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MCP Server

MCP Server

Give your AI agent Jinero's design tools over the Model Context Protocol — 22 read-only tools for fonts, colors, palettes, code and SVG on a hosted remote server. No npm, no key.

View in MCP Registry
Getting Started

Overview

A hosted, remote MCP server that gives your AI agent the same design tools humans use on jinero.online: 22 tools covering fonts (search, CSS, files, recognition by image), color math (contrast, shades, naming, extraction), curated palettes, code minify/convert/detect, SVG optimization and SCSS helpers. Every tool is a thin wrapper over the public REST API — one contract, one behavior. Published in the official MCP registry as online.jinero/jinero; the manifest lives at /.well-known/mcp/server.json.

# Remote endpoint (Streamable HTTP)
https://jinero.online/mcp

# Peek at the tool list without any client:
curl -s -X POST https://jinero.online/mcp \
  -H "Content-Type: application/json" \
  -H "Accept: application/json, text/event-stream" \
  -d '{"jsonrpc":"2.0","id":1,"method":"tools/list"}'
Getting Started

Connect a client

Works with any MCP client that supports remote (Streamable HTTP) servers: Claude Code, Claude Desktop, Cursor, Cline, Zed, Gemini CLI and friends. Older clients that only speak stdio can bridge with npx mcp-remote https://jinero.online/mcp.

# Claude Code (CLI)
claude mcp add --transport http jinero https://jinero.online/mcp
// Claude Desktop / Cursor / Cline — mcpServers config
{
  "mcpServers": {
    "jinero": {
      "type": "http",
      "url": "https://jinero.online/mcp"
    }
  }
}
Getting Started

Trust, safety & limits

Every tool declares MCP annotations so clients and security scanners can verify the posture instead of guessing: all 22 tools are read-only and idempotent. Submitted code and SVG are parsed and transformed as text — never executed, never stored. Uploaded images (font recognition, color extraction) are processed in memory and deleted immediately. Only three tools fetch a user-supplied URL (recognize_font, extract_colors, svg_to_datauri) — they are marked open-world and the fetches are SSRF-guarded (public http(s) only, size-capped). Anonymous, no API key, rate-limited at 60 req/min per IP.

// Annotations served in tools/list for every tool
{
  "readOnlyHint": true,
  "idempotentHint": true,
  "openWorldHint": false   // true only on the 3 URL-fetching tools
}
Fonts

search_fonts

Search the free font catalog by name, category, style tags, language coverage, variable/monospace flags and style count. Returns a paginated list of families with preview URLs and per-style metadata.

TOOL search_fonts read-only idempotent
ParameterTypeDescription
name string Fuzzy name match.
category string Comma-separated categories, e.g. 'serif,sans'.
langs string Comma-separated language codes, e.g. 'latin,cyrillic' — ALL must be supported.
style string Comma-separated style tags (handwriting, script, display, slab, rounded, condensed, expanded, stencil, pixel, blackletter, outline, retro) — ALL must match.
variable boolean Only variable fonts.
monospace boolean Only monospace fonts.
styles_min / styles_max integer Bounds on the number of styles.
order string likes (default) · downloads · views · name · created_at.
sort string asc · desc.
per_page / page integer Pagination (per_page 1–100, default 24). 
// tools/call arguments
{ "name": "inter", "category": "sans", "per_page": 2 }
Example response
{
  "current_page": 1,
  "data": [
    {
      "name": "Inter Tight",
      "slug": "inter-tight",
      "category": "sans",
      "variable": true,
      "monospace": false,
      "langs": ["latin", "cyrillic", "greek"],
      "style_tags": [],
      "styles_count": 18,
      "downloads": 2800,
      "likes_count": 1392,
      "regular_url": "https://jinero.online/storage/fonts/inter-tight/inter-tight-regular.woff2",
      "styles": [ { "weight": 100, "italic": false, "name": "Thin" }, "…" ]
    }
  ],
  "per_page": 2,
  "total": 4
}
Fonts

recognize_font

Identify which font is used in an image. Powered by our own CNN embedding model trained on the jinero catalog — it matches fonts by visual shape, so it needs no OCR and no readable text (Latin & Cyrillic). Send a tight crop of one line of text as a public image_url or as image_base64 (raw base64 / data URI — perfect for a local screenshot your agent just took). The image is processed in memory and deleted immediately. ~200 ms per call.

