Framesmith 1.7 – a quality gate that tells an AI agent when a UI is done

Framesmith 1.7, an open-source MCP server, provides AI coding agents with a visual canvas for UI design, enabling sketching, review, and approval before code generation. The tool includes a quality inspector that scores designs and highlights issues, and integrates with AI assistants via standard MCP protocol.

An open-source MCP server that gives your AI coding agent a visual canvas. Sketch the UI, review it in a browser, agree on the design — before any framework code gets written. Contents: Viewer viewer · Installation installation · Tools tools · Usage Example usage-example · Workflow workflow · Development development Above: the framesmith viewer. Workspaces and projects in the sidebar, canvases as live thumbnails on the right. AI agents create canvases via MCP tools; you browse them like Figma files. MCP Client → stdio → framesmith server ↓ Scene Graph in-memory JSON tree ↓ HTML/CSS Renderer inline styles ↓ Puppeteer headless Chromium → PNG Run npx -p framesmith framesmith-viewer to start the standalone browser viewer default port 3001 . Open any canvas to review it at multiple breakpoints, compare them side-by-side, inspect the underlying JSON, or archive / delete. Above: a single canvas in the detail view. The toolbar across the top exposes the breakpoint preview modes, Compare for side-by-side rendering, Fit for max-width, JSON for the raw scene graph, and lifecycle actions. Quality panel. The canvas detail view shows a read-only quality inspector on the right: the heuristic canvas evaluate score 0–100 , per-category bars, and the issue list — each cliché tell with its category · tell badge, severity, and suggestion. Issues that canvas autofix can resolve carry an auto-fixable tag, and clicking any issue highlights its node in the live preview. Every gallery card also shows a color-coded score badge so weak canvases stand out at a glance. The score matches what your agent sees over MCP same fast-mode evaluation, genre-relaxed by the canvas's preset — it's computed for display only and never written back. Design-system panel. A second inspector tab shows the canvas's effective design tokens — color swatches, type scale, spacing, and radius — resolved through the full workspace ▸ project ▸ canvas inheritance chain. Each section notes its dominant source layer, and any token that overrides it is tagged canvas / project so you can see at a glance what a given canvas customized versus inherited. The viewer is purely read-only — every canvas is authored through MCP tool calls from your AI assistant. Files persist to ~/.framesmith/canvases/ so the viewer keeps showing them across sessions. No clone or build needed — register framesmith with your MCP client via npx requires Node 20+ . claude mcp add framesmith -- npx -y framesmith Add to ~/.codex/config.toml : mcp servers.framesmith command = "npx" args = "-y", "framesmith" Add to ~/.cursor/mcp.json or per-project .cursor/mcp.json : { "mcpServers": { "framesmith": { "command": "npx", "args": "-y", "framesmith" } } } Add to ~/.codeium/windsurf/mcp config.json : { "mcpServers": { "framesmith": { "command": "npx", "args": "-y", "framesmith" } } } Add to .vscode/mcp.json project-scoped or your global MCP settings: { "servers": { "framesmith": { "command": "npx", "args": "-y", "framesmith" } } } framesmith speaks standard stdio MCP. Point your client at npx -y framesmith using whatever config shape your client expects. Optional:set FRAMESMITH VIEWER URL=http://localhost:3001 in the MCP server env to pin it to a long-lived standalone viewer process — see Running the viewer . git clone https://github.com/vicmaster/framesmith.git cd framesmith npm install npm run build then point your client at: node /path/to/framesmith/dist/index.js One-call onboarding — the recommended first call each session , and safe to run repeatedly idempotent . Binds the current repo if it isn't already canvases become checked-in JSON under .framesmith/ , ensures the convention projects exist, and returns the live state you need to start working. | Param | Type | Description | |---|---|---| dir | string? | Directory to bind / detect. Defaults to the nearest git repo root above the server working directory. | workspaceName | string? | Name for the workspace when binding fresh. Defaults to the repo folder name. | projects | string ? | Projects to ensure exist default: "Foundations", "UI" . Existing projects are never removed, so it's safe for adding feature/area projects like Onboarding . | Returns the bound workspace + project IDs binding re-keys IDs to repo- — use the ones init returns , the on-disk layout, the workspace-layer token count, a workflow cheatsheet, the current gotchas, the framesmith://guidelines URI, and the viewer URL. It does not seed design tokens — set those at the workspace layer with workspace set design system . The default Foundations project is just a canvas that visualizes the workspace tokens which is where the design system actually lives . Create a new canvas. If projectId is omitted, it lands in the built-in Untitled project of the Personal workspace. | Param | Type | Description | |---|---|---| name | string? | Canvas name | projectId | string? | Target project. Defaults to the built-in Untitled project. See project list . | The response also carries a diversification signal for the target project: the recently-built structures newest first and a hint to differ on at least one taxonomy axis, so successive canvases don't converge on the same layout. It's advisory — never blocking. List canvases. Excludes archived canvases by default. | Param | Type | Description | |---|---|---| projectId | string? | Scope to one