width containers), style guide compliance (CSS custom properties, no bare hex), and visual rhythm (4/8px spacing grid, tight spacing scale, palette size). Pass containerMaxWidth (your design system’s canonical container token, in px) to make the max-width check token-aware — it then flags containers that diverge from your system (too narrow OR too wide) instead of a generic 1200px heuristic. Returns pass/fail per check with specific fix instructions.
Parameters
htmloptionalurloptionalscroll_settleoptionalinteractionsoptionalviewportoptionalstrictoptionalcontainerMaxWidthoptionaladversarial_verifyoptionalcompactoptionalaudit_urlLayer 0 render-and-capture audit: renders a LIVE URL at each viewport×theme, scroll-settles (fires whileInView/IntersectionObserver reveals; plays preload=none videos), fires hover/click/focus interactions, and captures real pixels + the rendered DOM. Then runs the existing audit_page rule engine, per-element WCAG contrast, responsive-visibility (desktop-shown/mobile-hidden), blank-media detection, sliced-image edge symmetry, and hover-state white-wash detection over the captures. Every finding is tagged confirmed | likely-artifact | inconclusive with its evidence, ranked by severity. This is the tool that catches real-world visual nits invisible to HTML-string/geometry audits: cropped images, blank videos, hover white-wash, sliced exports, and hidden-on-mobile content. Requires headless chromium.
Parameters
urlrequiredviewportsoptionalthemesoptionalscroll_settleoptionalinteractionsoptionalcontainerMaxWidthoptionalincludeScreenshotsoptionaltimeoutMsoptionalcompactoptionalscore_pageScore an HTML/CSS page across 7 design categories (Structure, Typography, Color & palette, Spacing & rhythm, Accessibility, Responsive layout, Design tokens), each rated 0–10. Scores are derived deterministically from the same checks as audit_page — no browser required. Also returns the same overall 0–100 score and A–D grade audit_page produces, the weakest category, and the three categories Raven does not mechanically assess (brand, conversion, motion) with guidance on which tools to use for those.
Parameters
htmlrequiredstrictoptionalcontainerMaxWidthoptionalaudit_layoutEvaluate visual rhythm from a rendered page’s geometry. Call with no arguments to get a DevTools snippet to paste into your page — it prints {elements, viewport} JSON. Call again with that JSON to get alignment, gap-rhythm, and optical-balance scores. This is the complement to audit_page for things only visible once rendered.
Parameters
elementsoptionalviewportoptionalaudit_typographyAudit the typographic SCALE of a rendered page (pass url) or a pre-collected snapshot of text nodes. Emits a focused report: (a) MODULAR SCALE — detects the dominant ratio (~1.2/1.25/1.333/1.5) across distinct font sizes and flags off-scale outliers; (b) LINE-HEIGHT CONSISTENCY — unitless lh/fs ratio per node, identifies the body rhythm and flags outliers; (c) WEIGHT LADDER — distinct weights, flags >4 weights or non-standard CSS values. Returns scale, line_height, weight_ladder, nodes_analyzed, and findings[{rule,severity,selector,message,fix}]. Goes beyond audit_page’s pass/fail typography checks. url mode requires headless chromium.
Parameters
urloptionalnodesoptionalaudit_tap_targetsWCAG 2.5.5 / Apple 44pt tap-target audit for the web. Collects every interactive element (a, button, [role=button], input[type=submit/button/checkbox/radio], select, summary, label[for], [onclick], [tabindex>=0]) and emits a PER-ELEMENT fix table for any whose rendered width or height is below the minimum (default 44px): selector, role, visible text, measured w/h, pixel deficit per axis, and a concrete CSS fix. Sorted worst-first. Two modes: pass url (renders in headless chromium, measures real getBoundingClientRect) or pass elements[] snapshot (pure, no browser).
Parameters
urloptionalelementsoptionalminSizeoptionalaudit_contrastCompute WCAG contrast ratios for every text element on a rendered page (pass url) or from a supplied dom_snapshot. Reports AA (4.5:1 normal, 3:1 large) and AAA pass/fail per element and surfaces failing pairs with selector, ratio, and delta-to-pass — replacing manual eyedropper + ratio math.