TOOL recognize_font read-only idempotent fetches external URLs
ParameterTypeDescription
image_url string Public http(s) URL of the image. Provide either this or image_base64.
image_base64 string Base64-encoded image (raw base64 or data:image/…;base64 URI), max 8 MB decoded. Provide either this or image_url.
top_k integer Number of font matches to return (3–20, default 8). 
// tools/call arguments — URL variant
{ "image_url": "https://example.com/heading-crop.png", "top_k": 5 }

// …or send a local screenshot directly
{ "image_base64": "data:image/png;base64,iVBORw0KGgo…", "top_k": 5 }
Example response
{
  "matches": [
    { "slug": "lunasima", "name": "Lunasima", "category": "sans", "score": 0.8331,
      "family_url": "https://jinero.online/fonts/lunasima" },
    { "slug": "tajawal", "name": "Tajawal", "category": "sans", "score": 0.8213,
      "family_url": "https://jinero.online/fonts/tajawal" }
  ],
  "note": "Matched by a trained CNN embedding (visual shape), no OCR."
}
Fonts

get_font

Full metadata for one font family by slug: designer, license, category, language coverage, variable axes, every style, plus ready-made download/CSS/files URLs.

TOOL get_font read-only idempotent
ParameterTypeDescription
slug string Family slug, e.g. 'inter', 'playfair-display'. 
// tools/call arguments
{ "slug": "inter" }
Example response
{
  "name": "Inter",
  "slug": "inter",
  "category": "sans",
  "designer": "Rasmus Andersson",
  "license": "OFL",
  "license_url": "https://openfontlicense.org/open-font-license-official-text/",
  "variable": true,
  "monospace": false,
  "langs": ["latin", "cyrillic", "greek", "vietnamese"],
  "styles_count": 18,
  "download_url": "https://jinero.online/api/v1/fonts/inter/download",
  "files_url": "https://jinero.online/api/v1/fonts/inter/files",
  "css_url": "https://jinero.online/api/v1/fonts/css?family=inter",
  "fonts": [ { "weight": 400, "italic": false, "name": "Regular" }, "…" ]
}
Fonts

get_font_files

List every font file for a family — weight, italic flag, style name, format and a direct woff2/ttf URL with file size. Handy when the agent is writing custom @font-face rules or downloading specific weights.

TOOL get_font_files read-only idempotent
ParameterTypeDescription
slug string Family slug, e.g. 'inter'. 
// tools/call arguments
{ "slug": "inter" }
Example response
{
  "family": "Inter",
  "slug": "inter",
  "files": [
    { "weight": 100, "italic": false, "style": "Thin", "format": "woff2",
      "url": "https://jinero.online/storage/fonts/inter/inter-thin.woff2", "size": 111816 },
    { "weight": 400, "italic": false, "style": "Regular", "format": "ttf",
      "url": "https://jinero.online/storage/fonts/inter/inter-regular.ttf", "size": 876576 }
  ]
}
Fonts

get_fonts_css

Generate ready-to-paste @font-face CSS for a family spec — Google-Fonts-compatible syntax, including variable ranges. Returns plain CSS text the agent can drop straight into a stylesheet.

TOOL get_fonts_css read-only idempotent
ParameterTypeDescription
family string Family spec, e.g. "inter:wght@400,700" or a variable range "inter:[email protected]".
display string font-display value: swap (default) · auto · block · fallback · optional. 
// tools/call arguments
{ "family": "inter:wght@400,700", "display": "swap" }
Example response
/* jinero.online Fonts API */

@font-face {
  font-family: 'Inter';
  font-style: normal;
  font-weight: 400;
  font-display: swap;
  src: url('https://jinero.online/storage/fonts/inter/inter-regular.woff2') format('woff2');
}
/* … one block per requested weight … */
Fonts

get_font_download_url

Return the direct ZIP download URL for a font family (all styles in TTF + WOFF2, plus a ready fonts.css). The tool does not download anything itself — it hands the URL to the user or agent.