project | includeArchived | bool? | Include archived canvases default false | Returns { id, name, createdAt, lastModified, projectId, archived } . Canvas lifecycle. canvas move reassigns a canvas to a different project. canvas archive sets a soft-delete flag canvas stays on disk, hidden from default canvas list ; canvas unarchive clears it. canvas delete removes the canvas and its file permanently — irreversible. Get the URL of the live viewer plus per-canvas URLs. Share these with the user so they can open the design in their browser. No params. { "url": "http://localhost:3001", "gallery": "http://localhost:3001", "canvases": { "name": "Login", "viewer": "http://localhost:3001/canvas/abc123" } } canvas create already returns the per-canvas viewer URL in its response; reach for viewer url when you want the gallery URL or to enumerate every existing canvas's URL in one call. Top-level container CRUD. The built-in Personal workspace cannot be deleted, and workspace delete refuses if the workspace still contains projects move or delete them first . Mid-level container CRUD inside a workspace. The built-in Untitled project cannot be deleted. project delete refuses if the project still contains any canvases archived ones still count — move or delete them first . Bind a workspace to the current project directory so its canvases live in the repo as open JSON — a .framesmith/ directory checked in alongside the code, instead of the global ~/.framesmith store. Run it once per repo. | Param | Type | Description | |---|---|---| workspaceId | string? | Workspace whose projects + canvases migrate into the repo. Defaults to the built-in Personal workspace. | dir | string? | Directory to bind. Defaults to the nearest git repo root above the server's working directory. | It creates .framesmith/workspace.json the binding plus the design system, so a fresh clone resolves tokens identically and one subdirectory per project holding one slug-named file per canvas: .framesmith/ workspace.json workspace + projects + design system design-system/ design-tokens.json ui/ bloom-landing.json login-form.json It migrates the workspace's projects + canvases in and makes the repo the source of truth for the rest of the session. A canvas is either repo-bound or global, never both. Afterwards the server auto-detects .framesmith/ on startup walking up from its working directory . Commit .framesmith/ so designs travel with the code and diff cleanly in review. The bind also records the repo in ~/.framesmith/registry.json , so the standalone viewer shows bound repos alongside your global workspaces in one gallery it rebuilds that read-only mirror on launch and whenever the registry changes . Execute operations on the scene graph. Operations are line-separated strings: Insert a frame into the document root header=I "document", { type: "frame", layout: "horizontal", fill: " 1a1a2e", padding: 24, gap: 16, width: 1440, height: 80 } Insert text into the header I header, { type: "text", content: "My App", fontSize: 24, fontWeight: 700, color: " ffffff" } Update a node U "nodeId", { fill: " e94560" } Delete a node D "nodeId" Copy a node to a new parent copy=C "sourceId", "parentId", { fill: " 0f3460" } Move a node M "nodeId", "newParentId", 0 Replace a node entirely R "nodeId", { type: "text", content: "Replaced" } Returns { ok, nodeIds, results } . nodeIds maps each bound variable to the node ID it created — e.g. { "header": "n a1b2" } — so you can target those nodes in later calls bindings only live within a single call . results lists each op's outcome in order. Node types: frame , text , rectangle , ellipse , image , icon , path , component , instance , toggle , checkbox , radio , select Properties: fill , gradient , stroke , strokeWidth , cornerRadius , width , height , layout "horizontal" | "vertical" , gap , padding , alignItems , justifyContent , fontSize , fontFamily , fontWeight , color , content , textAlign , lineHeight , letterSpacing px , textDecoration , textTransform , fontVariationSettings , src , objectFit , opacity , shadow , shadows , blur , backdropBlur , backdropFilter , overflow , wrap , position , x , y , icon , iconSize , iconColor , iconStyle , checked , disabled , value , d , viewBox , strokeLinecap , strokeLinejoin , animation , transition , componentId , overrides Use textTransform: "uppercase" for uppercase labels don't bake casing into content , letterSpacing for tracking, and fontVariationSettings e.g. '"wght" 650' for variable-font axes. Render canvas to PNG returned as base64 image . | Param | Type | Description | |---|---|---| canvasId | string | Canvas ID | nodeId | string? | Specific node to capture | width | number? | Viewport width default 1440 | height | number? | Viewport height default 900 | scale | number? | Device scale default 2 | Read node data from the scene graph. | Param | Type | Description | |---|---|---| canvasId | string | Canvas ID | nodeIds | string ? | Node IDs to read default: root | maxDepth | number? | Max traversal depth default 5 | Get computed bounding boxes via browser rendering. | Param | Type | Description | |---|---|---| canvasId | string | Canvas ID | nodeId | string? | Root node to start from | maxDepth | number? | Max depth default 10 | Read and write design tokens colors, spacing, radius, typography . Use $tokenName in node properties to reference variables. { "colors": { "primary": " e94560", "bg": " 1a1a2e" }, "spacing": { "sm": 8, "md": 16, "lg": 24 }, "radius": { "sm": 4, "md": 8 } } Then use in nodes: { fill: "$primary", padding: "$md", cornerRadius: "$sm" } Set tokens at the workspace level — every project + canvas under the workspace inherits them. Resolution order at render is canvas.variables override → project.designSystem → workspace.designSystem → built-in defaults, with the rightmost layer winning. Per-category merge: setting only colors doesn't reset spacing . workspace set design system { workspaceId: "...", variables: { colors: { primary: " f59e0b", bg: " 0a0a0a" }, spacing: { sm: 8, md: 16, lg: 24 } } } workspace apply preset { workspaceId, preset } is a shortcut that copies a named preset "dark" , "light" , "material" , "minimal" into the workspace. Same shape, but at the project layer between workspace and canvas. Use for sub-brand overrides e.g., a Marketing project that overrides one color while inheriting everything else from the workspace . Fonts load by name automatically — naming a fontFamily in a typography token or on a node resolves it from Google Fonts at token-write time, with a render-time backstop catching anything else. Binaries are cached under ~/.framesmith/fonts/ , so renders are offline and deterministic after the first resolve; typography.body.fontFamily becomes the document default. An unresolvable family renders in the fallback stack and adds a Font warnings item to the screenshot/export result. set fonts covers explicit registration. Three forms, combinable: { "families": "Inter", "JetBrains Mono" , "fonts": { "family": "Inter", "url": "https://fonts.googleapis.com/css2?family=Inter:wght@400;700" }, { "family": "Brand Face", "url": "https://example.com/brand.woff2", "weight": 400 } } families — resolve by name from Google Fonts and merge into the existing declarations. fonts with a Google Fonts CSS URL fonts.googleapis.com/css2?... — faces are extracted from the stylesheet automatically. fonts with a direct binary URL .woff2 / .woff / .ttf / .otf or a data: URI — for non-Google sources. fonts replaces declarations wholesale pass to clear ; families merges. The renderer emits @font-face blocks plus <link rel="preconnect" per remote origin, with font-display: swap . Export a canvas or specific nodes to files on disk. | Param | Type | Description | |---|---|---| canvasId | string | Canvas ID | format | string | "png" , "jpeg" , "webp" , or "pdf" | outputPath | string | Directory to save files | nodeIds | string ? | Specific nodes to export default: full canvas | width | number? | Viewport width default 1440 | height | number? | Viewport height default 900 | scale | number? | Device scale default 2 | List available style guide presets. No params. Returns preset names and descriptions. Apply a style guide preset to a canvas. Merges preset design tokens into the canvas variables, and copies in any reusable components button , card , badge the preset defines so they can be instanced. The preset is also recorded in the canvas provenance + per-project build log. | Param | Type | Description | |---|---|---| canvasId | string | Canvas ID | preset | string | Preset name: "dark" , "light" , "material" , "minimal" | List available layout structures — named scaffolds you stamp onto a canvas and then populate. Returns each structure's name, kind , description, and for pages taxonomy axes. Distinct from presets: structures define layout skeleton , presets define color/token theme — they compose. | Param | Type | Description | |---|---|---| projectId | string? | If given, also return a diversification signal for the project recently-built structures + a hint to differ on ≥ 1 axis , so you pick a shape that contrasts with recent work. Omit it to get just the structure list. | Two kinds: — whole-page scaffolds stamped once at the canvas root: page marquee-hero , bento-grid , stat-led , editorial-longform , split-workbench , catalogue , dashboard , auth , pricing , settings , onboarding . Each is tagged on four independent axes — heroTreatment , density , rhythm , alignment — so you can deliberately vary page shape instead of defaulting to the same layout. Every page scaffold is regression-tested to score ≥ 90 with zero cliché tells across themes the pattern library's taste bar , so it's a non-slop starting point you adapt, not boilerplate.— reusable fragments stamped under component any node via targetId , repeatably: data-table header + 3 rows with avatar/name/email, role chip, status toggle, actions , form-field , toolbar , stat-card , toggle-row . A high-fidelity table costs one stamp instead of ~80 hand-placed nodes. Stamp a layout structure onto a canvas and return the placeholder node IDs to populate. Seeds neutral default colors so the scaffold renders even before a preset is applied. Populate the placeholders with batch design U ops, then screenshot to verify. Page scaffolds insert at the canvas root refusing on a non-empty canvas unless replace , record provenance metadata.provenance , and append to the per-project build log that feeds the diversification signal. Component scaffolds insert under targetId default root , repeatably — every stamp re-keys its node IDs form-field-1-… , form-field-2-… and returns an idMap template ID → live ID for follow-up ops. Component stamps don't touch provenance or the build log: they don't shape the page. | Param | Type | Description | |---|---|---| canvasId | string | Canvas ID | structure | string | Structure name use list structures , e.g. "marquee-hero" , "data-table" | replace | boolean? | Page scaffolds: if the root already has children, clear them before stamping. Default false refuses on a non-empty canvas | targetId | string? | Component scaffolds: node to stamp under default "document" | Import an HTML snippet + optional CSS as an editable canvas — the reverse of export . The markup renders headlessly and a computed-style DOM walk maps it to the scene graph: | Source | → Scene graph | |---|---| | flex/block container | frame + layout / gap / padding / alignItems / justifyContent / wrap | display: grid | rows of proportional columns from the computed track template grid-column spans honored — numeric spans win, else the box width decides ; irregular templates degrade to a stack with a warning. Recorded in report.layout | centered content margin: auto , max-width , flex-center | the parent centers alignItems and the child keeps its real width — max-width becomes the fluid width: "100%" + maxWidth idiom. Recorded in report.layout | | floats / inline-block / unmodeled multi-column CSS | geometry clustering: children's computed boxes group into row bands ≥50% vertical overlap, consistent column counts → rows of proportional columns. Conservative by design — anything that looks multi-column but doesn't cluster consistently imports as an honest stack with a stack-fallback entry + warning | <table / <tr / <td / <th | a vertical frame of horizontal row frames with proportional percentage cell widths from the computed boxes — colspan handled free ; thead / tbody unwrap, <caption becomes a text node, bottom borders become hairline divider frames. Recorded in report.layout | | text run | text size, weight, color, family, line-height, letter-spacing, transform, align | <img absolute/data URL | image | inline <svg | icon when the path data matches a bundled Lucide/Material glyph; else path | checkbox / radio / role="switch" / <select | the input-primitive node types, with live checked /selected state | | background / border / radius / shadow / opacity / overflow | fill / stroke + strokeWidth / cornerRadius / shadows / opacity / overflow | Lossy by design. Every import returns a report — counts, warnings dropped background images, grid containers, truncations , unmatched icons/fonts — and that report is the contract; the goal is an editable, honest starting point, not a pixel-perfect clone. Single-child wrapper divs collapse, same-style text runs merge, invisible nodes drop all tunable via flatten . | Param | Type | Description | |---|---|---| html | string | The snippet to import | css | string? | CSS to apply — e.g. the compiled Tailwind stylesheet. A bare Tailwind snippet has no runtime, so classes render unstyled without this | projectId | string? | Project to create the canvas in default project if omitted | name | string? | Canvas name default "Imported HTML" | selector | string? | Import only the first match within the snippet | width | number? | Container width layouts resolve against default 1440 | flatten | object? | { collapseWrappers, mergeTextRuns, dropInvisible, maxDepth } | tokenMatch | object? | { source: "workspace" | "designMd" | "tailwind" | "none", tolerance?, designMd? } — snap concrete values back to $token refs default: the target project's merged design system | tailwind | object? | { theme: { name: value } } — the project's @theme map; widens which class names map to $tokens | Token re-mapping makes the import a token-driven design instead of a pile of hex: Tailwind intent first — class names carry intent a computed value can't: bg-surface → fill: "$surface" , gap-4 → 16 , rounded-xl → 12 , text-sm font-semibold uppercase → typography props. Custom utilities resolve via tailwind.theme ; palette classes bg-red-500 map to the bundled v4 palette as hex literals generated from the official oklch values by Chrome itself — see scripts/generate-tailwind-palette.ts , so a bare snippet styles without compiled CSS; arbitrary values and unknowns fall through to computed styles. Geometry intent and palette literals only fill gaps the CSS didn't set; token-ref colors override computed literals. Nearest-color snapping second — remaining literal colors snap to the matched design system within tolerance exact matches always; near-ties between two tokens are reported and left literal , never guessed . Spacing/radius/fontSize values that equal a scale token are reported under report.scaleMatches .- Fonts seen in computed styles feed the font-by-name resolver, so the imported canvas renders in the same faces. Returns { canvasId, rootId, report } — report.snapped / literals / scaleMatches / warnings are the contract. Import a live page as an editable, token-mapped canvas — point at a running app and the screen becomes the design-of-record without redrawing. Same engine and token re-mapping as canvas import html , plus live-page controls: | Param | Type | Description | |---|---|---| url | string | The page to import http/https only | viewport | object? | { width, height } — the width layouts resolve against default 1440×900 | selector | string? | Import one component instead of the whole page default body | waitFor | string | number? | CSS selector to await, or a delay in ms — for client-rendered UI | auth | object? | { headers?, cookies? } for gated pages — used in a throwaway browser context, never persisted to the canvas, provenance, or report | projectId / name / flatten / tokenMatch / tailwind | — | Same as canvas import html | Relative image URLs resolve against the page; fonts seen in computed styles load through the font-by-name resolver so the canvas renders in the same faces. The source URL never auth is recorded in metadata.provenance.importedFrom . Drift detection — the design-of-record as a living contract . Re-imports a live page ephemerally no canvas created, nothing mutated and pixel-diffs it against an existing canvas at the same viewport: | Param | Type | Description | |---|---|---| canvasId | string | The canvas that is the design-of-record | url | string | The live page to compare http/https | viewport | object? | Compare size defaults to the canvas root size | selector / waitFor / auth | — | Same as canvas import url auth in a throwaway context, never persisted | Returns the diff image