Parameters
urloptionaldom_snapshotoptionalscreenshotoptionalsuggest_contrast_fixGiven failing WCAG color pairs, return the MINIMAL color change that clears the target ratio. For each {fg,bg} pair, computes the smallest foreground adjustment (and an alternative background adjustment) that reaches AA/AAA — with the achieved ratio and direction. Feeds directly from audit_contrast’s failing pairs: pass them here to get concrete passing values instead of brute-forcing colors by hand. Pure offline math.
Parameters
pairsoptionalleveloptionalaudit_responsive_visibilityRender a URL at multiple breakpoints and flag content elements that are visible on desktop but hidden on mobile (display:none / opacity:0 / visibility:hidden / zero-size). Categorises each flag as ’likely-oversight’ (content that vanishes on mobile — the hidden-on-mobile content bug) vs ’intentional’ (decorative). Returns a table of selector / hiding-class / mobile-visible / desktop-visible / category. Requires headless chromium.
Parameters
urlrequiredbreakpointsoptionalviewportHeightoptionalaudit_consistencyAudit multiple pages for cross-page consistency of content-container width and hero heading tier. Pass ≥2 pages ({name, html}) collected from different routes on the same site. Infers the canonical (modal) value from the corpus when no token is supplied, so you need not know the project’s design token in advance. Flags the issue #9 single-blob blind spot: pages that each pass audit_page but silently disagree with each other on container width or hero size class. Returns per-page extraction (container_px, container_classes, hero_classes, signatures), consistency dimensions with reference values, outlier page names, issues[], score (100/50/0 → A/C/D), and a plain-text summary. Pure offline — no browser, no network.
Parameters
pagesrequiredcontainer_tokenoptionalhero_tokenoptionalaudit_asset_integrityDetect PNG exports whose content is sliced/cut off at the bottom edge (e.g. a Figma export that ended mid-form). Dimension/ratio checks cannot catch cut content inside a correctly-sized file; this measures per-pixel luminance variance in the bottom strip — uniform background = clean, high-variance UI content running into the edge = likely-sliced. Accepts filesystem paths to PNGs.
Parameters
image_pathsrequiredaudit_contractVerify a wire contract (token list / field set / schemaVersion) is identical across N independent source files (iOS Swift, proxy JS, Android Kotlin). Flags missing/inconsistent tokens, schemaVersion drift, and prefix-ordering bugs (a contained token matched before the longer one). BLOCK/PASS verdict.
Parameters
contract_specrequiredfile_pathsrequiredaudit_api_contractRun adversarial queries against a live endpoint and return per-query verdict (shape-valid / shape-invalid / confident-wrong / uncertain) vs an expected shape schema + per-query expectations. Catches responses that are shape-valid but wrong.
Parameters
endpoint_urlrequiredqueriesrequiredexpected_shape_schemarequiredreview_diffReview added UI-code lines in a unified diff against the project’s own DESIGN.md tokens and active recorded design decisions. Returns a structured CI verdict with file/line findings and nearest-token suggestions. Agents should call this on every PR or diff that touches UI code before merge.
Parameters
diffrequiredprojectoptionaldesign_mdoptionalfail_onoptionalfail_on_governedoptionalpolish_diffReview added UI-code lines and propose deterministic DESIGN.md token substitutions without writing files. The returned unified patch applies on top of the reviewed diff’s post-image; applying it is an explicit, separate step by the caller. Re-verifies the hypothetical polished lines and leaves judgment-heavy findings in manual.
Parameters
diffrequiredprojectoptionaldesign_mdoptionalsearch_knowledgeSearch across all design principles, UI patterns, and business strategies. Use when you need to find specific guidance or don’t know which category to look in.
Parameters
queryrequiredlayeroptionalcreate_taste_profileCreate (or overwrite) a named taste profile — a portable design-judgment ruleset + precedent corpus persisted locally under ~/.raven/taste/<name>.json (override dir with RAVEN_TASTE_HOME). Pass explicit rules[] (rule_id, clause_text, category, severity_default block|warn|nit, negative_prompt, owner taste|raven, delegate_to), and/or a DESIGN.md-style markdown doc to ingest (## headings = categories; ’- ’ bullets = rules; ’(block)’/’(warn)’/’(nit)’ severity markers; ’(raven:<tool>)’ delegates a rule to an existing Raven audit tool; ’(scope:<surface>)’ scopes a rule to one surface; ’Do NOT …’ sentences become the rule’s negative prompt). Ingest RULES-SHAPED docs only (actionable design constraints under category headings) — brand-story/mythology docs produce noise rules, not judgment. Local-first: nothing leaves the machine.