TOOL get_font_download_url read-only idempotent
ParameterTypeDescription
slug string Family slug, e.g. 'inter'. 
// tools/call arguments
{ "slug": "inter" }
Example response
{
  "slug": "inter",
  "download_url": "https://jinero.online/api/v1/fonts/inter/download"
}
Colors

check_contrast

WCAG 2.1 contrast ratio between a foreground and background color, with AA/AAA pass flags for normal and large text — the same sRGB math Lighthouse uses.

TOOL check_contrast read-only idempotent
ParameterTypeDescription
fg string Foreground color: hex, rgb(), or hsl().
bg string Background color, same formats. 
// tools/call arguments
{ "fg": "#1d4ed8", "bg": "#ffffff" }
Example response
{
  "success": true,
  "ratio": 6.29,
  "ratio_string": "6.29:1",
  "aa":  { "normal": true,  "large": true },
  "aaa": { "normal": false, "large": true },
  "thresholds": { "aa_normal": 4.5, "aa_large": 3, "aaa_normal": 7, "aaa_large": 4.5 }
}
Colors

get_color_shades

A complete design-token set from one base color: tints, shades and five harmonic relationships (complementary, analogous, triadic, split-complementary, tetradic). Every color carries hex/rgb/hsl strings, luminance and a recommended text color.

TOOL get_color_shades read-only idempotent
ParameterTypeDescription
hex string Base color: hex, rgb(), or hsl().
step string Step percentage: 5, 10 (default), 20, 25.
limit integer Cap on tints/shades (default fills to ~100%). 
// tools/call arguments
{ "hex": "#3b82f6", "step": "20", "limit": 2 }
Example response
{
  "success": true,
  "base": { "hex": "#3b82f6", "hsl_string": "hsl(217, 91%, 60%)", "luminance": 0.2355,
            "text_color": "#000000", "contrast_on_white": 3.68 },
  "tints":  [ { "percent": 20, "hex": "#629bf8", "…": "…" } ],
  "shades": [ { "percent": 20, "hex": "#2f68c5", "…": "…" } ],
  "harmonies": { "complementary": ["…"], "analogous": ["…"], "triadic": ["…"] }
}
Colors

name_color

The closest human-readable name for one or many colors — nearest perceptual match against a ~31,000-color dataset. Great for labeling extracted palettes or generated swatches.

TOOL name_color read-only idempotent
ParameterTypeDescription
hex string One hex, or several comma-separated (up to 100), e.g. "#3b82f6,#000,#ff7f50". 
// tools/call arguments
{ "hex": "#3b82f6,#000,#ff7f50" }
Example response
{
  "success": true,
  "count": 3,
  "colors": [
    { "input": "#3B82F6", "name": "Dodger Blue", "hex": "#3E82FC", "exact": false, "distance": 10.91 },
    { "input": "#000000", "name": "Black",       "hex": "#000000", "exact": true,  "distance": 0 },
    { "input": "#FF7F50", "name": "Coral",       "hex": "#FF7F50", "exact": true,  "distance": 0 }
  ]
}
Colors

extract_colors

Extract a dominant-color palette from an image — k-means clustering with balanced / vibrant / muted modes. Send a public image_url or image_base64 (raw base64 / data URI — perfect for a local screenshot). The image is processed in memory and never stored. Every color comes back named: a labeled palette in one call.

