Glyphic

<div align="center"> <h1>Glyphic</h1> <p><b>AI agents can generate diagrams from structured JSON — without touching SVG.</b></p> <p>Typed JSON in, beautiful native SVG & PNG out, across 18 diagram types. Built for LLMs and autonomous agents — no fragile DSL, no headless browser.</p> </div>

<p align="center"> <a href="https://glyphic.web.app/generate">Live playground</a> · <a href="#quick-start">Quick Start</a> · <a href="./docs/examples/README.md">Examples Gallery</a> · <a href="./docs/README.md">Documentation</a> · <a href="#supported-diagrams">18 Diagram Types</a> </p>

Add it to your AI agent in 30 seconds — it runs over stdio via npx, no install: ``bash # Claude Code claude mcp add glyphic -- npx -y @glyphicjs/mcp-server `` For Cursor, Claude Desktop, VS Code, Windsurf, and Antigravity, see the MCP setup guide. Then just ask: “Draw an ERD for a blog with users, posts, and comments.”

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What

Glyphic is infrastructure for generating diagrams from structured data. You give it a strict, semantic JSON document — arrays of nodes and edges, or entities, or commits — and it returns a polished diagram as:

SVG — pure, scalable vector markup (accessible: role="img" + <title>).
PNG — high-resolution raster, rendered natively via Rust (@resvg/resvg-js).
React Flow JSON — nodes/edges mapped for an interactive React Flow canvas.

It supports 18 diagram types (architecture, sequence, ERD, UML class, state machines, flowcharts, Gantt, timelines, Sankey, Git trees, mindmaps, pie, quadrant, user journeys, Kanban, C4, treemaps, and a freeform canvas) behind a single validated schema.

You can use it three ways: as a library (@glyphicjs/core), as an MCP server (so Claude Desktop / Cursor can draw diagrams as a native tool), or as a self-hosted HTTP API.

Why

If an LLM needs to produce a diagram today, it has two bad options:

Draw raw SVG/Canvas. LLMs have no visual cortex — ask one to place nodes by absolute coordinate and they overlap, text overflows, and connectors cut straight through other shapes.
Emit a DSL like Mermaid. Mermaid's syntax is finicky (-->|label|) and a single typo crashes the whole render. It also relies on a headless browser (Puppeteer) to run its layout, which is slow, heavy, and awkward to run server-side.

Glyphic separates _semantics_ (what the diagram means) from _visuals_ (where things are drawn):

Machine-first JSON, not a DSL. The API surface is a strict Zod schema. Models emit ordinary JSON arrays — no fragile grammar to get wrong, and validation errors come back as precise, fixable messages instead of a crash.
Real layout engines, no DOM. Routing, intersections, and sizing are computed by mathematical graph engines (elkjs for graphs, d3-hierarchy/d3-sankey for data) — never a browser.
Native rasterization. SVG is compiled to PNG by Rust (@resvg/resvg-js) directly in Node. Fast, light, and deployable anywhere — no Chromium.

The result: agents produce correct, good-looking diagrams on the first try, and you run it as a normal Node dependency.

How

Pick the integration that fits you.

1. As a library

npm install @glyphicjs/core @glyphicjs/schema

import { processDiagram } from "@glyphicjs/core";
import { writeFileSync } from "node:fs";

const result = await processDiagram({
  type: "architecture",
  title: "Web App",
  nodes: [
    { id: "web", label: "Web App", shape: "rounded", icon: "fab-react" },
    { id: "api", label: "API", shape: "hexagon", icon: "fas-bolt" },
    { id: "db", label: "PostgreSQL", shape: "database", icon: "fas-database" }
  ],
  edges: [
    { source: "web", target: "api", label: "REST" },
    { source: "api", target: "db", label: "SQL" }
  ]
});

writeFileSync("diagram.png", result.png);   // Buffer (high-res PNG)
writeFileSync("diagram.svg", result.svg);   // string (scalable SVG)
console.log(result.reactFlow);              // interactive React Flow JSON

See the Core API reference.

2. As an MCP server (Claude Desktop / Cursor)

Add it to claude_desktop_config.json:

{
  "mcpServers": {
    "glyphic": { "command": "npx", "args": ["-y", "@glyphicjs/mcp-server"] }
  }
}

Restart Claude Desktop and ask: "Draw an architecture diagram of a React app behind an AWS load balancer talking to 3 Node services and a Postgres database." Claude emits the JSON, calls the tool, and the rendered PNG appears inline. See the MCP guide.

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Features

🧩 18 diagram types behind one validated schema — see them all.
🎨 Theming — built-in presets ("theme": "dark", plus light / pastel / mono) or a full custom palette. Theming guide.
🖌️ Styles — visual personality presets: "style": "compact" (default), clean, minimal, or hand-drawn sketch. Styles guide.
📺 Aspect-ratio framing — auto-fits diagrams to clean 16:9 / 9:16 frames (or set "aspectRatio"), by padding — never cropping.
🔤 Fonts — any Google Font ("fontFamily": "Outfit") or your own .ttf.
🖼️ Native icons — drop in any FontAwesome icon ("icon": "fas-database", "icon": "fab-aws") or your own SVG via customIcons.
📐 Real layout — elkjs + d3 compute routing, nesting (VPCs/clusters), and crow's-foot/UML markers with no overlaps.
⚡ Native PNG — Rust rasterization, no headless browser.
♿ Accessible output — every SVG ships with role="img" and a <title>.
🔒 Safe by construction — strict input validation, SVG output escaping/sanitization, and size limits to resist malicious input.
🧪 Multiple outputs — SVG, high-res PNG, and React Flow JSON from one call.

Supported Diagrams

18 first-class types — explore them in the Examples Gallery and the Diagram Types reference.

| | | | |---|---|---| | Architecture (nested VPCs/clusters) | C4 context | Flowchart | | Sequence | State machine | ERD (crow's-foot) | | UML Class | Mindmap | Gantt | | Timeline | User Journey | Kanban | | Pie | Quadrant | Sankey | | Git graph | Treemap | Canvas (freeform SVG) |

Monorepo architecture

A pnpm + Turborepo monorepo of three open-source libraries.

| Package | What it is | |---|---| | @glyphicjs/schema | The pure Zod validation layer — the LLM-facing contract. Validate model output before rendering. | | @glyphicjs/core | The engine: layout adapters, scene graph, SVG rendering, and rasterization. | | @glyphicjs/mcp-server | Official Model Context Protocol server — exposes Glyphic as a native tool to Claude Desktop / Cursor. |

Adding a new diagram type is one entry in packages/core/src/registry.ts plus a schema and a layout adapter — see CONTRIBUTING.

Documentation

📚 Documentation home
🖼️ Examples gallery — every type, rendered
🧩 Diagram types reference — schema for all 18 types
🖌️ Styles & aspect-ratio framing
🎨 Theming, fonts & icons
🛠️ Core API
🔌 MCP server
🤝 Contributing

License

LICENSE. Build incredible things.