Parameters
namerequiredrulesoptionalcorpusoptionalmarkdownoptionalget_taste_profileLoad a locally stored taste profile by name — returns its full rule catalog, precedent corpus, and per-project surface bindings. NOT a calibration step: bindings are per-surface and do not transfer — for design work on a project without a binding, call get_taste_interview and ask the user its questions before committing any direction.
Parameters
namerequiredget_taste_interviewSTART HERE on a NEW project: returns a deterministic calibration interview — built from the taste profile’s own voice/tone rules and eleven design dimensions (typography, spacing, color, layout, motion, imagery, entrance, loading, navigation, aesthetic, libraries), each grounded in what the profile already enforces and most carrying multiple-choice options — the libraries question names specialty tech (three.js, GSAP, anime.js, framer-motion, lottie, GraphQL, vanilla) in plain outcome language so a non-technical person can choose by what users would see, and states the default build target for sites: a Next.js app, unless the user prefers otherwise — asking how the taste should show up on THIS surface (e.g. a monochrome portfolio wants the one-accent rule at full block; a product site doesn’t want monochrome suggestions at all, and may tolerate a warmer voice). The voice question always renders the same message in three registers (formal-technical / warm-conversational / punchy-editorial) so the user picks by ear, not by adjective — asked even when the profile has zero voice rules. Every question carries skippable + priority (’core’|’extended’); only identity is required — skipping the rest is fine but leaves that item uncalibrated and silent in future audits. A ’references’ question invites example URLs/screenshots/files, each interviewed with follow-ups about what specifically draws the person (element + quality), folded into the matching design_notes and listed under design_notes.references. The interview closes with an open-ended ’special’ question (any texture, signature detail, motif, or easter egg nothing else asked about — stored as design_notes.special); once the person has other bound surfaces, it carries `suggestions` — the special touches they chose elsewhere — so the interview starts proposing their own style back. Ask the user the returned questions conversationally, then persist the answers with bind_taste_surface (dimension answers go in design_notes). Run this BEFORE the first audit_taste on any project that has no binding yet — audit results include a calibration_hint when calibration is missing. When a user dislikes generated/designed output on an ALREADY-calibrated project, re-run with mode:’refine’ instead of starting over — dissatisfaction is a calibration signal, not a dead end: it requires an existing binding, then interviews what specifically fell short, offers to keep/tighten/replace each stored design_notes value, re-asks voice, and offers to log a reject precedent via label_finding. mode defaults to ’kickoff’.
Parameters
profilerequiredprojectoptionalmodeoptionalbind_taste_surfacePersist a project’s surface calibration for a taste profile — the answers from get_taste_interview. A binding records: the surface string scoped rules match against (e.g. ’product-site’), URL hosts that identify the project in url-mode audits, per-rule severity overrides (block|warn|nit|off — ’off’ silences a rule on this surface), an optional voice/tone note, per-dimension design_notes (typography, spacing, color, layout, motion, imagery, entrance, loading, navigation, aesthetic, libraries, special — the interview’s design:* answers), and a first-class `references` array — the example sites the person pointed to. References are NOT lossy prose: each url is captured live and its PageTraits (scheme, luminance, animation/scroll motion, text density) are stored on the binding, then design_notes are consistency-checked against what the references ACTUALLY are. A ’dark, cinematic’ color note against two references that both render light comes back as a consistency_warning to surface to the user. Upserts by project name (~/.raven/taste/<profile>.surfaces.json). When the design_notes name an expensive technique (three.js/WebGL, GSAP scroll choreography, anime.js staggered motion, glassmorphism, a branded loader, lottie, kinetic display type…), the result carries build_hints — a concrete recipe + canonical public example sources per technique, so the builder sees the HOW at kickoff, BEFORE building; an expensive note is not license to drop it. After binding, audit_taste with project:’<name>’ or a bound url applies the calibration automatically: matching scoped rules run at full severity, non-matching ones are skipped, overrides re-tune the rest. ENFORCED: binding a BRAND-NEW surface with no calibration content (no design_notes/voice_note/references/overrides) is REFUSED — that is the fingerprint of a skipped kickoff interview. Run get_taste_interview, ask the USER, and bind their answers; the uncalibrated_ack escape hatch exists only for a user who was interviewed and deliberately skipped every dimension.
