Initial commit: pwweb - PipeWire WebUI

C++ backend with SSE streaming (reuses qpwgraph PipeWire callbacks). Svelte frontend with custom SVG canvas for port-level connections. Features: - Live PipeWire graph via SSE - Drag output->input port to connect - Double-click or select+Delete to disconnect - Node positions saved to localStorage - Pan (drag bg) and zoom (scroll) - Port type coloring (audio=green, midi=red, video=blue)
2026-03-29 22:40:07 +02:00
commit f8c57fbdd3
34 changed files with 24479 additions and 0 deletions
--- a/.gitignore
+++ b/.gitignore
@@ -0,0 +1,7 @@
+build/
+!build/.gitkeep
+frontend/node_modules/
+frontend/dist/
+*.o
+*.d
+pwweb
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -0,0 +1,43 @@
+cmake_minimum_required(VERSION 3.16)
+project(pwweb VERSION 0.1.0 LANGUAGES C CXX)
+
+set(CMAKE_CXX_STANDARD 17)
+set(CMAKE_CXX_STANDARD_REQUIRED ON)
+
+find_package(PkgConfig REQUIRED)
+pkg_check_modules(PW REQUIRED libpipewire-0.3)
+pkg_check_modules(SPA REQUIRED libspa-0.2)
+
+# ZLIB for cpp-httplib gzip compression
+find_package(ZLIB QUIET)
+
+add_executable(pwweb
+    src/main.cpp
+    src/graph_engine.cpp
+    src/web_server.cpp
+)
+
+target_include_directories(pwweb PRIVATE
+    src
+    src/third_party
+    ${PW_INCLUDE_DIRS}
+    ${SPA_INCLUDE_DIRS}
+)
+
+target_link_directories(pwweb PRIVATE
+    ${PW_LIBRARY_DIRS}
+    ${SPA_LIBRARY_DIRS}
+)
+
+target_link_libraries(pwweb PRIVATE
+    ${PW_LIBRARIES}
+    ${SPA_LIBRARIES}
+    pthread
+)
+
+if(ZLIB_FOUND)
+    target_link_libraries(pwweb PRIVATE ZLIB::ZLIB)
+    target_compile_definitions(pwweb PRIVATE CPPHTTPLIB_ZLIB_SUPPORT)
+endif()
+
+target_compile_options(pwweb PRIVATE ${PW_CFLAGS_OTHER} ${SPA_CFLAGS_OTHER})
--- a/frontend/.gitignore
+++ b/frontend/.gitignore
@@ -0,0 +1,24 @@
+# Logs
+logs
+*.log
+npm-debug.log*
+yarn-debug.log*
+yarn-error.log*
+pnpm-debug.log*
+lerna-debug.log*
+
+node_modules
+dist
+dist-ssr
+*.local
+
+# Editor directories and files
+.vscode/*
+!.vscode/extensions.json
+.idea
+.DS_Store
+*.suo
+*.ntvs*
+*.njsproj
+*.sln
+*.sw?
--- a/frontend/.vscode/extensions.json
+++ b/frontend/.vscode/extensions.json
@@ -0,0 +1,3 @@
+{
+  "recommendations": ["svelte.svelte-vscode"]
+}
--- a/frontend/README.md
+++ b/frontend/README.md
@@ -0,0 +1,47 @@
+# Svelte + TS + Vite
+
+This template should help get you started developing with Svelte and TypeScript in Vite.
+
+## Recommended IDE Setup
+
+[VS Code](https://code.visualstudio.com/) + [Svelte](https://marketplace.visualstudio.com/items?itemName=svelte.svelte-vscode).
+
+## Need an official Svelte framework?
+
+Check out [SvelteKit](https://github.com/sveltejs/kit#readme), which is also powered by Vite. Deploy anywhere with its serverless-first approach and adapt to various platforms, with out of the box support for TypeScript, SCSS, and Less, and easily-added support for mdsvex, GraphQL, PostCSS, Tailwind CSS, and more.
+
+## Technical considerations
+
+**Why use this over SvelteKit?**
+
+- It brings its own routing solution which might not be preferable for some users.
+- It is first and foremost a framework that just happens to use Vite under the hood, not a Vite app.
+
+This template contains as little as possible to get started with Vite + TypeScript + Svelte, while taking into account the developer experience with regards to HMR and intellisense. It demonstrates capabilities on par with the other `create-vite` templates and is a good starting point for beginners dipping their toes into a Vite + Svelte project.
+
+Should you later need the extended capabilities and extensibility provided by SvelteKit, the template has been structured similarly to SvelteKit so that it is easy to migrate.
+
+**Why `global.d.ts` instead of `compilerOptions.types` inside `jsconfig.json` or `tsconfig.json`?**
+
+Setting `compilerOptions.types` shuts out all other types not explicitly listed in the configuration. Using triple-slash references keeps the default TypeScript setting of accepting type information from the entire workspace, while also adding `svelte` and `vite/client` type information.
+
+**Why include `.vscode/extensions.json`?**
+
+Other templates indirectly recommend extensions via the README, but this file allows VS Code to prompt the user to install the recommended extension upon opening the project.
+
+**Why enable `allowJs` in the TS template?**
+
+While `allowJs: false` would indeed prevent the use of `.js` files in the project, it does not prevent the use of JavaScript syntax in `.svelte` files. In addition, it would force `checkJs: false`, bringing the worst of both worlds: not being able to guarantee the entire codebase is TypeScript, and also having worse typechecking for the existing JavaScript. In addition, there are valid use cases in which a mixed codebase may be relevant.
+
+**Why is HMR not preserving my local component state?**
+
+HMR state preservation comes with a number of gotchas! It has been disabled by default in both `svelte-hmr` and `@sveltejs/vite-plugin-svelte` due to its often surprising behavior. You can read the details [here](https://github.com/rixo/svelte-hmr#svelte-hmr).
+
+If you have state that's important to retain within a component, consider creating an external store which would not be replaced by HMR.
+
+```ts
+// store.ts
+// An extremely simple external store
+import { writable } from 'svelte/store'
+export default writable(0)
+```
--- a/frontend/index.html
+++ b/frontend/index.html
@@ -0,0 +1,13 @@
+<!doctype html>
+<html lang="en">
+  <head>
+    <meta charset="UTF-8" />
+    <link rel="icon" type="image/svg+xml" href="/favicon.svg" />
+    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
+    <title>pwweb - PipeWire Graph</title>
+  </head>
+  <body>
+    <div id="app"></div>
+    <script type="module" src="/src/main.ts"></script>
+  </body>
+</html>
--- a/frontend/package-lock.json
+++ b/frontend/package-lock.json
--- a/frontend/package.json
+++ b/frontend/package.json
@@ -0,0 +1,24 @@
+{
+  "name": "frontend",
+  "private": true,
+  "version": "0.0.0",
+  "type": "module",
+  "scripts": {
+    "dev": "vite",
+    "build": "vite build",
+    "preview": "vite preview",
+    "check": "svelte-check --tsconfig ./tsconfig.app.json && tsc -p tsconfig.node.json"
+  },
+  "devDependencies": {
+    "@sveltejs/vite-plugin-svelte": "^7.0.0",
+    "@tsconfig/svelte": "^5.0.8",
+    "@types/node": "^24.12.0",
+    "svelte": "^5.53.12",
+    "svelte-check": "^4.4.5",
+    "typescript": "~5.9.3",
+    "vite": "^8.0.1"
+  },
+  "dependencies": {
+    "@xyflow/svelte": "^1.5.2"
+  }
+}
--- a/frontend/public/favicon.svg
+++ b/frontend/public/favicon.svg
--- a/frontend/public/icons.svg
+++ b/frontend/public/icons.svg
@@ -0,0 +1,24 @@
+<svg xmlns="http://www.w3.org/2000/svg">
+  <symbol id="bluesky-icon" viewBox="0 0 16 17">
+    <g clip-path="url(#bluesky-clip)"><path fill="#08060d" d="M7.75 7.735c-.693-1.348-2.58-3.86-4.334-5.097-1.68-1.187-2.32-.981-2.74-.79C.188 2.065.1 2.812.1 3.251s.241 3.602.398 4.13c.52 1.744 2.367 2.333 4.07 2.145-2.495.37-4.71 1.278-1.805 4.512 3.196 3.309 4.38-.71 4.987-2.746.608 2.036 1.307 5.91 4.93 2.746 2.72-2.746.747-4.143-1.747-4.512 1.702.189 3.55-.4 4.07-2.145.156-.528.397-3.691.397-4.13s-.088-1.186-.575-1.406c-.42-.19-1.06-.395-2.741.79-1.755 1.24-3.64 3.752-4.334 5.099"/></g>
+    <defs><clipPath id="bluesky-clip"><path fill="#fff" d="M.1.85h15.3v15.3H.1z"/></clipPath></defs>
+  </symbol>
+  <symbol id="discord-icon" viewBox="0 0 20 19">
+    <path fill="#08060d" d="M16.224 3.768a14.5 14.5 0 0 0-3.67-1.153c-.158.286-.343.67-.47.976a13.5 13.5 0 0 0-4.067 0c-.128-.306-.317-.69-.476-.976A14.4 14.4 0 0 0 3.868 3.77C1.546 7.28.916 10.703 1.231 14.077a14.7 14.7 0 0 0 4.5 2.306q.545-.748.965-1.587a9.5 9.5 0 0 1-1.518-.74q.191-.14.372-.293c2.927 1.369 6.107 1.369 8.999 0q.183.152.372.294-.723.437-1.52.74.418.838.963 1.588a14.6 14.6 0 0 0 4.504-2.308c.37-3.911-.63-7.302-2.644-10.309m-9.13 8.234c-.878 0-1.599-.82-1.599-1.82 0-.998.705-1.82 1.6-1.82.894 0 1.614.82 1.599 1.82.001 1-.705 1.82-1.6 1.82m5.91 0c-.878 0-1.599-.82-1.599-1.82 0-.998.705-1.82 1.6-1.82.893 0 1.614.82 1.599 1.82 0 1-.706 1.82-1.6 1.82"/>
+  </symbol>
+  <symbol id="documentation-icon" viewBox="0 0 21 20">
+    <path fill="none" stroke="#aa3bff" stroke-linecap="round" stroke-linejoin="round" stroke-width="1.35" d="m15.5 13.333 1.533 1.322c.645.555.967.833.967 1.178s-.322.623-.967 1.179L15.5 18.333m-3.333-5-1.534 1.322c-.644.555-.966.833-.966 1.178s.322.623.966 1.179l1.534 1.321"/>
+    <path fill="none" stroke="#aa3bff" stroke-linecap="round" stroke-linejoin="round" stroke-width="1.35" d="M17.167 10.836v-4.32c0-1.41 0-2.117-.224-2.68-.359-.906-1.118-1.621-2.08-1.96-.599-.21-1.349-.21-2.848-.21-2.623 0-3.935 0-4.983.369-1.684.591-3.013 1.842-3.641 3.428C3 6.449 3 7.684 3 10.154v2.122c0 2.558 0 3.838.706 4.726q.306.383.713.671c.76.536 1.79.64 3.581.66"/>
+    <path fill="none" stroke="#aa3bff" stroke-linecap="round" stroke-linejoin="round" stroke-width="1.35" d="M3 10a2.78 2.78 0 0 1 2.778-2.778c.555 0 1.209.097 1.748-.047.48-.129.854-.503.982-.982.145-.54.048-1.194.048-1.749a2.78 2.78 0 0 1 2.777-2.777"/>
+  </symbol>
+  <symbol id="github-icon" viewBox="0 0 19 19">
+    <path fill="#08060d" fill-rule="evenodd" d="M9.356 1.85C5.05 1.85 1.57 5.356 1.57 9.694a7.84 7.84 0 0 0 5.324 7.44c.387.079.528-.168.528-.376 0-.182-.013-.805-.013-1.454-2.165.467-2.616-.935-2.616-.935-.349-.91-.864-1.143-.864-1.143-.71-.48.051-.48.051-.48.787.051 1.2.805 1.2.805.695 1.194 1.817.857 2.268.649.064-.507.27-.857.49-1.052-1.728-.182-3.545-.857-3.545-3.87 0-.857.31-1.558.8-2.104-.078-.195-.349-1 .077-2.078 0 0 .657-.208 2.14.805a7.5 7.5 0 0 1 1.946-.26c.657 0 1.328.092 1.946.26 1.483-1.013 2.14-.805 2.14-.805.426 1.078.155 1.883.078 2.078.502.546.799 1.247.799 2.104 0 3.013-1.818 3.675-3.558 3.87.284.247.528.714.528 1.454 0 1.052-.012 1.896-.012 2.156 0 .208.142.455.528.377a7.84 7.84 0 0 0 5.324-7.441c.013-4.338-3.48-7.844-7.773-7.844" clip-rule="evenodd"/>
+  </symbol>
+  <symbol id="social-icon" viewBox="0 0 20 20">
+    <path fill="none" stroke="#aa3bff" stroke-linecap="round" stroke-linejoin="round" stroke-width="1.35" d="M12.5 6.667a4.167 4.167 0 1 0-8.334 0 4.167 4.167 0 0 0 8.334 0"/>