changed regions in red , changePercent , changedPixels / totalPixels , and the import report. Both sides render at scale 1, so the percentage is comparable run-to-run — an unchanged page diffs at ~0%. CI pattern a pattern, not a shipped feature : after deploy, call canvas sync from url for each route ↔ canvas pair and fail the job when changePercent exceeds your threshold — design ↔ code divergence becomes a build failure instead of a surprise. Import a DESIGN.md https://github.com/VoltAgent/awesome-design-md file as a design system preset. Parses the Google Stitch format and extracts colors, typography, spacing, and border radius. It also extracts reusable component skeletons button , card , badge from the "Component Styling" section — apply preset then makes them available as instanceable components on the canvas. After importing, use apply preset to apply it to any canvas. | Param | Type | Description | |---|---|---| content | string? | Raw DESIGN.md content provide this OR filePath | filePath | string? | Absolute path to a DESIGN.md file | name | string? | Override the preset name | Compatible with the 55+ design systems in awesome-design-md https://github.com/VoltAgent/awesome-design-md Stripe, Notion, Figma, Vercel, Linear, etc. . Accepted token formats. Each category is read from a loosely-matched heading section Colors / Color Palette , Spacing , Border Radius / Radius , Typography . Within a section, tokens may be written as a list item - name: value , a 2-column table row | name | value | , or a name: value / name \ value line — where value is a color hex , rgba ... for colors, Npx for spacing/radius, and Npx optionally / weight , e.g. 16px / 600 for typography. Named spacing tokens md: 12px are honored verbatim; a scale is synthesized only when no named tokens are given and a Base unit: Npx is stated — otherwise nothing is fabricated. Radius accepts the scale names sm / md / lg / xl / full / pill . Render a canvas at multiple viewport sizes. Defaults to mobile 390x844 , tablet 768x1024 , and desktop 1440x900 . The renderer emits clamp for paddings ≥ 32px and font sizes ≥ 24px, so headlines and large spacing shrink proportionally at narrower viewports assuming a 1440px design width . Smaller values stay static. | Param | Type | Description | |---|---|---| canvasId | string | Canvas ID | breakpoints | array? | {label, width, height} — custom breakpoints | scale | number? | Device scale default 2 | Compare two canvases visually. Returns a diff image with changed regions highlighted in red. | Param | Type | Description | |---|---|---| canvasId1 | string | First canvas ID | canvasId2 | string | Second canvas ID | width | number? | Viewport width default 1440 | height | number? | Viewport height default 900 | scale | number? | Device scale default 1 | Auto-score a design against quality heuristics. Returns an overall score 0–100 , per-category scores, and per-node actionable issues. Designed for generator-evaluator loops: build with batch design , score with canvas evaluate , fix the issues targeting the returned nodeId s, repeat. | Param | Type | Description | |---|---|---| canvasId | string | Canvas ID to evaluate | mode | "fast" | "detailed" | "llm" | "fast" = JSON-tree analysis only <100ms . "detailed" adds Puppeteer-based pixel-level overlap checks. "llm" runs fast-mode heuristics plus a vision-model critique provider picked from FRAMESMITH LLM PROVIDER or whichever of ANTHROPIC API KEY / OPENAI API KEY is set — costs one paid API call per invocation . Default "fast" . | categories | string ? | Subset of spacing , color , typography , structure , consistency , cliche . Defaults to all. | genre | string? | Style that relaxes specific cliche gates e.g. "material" allows purple . Defaults to the canvas's provenance preset if stamped. | Categories and what they check | Category | Weight | Checks | |---|---|---| spacing | 20 | Off-scale padding/gap values, too many unique spacing values | color | 25 | WCAG AA contrast ratios for text against nearest background | typography | 20 | Type-scale ratios 1.15–1.75 , font-family count, weight variation | structure | 15 | Tree depth, naming coverage, design-token usage %, component reuse | consistency | 20 | Frames missing layout , inconsistent sibling padding, sibling overlap detailed mode | cliche | 15 | Machine-made tells: default purple/indigo accent, gradient/glow overuse, fake browser/OS chrome traffic-light dots , the hanging eyebrow-beside-heading header, fabricated metrics/testimonials/logos, eyebrow rhythm an eyebrow above nearly every section , slop copy stock AI phrasing — filler verbs, scroll cues, placeholder names, hype labels , radius consistency too many distinct corner radii , pure black/white 000000 ink / ffffff page vs off-black/off-white , accent consistency multiple competing accent hues . Each issue carries a tell discriminator; all advisory warning/info . Relaxable per genre . | Return shape { "overallScore": 87, "categories": { "name": "spacing", "score": 90, "issueCount": 1, "weight": 20 } , "issues": { "category": "color", "severity": "error", "nodeId": "abc123", "message": "Text \"Sign In\" has contrast ratio 2.8:1 against 1a1a2e. WCAG AA requires 4.5:1.", "suggestion": "Increase contrast by darkening/lightening the text or background." } , "summary": "Overall quality: Good 87/100 . Strongest: spacing 90/100 . Weakest: color 75/100 ...", "stats": { "totalNodes": 14, "textNodes": 5, "frameNodes": 8, "maxDepth": 4, "tokenUsagePercent": 61, "componentReusePercent": 0 }, "mode": "fast" } With mode: "llm" Phase 13 , the vision model scores a fixed rubric — five axes, each 1–5 with a rationale — instead of one opaque number. The verdict is stamped on the canvas