Parameters
profilerequiredprojectrequiredsurfacerequiredhostsoptionaloverridesoptionalvoice_noteoptionaldesign_notesoptionalreferencesoptionaluncalibrated_ackoptionalrecord_taste_decisionThe Taste Engine’s learning loop — record a taste, direction, or design decision the MOMENT it is made during real work (an accent chosen, a nav pattern rejected, a name direction picked, a type pairing approved), not just at interview time. Each record carries the project, a short dimension name (a standard one like color/navigation or a new category like iconography/sound), what was chosen in the user’s words, the alternatives rejected, why, and a source: ’user-directed’ (the user asked for it), ’user-approved’ (the user accepted a proposal), or ’user-corrected’ (the user overrode a generated choice — the highest-signal record). Recorded decisions evolve every future get_taste_interview kickoff: recurring choices return as suggested defaults on their dimension’s question, and decision categories no standard question covers become NEW interview questions. Record liberally — every committed decision is calibration data.
Parameters
profilerequiredprojectrequireddimensionrequireddecisionrequiredrejectedoptionalwhyoptionalsourceoptionallist_taste_decisionsList the taste/direction/design decisions recorded for a profile (see record_taste_decision), optionally filtered by project or dimension — the ledger that evolves the kickoff interview.
Parameters
profilerequiredprojectoptionaldimensionoptionallist_taste_profilesList locally stored taste profiles with rule/corpus counts and last-updated timestamps.
No parameters
generate_taste_portraitRender a bound Taste Engine surface as a self-contained designed HTML portrait. Pass project to render one binding, or omit project to render every binding plus a gallery index.html. Portraits are generated from the local taste store and should be verified with audit_taste against their own surface/project before sharing — pass document_kind:’portrait’ on that audit: a portrait is a document ABOUT the surface, so design_notes (three.js scenes, branded loaders…) are not acceptance criteria for it; profile rules still bind in full.
Parameters
profilerequiredprojectoptionaloutput_dirrequiredaudit_tasteJudge a target against a taste profile. Pass html (static page/CSS), text (a copy block), or url (rendered headless; also runs delegated WCAG-contrast/tap-target measurements for owner:raven rules). owner:taste rules run deterministic detectors — gradients, glow/neon (large-blur colored shadows), second accent hue, banned-word lists from the rule’s negative prompt; clauses with no deterministic detector are reported honestly under not_assessed instead of guessed. owner:raven rules route through Raven’s existing audit engines (page checks, contrast, tap targets) and fold results in under the delegating rule_id. Every finding cites an existing rule_id + concrete evidence — the engine prefers silence over a speculative nit. accept-verdict corpus precedents suppress previously-approved patterns. When the resolved binding carries design_notes, audit_taste VERIFIES each note against the artifact instead of only echoing it: url mode measures the rendered page’s traits (scheme/luminance, canvas+WebGL, animations, scroll effects, text density, fonts, heading scale, loader, backdrop-filter), html mode extracts what it can statically, and every note comes back in note_assessments as present/partial/missing/unverifiable with trait-number evidence — design_notes are ACCEPTANCE CRITERIA for a build, not mood words. Missing notes become fidelity_findings (NOTE-<key>, warn — block when a named library like three.js/gsap/lottie/anime.js or a branded loader is wholly absent), the target is compared against the binding’s captured references (REF-* deltas on scheme, density, motion, type scale), and sparse-and-empty pages are flagged (TASTE-restraint-earned: sparseness must be earned by craft density, not achieved by deletion). fidelity_findings count toward the verdict. When a note names an expensive technique (three.js/WebGL, GSAP scroll choreography, anime.js staggered motion, glassmorphism, a branded loader, lottie, kinetic display type…), the result carries build_hints — a concrete recipe + canonical public example sources for that technique, so a failing audit hands the fix ammunition next to the missing finding; an expensive note is never license to drop it. Rules may carry a scope (e.g. portfolio-monochrome); pass surface to say what you’re judging — scoped rules run at full severity on a matching surface, are skipped (reported under skipped_out_of_scope) on a non-matching one, and can warn but never block when surface is omitted. Better: pass project (or audit a bound url host) so a saved surface binding supplies the surface, per-rule overrides, and voice note automatically — on a NEW project with no binding, run get_taste_interview first (results carry a calibration_hint when calibration is missing). Verdict: BLOCK (any block finding) / WARN (any warn) / PASS.