+    <path fill="none" stroke="#aa3bff" stroke-linecap="round" stroke-linejoin="round" stroke-width="1.35" d="M2.5 16.667a5.833 5.833 0 0 1 8.75-5.053m3.837.474.513 1.035c.07.144.257.282.414.309l.93.155c.596.1.736.536.307.965l-.723.73a.64.64 0 0 0-.152.531l.207.903c.164.715-.213.991-.84.618l-.872-.52a.63.63 0 0 0-.577 0l-.872.52c-.624.373-1.003.094-.84-.618l.207-.903a.64.64 0 0 0-.152-.532l-.723-.729c-.426-.43-.289-.864.306-.964l.93-.156a.64.64 0 0 0 .412-.31l.513-1.034c.28-.562.735-.562 1.012 0"/>
+  </symbol>
+  <symbol id="x-icon" viewBox="0 0 19 19">
+    <path fill="#08060d" fill-rule="evenodd" d="M1.893 1.98c.052.072 1.245 1.769 2.653 3.77l2.892 4.114c.183.261.333.48.333.486s-.068.089-.152.183l-.522.593-.765.867-3.597 4.087c-.375.426-.734.834-.798.905a1 1 0 0 0-.118.148c0 .01.236.017.664.017h.663l.729-.83c.4-.457.796-.906.879-.999a692 692 0 0 0 1.794-2.038c.034-.037.301-.34.594-.675l.551-.624.345-.392a7 7 0 0 1 .34-.374c.006 0 .93 1.306 2.052 2.903l2.084 2.965.045.063h2.275c1.87 0 2.273-.003 2.266-.021-.008-.02-1.098-1.572-3.894-5.547-2.013-2.862-2.28-3.246-2.273-3.266.008-.019.282-.332 2.085-2.38l2-2.274 1.567-1.782c.022-.028-.016-.03-.65-.03h-.674l-.3.342a871 871 0 0 1-1.782 2.025c-.067.075-.405.458-.75.852a100 100 0 0 1-.803.91c-.148.172-.299.344-.99 1.127-.304.343-.32.358-.345.327-.015-.019-.904-1.282-1.976-2.808L6.365 1.85H1.8zm1.782.91 8.078 11.294c.772 1.08 1.413 1.973 1.425 1.984.016.017.241.02 1.05.017l1.03-.004-2.694-3.766L7.796 5.75 5.722 2.852l-1.039-.004-1.039-.004z" clip-rule="evenodd"/>
+  </symbol>
+</svg>
--- a/frontend/src/App.svelte
+++ b/frontend/src/App.svelte
@@ -0,0 +1,14 @@
+<script lang="ts">
+  import GraphCanvas from './components/GraphCanvas.svelte';
+</script>
+
+<GraphCanvas />
+
+<style>
+  :global(body) {
+    margin: 0;
+    padding: 0;
+    overflow: hidden;
+    background: #14141e;
+  }
+</style>
--- a/frontend/src/app.css
+++ b/frontend/src/app.css
@@ -0,0 +1,53 @@
+*, *::before, *::after {
+  box-sizing: border-box;
+}
+
+html, body {
+  margin: 0;
+  padding: 0;
+  width: 100%;
+  height: 100%;
+  overflow: hidden;
+  background: #1a1a2e;
+  color: #ccc;
+  font-family: monospace;
+}
+
+/* Force xyflow dark theme */
+:root {
+  --xy-background-color: #1a1a2e;
+  --xy-node-background-color: #1e1e2e;
+  --xy-node-border-color: #555;
+  --xy-edge-stroke-color: #888;
+  --xy-handle-background-color: #888;
+  --xy-handle-border-color: #555;
+  --xy-attribution-background-color: rgba(0,0,0,0.5);
+}
+
+.svelte-flow {
+  background: #1a1a2e !important;
+}
+
+.svelte-flow__edge-path {
+  stroke-linecap: round;
+}
+
+.svelte-flow__controls button {
+  background: #2a2a3e !important;
+  color: #aaa !important;
+  border: 1px solid #444 !important;
+  fill: #aaa !important;
+}
+
+.svelte-flow__controls button:hover {
+  background: #3a3a4e !important;
+}
+
+.svelte-flow__minimap {
+  background: #1a1a2e !important;
+  border: 1px solid #444 !important;
+}
+
+.svelte-flow__background {
+  background: #1a1a2e;
+}
--- a/frontend/src/assets/hero.png
+++ b/frontend/src/assets/hero.png
--- a/frontend/src/assets/svelte.svg
+++ b/frontend/src/assets/svelte.svg
@@ -0,0 +1 @@
+<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" aria-hidden="true" role="img" class="iconify iconify--logos" width="26.6" height="32" preserveAspectRatio="xMidYMid meet" viewBox="0 0 256 308"><path fill="#FF3E00" d="M239.682 40.707C211.113-.182 154.69-12.301 113.895 13.69L42.247 59.356a82.198 82.198 0 0 0-37.135 55.056a86.566 86.566 0 0 0 8.536 55.576a82.425 82.425 0 0 0-12.296 30.719a87.596 87.596 0 0 0 14.964 66.244c28.574 40.893 84.997 53.007 125.787 27.016l71.648-45.664a82.182 82.182 0 0 0 37.135-55.057a86.601 86.601 0 0 0-8.53-55.577a82.409 82.409 0 0 0 12.29-30.718a87.573 87.573 0 0 0-14.963-66.244"></path><path fill="#FFF" d="M106.889 270.841c-23.102 6.007-47.497-3.036-61.103-22.648a52.685 52.685 0 0 1-9.003-39.85a49.978 49.978 0 0 1 1.713-6.693l1.35-4.115l3.671 2.697a92.447 92.447 0 0 0 28.036 14.007l2.663.808l-.245 2.659a16.067 16.067 0 0 0 2.89 10.656a17.143 17.143 0 0 0 18.397 6.828a15.786 15.786 0 0 0 4.403-1.935l71.67-45.672a14.922 14.922 0 0 0 6.734-9.977a15.923 15.923 0 0 0-2.713-12.011a17.156 17.156 0 0 0-18.404-6.832a15.78 15.78 0 0 0-4.396 1.933l-27.35 17.434a52.298 52.298 0 0 1-14.553 6.391c-23.101 6.007-47.497-3.036-61.101-22.649a52.681 52.681 0 0 1-9.004-39.849a49.428 49.428 0 0 1 22.34-33.114l71.664-45.677a52.218 52.218 0 0 1 14.563-6.398c23.101-6.007 47.497 3.036 61.101 22.648a52.685 52.685 0 0 1 9.004 39.85a50.559 50.559 0 0 1-1.713 6.692l-1.35 4.116l-3.67-2.693a92.373 92.373 0 0 0-28.037-14.013l-2.664-.809l.246-2.658a16.099 16.099 0 0 0-2.89-10.656a17.143 17.143 0 0 0-18.398-6.828a15.786 15.786 0 0 0-4.402 1.935l-71.67 45.674a14.898 14.898 0 0 0-6.73 9.975a15.9 15.9 0 0 0 2.709 12.012a17.156 17.156 0 0 0 18.404 6.832a15.841 15.841 0 0 0 4.402-1.935l27.345-17.427a52.147 52.147 0 0 1 14.552-6.397c23.101-6.006 47.497 3.037 61.102 22.65a52.681 52.681 0 0 1 9.003 39.848a49.453 49.453 0 0 1-22.34 33.12l-71.664 45.673a52.218 52.218 0 0 1-14.563 6.398"></path></svg>
--- a/frontend/src/assets/vite.svg
+++ b/frontend/src/assets/vite.svg
--- a/frontend/src/components/GraphCanvas.svelte
+++ b/frontend/src/components/GraphCanvas.svelte
@@ -0,0 +1,496 @@
+<script lang="ts">
+  import { onMount, onDestroy } from 'svelte';
+  import {
+    nodes, ports, links, connected,
+    portById,
+    initGraph, destroyGraph,
+    connectPorts, disconnectPorts,
+  } from '../lib/stores';
+  import type { Node, Port, Link } from '../lib/types';
+
+  // Viewport state
+  let viewBox = $state({ x: -100, y: -40, w: 1200, h: 700 });
+  let dragging = $state<{ type: string; startX: number; startY: number; origX: number; origY: number; nodeId?: string } | null>(null);
+  let connecting = $state<{ outputPortId: number; outputX: number; outputY: number; mouseX: number; mouseY: number; portType: string } | null>(null);
+  let hoveredPort = $state<number | null>(null);
+  let selectedEdge = $state<string | null>(null);
+  let svgEl: SVGElement | null = null;
+
+  // Node positions
+  const POS_KEY = 'pwweb_pos';
+  function loadPos(): Record<string, { x: number; y: number }> {
+    try { return JSON.parse(localStorage.getItem(POS_KEY) || '{}'); } catch { return {}; }
+  }
+  function savePos(pos: Record<string, { x: number; y: number }>) {
+    try { localStorage.setItem(POS_KEY, JSON.stringify(pos)); } catch {}
+  }
+  let nodePositions = $state(loadPos());
+
+  // Layout defaults
+  function getDefaultPositions(n: Node[]): Record<string, { x: number; y: number }> {
+    const out = n.filter(nd => nd.mode === 'output');
+    const inp = n.filter(nd => nd.mode === 'input');
+    const other = n.filter(nd => nd.mode !== 'output' && nd.mode !== 'input');
+    const result: Record<string, { x: number; y: number }> = {};
+    let i = 0;
+    for (const nd of out) {
+      if (!result[nd.id]) result[nd.id] = { x: 0, y: (i % 8) * 100 };
+      i++;
+    }
+    i = 0;
+    for (const nd of other) {
+      if (!result[nd.id]) result[nd.id] = { x: 320, y: (i % 8) * 100 };
+      i++;
+    }
+    i = 0;
+    for (const nd of inp) {
+      if (!result[nd.id]) result[nd.id] = { x: 640, y: (i % 8) * 100 };
+      i++;
+    }
+    return result;
+  }
+
+  // Compute layout
+  let graphNodes = $derived.by(() => {
+    const n = $nodes;
+    const p = $ports;
+    const portMap = new Map<number, Port>();
+    for (const port of p) portMap.set(port.id, port);
+
+    const defaults = getDefaultPositions(n);
+    const pos = { ...defaults, ...nodePositions };
+
+    return n.map(nd => {
+      const ndPorts = nd.port_ids.map(pid => portMap.get(pid)).filter(Boolean) as Port[];
+      const inPorts = ndPorts.filter(pp => pp.mode === 'input');
+      const outPorts = ndPorts.filter(pp => pp.mode === 'output');
+      const nodePos = pos[String(nd.id)] || { x: 0, y: 0 };
+
+      // Compute node dimensions
+      const maxPorts = Math.max(inPorts.length, outPorts.length, 1);
+      const headerH = 24;
+      const portH = 18;
+      const height = headerH + maxPorts * portH + 6;
+      const width = 200;
+
+      // Compute port positions
+      const portPositions = new Map<number, { x: number; y: number }>();
+      let yi = headerH;
+      for (const port of inPorts) {
+        portPositions.set(port.id, { x: nodePos.x, y: nodePos.y + yi + portH / 2 });
+        yi += portH;
+      }
+      let yo = headerH;
+      for (const port of outPorts) {
+        portPositions.set(port.id, { x: nodePos.x + width, y: nodePos.y + yo + portH / 2 });
+        yo += portH;
+      }
+
+      return {
+        ...nd,
+        x: nodePos.x,
+        y: nodePos.y,
+        width,
+        height,
+        inPorts,
+        outPorts,
+        portPositions,
+      };
+    });
+  });
+
+  let graphLinks = $derived.by(() => {
+    const l = $links;
+    const p = $ports;
+    const portMap = new Map<number, Port>();
+    for (const port of p) portMap.set(port.id, port);
+
+    return l.map(link => {
+      const outPort = portMap.get(link.output_port_id);
+      const inPort = portMap.get(link.input_port_id);
+      return { ...link, outPort, inPort };
+    }).filter(l => l.outPort && l.inPort) as Array<Link & { outPort: Port; inPort: Port }>;
+  });
+
+  // Port positions lookup across all nodes
+  function getPortPos(portId: number): { x: number; y: number } | null {
+    for (const node of graphNodes) {
+      const pos = node.portPositions.get(portId);
+      if (pos) return pos;
+    }
+    return null;
+  }
+
+  function portColor(pt: string): string {
+    switch (pt) {
+      case 'audio': return '#4a9';
+      case 'midi':  return '#a44';
+      case 'video': return '#49a';
+      default:      return '#999';
+    }
+  }
+
+  function shortName(name: string): string {
+    const idx = name.lastIndexOf(':');
+    return idx >= 0 ? name.substring(idx + 1) : name;
+  }
+
+  // Bezier curve between two points
+  function bezierPath(x1: number, y1: number, x2: number, y2: number): string {
+    const dx = Math.abs(x2 - x1) * 0.5;
+    return `M ${x1} ${y1} C ${x1 + dx} ${y1}, ${x2 - dx} ${y2}, ${x2} ${y2}`;
+  }
+
+  // Mouse events
+  function svgPoint(e: MouseEvent): { x: number; y: number } {
+    if (!svgEl) return { x: e.clientX, y: e.clientY };