TOOL extract_colors read-only idempotent fetches external URLs
ParameterTypeDescription
image_url string Public image URL (server-side fetch, capped at 10 MB, image/* only). Provide either this or image_base64.
image_base64 string Base64-encoded image (raw base64 or data:image/…;base64 URI), max 10 MB decoded. Provide either this or image_url.
count integer How many colors to return: 2–16, default 8.
mode string balanced (default) · vibrant · muted. 
// tools/call arguments — URL variant
{ "image_url": "https://example.com/cover.jpg", "count": 6, "mode": "vibrant" }

// …or send a local screenshot directly
{ "image_base64": "data:image/png;base64,iVBORw0KGgo…", "count": 6 }
Example response
{
  "success": true,
  "mode": "vibrant",
  "colors": [
    { "hex": "#f9f9f9", "percent": 90.8, "name": "White", "name_exact": false,
      "rgb": { "r": 249, "g": 249, "b": 249 }, "hsl": { "h": 0, "s": 0, "l": 97.6 } },
    { "hex": "#1d1c1b", "percent": 5.8, "name": "Cod Gray", "name_exact": false, "…": "…" }
  ]
}
Palettes

search_palettes

Search the curated color-palette catalog by name, tone, temperature, mood, harmony, exact color count and tags. Returns a paginated list — each palette with its hex colors and classification.

TOOL search_palettes read-only idempotent
ParameterTypeDescription
name string Fuzzy name match.
tone string light · dark · mixed.
temperature string warm · cool · neutral.
mood string e.g. pastel, muted, earthy, vibrant, monochrome.
harmony string e.g. analogous, complementary, triadic, monochromatic.
color_count integer Exact number of colors (2–10).
tags array Tag slugs — ALL must match.
order string newest (default) · popular · name.
per_page / page integer Pagination (per_page 1–100, default 24). 
// tools/call arguments
{ "tone": "light", "mood": "pastel", "per_page": 1 }
Example response
{
  "current_page": 1,
  "data": [
    {
      "id": 6267,
      "name": "5-Color Darling Bud Palette",
      "colors": ["#ffffff", "#e7b7fb", "#b0cbfc", "#f98bf7", "#f7cefc"],
      "color_count": 5,
      "tone": "mixed",
      "temperature": "neutral"
    }
  ],
  "total": 6267
}
Palettes

get_palette

One palette by id: its hex colors, name, tone, temperature, mood, harmony and tags.

TOOL get_palette read-only idempotent
ParameterTypeDescription
id integer Palette id (from search_palettes). 
// tools/call arguments
{ "id": 6267 }
Example response
{
  "success": true,
  "palette": {
    "id": 6267,
    "name": "5-Color Darling Bud Palette",
    "colors": ["#ffffff", "#e7b7fb", "#b0cbfc", "#f98bf7", "#f7cefc"],
    "color_count": 5,
    "tone": "mixed",
    "temperature": "neutral",
    "tags": []
  }
}
Code

minify_code

Minify or beautify JS, CSS, HTML, SVG, JSON or XML. The code is only parsed and re-printed as text — never executed, never stored. Set type=auto to let the server sniff the language.

TOOL minify_code read-only idempotent
ParameterTypeDescription
code string Source text to transform.
type string js · css · html · svg · json · xml · auto.
mode string minify (default) · beautify.
keep_license boolean Preserve /*! … */ license comments when minifying. 
// tools/call arguments
{ "code": ".a { color: #ffffff; margin: 0px; }", "type": "css" }
Example response
{
  "success": true,
  "type": "css",
  "mode": "minify",
  "output": ".a{color:#fff;margin:0}",
  "original_size": 47,
  "output_size": 23,
  "savings_percent": 51.1
}
Code

detect_code

Detect the language/format of a code snippet — static analysis only, the snippet is never executed. Also reports which converters can take the detected format as input.

TOOL detect_code read-only idempotent
ParameterTypeDescription
code string Snippet to inspect. Max 200,000 chars. 
// tools/call arguments
{ "code": "const x = () => 42;" }
Example response
{
  "success": true,
  "detected_type": "esm",
  "confidence": "medium",
  "available_targets": [ { "to": "cjs", "label": "ESM → CommonJS" } ]
}
Code

convert_code

Convert code between text formats — JSON↔YAML, JSON→TOML, CSS↔SCSS, ESM→CJS and more. Pure text transformation: the source is parsed and re-serialized, never executed, never stored. Use list_code_converters for the full list of from/to pairs and per-converter options.