Parameters
profilerequiredhtmloptionaltextoptionalurloptionalsurfaceoptionalprojectoptionaldocument_kindoptionallabel_findingAppend a labeled precedent to a taste profile’s corpus — the growth loop. Use when a human accepts/revises/rejects an audit_taste finding or labels a new wrong→right example. Append-only: existing records are never rewritten. accept-verdict precedents suppress matching findings in future audit_taste runs.
Parameters
profilerequiredartifactrequiredverdictrequiredviolated_rulerequiredseverityoptionalwrongrequiredrightrequireddecision_addAdd an active decision to the local Decision Graph.
Parameters
statementrequiredrationaleoptionalscoperequiredcomponent_refrequiredalternatives_rejectedoptionalauthoroptionaldecision_draftCapture a decision from working context with the why deferred for later confirmation.
Parameters
statementrequiredscoperequiredcomponent_refrequiredalternatives_rejectedoptionaldecision_commitCommit or confirm the rationale for a draft or extracted decision.
Parameters
idrequiredrationalerequiredsimilarity_thresholdoptionaldecision_evidenceAttach quantitative or qualitative evidence to an existing decision.
Parameters
decision_idrequiredtyperequiredsource_refrequiredresult_summaryrequiredconfidencerequiredconfoundsoptionaldecision_getGet a Decision Graph node and every node connected to it by an edge in either direction.
Parameters
idrequireddecision_listList decisions in the local Decision Graph. Defaults to active decisions.
Parameters
statusoptionalinclude_candidatesoptionaldrafts_onlyoptionaldecision_historyReturn the complete supersession lineage for a decision, ordered oldest to newest.
Parameters
idrequireddecision_supersedeExplicitly supersede one decision with another while preserving both nodes and their lineage.
Parameters
old_idrequirednew_idrequireddecision_scopeNarrow two decisions to distinct scopes so both can remain active alongside one another.
Parameters
id_arequiredid_brequiredscope_arequiredscope_brequiredgap_scanScan the local Decision Graph for uncovered components, weak rationales, contested decisions, and derived staleness. Schedulers should call with digest_only:true and treat actionable:false as a no-op.
Parameters
use_casesoptionalreference_systemsoptionaldigest_onlyoptionaldecision_importMine local git history and decision-bearing Markdown into provenance-tagged Decision Graph extraction prompts. Imported history remains review-only until decision_commit.
Parameters
repo_pathrequireddoc_globsoptionalmax_commitsoptionalmax_chunk_charsoptionalingest_transcriptStore a transcript source and return an extraction prompt for the calling agent’s model. Raven makes no model or network call.
Parameters
textrequiredsource_metarequiredingest_transcript_resultsParse model-produced extraction JSON into reviewable Decision Graph candidates linked to their source. Nothing is auto-confirmed.
Parameters
source_idrequiredextraction_jsonrequiredread_design_mdParse a DESIGN.md file and return its frontmatter, Markdown body, and flattened token index.
Parameters
pathrequiredinit_design_mdInitialize a DESIGN.md file from a stored Raven token system, a getdesign.md starter slug, or a blank template.
Parameters
pathrequiredfromoptionalupdate_design_mdUpdate one DESIGN.md token surgically while preserving the Markdown body.
Parameters
pathrequiredsetoptionalrenameoptionalremoveoptionalstart_grab_sessionStart a capability-keyed Raven grab bridge on loopback. Proxy mode is the preferred zero-paste path: it serves a running local app with the overlay injected into HTML; the manual script tag remains available when needed.
Parameters
pathrequiredportoptionalproxy_targetoptionalroleoptionalget_grabbed_elementsDrain the current grab queue, optionally waiting up to timeout_ms for the next selection.
Parameters
timeout_msoptionalstop_grab_sessionStop the current grab bridge and clear its queued selections.
No parameters
get_grab_layersRead the latest non-mutating layer-tree snapshot captured by the active local grab session. Any fixed/flexible permissions are cooperative advisory metadata: display labels only, not enforced.