+    const pt = (svgEl as any).createSVGPoint();
+    pt.x = e.clientX;
+    pt.y = e.clientY;
+    const ctm = (svgEl as SVGGraphicsElement).getScreenCTM();
+    if (!ctm) return { x: e.clientX, y: e.clientY };
+    const svgP = pt.matrixTransform(ctm.inverse());
+    return { x: svgP.x, y: svgP.y };
+  }
+
+  function onMouseDown(e: MouseEvent) {
+    const pt = svgPoint(e);
+    const target = e.target as HTMLElement;
+
+    // Check if clicking on a port circle
+    if (target.classList.contains('port-circle')) {
+      const portId = Number(target.dataset.portId);
+      const port = $portById.get(portId);
+      if (port && port.mode === 'output') {
+        const pos = getPortPos(portId);
+        if (pos) {
+          connecting = {
+            outputPortId: portId,
+            outputX: pos.x,
+            outputY: pos.y,
+            mouseX: pt.x,
+            mouseY: pt.y,
+            portType: port.port_type,
+          };
+        }
+      }
+      return;
+    }
+
+    // Check if clicking on a node header (to drag)
+    if (target.classList.contains('node-header') || target.closest('.node-group')) {
+      const nodeGroup = target.closest('.node-group') as HTMLElement;
+      if (nodeGroup) {
+        const nodeId = nodeGroup.dataset.nodeId!;
+        const nd = graphNodes.find(n => String(n.id) === nodeId);
+        if (nd) {
+          dragging = {
+            type: 'node',
+            startX: pt.x,
+            startY: pt.y,
+            origX: nd.x,
+            origY: nd.y,
+            nodeId,
+          };
+        }
+        return;
+      }
+    }
+
+    // Check if clicking on an edge
+    if (target.classList.contains('edge-path')) {
+      selectedEdge = target.dataset.edgeId || null;
+      return;
+    }
+
+    // Click on background: pan
+    selectedEdge = null;
+    dragging = { type: 'pan', startX: e.clientX, startY: e.clientY, origX: viewBox.x, origY: viewBox.y };
+  }
+
+  function onMouseMove(e: MouseEvent) {
+    if (!dragging && !connecting) return;
+    const pt = svgPoint(e);
+
+    if (connecting) {
+      connecting.mouseX = pt.x;
+      connecting.mouseY = pt.y;
+      return;
+    }
+
+    if (!dragging) return;
+
+    if (dragging.type === 'node' && dragging.nodeId) {
+      const dx = pt.x - dragging.startX;
+      const dy = pt.y - dragging.startY;
+      nodePositions[dragging.nodeId] = {
+        x: dragging.origX + dx,
+        y: dragging.origY + dy,
+      };
+      nodePositions = nodePositions; // trigger reactivity
+    } else if (dragging.type === 'pan') {
+      const dx = (e.clientX - dragging.startX) * (viewBox.w / (svgEl?.clientWidth || 1));
+      const dy = (e.clientY - dragging.startY) * (viewBox.h / (svgEl?.clientHeight || 1));
+      viewBox.x = dragging.origX - dx;
+      viewBox.y = dragging.origY - dy;
+    }
+  }
+
+  function onMouseUp(e: MouseEvent) {
+    if (connecting) {
+      const target = e.target as HTMLElement;
+      if (target.classList.contains('port-circle')) {
+        const inputPortId = Number(target.dataset.portId);
+        const port = $portById.get(inputPortId);
+        if (port && port.mode === 'input' && port.port_type === connecting.portType) {
+          connectPorts(connecting.outputPortId, inputPortId);
+        }
+      }
+      connecting = null;
+    }
+
+    if (dragging?.type === 'node' && dragging.nodeId) {
+      savePos(nodePositions);
+    }
+
+    dragging = null;
+  }
+
+  function onWheel(e: WheelEvent) {
+    e.preventDefault();
+    const pt = svgPoint(e);
+    const factor = e.deltaY > 0 ? 1.1 : 0.9;
+    const nw = viewBox.w * factor;
+    const nh = viewBox.h * factor;
+    viewBox.x = pt.x - (pt.x - viewBox.x) * factor;
+    viewBox.y = pt.y - (pt.y - viewBox.y) * factor;
+    viewBox.w = nw;
+    viewBox.h = nh;
+  }
+
+  function onEdgeDblClick(e: MouseEvent) {
+    const target = e.target as HTMLElement;
+    if (target.classList.contains('edge-path')) {
+      const edgeId = target.dataset.edgeId;
+      const link = $links.find(l => String(l.id) === edgeId);
+      if (link) {
+        disconnectPorts(link.output_port_id, link.input_port_id);
+      }
+    }
+  }
+
+  function onKey(e: KeyboardEvent) {
+    if ((e.key === 'Delete' || e.key === 'Backspace') && selectedEdge) {
+      const link = $links.find(l => String(l.id) === selectedEdge);
+      if (link) {
+        disconnectPorts(link.output_port_id, link.input_port_id);
+        selectedEdge = null;
+      }
+    }
+  }
+
+  onMount(() => { initGraph(); });
+  onDestroy(() => { destroyGraph(); });
+</script>
+
+<svelte:window onkeydown={onKey} />
+
+<div class="wrap">
+  <div class="bar">
+    <span class="dot" class:on={$connected}></span>
+    <span>{$connected ? 'Connected' : 'Disconnected'}</span>
+    <span class="st">{$nodes.length} nodes | {$ports.length} ports | {$links.length} links</span>
+    <span class="help">Drag port->port to connect. Dbl-click wire to disconnect. Scroll to zoom. Drag bg to pan.</span>
+  </div>
+
+  <!-- svelte-ignore a11y_no_static_element_interactions -->
+  <svg
+    bind:this={svgEl}
+    viewBox="{viewBox.x} {viewBox.y} {viewBox.w} {viewBox.h}"
+    onmousedown={onMouseDown}
+    onmousemove={onMouseMove}
+    onmouseup={onMouseUp}
+    onwheel={onWheel}
+    ondblclick={onEdgeDblClick}
+    class="canvas"
+  >
+    <!-- Edges -->
+    {#each graphLinks as link (link.id)}
+      {@const outPos = getPortPos(link.output_port_id)}
+      {@const inPos = getPortPos(link.input_port_id)}
+      {#if outPos && inPos}
+        {@const color = portColor(link.outPort.port_type)}
+        <path
+          d={bezierPath(outPos.x, outPos.y, inPos.x, inPos.y)}
+          stroke={selectedEdge === String(link.id) ? '#fff' : color}
+          stroke-width={selectedEdge === String(link.id) ? 3 : 2}
+          fill="none"
+          class="edge-path"
+          data-edge-id={String(link.id)}
+        />
+      {/if}
+    {/each}
+
+    <!-- Connecting line (while dragging) -->
+    {#if connecting}
+      <path
+        d={bezierPath(connecting.outputX, connecting.outputY, connecting.mouseX, connecting.mouseY)}
+        stroke={portColor(connecting.portType)}
+        stroke-width="2"
+        stroke-dasharray="6 3"
+        fill="none"
+        opacity="0.8"
+      />
+    {/if}
+
+    <!-- Nodes -->
+    {#each graphNodes as nd (nd.id)}
+      {@const headerColor = nd.mode === 'output' ? '#2a3a2a' : nd.mode === 'input' ? '#3a2a2a' : '#2a2a3a'}
+      {@const borderColor = nd.mode === 'output' ? '#4a9' : nd.mode === 'input' ? '#a44' : '#555'}
+
+      <g class="node-group" data-node-id={String(nd.id)}>
+        <!-- Background -->
+        <rect
+          x={nd.x} y={nd.y}
+          width={nd.width} height={nd.height}
+          rx="5" ry="5"
+          fill="#1e1e2e"
+          stroke={borderColor}
+          stroke-width="1"
+        />
+
+        <!-- Header -->
+        <rect
+          x={nd.x} y={nd.y}
+          width={nd.width} height="24"
+          rx="5" ry="5"
+          fill={headerColor}
+          class="node-header"
+        />
+        <rect
+          x={nd.x} y={nd.y + 18}
+          width={nd.width} height="6"
+          fill={headerColor}
+        />
+        <text
+          x={nd.x + 6} y={nd.y + 16}
+          font-size="11" font-family="monospace"
+          fill="#ddd" font-weight="bold"
+        >
+          {nd.name.length > 28 ? nd.name.substring(0, 25) + '...' : nd.name}
+        </text>
+
+        <!-- Input ports (left side) -->
+        {#each nd.inPorts as port, i (port.id)}
+          {@const py = nd.y + 24 + i * 18 + 9}
+          <circle
+            cx={nd.x} cy={py}
+            r="5"
+            fill={portColor(port.port_type)}
+            stroke="#fff"
+            stroke-width={hoveredPort === port.id ? 2 : 0.5}
+            class="port-circle"
+            data-port-id={String(port.id)}
+            onmouseenter={() => { hoveredPort = port.id; }}
+            onmouseleave={() => { hoveredPort = null; }}
+          />
+          <text
+            x={nd.x + 10} y={py + 4}
+            font-size="10" font-family="monospace"
+            fill="#aaa"
+          >{shortName(port.name)}</text>
+        {/each}
+
+        <!-- Output ports (right side) -->
+        {#each nd.outPorts as port, i (port.id)}
+          {@const py = nd.y + 24 + i * 18 + 9}
+          <text
+            x={nd.x + nd.width - 10} y={py + 4}
+            font-size="10" font-family="monospace"
+            fill="#aaa"
+            text-anchor="end"
+          >{shortName(port.name)}</text>
+          <circle
+            cx={nd.x + nd.width} cy={py}
+            r="5"
+            fill={portColor(port.port_type)}
+            stroke="#fff"
+            stroke-width={hoveredPort === port.id ? 2 : 0.5}
+            class="port-circle"
+            data-port-id={String(port.id)}
+            onmouseenter={() => { hoveredPort = port.id; }}
+            onmouseleave={() => { hoveredPort = null; }}
+          />
+        {/each}
+      </g>
+    {/each}
+  </svg>
+</div>
+
+<style>
+  .wrap {
+    width: 100%;
+    height: 100vh;
+    background: #1a1a2e;
+    position: relative;
+    overflow: hidden;
+  }
+
+  .canvas {
+    width: 100%;
+    height: 100%;
+    display: block;
+    cursor: default;
+  }
+
+  .bar {
+    position: absolute;
+    top: 0;
+    left: 0;
+    right: 0;
+    z-index: 10;
+    display: flex;
+    align-items: center;
+    gap: 8px;
+    padding: 6px 16px;
+    background: rgba(20, 20, 30, 0.95);
+    border-bottom: 1px solid #333;
+    font-size: 12px;
+    color: #aaa;
+    font-family: monospace;
+  }
+
+  .dot {
+    width: 8px;
+    height: 8px;
+    border-radius: 50%;
+    background: #a44;
+    display: inline-block;
+  }
+  .dot.on { background: #4a9; }
+
+  .st { margin-left: auto; color: #666; }
+  .help { color: #555; font-size: 11px; margin-left: 16px; }
+
+  .port-circle {
+    cursor: crosshair;
+  }
+  .port-circle:hover {
+    filter: brightness(1.5);
+  }
+
+  .edge-path {
+    cursor: pointer;
+    pointer-events: stroke;
+  }
+  .edge-path:hover {
+    stroke-width: 4;
+  }
+
+  .node-header {
+    cursor: grab;
+  }
+  .node-group:hover rect {
+    filter: brightness(1.1);
+  }
+</style>