TOOL convert_code read-only idempotent
ParameterTypeDescription
code string Source code to convert.
from string Source format id (see list_code_converters).
to string Target format id.
options object Per-converter options (see optionsSchema in list_code_converters). 
// tools/call arguments
{ "code": "{\"name\":\"jinero\"}", "from": "json", "to": "yaml" }
Example response
{
  "success": true,
  "from": "json",
  "to": "yaml",
  "output": "name: jinero\n",
  "notes": null
}
Code

list_code_converters

The registry of available converters: from/to ids, human labels and each converter's option schema. No parameters.

TOOL list_code_converters read-only idempotent 
// tools/call arguments
{ }
Example response
{
  "success": true,
  "converters": [
    { "id": "json_to_yaml", "from": "json", "to": "yaml", "label": "JSON → YAML",
      "optionsSchema": { "indent": [2, 4], "sortKeys": false } },
    { "id": "yaml_to_json", "from": "yaml", "to": "json", "label": "YAML → JSON", "…": "…" }
  ]
}
SVG

optimize_svg

Optimize and clean SVG markup with SVGO — pure markup transformation, nothing is executed or stored. Returns the minified SVG plus before/after sizes.

TOOL optimize_svg read-only idempotent
ParameterTypeDescription
svg string SVG source. Max 500,000 chars.
preset string safe · balanced (default) · aggressive. 
// tools/call arguments
{ "svg": "<svg xmlns=\"…\" width=\"24\" height=\"24\"><rect …/></svg>", "preset": "balanced" }
Example response
{
  "success": true,
  "preset": "balanced",
  "output": "<svg xmlns=\"http://www.w3.org/2000/svg\" width=\"24\" height=\"24\"><path fill=\"#f00\" d=\"M2 2h20v20H2z\"/></svg>",
  "original_size": 136,
  "optimized_size": 106,
  "savings_percent": 22.1
}
SVG

svg_to_datauri

Encode an SVG (or a fetched image) as a CSS-ready data: URI — URL-encoded and base64 variants plus a ready background-image snippet. Provide either raw svg markup or a public url.

TOOL svg_to_datauri read-only idempotent fetches external URLs
ParameterTypeDescription
svg string Raw SVG markup. Mutually exclusive with url.
url string Public image URL the server will fetch.
encoding string utf8 · base64. Defaults: utf8 for SVG, base64 for raster.
quotes string single · double (default) — quote style in the CSS snippet. 
// tools/call arguments
{ "svg": "<svg xmlns=\"http://www.w3.org/2000/svg\"><circle r=\"4\"/></svg>" }
Example response
{
  "success": true,
  "mime_type": "image/svg+xml",
  "primary_label": "URL-encoded Data URI",
  "primary_output": "data:image/svg+xml,%3Csvg xmlns=%22http…%3E",
  "secondary_label": "Base64 Data URI",
  "secondary_output": "data:image/svg+xml;base64,PHN2ZyB4bWxu…",
  "css_output": "background-image: url(\"data:image/svg+xml,%3Csvg…%3E\");"
}
SVG

list_svg_presets

The available SVG optimization presets and what each one does. No parameters.

TOOL list_svg_presets read-only idempotent 
// tools/call arguments
{ }
Example response
{
  "presets": [
    { "key": "safe",       "name": "Safe",       "description": "Minimal optimization, preserves most attributes" },
    { "key": "balanced",   "name": "Balanced",   "description": "Good compression with minimal visual changes" },
    { "key": "aggressive", "name": "Aggressive", "description": "Maximum compression, may affect some SVG features" }
  ]
}
Dev

list_scss_mixins

Browse the SCSS mixin catalog — id, title and a one-liner for each, optionally filtered by group or fuzzy search. Set fields=full to include sources in the listing.

TOOL list_scss_mixins read-only idempotent
ParameterTypeDescription
group string Bootstrap · Project · Pattern · Placeholder.
search string Fuzzy substring across id/title/description.
fields string summary (default) · full. 
// tools/call arguments
{ "search": "centerer", "fields": "summary" }
Example response
{
  "success": true,
  "count": 1,
  "groups": ["Bootstrap", "Project", "Pattern", "Placeholder"],
  "items": [
    { "id": "centerer", "title": "centerer()", "group": "Project",
      "short": "Absolute centering helper with axis toggles." }
  ]
}
Dev

get_scss_mixin

One SCSS mixin by id — full SCSS/Sass/Less source, parameters and a usage demo.