Parameters
pageoptionalmove_grab_layerQueue a same-page layer reorder or reparent intent (previewed when measuredRects are supplied, otherwise proposed) without mutating the live page. Reparent moves a node to a different parent (toParentSelector); reorder keeps a single parentSelector. Permissions and fixed/flexible roles are cooperative advisory metadata: display labels only, not enforced; caller-supplied roles are rejected. Shadow-root and iframe boundaries are out of scope.
Parameters
operationrequiredpagerequiredparentSelectoroptionalfromParentSelectoroptionaltoParentSelectoroptionalfromIndexrequiredtoIndexrequiredorderedSelectorsrequiredbaselineOrderoptionaltoBaselineOrderoptionalselectionOrderoptionalmeasuredRectsrequiredapproximaterequireddomSnapshotHashrequiredtoDomSnapshotHashoptionalfromSelectoroptionalroleoptionalget_grab_operationRead or update one durable grab change, list legacy reorder operations, or request the unified style+reorder batch. Applied/rejected/superseded changes leave the pending set.
Parameters
operation_idoptionalmarkoptionalbatchoptionalget_page_templateRead the page-scoped template slots from the active grab session’s DESIGN.md and merge the overlay’s latest selector validation. fixed/flexible roles and allowedTokens are cooperative advisory metadata: display labels only, not enforced.
Parameters
pagerequiredset_template_slotPersist an array of page-scoped template slots in one batched DESIGN.md update. fixed/flexible roles and allowedTokens are cooperative advisory metadata: display labels only, not enforced.
Parameters
pagerequiredtemplate_idoptionalslotsrequiredlist_templatesList templates and their registered page pathnames from the active grab session. Template permissions and allowedTokens are cooperative advisory metadata: display labels only, not enforced.
No parameters
list_creative_modelsBrowse Raven’s provider-agnostic creative model catalog. These are capability slots for image, video, 3D, audio, character consistency, and creative analysis. Use a configured RAVEN_CREATIVE_RUNNER to route jobs to any local CLI or API wrapper.
Parameters
media_typeoptionalcapabilityoptionallist_creative_presetsBrowse Raven creative presets for product photoshoots, marketplace cards, UGC ads, TV spots, cinematic reveals, social launch packs, storyboards, and infographics.
Parameters
media_typeoptionalsearchoptionalcreate_brand_profileCreate or update a local brand profile used by Raven creative jobs. Stores colors, fonts, tone, audience, constraints, product notes, and asset references locally under ~/.raven/creative by default.
Parameters
namerequiredidoptionaldescriptionoptionalcolorsoptionalfontsoptionaltoneoptionalaudienceoptionalproductoptionalconstraintsoptionalasset_idsoptionalget_brand_profileRead a local Raven creative brand profile by ID.
Parameters
idrequiredlist_brand_profilesList local Raven creative brand profiles.
No parameters
register_creative_assetRegister a local or remote creative asset for Raven jobs. This is the local-first analog of upload: Raven stores metadata and a URI/path, not the file bytes.
Parameters
urirequiredtyperequirednameoptionaldescriptionoptionaltagsoptionalmetadataoptionalcreate_character_profileCreate a local character/identity reference profile for consistent image or video generation. Raven stores reference asset IDs and provider-training payloads; actual identity training happens only through a configured provider runner.
Parameters
namerequiredreference_asset_idsrequiredidoptionaldescriptionoptionalconsistency_notesoptionalprovider_training_idoptionalmetadataoptionalcreate_generation_jobCreate a Raven creative generation job for image, video, 3D, audio, campaign, or analysis. Returns a brand-aware provider payload. If execute=true and RAVEN_CREATIVE_RUNNER is configured, Raven submits the job to that local runner.
Parameters
media_typerequiredpromptrequiredobjectiveoptionalmodeloptionalprovideroptionalpresetoptionalbrand_profile_idoptionalcharacter_profile_idoptionalreference_asset_idsoptionalaspect_ratiooptionalduration_secondsoptionaloutput_countoptionalqualityoptionalchanneloptionalexecuteoptionalget_generation_jobRead a Raven creative generation job by ID.
Parameters
idrequiredlist_generation_jobsList local Raven creative generation jobs.
Parameters
statusoptionalmedia_typeoptionallimitoptionalplan_creative_campaignPlan a multi-asset creative campaign and optionally create draft generation jobs. Covers Higgsfield-like workflows: product photos, UGC/video ads, marketplace cards, launch/social packs, storyboards, and channel cutdowns.