metadata.critique and the per-project build log so quality is auditable over time. Add floor 1–5, default 3, or FRAMESMITH CRITIQUE FLOOR to set the per-axis threshold that trips needsRevision . { "llmCritique": { "provider": "anthropic", "model": "claude-sonnet-4-6", "rubric": { "hierarchy": { "score": 4, "rationale": "clear primary metric, secondary stats recede" }, "execution": { "score": 4, "rationale": "tidy alignment and consistent spacing" }, "specificity": { "score": 3, "rationale": "reads a touch generic for a dashboard" }, "restraint": { "score": 5, "rationale": "flat surfaces, no gratuitous effects" }, "variety": { "score": 2, "rationale": "the default centered three-card row" } }, "score": 72, "summary": "Clean, restrained dashboard; layout is conventional.", "suggestions": "break the symmetric three-card row with an asymmetric feature tile" , "needsRevision": true, "failingAxes": { "axis": "variety", "score": 2, "rationale": "the default centered three-card row" } } } Axes: hierarchy focal order , execution craft — alignment/spacing/contrast , specificity designed-for-purpose vs generic , restraint no overdone effects — the LLM sibling of the cliche category , variety avoids same-shape sameness . score is derived : round mean axisScores / 5 100 . To close the loop automatically, see canvas revise . Provider selection: FRAMESMITH LLM PROVIDER env var anthropic | openai , else falls back to whichever of ANTHROPIC API KEY / OPENAI API KEY is set. Default models: claude-sonnet-4-6 / gpt-4.1 override via FRAMESMITH LLM ANTHROPIC MODEL / FRAMESMITH LLM OPENAI MODEL . Adding a third provider is one entry in the judges table in src/llm-judge.ts . Example generator-evaluator loop js batch design { canvasId, operations: "..." } const r = canvas evaluate { canvasId, mode: "fast" } // r.issues .nodeId points to exactly what to fix batch design { canvasId, operations: U "${r.issues 0 .nodeId}", { color: " ffffff" } } canvas evaluate { canvasId } // re-score Issues that have a mechanical fix come back with an extra fix: { op, rationale } field — see canvas autofix below. Runs canvas evaluate in fast mode and returns just the subset of issues with a mechanically derived fix — no judgement calls. Each fix carries a ready-to-paste batch design Update op string. Closes the generator-evaluator loop without a second AI hop. | Param | Type | Description | |---|---|---| canvasId | string | Canvas to autofix | categories | string ? | Restrict to fixes from these categories default: all | genre | string? | Style that relaxes specific cliche gates e.g. "material" allows purple . Defaults to the canvas's provenance preset if stamped. | What gets auto-fixed Spacing — off-scale gap or scalar padding snaps to the nearest scale value. Array padding is skipped ambiguous which index . Consistency — frames with multiple children but no layout get layout: "vertical" . Color — recoverable WCAG contrast failures get color: " 000000" or " FFFFFF" , whichever wins against the resolved background. Failures so bad that neither black nor white meets the threshold are not auto-fixed the background also needs to change . Cliché — a known-default purple/indigo accent 6366f1 and friends written literally on a node swaps to a neutral accent; a dedicated fake-chrome strip a row that is just traffic-light dots gets a D ... delete; pure-black ink 000000 text/icon/stroke softens to off-black. Taste-dependent tells gradient/glow overuse, the hanging header, fabricated copy, eyebrow rhythm, slop copy, mixed radius systems, competing accents are reported by canvas evaluate with a suggestion but carry no auto-fix op. Return shape { "totalIssues": 18, "fixableCount": 5, "fixes": { "nodeId": "abc123", "category": "color", "op": "U \"abc123\", { color: \" 000000\" } ", "rationale": "Switch text color to 000000 for WCAG AA contrast against F8FAFC", "message": "Text \"Sign In\" has contrast ratio 2.8:1 against F8FAFC. WCAG AA requires 4.5:1." } } Apply the ops by joining them with newlines and passing to batch design , then re-evaluate. Closes the critique loop Phase 13 . Judges the canvas against the rubric; if any axis is below the floor, asks an LLM for targeted batch design ops that raise the failing axes, applies them, re-renders, and re-judges — up to maxIterations passes. Mutates the canvas. Opt-in and bounded; it never runs implicitly. | Param | Type | Description | |---|---|---| canvasId | string | Canvas to revise | maxIterations | number? | Revise passes, 1–3 default 1 | floor | number? | Per-axis rubric floor 1–5 default 3 / FRAMESMITH CRITIQUE FLOOR | provider | "anthropic" | "openai" ? | Force an LLM provider default auto-detect | Loop & safety - Each pass: render → judge → if needsRevision , revise the failing axes → apply validated through batch design → re-render → re-judge. Stops when the canvas passes passed , at the cap max-iterations , when a pass doesn't improve the overall no-improvement — the regressing edit is reverted , when the reviser returns nothing no-ops , or when an op fails to apply apply-error — the partial edit is reverted .