--- a/frontend/src/components/PortNode.svelte
+++ b/frontend/src/components/PortNode.svelte
@@ -0,0 +1,137 @@
+<script lang="ts">
+  import { Handle, Position } from '@xyflow/svelte';
+  import type { Port } from '../lib/types';
+
+  let { data }: { data: {
+    label: string;
+    nodeType: string;
+    mode: string;
+    inputs: Port[];
+    outputs: Port[];
+  } } = $props();
+
+  function portColor(portType: string): string {
+    switch (portType) {
+      case 'audio': return '#4a9';
+      case 'midi':  return '#a44';
+      case 'video': return '#49a';
+      default:      return '#999';
+    }
+  }
+
+  function shortName(name: string): string {
+    const idx = name.lastIndexOf(':');
+    return idx >= 0 ? name.substring(idx + 1) : name;
+  }
+</script>
+
+<div class="port-node" class:output-node={data.mode === 'output'} class:input-node={data.mode === 'input'}>
+  <div class="node-header">
+    <span class="node-type-label">{data.nodeType}</span>
+    <span class="node-label" title={data.label}>{data.label}</span>
+  </div>
+
+  <div class="node-body">
+    {#if data.inputs.length > 0}
+      <div class="ports-column">
+        {#each data.inputs as port (port.id)}
+          <div class="port" style="--pc: {portColor(port.port_type)}">
+            <Handle
+              type="target"
+              position={Position.Left}
+              id={String(port.id)}
+              class="port-handle"
+              style="background:{portColor(port.port_type)};border-color:{portColor(port.port_type)}"
+            />
+            <span class="port-name">{shortName(port.name)}</span>
+          </div>
+        {/each}
+      </div>
+    {/if}
+
+    {#if data.outputs.length > 0}
+      <div class="ports-column">
+        {#each data.outputs as port (port.id)}
+          <div class="port out" style="--pc: {portColor(port.port_type)}">
+            <span class="port-name">{shortName(port.name)}</span>
+            <Handle
+              type="source"
+              position={Position.Right}
+              id={String(port.id)}
+              class="port-handle"
+              style="background:{portColor(port.port_type)};border-color:{portColor(port.port_type)}"
+            />
+          </div>
+        {/each}
+      </div>
+    {/if}
+  </div>
+</div>
+
+<style>
+  .port-node {
+    background: #1e1e2e;
+    border: 1px solid #555;
+    border-radius: 6px;
+    min-width: 150px;
+    font-family: monospace;
+    font-size: 12px;
+    color: #ccc;
+    box-shadow: 0 2px 8px rgba(0,0,0,0.5);
+  }
+  .output-node { border-color: #4a9; }
+  .input-node { border-color: #a44; }
+
+  .node-header {
+    background: #2a2a3e;
+    padding: 5px 8px;
+    display: flex;
+    align-items: center;
+    gap: 6px;
+    border-bottom: 1px solid #444;
+    border-radius: 6px 6px 0 0;
+  }
+  .node-type-label {
+    font-size: 9px;
+    color: #777;
+    text-transform: uppercase;
+  }
+  .node-label {
+    font-weight: bold;
+    white-space: nowrap;
+    overflow: hidden;
+    text-overflow: ellipsis;
+    color: #ddd;
+    flex: 1;
+    font-size: 11px;
+  }
+
+  .node-body { padding: 2px 0; }
+  .ports-column { display: flex; flex-direction: column; }
+  .ports-column + .ports-column { border-top: 1px solid #333; }
+
+  .port {
+    display: flex;
+    align-items: center;
+    padding: 3px 6px;
+    position: relative;
+  }
+  .port.out { justify-content: flex-end; }
+
+  .port-name {
+    font-size: 11px;
+    color: #aaa;
+  }
+
+  :global(.port-handle) {
+    width: 8px !important;
+    height: 8px !important;
+    min-width: 8px !important;
+    min-height: 8px !important;
+    border: 1px solid #888 !important;
+    border-radius: 50% !important;
+    position: relative !important;
+    top: 0 !important;
+    transform: none !important;
+  }
+</style>
--- a/frontend/src/lib/Counter.svelte
+++ b/frontend/src/lib/Counter.svelte
@@ -0,0 +1,10 @@
+<script lang="ts">
+  let count: number = $state(0)
+  const increment = () => {
+    count += 1
+  }
+</script>
+
+<button class="counter" onclick={increment}>
+  Count is {count}
+</button>
--- a/frontend/src/lib/stores.ts
+++ b/frontend/src/lib/stores.ts
@@ -0,0 +1,64 @@
+import { writable, derived, get } from 'svelte/store';
+import type { Node, Port, Link, GraphMessage } from './types';
+import { subscribe, connectPorts, disconnectPorts } from './ws';
+
+// Raw graph stores
+export const nodes = writable<Node[]>([]);
+export const ports = writable<Port[]>([]);
+export const links = writable<Link[]>([]);
+export const connected = writable(false);
+
+// Port lookup map
+export const portById = derived(ports, ($ports) => {
+  const map = new Map<number, Port>();
+  for (const p of $ports) map.set(p.id, p);
+  return map;
+});
+
+// Node lookup map
+export const nodeById = derived(nodes, ($nodes) => {
+  const map = new Map<number, Node>();
+  for (const n of $nodes) map.set(n.id, n);
+  return map;
+});
+
+// Initialize: fetch via REST immediately, then subscribe to WS for updates
+let unsubscribe: (() => void) | null = null;
+
+function applyGraph(graph: GraphMessage) {
+  nodes.set(graph.nodes);
+  ports.set(graph.ports);
+  links.set(graph.links);
+  connected.set(true);
+}
+
+export async function initGraph() {
+  if (unsubscribe) return;
+
+  // 1. Fetch initial state via REST API (works immediately, no WS needed)
+  try {
+    const res = await fetch('/api/graph');
+    if (res.ok) {
+      const graph: GraphMessage = await res.json();
+      applyGraph(graph);
+    }
+  } catch (e) {
+    console.warn('[graph] REST fetch failed:', e);
+  }
+
+  // 2. Subscribe to WebSocket for live updates
+  unsubscribe = subscribe((graph: GraphMessage) => {
+    applyGraph(graph);
+  });
+}
+
+export function destroyGraph() {
+  if (unsubscribe) {
+    unsubscribe();
+    unsubscribe = null;
+    connected.set(false);
+  }
+}
+
+// Re-export connection functions
+export { connectPorts, disconnectPorts };
--- a/frontend/src/lib/types.ts
+++ b/frontend/src/lib/types.ts
@@ -0,0 +1,47 @@
+// Types matching the C++ backend JSON protocol
+
+export interface Port {
+  id: number;
+  node_id: number;
+  name: string;
+  mode: 'input' | 'output' | 'duplex' | 'none';
+  port_type: 'audio' | 'midi' | 'video' | 'other';
+  flags: number;
+}
+
+export interface Node {
+  id: number;
+  name: string;
+  nick: string;
+  media_name: string;
+  mode: 'input' | 'output' | 'duplex' | 'none';
+  node_type: string;
+  port_ids: number[];
+}
+
+export interface Link {
+  id: number;
+  output_port_id: number;
+  input_port_id: number;
+}
+
+export interface GraphMessage {
+  type: 'graph';
+  nodes: Node[];
+  ports: Port[];
+  links: Link[];
+}
+
+export interface ConnectMessage {
+  type: 'connect';
+  output_port_id: number;
+  input_port_id: number;
+}
+
+export interface DisconnectMessage {
+  type: 'disconnect';
+  output_port_id: number;
+  input_port_id: number;
+}
+
+export type WsMessage = ConnectMessage | DisconnectMessage;
--- a/frontend/src/lib/ws.ts
+++ b/frontend/src/lib/ws.ts
@@ -0,0 +1,83 @@
+import type { GraphMessage } from './types';
+
+type GraphListener = (graph: GraphMessage) => void;
+
+let es: EventSource | null = null;
+let listeners: GraphListener[] = [];
+let reconnectTimer: ReturnType<typeof setTimeout> | null = null;
+
+function connect() {
+  if (es && es.readyState === EventSource.OPEN) return;
+
+  const url = '/events';
+  console.log('[sse] connecting to', url);
+  es = new EventSource(url);
+
+  es.onopen = () => {
+    console.log('[sse] connected');
+  };
+
+  es.onmessage = (event) => {
+    try {
+      const data = JSON.parse(event.data);
+      if (data.type === 'graph') {
+        for (const fn of listeners) {
+          fn(data as GraphMessage);
+        }
+      }
+    } catch (e) {
+      console.warn('[sse] parse error:', e);
+    }
+  };
+
+  es.onerror = () => {
+    console.log('[sse] disconnected, reconnecting in 2s...');
+    es?.close();
+    es = null;
+    if (!reconnectTimer && listeners.length > 0) {
+      reconnectTimer = setTimeout(() => {
+        reconnectTimer = null;
+        connect();
+      }, 2000);
+    }
+  };
+}
+
+export function subscribe(fn: GraphListener): () => void {
+  listeners.push(fn);
+  connect();
+  return () => {
+    listeners = listeners.filter(l => l !== fn);
+    if (listeners.length === 0 && es) {
+      es.close();
+      es = null;
+      if (reconnectTimer) {
+        clearTimeout(reconnectTimer);
+        reconnectTimer = null;
+      }
+    }
+  };
+}
+
+async function postCommand(endpoint: string, outputPortId: number, inputPortId: number) {
+  try {
+    await fetch(endpoint, {
+      method: 'POST',
+      headers: { 'Content-Type': 'application/json' },
+      body: JSON.stringify({
+        output_port_id: outputPortId,
+        input_port_id: inputPortId,
+      }),
+    });
+  } catch (e) {
+    console.error('[api] POST', endpoint, 'failed:', e);
+  }
+}
+
+export function connectPorts(outputPortId: number, inputPortId: number) {
+  postCommand('/api/connect', outputPortId, inputPortId);
+}
+
+export function disconnectPorts(outputPortId: number, inputPortId: number) {
+  postCommand('/api/disconnect', outputPortId, inputPortId);
+}
--- a/frontend/src/main.ts
+++ b/frontend/src/main.ts
@@ -0,0 +1,9 @@
+import { mount } from 'svelte'
+import './app.css'
+import App from './App.svelte'
+
+const app = mount(App, {
+  target: document.getElementById('app')!,
+})
+
+export default app
--- a/frontend/svelte.config.js
+++ b/frontend/svelte.config.js
@@ -0,0 +1,2 @@
+/** @type {import("@sveltejs/vite-plugin-svelte").SvelteConfig} */
+export default {}
--- a/frontend/tsconfig.app.json
+++ b/frontend/tsconfig.app.json
@@ -0,0 +1,21 @@
+{
+  "extends": "@tsconfig/svelte/tsconfig.json",
+  "compilerOptions": {
+    "tsBuildInfoFile": "./node_modules/.tmp/tsconfig.app.tsbuildinfo",
+    "target": "ES2023",
+    "useDefineForClassFields": true,
+    "module": "ESNext",
+    "types": ["svelte", "vite/client"],
+    "noEmit": true,
+    /**
+     * Typecheck JS in `.svelte` and `.js` files by default.
+     * Disable checkJs if you'd like to use dynamic types in JS.
+     * Note that setting allowJs false does not prevent the use
+     * of JS in `.svelte` files.