TOOL get_scss_mixin read-only idempotent
ParameterTypeDescription
id string Mixin id (kebab-case), e.g. 'centerer', 'media-breakpoint-up'. 
// tools/call arguments
{ "id": "centerer" }
Example response
{
  "success": true,
  "mixin": {
    "id": "centerer",
    "title": "centerer()",
    "group": "Project",
    "short": "Absolute centering helper with axis toggles.",
    "scss": "@mixin centerer($horizontal: true, $vertical: true) { … }",
    "demo": "…",
    "url": "https://jinero.online/dev/scss-mixins#centerer"
  }
}
Dev

generate_clamp

Calculate a fluid CSS clamp() expression for responsive sizing between two viewport widths. Pure calculation — returns the CSS snippet in px and rem variants plus the underlying math.

TOOL generate_clamp read-only idempotent
ParameterTypeDescription
min_fs number Minimum size in px.
max_fs number Maximum size in px.
min_vw number Viewport width at min_fs (default 320).
max_vw number Viewport width at max_fs (default 1440).
unit string px · rem (default) · both.
root number Root font-size in px for rem conversion (default 16). 
// tools/call arguments
{ "min_fs": 16, "max_fs": 24 }
Example response
{
  "success": true,
  "css": "clamp(1rem, 0.8571rem + 0.7143vw, 1.5rem)",
  "variants": {
    "px":  "clamp(16px, 13.7143px + 0.7143vw, 24px)",
    "rem": "clamp(1rem, 0.8571rem + 0.7143vw, 1.5rem)"
  },
  "math": { "slope": 0.007143, "intercept_px": 13.7143, "vw_coefficient": 0.7143 }
}

About the jinero.online MCP server

A hosted Model Context Protocol server that puts Jinero's font, color, palette, code and SVG tools in the hands of any AI agent — 22 read-only, annotated tools over one URL.

Read-only by design

All 22 tools declare readOnlyHint + idempotentHint MCP annotations. Submitted code and SVG are parsed as text and never executed; images are processed in memory and never stored.

No key, no install

A hosted remote server over Streamable HTTP — add one URL to your MCP client and go. Anonymous, rate-limited at 60 req/min per IP.

Font recognition built in

recognize_font identifies fonts from a screenshot with our own CNN embedding model — by visual shape, no OCR, Latin & Cyrillic — via URL or base64.

One contract with the REST API

Every MCP tool calls the same controllers as the public REST API, so behavior, limits and response shapes stay identical across both surfaces.

Frequently Asked Questions

No. The server is anonymous and free, rate-limited at 60 requests/min per IP. It is published in the official MCP registry as online.jinero/jinero.

Every tool is read-only and idempotent, and says so via MCP annotations (readOnlyHint, idempotentHint) that your client can verify in tools/list. Code sent to minify/convert/detect is parsed as text and never executed. Only three tools fetch a URL you supply (recognize_font, extract_colors, svg_to_datauri); those fetches are SSRF-guarded and size-capped, and uploaded images are never stored.

Any MCP client with remote (Streamable HTTP) support: Claude Code, Claude Desktop, Cursor, Cline, Zed, Gemini CLI and others. Older stdio-only clients can bridge with npx mcp-remote https://jinero.online/mcp.

Two ways: a public image_url, or image_base64 with raw base64 / a data URI (max 8 MB decoded) — so an agent can send a local screenshot directly without hosting it anywhere. Recognition matches by visual letterform shape with our own CNN model, so it needs no OCR and works for Latin and Cyrillic.

Same engine, different transport. MCP tools call the same controllers as the documented REST endpoints, so parameters and response shapes match. Use REST from your own code; use MCP to hand the tools to an AI agent.

At https://jinero.online/.well-known/mcp/server.json, and in the official MCP registry (registry.modelcontextprotocol.io) under the name online.jinero/jinero.