- Every accepted pass re-stamps metadata.critique + the build log. Costs ≥2 paid API calls per pass one judge + one revise and renders between passes Chrome required . Return shape { "iterations": { "pass": 1, "overallBefore": 72, "failingAxes": "variety" , "opsApplied": "U \"cards\", { ... } ", "overallAfter": 84 } , "finalVerdict": { "rubric": { "...": {} }, "score": 84, "needsRevision": false, "failingAxes": }, "stoppedReason": "passed" } — markdown authoring guide: width strategies fixed / percentage / fluid+cap / floor / fit-content , responsive hint semantics framesmith://guidelines stack / wrap / fixed , common patterns pricing tiers, two-column hero, tag list, toolbar , and anti-patterns. Source:. docs/GUIDELINES.md npm run bench runs canvas evaluate over a fixed corpus of canvases a high-quality dashboard hero, a minimal well-formed canvas, an intentional-contrast-failure canvas and diffs the result against benchmark/baselines.json /vicmaster/framesmith/blob/master/benchmark/baselines.json . Catches drift in scoring across renderer / evaluator changes — exit code is nonzero on any score, issue-count, or issue-message change. Re-baseline with npx tsx benchmark/run.ts --update after intentional evaluator rewrites.Nodes support linear and radial gradients via the gradient property: Linear gradient angle in degrees I "parent", { type: "frame", width: 400, height: 200, gradient: { type: "linear", angle: 135, stops: {color: " 667eea", position: 0}, {color: " 764ba2", position: 100} } } Radial gradient I "parent", { type: "frame", width: 200, height: 200, gradient: { type: "radial", stops: {color: " fff", position: 0}, {color: " 000", position: 100} } } When gradient is set, it takes precedence over fill . Both can coexist fill as fallback . Structured shadows, blur filters, and backdrop blur: Structured shadow supports multiple shadows I "parent", { type: "frame", fill: " fff", shadows: {x: 0, y: 4, blur: 12, spread: 0, color: "rgba 0,0,0,0.15 "} } Blur filter I "parent", { type: "frame", fill: " 3b82f6", blur: 4 } Backdrop blur single-function shorthand for blur I "parent", { type: "frame", fill: "rgba 255,255,255,0.5 ", backdropBlur: 8 } Glassmorphism composable backdrop-filter: blur + saturate + brightness + contrast I "parent", { type: "frame", fill: "rgba 255, 255, 255, 0.4 ", backdropFilter: { blur: 12, saturate: 180, brightness: 110 } } The structured backdropFilter form takes precedence over backdropBlur when both are set. The renderer also emits the -webkit-backdrop-filter prefix so glass effects render in Safari/iOS without extra work. The legacy shadow string property still works for simple cases. Two bundled sets are available via the icon node type, rendering as inline SVGs with configurable size and color: Lucide 1,900+, stroke style — unprefixed names, browse here https://lucide.dev : I "parent", { type: "icon", icon: "search", iconSize: 24, iconColor: " 888" } I "parent", { type: "icon", icon: "heart", iconSize: 32, iconColor: " ef4444" } Material Symbols 3,800+, fill style — material: prefix, browse here https://fonts.google.com/icons : I "parent", { type: "icon", icon: "material:check", iconSize: 24, iconColor: " b71421" } I "parent", { type: "icon", icon: "material:settings", iconStyle: "rounded" } I "parent", { type: "icon", icon: "material:star-fill" } "-fill" suffix = filled variant iconStyle picks the Material variant "outlined" default, "rounded" , "sharp" ; it's ignored for Lucide. toggle , checkbox , radio , and select are first-class node types — static renders with a checked / value / disabled state, so app UI doesn't have to be faked from frames and ellipses: I "parent", { type: "toggle", checked: true } I "parent", { type: "checkbox", checked: true } I "parent", { type: "radio" } I "parent", { type: "select", value: "Administrator", width: 220 } I "parent", { type: "select" } renders a muted "Select…" placeholder I "parent", { type: "toggle", checked: true, disabled: true } 50% opacity Colors default from the design system — $accent falling back to $primary for active states, $border for outlines, $bg-surface / $text-primary for the select — with neutral fallbacks on unthemed canvases. Explicit fill / stroke / color override. Defaults: toggle 44×24, checkbox/radio 18×18, select fit-content give it a width for form layouts . For custom shapes and brand marks beyond the Lucide library, use the path node type with a raw SVG d attribute: I "parent", { type: "path", width: 24, height: 24, d: "M 12 2 L 22 22 L 2 22 Z", fill: " f59e0b" } With stroke + viewBox defaults to 0 0 width height I "parent", { type: "path", width: 48, height: 48, viewBox: "0 0 24 24", d: "M 12 2 L 22 22 L 2 22 Z", fill: "none", stroke: " 000", strokeWidth: 2, strokeLinecap: "round", strokeLinejoin: "round" } fill / stroke / strokeWidth apply to the path itself not the wrapper . d and viewBox are validated for safe characters — anything that could break out of the attribute is rejected. Reference a built-in keyframe to make a node animate in on page load. The renderer auto-emits the @keyframes block only when referenced. I "hero", { type: "frame", animation: { name: "fadeIn", duration: 400 } } I "title", { type: "text", animation: { name: "slideUp", duration: 300, delay: 100 } } Built-in keyframe names: fadeIn , slideUp , slideDown , scaleIn . All end at the natural resting state with animation-fill-mode: both , so the start state applies pre-animation and the end state sticks after. animation : { name, duration?: 300ms, delay?: 0ms, easing?: "ease-out", iteration?: 1 | "infinite" } . Easing is whitelisted: ease , ease-in , ease-out , ease-in-out , linear anything else falls back to ease-out . transition : { property?: "all", duration, easing?: "ease", delay?: 0ms } . Transitions only fire on state change, so they're inert until interactive states exist in the renderer — included today so a future hover/focus PR has a place to land. Define reusable components and create instances with overrides: Define a component a frame subtree that gets registered card=I "document", { type: "component", name: "Card", width: 300, fill: " 1a1a1a", cornerRadius: 12, layout: "vertical", padding: 16, gap: 8 } I card, { type: "text", name: "title", content: "Default Title", fontSize: 20, color: " fff" } I card, { type: "text", name: "subtitle", content: "Default subtitle", fontSize: 