+     */
+    "allowJs": true,
+    "checkJs": true,
+    "moduleDetection": "force"
+  },
+  "include": ["src/**/*.ts", "src/**/*.js", "src/**/*.svelte"]
+}
--- a/frontend/tsconfig.json
+++ b/frontend/tsconfig.json
@@ -0,0 +1,7 @@
+{
+  "files": [],
+  "references": [
+    { "path": "./tsconfig.app.json" },
+    { "path": "./tsconfig.node.json" }
+  ]
+}
--- a/frontend/tsconfig.node.json
+++ b/frontend/tsconfig.node.json
@@ -0,0 +1,26 @@
+{
+  "compilerOptions": {
+    "tsBuildInfoFile": "./node_modules/.tmp/tsconfig.node.tsbuildinfo",
+    "target": "ES2023",
+    "lib": ["ES2023"],
+    "module": "ESNext",
+    "types": ["node"],
+    "skipLibCheck": true,
+
+    /* Bundler mode */
+    "moduleResolution": "bundler",
+    "allowImportingTsExtensions": true,
+    "verbatimModuleSyntax": true,
+    "moduleDetection": "force",
+    "noEmit": true,
+
+    /* Linting */
+    "strict": true,
+    "noUnusedLocals": true,
+    "noUnusedParameters": true,
+    "erasableSyntaxOnly": true,
+    "noFallthroughCasesInSwitch": true,
+    "noUncheckedSideEffectImports": true
+  },
+  "include": ["vite.config.ts"]
+}
--- a/frontend/vite.config.ts
+++ b/frontend/vite.config.ts
@@ -0,0 +1,20 @@
+import { defineConfig } from 'vite'
+import { svelte } from '@sveltejs/vite-plugin-svelte'
+
+// https://vite.dev/config/
+export default defineConfig({
+  plugins: [svelte()],
+  server: {
+    port: 5173,
+    proxy: {
+      '/api': {
+        target: 'http://localhost:9876',
+        changeOrigin: true,
+      },
+      '/events': {
+        target: 'http://localhost:9876',
+        changeOrigin: true,
+      },
+    },
+  },
+})
--- a/src/graph_engine.cpp
+++ b/src/graph_engine.cpp
@@ -0,0 +1,773 @@
+#include "graph_engine.h"
+
+#include <pipewire/pipewire.h>
+#include <spa/utils/result.h>
+#include <spa/utils/list.h>
+
+#include <cstring>
+#include <algorithm>
+#include <chrono>
+#include <thread>
+
+// Default port type strings (must match qpwgraph)
+#define DEFAULT_AUDIO_TYPE "32 bit float mono audio"
+#define DEFAULT_MIDI_TYPE  "8 bit raw midi"
+#define DEFAULT_MIDI2_TYPE "32 bit raw UMP"
+#define DEFAULT_VIDEO_TYPE "32 bit float RGBA video"
+#define DEFAULT_OTHER_TYPE "PIPEWIRE_PORT_TYPE"
+
+using namespace pwgraph;
+
+// ============================================================================
+// Pending/sync helpers (ported from qpwgraph_pipewire.cpp)
+// ============================================================================
+
+static void add_pending(GraphEngine::Object *obj, GraphEngine::PwData &pw) {
+    if (obj->pending_seq == 0)
+        spa_list_append(&pw.pending, &obj->pending_link);
+    obj->pending_seq = pw_core_sync(pw.core, 0, obj->pending_seq);
+    pw.pending_seq = obj->pending_seq;
+}
+
+static void remove_pending(GraphEngine::Object *obj) {
+    if (obj->pending_seq != 0) {
+        spa_list_remove(&obj->pending_link);
+        obj->pending_seq = 0;
+    }
+}
+
+// ============================================================================
+// Proxy helpers
+// ============================================================================
+
+static void destroy_proxy(GraphEngine::Object *obj) {
+    if (obj->proxy) {
+        pw_proxy_destroy((pw_proxy*)obj->proxy);
+        obj->proxy = nullptr;
+    }
+    spa_hook_remove(&obj->object_listener);
+    spa_hook_remove(&obj->proxy_listener);
+    remove_pending(obj);
+    if (obj->info && obj->destroy_info) {
+        obj->destroy_info(obj->info);
+        obj->info = nullptr;
+    }
+}
+
+// ============================================================================
+// Node events (ported from qpwgraph_pipewire.cpp lines 224-278)
+// ============================================================================
+
+static void on_node_info(void *data, const struct pw_node_info *info) {
+    auto *obj = static_cast<GraphEngine::Object*>(data);
+    if (!obj) return;
+
+    info = pw_node_info_update((struct pw_node_info*)obj->info, info);
+    obj->info = (void*)info;
+
+    if (info && (info->change_mask & PW_NODE_CHANGE_MASK_PROPS)) {
+        auto *nobj = static_cast<GraphEngine::NodeObj*>(obj);
+        if (info->props) {
+            const char *media_name = spa_dict_lookup(info->props, PW_KEY_MEDIA_NAME);
+            if (media_name && strlen(media_name) > 0)
+                nobj->node.media_name = media_name;
+        }
+        nobj->node.changed = true;
+        nobj->node.ready = true;
+    }
+}
+
+static const struct pw_node_events node_events = {
+    .version = PW_VERSION_NODE_EVENTS,
+    .info = on_node_info,
+};
+
+// ============================================================================
+// Port events
+// ============================================================================
+
+static void on_port_info(void *data, const struct pw_port_info *info) {
+    auto *obj = static_cast<GraphEngine::Object*>(data);
+    if (!obj) return;
+    info = pw_port_info_update((struct pw_port_info*)obj->info, info);
+    obj->info = (void*)info;
+}
+
+static const struct pw_port_events port_events = {
+    .version = PW_VERSION_PORT_EVENTS,
+    .info = on_port_info,
+};
+
+// ============================================================================
+// Link events
+// ============================================================================
+
+static void on_link_info(void *data, const struct pw_link_info *info) {
+    auto *obj = static_cast<GraphEngine::Object*>(data);
+    if (!obj) return;
+    info = pw_link_info_update((struct pw_link_info*)obj->info, info);
+    obj->info = (void*)info;
+}
+
+static const struct pw_link_events link_events = {
+    .version = PW_VERSION_LINK_EVENTS,
+    .info = on_link_info,
+};
+
+// ============================================================================
+// Proxy events
+// ============================================================================
+
+static void on_proxy_removed(void *data) {
+    auto *obj = static_cast<GraphEngine::Object*>(data);
+    if (obj && obj->proxy) {
+        pw_proxy *proxy = (pw_proxy*)obj->proxy;
+        obj->proxy = nullptr;
+        pw_proxy_destroy(proxy);
+    }
+}
+
+static void on_proxy_destroy(void *data) {
+    auto *obj = static_cast<GraphEngine::Object*>(data);
+    if (obj)
+        destroy_proxy(obj);
+}
+
+static const struct pw_proxy_events proxy_events = {
+    .version = PW_VERSION_PROXY_EVENTS,
+    .destroy = on_proxy_destroy,
+    .removed = on_proxy_removed,
+};
+
+// ============================================================================
+// Object proxy creation (adapted from qpwgraph_pipewire::Object::create_proxy)
+// ============================================================================
+
+static void create_proxy_for_object(GraphEngine::Object *obj, GraphEngine *engine) {
+    if (obj->proxy) return;
+
+    const char *proxy_type = nullptr;
+    uint32_t version = 0;
+    void (*destroy_info)(void*) = nullptr;
+    const void *events = nullptr;
+
+    switch (obj->type) {
+    case GraphEngine::Object::ObjNode:
+        proxy_type = PW_TYPE_INTERFACE_Node;
+        version = PW_VERSION_NODE;
+        destroy_info = (void(*)(void*))pw_node_info_free;
+        events = &node_events;
+        break;
+    case GraphEngine::Object::ObjPort:
+        proxy_type = PW_TYPE_INTERFACE_Port;
+        version = PW_VERSION_PORT;
+        destroy_info = (void(*)(void*))pw_port_info_free;
+        events = &port_events;
+        break;
+    case GraphEngine::Object::ObjLink:
+        proxy_type = PW_TYPE_INTERFACE_Link;
+        version = PW_VERSION_LINK;
+        destroy_info = (void(*)(void*))pw_link_info_free;
+        events = &link_events;
+        break;
+    }
+
+    auto &pw = engine->pwData();
+    pw_proxy *proxy = (pw_proxy*)pw_registry_bind(
+        pw.registry, obj->id, proxy_type, version, 0);
+    if (proxy) {
+        obj->proxy = proxy;
+        obj->destroy_info = destroy_info;
+        obj->pending_seq = 0;
+        pw_proxy_add_object_listener(proxy,
+            &obj->object_listener, events, obj);
+        pw_proxy_add_listener(proxy,
+            &obj->proxy_listener, &proxy_events, obj);
+    }
+}
+
+// ============================================================================
+// Core events (sync/error handling)
+// ============================================================================
+
+static void on_core_done(void *data, uint32_t id, int seq) {
+    auto *engine = static_cast<GraphEngine*>(data);
+    auto &pw = engine->pwData();
+
+    if (id == PW_ID_CORE) {
+        pw.last_seq = seq;
+        if (pw.pending_seq == seq)
+            pw_thread_loop_signal(pw.loop, false);
+    }
+}
+
+static void on_core_error(void *data, uint32_t id, int seq, int res, const char *message) {
+    auto *engine = static_cast<GraphEngine*>(data);
+    auto &pw = engine->pwData();
+
+    if (id == PW_ID_CORE) {
+        pw.last_res = res;
+        if (res == -EPIPE)
+            pw.error = true;
+    }
+    pw_thread_loop_signal(pw.loop, false);
+}
+
+static const struct pw_core_events core_events = {
+    .version = PW_VERSION_CORE_EVENTS,
+    .info = nullptr,
+    .done = on_core_done,
+    .error = on_core_error,
+};
+
+// ============================================================================
+// Link proxy sync (for connect/disconnect operations)
+// ============================================================================
+
+static int link_proxy_sync(GraphEngine *engine) {
+    auto &pw = engine->pwData();
+
+    if (pw_thread_loop_in_thread(pw.loop))
+        return 0;
+
+    pw.pending_seq = pw_proxy_sync((pw_proxy*)pw.core, pw.pending_seq);
+
+    while (true) {
+        pw_thread_loop_wait(pw.loop);
+        if (pw.error)
+            return pw.last_res;
+        if (pw.pending_seq == pw.last_seq)
+            break;
+    }
+
+    return 0;
+}
+
+static void on_link_proxy_error(void *data, int seq, int res, const char *message) {
+    int *link_res = (int*)data;
+    *link_res = res;
+}
+
+static const struct pw_proxy_events link_proxy_events = {
+    .version = PW_VERSION_PROXY_EVENTS,
+    .error = on_link_proxy_error,
+};
+
+// ============================================================================
+// Registry events (the main entry point — ported from qpwgraph lines 425-568)
+// ============================================================================
+
+static void on_registry_global(void *data,
+    uint32_t id, uint32_t permissions,
+    const char *type, uint32_t version,
+    const struct spa_dict *props)
+{
+    if (!props) return;
+
+    auto *engine = static_cast<GraphEngine*>(data);
+
+    if (strcmp(type, PW_TYPE_INTERFACE_Node) == 0) {
+        // Parse node properties (ported from qpwgraph lines 444-489)
+        const char *str = spa_dict_lookup(props, PW_KEY_NODE_DESCRIPTION);
+        const char *nick = spa_dict_lookup(props, PW_KEY_NODE_NICK);
+        if (!str || strlen(str) < 1) str = nick;
+        if (!str || strlen(str) < 1) str = nick = spa_dict_lookup(props, PW_KEY_NODE_NAME);
+        if (!str || strlen(str) < 1) str = "node";
+
+        std::string node_name;
+        const char *app = spa_dict_lookup(props, PW_KEY_APP_NAME);
+        if (app && strlen(app) > 0 && strcmp(app, str) != 0) {
+            node_name += app;
+            node_name += '/';
+        }
+        node_name += str;
+        std::string node_nick = (nick ? nick : str);
+
+        PortMode node_mode = PortMode::None;
+        uint8_t node_types = 0;
+
+        str = spa_dict_lookup(props, PW_KEY_MEDIA_CLASS);
+        if (str) {
+            if (strstr(str, "Source") || strstr(str, "Output"))
+                node_mode = PortMode::Output;
+            else if (strstr(str, "Sink") || strstr(str, "Input"))
+                node_mode = PortMode::Input;
+            if (strstr(str, "Audio")) node_types |= (uint8_t)NodeType::Audio;
+            if (strstr(str, "Video")) node_types |= (uint8_t)NodeType::Video;
+            if (strstr(str, "Midi"))  node_types |= (uint8_t)NodeType::Midi;
+        }
+        if (node_mode == PortMode::None) {
+            str = spa_dict_lookup(props, PW_KEY_MEDIA_CATEGORY);
+            if (str && strstr(str, "Duplex"))
+                node_mode = PortMode::Duplex;
+        }
+
+        // Create node object
+        auto *nobj = new GraphEngine::NodeObj(id);
+        nobj->node.id = id;
+        nobj->node.name = node_name;
+        nobj->node.nick = node_nick;
+        nobj->node.mode = node_mode;
+        nobj->node.node_type = NodeType(node_types);
+        nobj->node.mode2 = node_mode;
+        nobj->node.ready = false;
+        nobj->node.changed = false;
+
+        engine->addObject(id, nobj);
+        create_proxy_for_object(nobj, engine);
+        engine->notifyChanged();
+    }
+    else if (strcmp(type, PW_TYPE_INTERFACE_Port) == 0) {
+        // Parse port properties (ported from qpwgraph lines 492-535)
+        const char *str = spa_dict_lookup(props, PW_KEY_NODE_ID);
+        const uint32_t node_id = (str ? (uint32_t)atoi(str) : 0);
+
+        std::string port_name;
+        str = spa_dict_lookup(props, PW_KEY_PORT_ALIAS);
+        if (!str) str = spa_dict_lookup(props, PW_KEY_PORT_NAME);
+        if (!str) str = "port";
+        port_name = str;
+
+        auto *node_obj = engine->findNode(node_id);
+
+        uint32_t port_type = engine->otherPortType();
+        str = spa_dict_lookup(props, PW_KEY_FORMAT_DSP);
+        if (str) {
+            port_type = hashType(str);
+        } else if (node_obj && (node_obj->node.node_type & NodeType::Video) != NodeType::None) {
+            port_type = engine->videoPortType();
+        }
+
+        PortMode port_mode = PortMode::None;
+        str = spa_dict_lookup(props, PW_KEY_PORT_DIRECTION);
+        if (str) {
+            if (strcmp(str, "in") == 0)       port_mode = PortMode::Input;
+            else if (strcmp(str, "out") == 0)  port_mode = PortMode::Output;
+        }
+
+        uint8_t port_flags = 0;
+        if (node_obj && (node_obj->node.mode2 != PortMode::Duplex))
+            port_flags |= (uint8_t)PortFlags::Terminal;