Parameters
campaign_namerequiredproduct_or_offerrequiredaudiencerequiredgoalrequiredchannelsrequiredbrand_profile_idoptionalsource_asset_idsoptionalformatsoptionalvariants_per_formatoptionalcreate_jobsoptionalscore_creativeScore a creative prompt, script, or ad concept for hook strength, benefit clarity, product signal, call-to-action, channel fit, audience fit, and brand fit. This is a transparent heuristic, not a proprietary prediction model.
Parameters
creative_textrequiredchanneloptionalbrand_profile_idoptionalaudienceoptionaltalon_scanRun Raven’s deterministic detector engine over a page — no LLM, pure measurement. Covers color-system discipline (palette budget, near-duplicate hex, hue diversity), spacing-grid conformance (base-unit, scale count), type-scale/rhythm (size count, body line-height, measure, font-family budget), heading/landmark structure, motion-duration/easing sanity (flashing-animation risk, prefers-reduced-motion coverage), and orphan-stretch/horizontal-overflow geometry. Pass html, url (rendered headless), or pre-measured elements+viewport (the same DevTools-snippet shape audit_layout takes — required for the two geometry rules). Every finding cites the src/data/principles/*.json entry it derives from. Pass project (and profile) to resolve a saved taste surface binding (see bind_taste_surface) — a finding the binding silences via an ’off’ override is still returned, flagged waived_by_taste:true, never dropped.
Parameters
htmloptionalurloptionalelementsoptionalviewportoptionalsurfaceoptionalprojectoptionalprofileoptionaltalon_rulesEnumerate Raven’s Talon detector rule corpus — id, category, severity, taste scope, and the src/data/principles/*.json entry each rule cites. No scan required; use this to show a client ’why’ before or instead of running talon_scan.
No parameters
raven_reflectSummarize how Raven has been used on this machine over the last N days. Reports which tools are called most, which audit warnings fire repeatedly (→ likely gaps in Raven’s knowledge), which patterns and design systems you look up, and which companies you ask for brand styles. Call this when the user asks ’what have I been building with Raven’ or ’what’s Raven missing’. All data is read from a local log ($RAVEN_USAGE_LOG or ~/.raven/usage.jsonl) — nothing is fetched over the network.
Parameters
daysoptionalraven_registerRegister your email to receive design updates and provide feedback to the Raven creator. Call this when a user wants to register, give feedback, or connect with the Raven team.
Parameters
emailrequirednameoptionalTranscripts
You don’t need to call tools directly. Say what you are building or checking, and Claude can call the relevant Raven tool.
Build a pricing page with Raven guidance
“Build me a pricing page with 3 tiers for a developer tool. Use Stripe’s design tokens.”
Raven can call get_pattern("pricing-page"), get_principles("pricing page"), and get_design_system("stripe"); Claude then builds from those returned rules and tokens.
Evaluate an existing design
“This signup form has 8 fields including phone number and company size. No social login. The submit button says ‘Submit’. No inline validation. Evaluate it for conversion and usability.”
Raven calls evaluate_design and returns matched principles, likely violations, and specific fixes.
Pre-launch checklist
“Give me a pre-launch checklist for this mobile landing page”
Returns a categorized checklist covering the pattern’s requirements, accessibility, and platform-specific items.
Compose a custom design system
“Create a design system that uses Linear’s color palette with Stripe’s typography and spacing”
Raven calls compose_system to merge tokens from both systems into one set, output as CSS variables or W3C DTCG format.
Generate a complete design system
“Generate a bold design system for my startup called NightOwl. Brand color is #8B5CF6. Export as HTML so I can share it.”
Raven calls generate_design_system to create a token set — colors, typography, spacing, radius, elevation, motion — and exports a self-contained HTML documentation page you can open in a browser or print to PDF.
Search across everything
“What does Raven know about color contrast?”
Searches the full corpus — 132 design principles (UX, content, research, service-design, and brand), 23 UI and content pattern sets, and 5 business-strategy domains — for relevant guidance.
Contract
The design knowledge lives in src/data/ as static JSON, loaded into memory when the server starts. No database, no external service — a knowledge lookup runs in-process.