14, color: " 888" } Create instances with overrides matched by child name I "document", { type: "instance", componentId: card, overrides: { title: { content: "My Card" }, subtitle: { content: "Custom text" } } } Here's a complete session building a login card: 1. Create a canvas and set design tokens canvas create { name: "Login" } → { "canvasId": "abc123", "rootId": "xyz789", "name": "Login", "projectId": "default-project", "viewerUrl": "http://localhost:3001/canvas/abc123", "galleryUrl": "http://localhost:3001" } set variables { canvasId: "abc123", variables: { colors: { bg: " 0a0a0a", surface: " 1a1a2e", accent: " e94560", text: " ffffff" }, spacing: { sm: 8, md: 16, lg: 24, xl: 32 }, radius: { md: 8, lg: 16 } } } 2. Build the layout with batch design batch design { canvasId: "abc123", operations: page=I "document", { type: "frame", width: 1440, height: 900, fill: "$bg", layout: "vertical", alignItems: "center", justifyContent: "center" } card=I page, { type: "frame", width: 400, fill: "$surface", cornerRadius: "$lg", padding: 32, 32, 32, 32 , layout: "vertical", gap: 24 } I card, { type: "text", content: "Sign In", fontSize: 28, fontWeight: 700, color: "$text" } I card, { type: "frame", width: "100%", height: 44, fill: " ffffff10", cornerRadius: "$md", padding: 0, 16, 0, 16 , layout: "horizontal", alignItems: "center" } I card, { type: "frame", width: "100%", height: 44, fill: " ffffff10", cornerRadius: "$md", padding: 0, 16, 0, 16 , layout: "horizontal", alignItems: "center" } btn=I card, { type: "frame", width: "100%", height: 44, fill: "$accent", cornerRadius: "$md", layout: "horizontal", alignItems: "center", justifyContent: "center" } I btn, { type: "text", content: "Continue", fontSize: 16, fontWeight: 600, color: "$text" } } 3. Take a screenshot to see the result screenshot { canvasId: "abc123" } → returns base64 PNG image 4. Iterate — update the button color and verify batch design { canvasId: "abc123", operations: U "btn-id", { fill: " 3b82f6" } } screenshot { canvasId: "abc123" } The viewer runs in one of two modes — embedded auto-starts inside the MCP server process or standalone long-lived in its own terminal . Standalone is recommended; the embedded mode stops the moment your MCP session ends, so any viewer URL you shared becomes unreachable. In a separate terminal tab — stays alive independently of any MCP session npx -p framesmith framesmith-viewer Or on a specific port npx -p framesmith framesmith-viewer 3004 Working from a clone instead of npm? Run npm run viewer or npm run viewer -- 3004 from the repo root — same standalone viewer, run from source. The standalone viewer: Persists across sessions — URLs keep working after Claude / Cursor / Windsurf finishes Shared across projects — multiple MCP sessions from different projects all use the same viewer Auto-detects new canvases — watches ~/.framesmith/canvases/ for changes and picks them up immediately Auto-detected by MCP — when the MCP server starts, it probes for a running standalone viewer and uses it instead of starting its own Gallery / — browse all canvases as clickable cards with live thumbnails Project /project/:id — same gallery but scoped to one project Archive /archive — soft-deleted canvases with restore / permadelete actions Canvas detail /canvas/:id — full rendered design with responsive viewport buttons Mobile / Tablet / Desktop , Compare mode, Fit toggle, and JSON inspector Raw HTML /canvas/:id/html — the rendered HTML for embedding or inspection JSON API /api/canvases , /api/canvas/:id/meta — programmatic access Live auto-refresh — the viewer polls for changes every 2 seconds, so the browser updates automatically as your agent runs batch design All canvases persist to ~/.framesmith/canvases/ as JSON files and survive process restarts. Set FRAMESMITH VIEWER URL in the MCP server env to point at a viewer running on a non-default port. - Start the standalone viewer in a terminal tab: npx -p framesmith framesmith-viewer canvas create → get canvas ID- Open the viewer URL in your browser for live preview apply preset or set variables → set up design tokens batch design → build the UI with frames, text, icons, components, gradients- Watch the viewer auto-refresh as you design screenshot responsive → preview at mobile/tablet/desktop sizes canvas diff → compare before/after changes visually export → save final designs to PNG/PDF files git clone https://github.com/vicmaster/framesmith.git cd framesmith npm install npm run build | Command | What it does | |---|---| npm run build | Compile TypeScript to dist/ . Required before the installed MCP server picks up changes — it loads dist/index.js . | npm run dev | Run the server directly via tsx for local iteration. Does not affect the registered MCP server. | npm run viewer port | Start the standalone viewer default auto-picks from 3001 . | npx tsx test- .ts | Run ad-hoc test scripts at the repo root. | | Variable | Purpose | |---|---| FRAMESMITH VIEWER URL | Point the MCP server at an external viewer skips starting an embedded one . | FRAMESMITH VIEWER PORT | Override the standalone viewer's port. | FRAMESMITH CHROME PATH | Chrome binary for screenshots/exports falls back to PUPPETEER EXECUTABLE PATH , then the Puppeteer-managed Chrome . Set it in the MCP server's env config — clients often launch servers with a minimal env. | - ESM only "type": "module" . Imports in TypeScript source use .js extensions even when the source file is .ts . - Don't edit dist/ — it's regenerated by tsc . - New MCP tool? Register it in src/index.ts , document it in the Tools section above, and update VISION.md 's phase checklist. MIT — see LICENSE /vicmaster/framesmith/blob/master/LICENSE . Copyright c 2026 Victor Velazquez.