+        str = spa_dict_lookup(props, PW_KEY_PORT_PHYSICAL);
+        if (str && pw_properties_parse_bool(str))
+            port_flags |= (uint8_t)PortFlags::Physical;
+        str = spa_dict_lookup(props, PW_KEY_PORT_TERMINAL);
+        if (str && pw_properties_parse_bool(str))
+            port_flags |= (uint8_t)PortFlags::Terminal;
+        str = spa_dict_lookup(props, PW_KEY_PORT_MONITOR);
+        if (str && pw_properties_parse_bool(str))
+            port_flags |= (uint8_t)PortFlags::Monitor;
+        str = spa_dict_lookup(props, PW_KEY_PORT_CONTROL);
+        if (str && pw_properties_parse_bool(str))
+            port_flags |= (uint8_t)PortFlags::Control;
+
+        if (!node_obj) return; // Node not ready yet
+
+        auto *pobj = new GraphEngine::PortObj(id);
+        pobj->port.id = id;
+        pobj->port.node_id = node_id;
+        pobj->port.name = port_name;
+        pobj->port.mode = port_mode;
+        pobj->port.port_type = port_type;
+        pobj->port.flags = PortFlags(port_flags);
+
+        // Update node's mode2 if port direction differs
+        if ((node_obj->node.mode2 & port_mode) == PortMode::None)
+            node_obj->node.mode2 = PortMode::Duplex;
+
+        node_obj->node.port_ids.push_back(id);
+        node_obj->node.changed = true;
+
+        engine->addObject(id, pobj);
+        create_proxy_for_object(pobj, engine);
+        engine->notifyChanged();
+    }
+    else if (strcmp(type, PW_TYPE_INTERFACE_Link) == 0) {
+        // Parse link properties (ported from qpwgraph lines 538-545)
+        const char *str = spa_dict_lookup(props, PW_KEY_LINK_OUTPUT_PORT);
+        const uint32_t port1_id = (str ? (uint32_t)pw_properties_parse_int(str) : 0);
+        str = spa_dict_lookup(props, PW_KEY_LINK_INPUT_PORT);
+        const uint32_t port2_id = (str ? (uint32_t)pw_properties_parse_int(str) : 0);
+
+        // Validate
+        auto *p1 = engine->findPort(port1_id);
+        auto *p2 = engine->findPort(port2_id);
+        if (!p1 || !p2) return;
+        if ((p1->port.mode & PortMode::Output) == PortMode::None) return;
+        if ((p2->port.mode & PortMode::Input) == PortMode::None) return;
+
+        auto *lobj = new GraphEngine::LinkObj(id);
+        lobj->link.id = id;
+        lobj->link.port1_id = port1_id;
+        lobj->link.port2_id = port2_id;
+
+        p1->port.link_ids.push_back(id);
+
+        engine->addObject(id, lobj);
+        create_proxy_for_object(lobj, engine);
+        engine->notifyChanged();
+    }
+}
+
+static void on_registry_global_remove(void *data, uint32_t id) {
+    auto *engine = static_cast<GraphEngine*>(data);
+    engine->removeObject(id);
+    engine->notifyChanged();
+}
+
+static const struct pw_registry_events registry_events = {
+    .version = PW_VERSION_REGISTRY_EVENTS,
+    .global = on_registry_global,
+    .global_remove = on_registry_global_remove,
+};
+
+// ============================================================================
+// GraphEngine::Object
+// ============================================================================
+
+GraphEngine::Object::Object(uint32_t id, Type type)
+    : id(id), type(type), proxy(nullptr), info(nullptr),
+      destroy_info(nullptr), pending_seq(0)
+{
+    spa_zero(proxy_listener);
+    spa_zero(object_listener);
+    spa_list_init(&pending_link);
+}
+
+GraphEngine::Object::~Object() {
+    if (proxy) {
+        destroy_proxy(this);
+    }
+}
+
+// ============================================================================
+// GraphEngine
+// ============================================================================
+
+GraphEngine::GraphEngine()
+    : m_on_change(nullptr), m_running(false)
+{
+    m_audio_type = hashType(DEFAULT_AUDIO_TYPE);
+    m_midi_type  = hashType(DEFAULT_MIDI_TYPE);
+    m_midi2_type = hashType(DEFAULT_MIDI2_TYPE);
+    m_video_type = hashType(DEFAULT_VIDEO_TYPE);
+    m_other_type = hashType(DEFAULT_OTHER_TYPE);
+
+    memset(&m_pw, 0, sizeof(m_pw));
+    spa_list_init(&m_pw.pending);
+}
+
+GraphEngine::~GraphEngine() {
+    close();
+}
+
+bool GraphEngine::open() {
+    std::lock_guard<std::mutex> lock(m_mutex);
+
+    pw_init(nullptr, nullptr);
+
+    memset(&m_pw, 0, sizeof(m_pw));
+    spa_list_init(&m_pw.pending);
+    m_pw.pending_seq = 0;
+
+    m_pw.loop = pw_thread_loop_new("pwweb_loop", nullptr);
+    if (!m_pw.loop) {
+        fprintf(stderr, "pw_thread_loop_new failed\n");
+        pw_deinit();
+        return false;
+    }
+
+    pw_thread_loop_lock(m_pw.loop);
+
+    struct pw_loop *loop = pw_thread_loop_get_loop(m_pw.loop);
+    m_pw.context = pw_context_new(loop, nullptr, 0);
+    if (!m_pw.context) {
+        fprintf(stderr, "pw_context_new failed\n");
+        pw_thread_loop_unlock(m_pw.loop);
+        pw_thread_loop_destroy(m_pw.loop);
+        pw_deinit();
+        return false;
+    }
+
+    m_pw.core = pw_context_connect(m_pw.context, nullptr, 0);
+    if (!m_pw.core) {
+        fprintf(stderr, "pw_context_connect failed\n");
+        pw_thread_loop_unlock(m_pw.loop);
+        pw_context_destroy(m_pw.context);
+        pw_thread_loop_destroy(m_pw.loop);
+        pw_deinit();
+        return false;
+    }
+
+    pw_core_add_listener(m_pw.core,
+        &m_pw.core_listener, &core_events, this);
+
+    m_pw.registry = pw_core_get_registry(m_pw.core,
+        PW_VERSION_REGISTRY, 0);
+
+    pw_registry_add_listener(m_pw.registry,
+        &m_pw.registry_listener, &registry_events, this);
+
+    m_pw.pending_seq = 0;
+    m_pw.last_seq = 0;
+    m_pw.last_res = 0;
+    m_pw.error = false;
+
+    m_running = true;
+
+    pw_thread_loop_start(m_pw.loop);
+    pw_thread_loop_unlock(m_pw.loop);
+
+    fprintf(stderr, "pwweb: PipeWire connected\n");
+    return true;
+}
+
+void GraphEngine::close() {
+    if (!m_pw.loop) return;
+
+    m_running = false;
+
+    pw_thread_loop_lock(m_pw.loop);
+
+    clearObjects();
+
+    pw_thread_loop_unlock(m_pw.loop);
+
+    if (m_pw.loop)
+        pw_thread_loop_stop(m_pw.loop);
+
+    if (m_pw.registry) {
+        spa_hook_remove(&m_pw.registry_listener);
+        pw_proxy_destroy((pw_proxy*)m_pw.registry);
+    }
+
+    if (m_pw.core) {
+        spa_hook_remove(&m_pw.core_listener);
+        pw_core_disconnect(m_pw.core);
+    }
+
+    if (m_pw.context)
+        pw_context_destroy(m_pw.context);
+
+    if (m_pw.loop)
+        pw_thread_loop_destroy(m_pw.loop);
+
+    memset(&m_pw, 0, sizeof(m_pw));
+
+    pw_deinit();
+
+    fprintf(stderr, "pwweb: PipeWire disconnected\n");
+}
+
+void GraphEngine::setOnChange(ChangeCallback cb) {
+    std::lock_guard<std::mutex> lock(m_mutex);
+    m_on_change = std::move(cb);
+}
+
+void GraphEngine::notifyChanged() {
+    // Called from PipeWire thread — invoke callback outside lock
+    ChangeCallback cb;
+    {
+        std::lock_guard<std::mutex> lock(m_mutex);
+        cb = m_on_change;
+    }
+    if (cb) cb();
+}
+
+// ============================================================================
+// Object management
+// ============================================================================
+
+void GraphEngine::addObject(uint32_t id, Object *obj) {
+    m_objects_by_id[id] = obj;
+    m_objects.push_back(obj);
+}
+
+GraphEngine::Object *GraphEngine::findObject(uint32_t id) const {
+    auto it = m_objects_by_id.find(id);
+    return (it != m_objects_by_id.end()) ? it->second : nullptr;
+}
+
+void GraphEngine::removeObject(uint32_t id) {
+    auto it = m_objects_by_id.find(id);
+    if (it == m_objects_by_id.end()) return;
+
+    Object *obj = it->second;
+    m_objects_by_id.erase(it);
+
+    auto vit = std::find(m_objects.begin(), m_objects.end(), obj);
+    if (vit != m_objects.end())
+        m_objects.erase(vit);
+
+    // If it's a port, remove from parent node's port list
+    if (obj->type == Object::ObjPort) {
+        auto *pobj = static_cast<PortObj*>(obj);
+        auto *nobj = findNode(pobj->port.node_id);
+        if (nobj) {
+            auto &pids = nobj->node.port_ids;
+            pids.erase(std::remove(pids.begin(), pids.end(), id), pids.end());
+            nobj->node.changed = true;
+        }
+        // Remove any links involving this port
+        auto link_ids_copy = pobj->port.link_ids;
+        for (uint32_t lid : link_ids_copy) {
+            removeObject(lid);
+        }
+    }
+
+    // If it's a node, remove all its ports
+    if (obj->type == Object::ObjNode) {
+        auto *nobj = static_cast<NodeObj*>(obj);
+        auto port_ids_copy = nobj->node.port_ids;
+        for (uint32_t pid : port_ids_copy) {
+            removeObject(pid);
+        }
+    }
+
+    // If it's a link, remove from output port's link list
+    if (obj->type == Object::ObjLink) {
+        auto *lobj = static_cast<LinkObj*>(obj);
+        auto *pobj = findPort(lobj->link.port1_id);
+        if (pobj) {
+            auto &lids = pobj->port.link_ids;
+            lids.erase(std::remove(lids.begin(), lids.end(), id), lids.end());
+        }
+    }
+
+    delete obj;
+}
+
+void GraphEngine::clearObjects() {
+    for (auto *obj : m_objects)
+        delete obj;
+    m_objects.clear();
+    m_objects_by_id.clear();
+}
+
+GraphEngine::NodeObj *GraphEngine::findNode(uint32_t node_id) const {
+    Object *obj = findObject(node_id);
+    return (obj && obj->type == Object::ObjNode) ? static_cast<NodeObj*>(obj) : nullptr;
+}
+
+GraphEngine::PortObj *GraphEngine::findPort(uint32_t port_id) const {
+    Object *obj = findObject(port_id);
+    return (obj && obj->type == Object::ObjPort) ? static_cast<PortObj*>(obj) : nullptr;
+}
+
+GraphEngine::LinkObj *GraphEngine::findLink(uint32_t link_id) const {
+    Object *obj = findObject(link_id);
+    return (obj && obj->type == Object::ObjLink) ? static_cast<LinkObj*>(obj) : nullptr;
+}
+
+// ============================================================================
+// Snapshot (thread-safe graph state)
+// ============================================================================
+
+GraphEngine::Snapshot GraphEngine::snapshot() const {
+    std::lock_guard<std::mutex> lock(m_mutex);
+
+    Snapshot snap;
+    for (auto *obj : m_objects) {
+        switch (obj->type) {
+        case Object::ObjNode:
+            snap.nodes.push_back(static_cast<NodeObj*>(obj)->node);
+            break;
+        case Object::ObjPort:
+            snap.ports.push_back(static_cast<PortObj*>(obj)->port);
+            break;
+        case Object::ObjLink:
+            snap.links.push_back(static_cast<LinkObj*>(obj)->link);
+            break;
+        }
+    }
+    return snap;
+}
+
+// ============================================================================
+// Connect/Disconnect (ported from qpwgraph_pipewire::connectPorts)
+// ============================================================================
+
+bool GraphEngine::connectPorts(uint32_t output_port_id, uint32_t input_port_id) {
+    if (!m_pw.loop) return false;
+
+    pw_thread_loop_lock(m_pw.loop);
+
+    PortObj *p1 = findPort(output_port_id);
+    PortObj *p2 = findPort(input_port_id);
+
+    if (!p1 || !p2 ||
+        (p1->port.mode & PortMode::Output) == PortMode::None ||
+        (p2->port.mode & PortMode::Input)  == PortMode::None ||
+        p1->port.port_type != p2->port.port_type) {
+        pw_thread_loop_unlock(m_pw.loop);
+        return false;
+    }
+
+    // Create link via PipeWire (adapted from qpwgraph lines 858-891)
+    char val[4][16];
+    snprintf(val[0], sizeof(val[0]), "%u", p1->port.node_id);
+    snprintf(val[1], sizeof(val[1]), "%u", p1->id);
+    snprintf(val[2], sizeof(val[2]), "%u", p2->port.node_id);
+    snprintf(val[3], sizeof(val[3]), "%u", p2->id);
+
+    struct spa_dict props;
+    struct spa_dict_item items[6];
+    props = SPA_DICT_INIT(items, 0);
+    items[props.n_items++] = SPA_DICT_ITEM_INIT(PW_KEY_LINK_OUTPUT_NODE, val[0]);
+    items[props.n_items++] = SPA_DICT_ITEM_INIT(PW_KEY_LINK_OUTPUT_PORT, val[1]);
+    items[props.n_items++] = SPA_DICT_ITEM_INIT(PW_KEY_LINK_INPUT_NODE,  val[2]);
+    items[props.n_items++] = SPA_DICT_ITEM_INIT(PW_KEY_LINK_INPUT_PORT,  val[3]);
+    items[props.n_items++] = SPA_DICT_ITEM_INIT(PW_KEY_OBJECT_LINGER,    "true");
+    const char *str = getenv("PIPEWIRE_LINK_PASSIVE");
+    if (str && pw_properties_parse_bool(str))
+        items[props.n_items++] = SPA_DICT_ITEM_INIT(PW_KEY_LINK_PASSIVE, "true");
+
+    pw_proxy *proxy = (pw_proxy*)pw_core_create_object(m_pw.core,
+        "link-factory", PW_TYPE_INTERFACE_Link, PW_VERSION_LINK, &props, 0);
+
+    if (proxy) {
+        int link_res = 0;
+        spa_hook listener;
+        spa_zero(listener);
+        pw_proxy_add_listener(proxy,
+            &listener, &link_proxy_events, &link_res);
+        link_proxy_sync(this);
+        spa_hook_remove(&listener);
+        pw_proxy_destroy(proxy);
+    }
+
+    pw_thread_loop_unlock(m_pw.loop);
+    return (proxy != nullptr);
+}
+
+bool GraphEngine::disconnectPorts(uint32_t output_port_id, uint32_t input_port_id) {
+    if (!m_pw.loop) return false;
+
+    pw_thread_loop_lock(m_pw.loop);
+
+    PortObj *p1 = findPort(output_port_id);
+    PortObj *p2 = findPort(input_port_id);
+
+    if (!p1 || !p2) {
+        pw_thread_loop_unlock(m_pw.loop);
+        return false;
+    }
+
+    // Find and destroy matching link (adapted from qpwgraph lines 846-853)
+    bool found = false;
+    for (uint32_t lid : p1->port.link_ids) {
+        LinkObj *link = findLink(lid);
+        if (link && link->link.port1_id == output_port_id &&
+                     link->link.port2_id == input_port_id) {
+            pw_registry_destroy(m_pw.registry, lid);
+            link_proxy_sync(this);
+            found = true;
+            break;
+        }
+    }
+
+    pw_thread_loop_unlock(m_pw.loop);
+    return found;
+}
+
+// end of graph_engine.cpp
--- a/src/graph_engine.h
+++ b/src/graph_engine.h
@@ -0,0 +1,131 @@
+#pragma once
+
+#include "graph_types.h"
+#include <functional>
+#include <mutex>
+#include <vector>
+#include <unordered_map>
+#include <thread>
+#include <atomic>
+
+#include <pipewire/utils.h>     // pw_thread_loop, etc.