Knowledge tools answer from the bundle with no network round-trip, so an agent gets the same answer every time. The render audits (audit_url, audit_page) fetch the page you point them at.
src/data/
principles/ # 76 principles across 12 files
nielsen-heuristics.json laws-of-ux.json
gestalt.json accessibility.json
typography.json color-theory.json
color-systems.json spacing-systems.json
mobile-ux.json d4d.json
responsive-layout.json component-architecture.json
patterns/ # 14 UI patterns
signup-flow.json pricing-page.json
navigation.json forms.json
landing-page.json dashboard.json
modals-dialogs.json empty-states.json
error-states.json loading-states.json
cta.json social-proof.json
mobile-conversion.json dropdown-menu.json
business/ # 5 strategy domains
monetization.json retention.json onboarding.json
growth.json metrics.json
tokens/ # 12 design systems
registry.json
systems/stripe.json, linear.json, apple-hig.json, …
content/ # v1.2 — content design systems
systems/ # 4 brand voice guides (Mailchimp, GOV.UK,
# Polaris, Atlassian)
principles/ # 11 UX-writing principles
patterns/ # 4 content patterns (errors, empty states,
# notifications, form validation)
research/ # v1.3 — research & data analysis
principles/ # 11 research fundamentals
methods/ # qualitative, quantitative, usability
frameworks/ # HEART, AARRR, North Star, funnel, RICE, OKRs
service-design/ # v1.3 — service design
principles/ # Stickdorn, Shostack, moments of truth,
# peak-end, handoff, human help
patterns/ # blueprinting, handoff, signup-as-service,
# omnichannel, moments of truth
frameworks/ # GOV.UK Service Standard (14 points)
brand/ # v1.3 — brand & visual design
principles/ # logo, gradient, imagery, hierarchy, system
trends/ # 2026-current-trends.jsonEach token has:
$value — the token value$type — color, dimension, fontFamily, fontWeight, number, etc.$description — what the token is forRequest tokens in three formats:
// W3C DTCG (default) — standards-compliant JSON
get_design_system({ id: "stripe", format: "dtcg" })
// CSS Custom Properties — drop into your stylesheet
get_design_system({ id: "stripe", format: "css" })
// Output: :root { --stripe-color-primary: #635bff; ... }
// Flat — simple key-value pairs
get_design_system({ id: "stripe", format: "flat" })
// Output: [{ path: "color.primary", value: "#635bff", type: "color" }]| System | ID | Status | Category |
|---|---|---|---|
| Stripe | stripe | Live | fintech |
| Linear | linear | Live | productivity |
| Apple HIG | apple-hig | Live | platform |
| Material Design 3 | material-design | Live | platform |
| Vercel | vercel | Live | developer |
| shadcn/ui | shadcn | Live | component-library |
| GitHub Primer | github-primer | Live | developer |
| Notion | notion | Live | productivity |
| Supabase | supabase | Live | developer |
| Tailwind CSS | tailwind | Live | framework |
| Spotify | spotify | Live | consumer |
| Airbnb | airbnb | Live | consumer |
Notes
The design knowledge — principles, patterns, tokens, business and service-design guidance — is bundled locally: ~640KB of curated JSON that runs on your machine with no network round-trip. The render audits (audit_url, audit_page) fetch the page you point them at, and raven_register posts your email only if you opt into release updates. No auth tokens are required to use the knowledge tools.
Raven works with any MCP-compatible client. Claude Code and Claude Desktop have native MCP support. Other tools are adding MCP support — check your client’s documentation.
Yes. Add a JSON file to src/data/tokens/systems/ following the W3C DTCG format, and register it in registry.json. See stripe.json as a reference.
Yes. Add JSON files to src/data/principles/ or src/data/patterns/. Follow the existing file structure. Raven loads all JSON files in those directories automatically.
npm update -g raven-mcp132 principles curated from Nielsen Norman Group, Laws of UX, Gestalt psychology, WCAG 2.2, typography and color theory, mobile UX (touch targets, nav consistency, font sizing), responsive layout, component architecture, UX writing (Mailchimp, GOV.UK), research fundamentals, service design (Stickdorn, Shostack, Carlzon’s moments of truth, GOV.UK Service Standard), and brand systems (Pentagram, Brand New, public brand guidelines from Stripe, Airbnb, Linear, Vercel). 23 pattern sets based on conversion research, service-design practice, and copy-design evidence. Design tokens extracted from public-facing design systems. Metrics frameworks from Google, Amplitude, Dave McClure, and Intercom.