+#include <spa/utils/list.h>     // spa_list
+#include <spa/utils/hook.h>     // spa_hook
+
+struct pw_thread_loop;
+struct pw_context;
+struct pw_core;
+struct pw_registry;
+
+namespace pwgraph {
+
+class GraphEngine {
+public:
+    using ChangeCallback = std::function<void()>;
+
+    GraphEngine();
+    ~GraphEngine();
+
+    bool open();
+    void close();
+
+    // Set callback invoked when graph changes
+    void setOnChange(ChangeCallback cb);
+
+    // Thread-safe snapshot of the current graph state
+    struct Snapshot {
+        std::vector<Node> nodes;
+        std::vector<Port> ports;
+        std::vector<Link> links;
+    };
+    Snapshot snapshot() const;
+
+    // Connect/disconnect two ports (thread-safe, blocks until done)
+    bool connectPorts(uint32_t output_port_id, uint32_t input_port_id);
+    bool disconnectPorts(uint32_t output_port_id, uint32_t input_port_id);
+
+    // PipeWire internal data (exposed for C callbacks)
+    struct PwData {
+        pw_thread_loop *loop;
+        pw_context      *context;
+        pw_core         *core;
+        spa_hook         core_listener;
+        pw_registry     *registry;
+        spa_hook         registry_listener;
+        int              pending_seq;
+        spa_list         pending;   // doubly-linked list head for pending syncs
+        int              last_seq;
+        int              last_res;
+        bool             error;
+    };
+
+    PwData& pwData() { return m_pw; }
+
+    // Object management (called from C callbacks)
+    struct Object {
+        enum Type { ObjNode, ObjPort, ObjLink };
+        uint32_t id;
+        Type     type;
+        void    *proxy;
+        void    *info;
+        void   (*destroy_info)(void*);
+        spa_hook proxy_listener;
+        spa_hook object_listener;
+        int      pending_seq;
+        spa_list pending_link;
+
+        Object(uint32_t id, Type type);
+        virtual ~Object();
+    };
+
+    struct NodeObj : Object {
+        NodeObj(uint32_t id) : Object(id, ObjNode) {}
+        Node node;
+    };
+
+    struct PortObj : Object {
+        PortObj(uint32_t id) : Object(id, ObjPort) {}
+        Port port;
+    };
+
+    struct LinkObj : Object {
+        LinkObj(uint32_t id) : Object(id, ObjLink) {}
+        Link link;
+    };
+
+    void    addObject(uint32_t id, Object *obj);
+    Object *findObject(uint32_t id) const;
+    void    removeObject(uint32_t id);
+    void    clearObjects();
+
+    NodeObj *findNode(uint32_t node_id) const;
+    PortObj *findPort(uint32_t port_id) const;
+    LinkObj *findLink(uint32_t link_id) const;
+
+    void notifyChanged();
+
+private:
+    PwData m_pw;
+
+    mutable std::mutex m_mutex;  // protects m_objects and graph data
+    std::unordered_map<uint32_t, Object*> m_objects_by_id;
+    std::vector<Object*> m_objects;
+
+    ChangeCallback m_on_change;
+    std::atomic<bool> m_running;
+
+    // Port type hashes
+    uint32_t m_audio_type;
+    uint32_t m_midi_type;
+    uint32_t m_midi2_type;
+    uint32_t m_video_type;
+    uint32_t m_other_type;
+
+public:
+    uint32_t audioPortType() const { return m_audio_type; }
+    uint32_t midiPortType()  const { return m_midi_type; }
+    uint32_t videoPortType() const { return m_video_type; }
+    uint32_t otherPortType() const { return m_other_type; }
+};
+
+} // namespace pwgraph
--- a/src/graph_types.h
+++ b/src/graph_types.h
@@ -0,0 +1,105 @@
+#pragma once
+
+#include <string>
+#include <vector>
+#include <unordered_map>
+#include <cstdint>
+
+namespace pwgraph {
+
+enum class PortMode : uint8_t {
+    None   = 0,
+    Input  = 1,
+    Output = 2,
+    Duplex = Input | Output
+};
+
+enum class NodeType : uint8_t {
+    None  = 0,
+    Audio = 1,
+    Video = 2,
+    Midi  = 4
+};
+
+enum class PortFlags : uint8_t {
+    None     = 0,
+    Physical = 1,
+    Terminal = 2,
+    Monitor  = 4,
+    Control  = 8
+};
+
+inline PortFlags operator|(PortFlags a, PortFlags b) {
+    return static_cast<PortFlags>(static_cast<uint8_t>(a) | static_cast<uint8_t>(b));
+}
+inline PortFlags operator&(PortFlags a, PortFlags b) {
+    return static_cast<PortFlags>(static_cast<uint8_t>(a) & static_cast<uint8_t>(b));
+}
+
+// Bitwise operators for PortMode
+inline PortMode operator|(PortMode a, PortMode b) {
+    return static_cast<PortMode>(static_cast<uint8_t>(a) | static_cast<uint8_t>(b));
+}
+inline PortMode operator&(PortMode a, PortMode b) {
+    return static_cast<PortMode>(static_cast<uint8_t>(a) & static_cast<uint8_t>(b));
+}
+
+// Bitwise operators for NodeType
+inline NodeType operator|(NodeType a, NodeType b) {
+    return static_cast<NodeType>(static_cast<uint8_t>(a) | static_cast<uint8_t>(b));
+}
+inline NodeType operator&(NodeType a, NodeType b) {
+    return static_cast<NodeType>(static_cast<uint8_t>(a) & static_cast<uint8_t>(b));
+}
+
+struct Node {
+    uint32_t    id;
+    std::string name;
+    std::string nick;
+    std::string media_name;
+    PortMode    mode;       // from media class (Source=Output, Sink=Input)
+    NodeType    node_type;
+    PortMode    mode2;      // derived from actual port directions
+    bool        ready;
+    bool        changed;
+
+    std::vector<uint32_t> port_ids;  // child port IDs
+
+    Node() : id(0), mode(PortMode::None), node_type(NodeType::None),
+             mode2(PortMode::None), ready(false), changed(false) {}
+};
+
+struct Link;
+
+struct Port {
+    uint32_t    id;
+    uint32_t    node_id;
+    std::string name;
+    PortMode    mode;
+    uint32_t    port_type;  // hashed type string
+    PortFlags   flags;
+
+    std::vector<uint32_t> link_ids;  // links where this is the output port
+
+    Port() : id(0), node_id(0), mode(PortMode::None),
+             port_type(0), flags(PortFlags::None) {}
+};
+
+struct Link {
+    uint32_t id;
+    uint32_t port1_id;  // output port
+    uint32_t port2_id;  // input port
+
+    Link() : id(0), port1_id(0), port2_id(0) {}
+};
+
+// Simple hash function for port type strings (matches qpwgraph_item::itemType)
+inline uint32_t hashType(const std::string& s) {
+    uint32_t h = 5381;
+    for (char c : s) {
+        h = ((h << 5) + h) + static_cast<uint32_t>(c);
+    }
+    return h;
+}
+
+} // namespace pwgraph
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -0,0 +1,69 @@
+#include "graph_engine.h"
+#include "web_server.h"
+
+#include <csignal>
+#include <cstdio>
+#include <cstdlib>
+#include <unistd.h>
+#include <atomic>
+
+static std::atomic<bool> g_running(true);
+
+static void signal_handler(int sig) {
+    g_running = false;
+    fprintf(stderr, "\npwweb: caught signal %d, shutting down...\n", sig);
+}
+
+int main(int argc, char *argv[]) {
+    int port = 9876;
+
+    // Parse optional port argument
+    if (argc > 1) {
+        port = atoi(argv[1]);
+        if (port <= 0 || port > 65535) {
+            fprintf(stderr, "usage: pwweb [port]\n");
+            return 1;
+        }
+    }
+
+    signal(SIGINT, signal_handler);
+    signal(SIGTERM, signal_handler);
+
+    pwgraph::GraphEngine engine;
+
+    fprintf(stderr, "pwweb: connecting to PipeWire...\n");
+    if (!engine.open()) {
+        fprintf(stderr, "pwweb: failed to connect to PipeWire.\n");
+        fprintf(stderr, "  Make sure XDG_RUNTIME_DIR is set: export XDG_RUNTIME_DIR=/run/user/$(id -u)\n");
+        return 1;
+    }
+
+    pwgraph::WebServer server(engine, port);
+
+    // Wire change notifications to broadcast
+    engine.setOnChange([&server]() {
+        server.broadcastGraph();
+    });
+
+    if (!server.start()) {
+        fprintf(stderr, "pwweb: failed to start web server on port %d\n", port);
+        engine.close();
+        return 1;
+    }
+
+    fprintf(stderr, "pwweb: server running at http://localhost:%d\n", port);
+    fprintf(stderr, "pwweb: API at http://localhost:%d/api/graph\n", port);
+    fprintf(stderr, "pwweb: press Ctrl+C to stop\n");
+
+    // Main loop — just wait for shutdown signal
+    while (g_running) {
+        std::this_thread::sleep_for(std::chrono::milliseconds(200));
+    }
+
+    fprintf(stderr, "pwweb: shutting down...\n");
+    server.stop();
+    engine.close();
+
+    fprintf(stderr, "pwweb: goodbye.\n");
+    return 0;
+}
--- a/src/third_party/httplib.h
+++ b/src/third_party/httplib.h
--- a/src/web_server.cpp
+++ b/src/web_server.cpp
@@ -0,0 +1,314 @@
+#include "web_server.h"
+#include <sstream>
+#include <iomanip>
+#include <cstdio>
+#include <algorithm>
+#include <condition_variable>
+
+using namespace pwgraph;
+
+// ============================================================================
+// JSON serialization helpers
+// ============================================================================
+
+static std::string escapeJson(const std::string &s) {
+    std::ostringstream o;
+    for (char c : s) {
+        switch (c) {
+        case '"':  o << "\\\""; break;
+        case '\\': o << "\\\\"; break;
+        case '\b': o << "\\b";  break;
+        case '\f': o << "\\f";  break;
+        case '\n': o << "\\n";  break;
+        case '\r': o << "\\r";  break;
+        case '\t': o << "\\t";  break;
+        default:
+            if (static_cast<unsigned char>(c) < 0x20) {
+                o << "\\u" << std::hex << std::setw(4) << std::setfill('0')
+                  << (int)(unsigned char)c;
+            } else {
+                o << c;
+            }
+        }
+    }
+    return o.str();
+}
+
+static const char *portModeStr(PortMode m) {
+    switch (m) {
+    case PortMode::Input:  return "input";
+    case PortMode::Output: return "output";
+    case PortMode::Duplex: return "duplex";
+    default: return "none";
+    }
+}
+
+static std::string nodeTypeStr(NodeType t) {
+    std::string result;
+    if ((t & NodeType::Audio) != NodeType::None) {
+        if (!result.empty()) result += '+';
+        result += "audio";
+    }
+    if ((t & NodeType::Video) != NodeType::None) {
+        if (!result.empty()) result += '+';
+        result += "video";
+    }
+    if ((t & NodeType::Midi) != NodeType::None) {
+        if (!result.empty()) result += '+';
+        result += "midi";
+    }
+    return result.empty() ? "other" : result;
+}
+
+std::string WebServer::buildGraphJson() const {
+    auto snap = m_engine.snapshot();
+
+    std::ostringstream json;
+    json << "{\"type\":\"graph\",\"nodes\":[";
+
+    bool first_node = true;
+    for (auto &n : snap.nodes) {
+        if (!n.ready) continue;
+        if (!first_node) json << ",";
+        first_node = false;
+
+        json << "{\"id\":" << n.id
+             << ",\"name\":\"" << escapeJson(n.name) << "\""
+             << ",\"nick\":\"" << escapeJson(n.nick) << "\""
+             << ",\"media_name\":\"" << escapeJson(n.media_name) << "\""
+             << ",\"mode\":\"" << portModeStr(n.mode) << "\""
+             << ",\"node_type\":\"" << nodeTypeStr(n.node_type) << "\""
+             << ",\"port_ids\":[";
+        bool first_p = true;
+        for (uint32_t pid : n.port_ids) {
+            if (!first_p) json << ",";
+            first_p = false;
+            json << pid;
+        }
+        json << "]}";
+    }
+
+    json << "],\"ports\":[";
+
+    bool first_port = true;
+    for (auto &p : snap.ports) {
+        if (!first_port) json << ",";
+        first_port = false;
+
+        std::string port_type_name;
+        uint32_t pt = p.port_type;
+        if (pt == m_engine.audioPortType())      port_type_name = "audio";
+        else if (pt == m_engine.midiPortType())   port_type_name = "midi";
+        else if (pt == m_engine.videoPortType())  port_type_name = "video";
+        else                                       port_type_name = "other";
+
+        json << "{\"id\":" << p.id
+             << ",\"node_id\":" << p.node_id
+             << ",\"name\":\"" << escapeJson(p.name) << "\""
+             << ",\"mode\":\"" << portModeStr(p.mode) << "\""
+             << ",\"port_type\":\"" << port_type_name << "\""
+             << ",\"flags\":" << (int)(uint8_t)p.flags
+             << "}";
+    }
+
+    json << "],\"links\":[";
+
+    bool first_link = true;
+    for (auto &l : snap.links) {
+        if (!first_link) json << ",";
+        first_link = false;
+
+        json << "{\"id\":" << l.id
+             << ",\"output_port_id\":" << l.port1_id
+             << ",\"input_port_id\":" << l.port2_id << "}";
+    }
+
+    json << "]}";
+    return json.str();
+}
+
+// ============================================================================
+// WebServer
+// ============================================================================
+
+WebServer::WebServer(GraphEngine &engine, int port)
+    : m_engine(engine), m_port(port), m_running(false)
+{
+}
+
+WebServer::~WebServer() {
+    stop();
+}
+
+bool WebServer::start() {
+    setupRoutes();
+
+    m_running = true;
+    m_thread = std::thread([this]() {
+        fprintf(stderr, "pwweb: starting web server on port %d\n", m_port);
+        if (!m_http.listen("0.0.0.0", m_port)) {
+            fprintf(stderr, "pwweb: failed to bind to port %d\n", m_port);
+            m_running = false;
+        }
+    });
+
+    std::this_thread::sleep_for(std::chrono::milliseconds(200));
+    return m_running;
+}
+
+void WebServer::stop() {
+    if (m_running) {
+        m_running = false;
+        // Close all SSE clients so their loops exit
+        {
+            std::lock_guard<std::mutex> lock(m_sse_mutex);
+            for (auto *sink : m_sse_clients)
+                sink->done();
+            m_sse_clients.clear();
+        }
+        m_http.stop();
+        if (m_thread.joinable())
+            m_thread.join();
+    }
+}
+
+void WebServer::broadcastGraph() {
+    if (!m_running) return;
+    std::string json = buildGraphJson();
+
+    std::lock_guard<std::mutex> lock(m_sse_mutex);
+    for (auto it = m_sse_clients.begin(); it != m_sse_clients.end(); ) {
+        auto *sink = *it;
+        std::string msg = "data: " + json + "\n\n";
+        if (sink->write(msg.c_str(), msg.size())) {
+            ++it;
+        } else {
+            it = m_sse_clients.erase(it);
+        }
+    }
+}
+
+void WebServer::setupRoutes() {
+    // Serve frontend static files from ./frontend/dist
+    m_http.set_mount_point("/", "./frontend/dist");
+
+    // SSE endpoint: long-lived event stream
+    m_http.Get("/events", [this](const httplib::Request &req, httplib::Response &res) {
+        res.set_header("Content-Type", "text/event-stream");
+        res.set_header("Cache-Control", "no-cache");
+        res.set_header("Connection", "keep-alive");
+        res.set_header("Access-Control-Allow-Origin", "*");
+
+        res.set_content_provider(
+            "text/event-stream",
+            [this](size_t /*offset*/, httplib::DataSink &sink) {
+                // Register this SSE client
+                {
+                    std::lock_guard<std::mutex> lock(m_sse_mutex);
+                    m_sse_clients.insert(&sink);
+                }
+                fprintf(stderr, "pwweb: SSE client connected (total: %zu)\n",
+                        m_sse_clients.size());
+
+                // Send initial graph state
+                {
+                    std::string json = buildGraphJson();
+                    std::string msg = "data: " + json + "\n\n";
+                    sink.write(msg.c_str(), msg.size());
+                }
+
+                // Block until connection closes or server stops
+                std::mutex mtx;
+                std::unique_lock<std::mutex> lock(mtx);
+                std::condition_variable cv;
+                auto sink_ptr = &sink;
+
+                // Poll: check if sink is still open, broadcast triggers via broadcastGraph()
+                while (m_running && sink.write("", 0)) {
+                    // write with 0 bytes keeps connection alive; sleep between checks
+                    // Actually, we need to block. Let's use a simpler approach:
+                    // just block on a condition variable that gets notified
+                    cv.wait_for(lock, std::chrono::seconds(30), [&] {
+                        return !m_running;
+                    });
+                    // Send a SSE comment as keepalive
+                    if (m_running) {
+                        std::string keepalive = ": keepalive\n\n";
+                        if (!sink.write(keepalive.c_str(), keepalive.size()))
+                            break;
+                    }
+                }
+
+                // Unregister
+                {
+                    std::lock_guard<std::mutex> l(m_sse_mutex);
+                    m_sse_clients.erase(sink_ptr);
+                }
+                fprintf(stderr, "pwweb: SSE client disconnected (remaining: %zu)\n",
+                        m_sse_clients.size());
+
+                sink.done();
+                return false; // stop calling this callback
+            }
+        );
+    });
+
+    // REST API: GET /api/graph
+    m_http.Get("/api/graph", [this](const httplib::Request &, httplib::Response &res) {
+        std::string json = buildGraphJson();
+        res.set_content(json, "application/json");
+        res.set_header("Access-Control-Allow-Origin", "*");
+    });
+
+    // REST API: POST /api/connect
+    m_http.Post("/api/connect", [this](const httplib::Request &req, httplib::Response &res) {
+        uint32_t out_id = 0, in_id = 0;
+        if (sscanf(req.body.c_str(),
+                "{\"output_port_id\":%u,\"input_port_id\":%u}", &out_id, &in_id) == 2 ||
+            sscanf(req.body.c_str(),
+                "{\"output_port_id\":%u, \"input_port_id\":%u}", &out_id, &in_id) == 2)
+        {
+            bool ok = m_engine.connectPorts(out_id, in_id);
+            if (ok) broadcastGraph();
+            res.set_content(
+                ok ? "{\"ok\":true}" : "{\"ok\":false,\"error\":\"connect failed\"}",
+                "application/json");
+        } else {
+            res.status = 400;
+            res.set_content("{\"error\":\"invalid json\"}", "application/json");
+        }
+        res.set_header("Access-Control-Allow-Origin", "*");
+    });
+
+    // REST API: POST /api/disconnect
+    m_http.Post("/api/disconnect", [this](const httplib::Request &req, httplib::Response &res) {
+        uint32_t out_id = 0, in_id = 0;
+        if (sscanf(req.body.c_str(),
+                "{\"output_port_id\":%u,\"input_port_id\":%u}", &out_id, &in_id) == 2 ||
+            sscanf(req.body.c_str(),
+                "{\"output_port_id\":%u, \"input_port_id\":%u}", &out_id, &in_id) == 2)
+        {
+            bool ok = m_engine.disconnectPorts(out_id, in_id);
+            if (ok) broadcastGraph();
+            res.set_content(
+                ok ? "{\"ok\":true}" : "{\"ok\":false,\"error\":\"disconnect failed\"}",
+                "application/json");
+        } else {
+            res.status = 400;
+            res.set_content("{\"error\":\"invalid json\"}", "application/json");
+        }
+        res.set_header("Access-Control-Allow-Origin", "*");
+    });
+
+    // CORS preflight
+    auto cors_handler = [](const httplib::Request &, httplib::Response &res) {
+        res.set_header("Access-Control-Allow-Origin", "*");
+        res.set_header("Access-Control-Allow-Methods", "POST, OPTIONS");
+        res.set_header("Access-Control-Allow-Headers", "Content-Type");
+        res.status = 204;
+    };
+    m_http.Options("/api/connect", cors_handler);
+    m_http.Options("/api/disconnect", cors_handler);
+}
+
+// end of web_server.cpp
--- a/src/web_server.h
+++ b/src/web_server.h
@@ -0,0 +1,39 @@
+#pragma once
+
+#include "graph_engine.h"
+#include <httplib.h>
+#include <thread>
+#include <mutex>
+#include <set>
+#include <atomic>
+#include <functional>
+
+namespace pwgraph {
+
+class WebServer {
+public:
+    WebServer(GraphEngine &engine, int port = 9876);
+    ~WebServer();
+
+    bool start();
+    void stop();
+
+    // Broadcast graph update to all connected SSE clients
+    void broadcastGraph();
+
+private:
+    void setupRoutes();
+    std::string buildGraphJson() const;
+
+    GraphEngine &m_engine;
+    int m_port;
+    httplib::Server m_http;
+    std::thread m_thread;
+    std::atomic<bool> m_running;
+
+    // SSE clients
+    mutable std::mutex m_sse_mutex;
+    std::set<httplib::DataSink *> m_sse_clients;
+};
+
+} // namespace pwgraph
				`@@ -0,0 +1 @@`
				<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" aria-hidden="true" role="img" class="iconify iconify--logos" width="26.6" height="32" preserveAspectRatio="xMidYMid meet" viewBox="0 0 256 308"><path fill="#FF3E00" d="M239.682 40.707C211.113-.182 154.69-12.301 113.895 13.69L42.247 59.356a82.198 82.198 0 0 0-37.135 55.056a86.566 86.566 0 0 0 8.536 55.576a82.425 82.425 0 0 0-12.296 30.719a87.596 87.596 0 0 0 14.964 66.244c28.574 40.893 84.997 53.007 125.787 27.016l71.648-45.664a82.182 82.182 0 0 0 37.135-55.057a86.601 86.601 0 0 0-8.53-55.577a82.409 82.409 0 0 0 12.29-30.718a87.573 87.573 0 0 0-14.963-66.244"></path><path fill="#FFF" d="M106.889 270.841c-23.102 6.007-47.497-3.036-61.103-22.648a52.685 52.685 0 0 1-9.003-39.85a49.978 49.978 0 0 1 1.713-6.693l1.35-4.115l3.671 2.697a92.447 92.447 0 0 0 28.036 14.007l2.663.808l-.245 2.659a16.067 16.067 0 0 0 2.89 10.656a17.143 17.143 0 0 0 18.397 6.828a15.786 15.786 0 0 0 4.403-1.935l71.67-45.672a14.922 14.922 0 0 0 6.734-9.977a15.923 15.923 0 0 0-2.713-12.011a17.156 17.156 0 0 0-18.404-6.832a15.78 15.78 0 0 0-4.396 1.933l-27.35 17.434a52.298 52.298 0 0 1-14.553 6.391c-23.101 6.007-47.497-3.036-61.101-22.649a52.681 52.681 0 0 1-9.004-39.849a49.428 49.428 0 0 1 22.34-33.114l71.664-45.677a52.218 52.218 0 0 1 14.563-6.398c23.101-6.007 47.497 3.036 61.101 22.648a52.685 52.685 0 0 1 9.004 39.85a50.559 50.559 0 0 1-1.713 6.692l-1.35 4.116l-3.67-2.693a92.373 92.373 0 0 0-28.037-14.013l-2.664-.809l.246-2.658a16.099 16.099 0 0 0-2.89-10.656a17.143 17.143 0 0 0-18.398-6.828a15.786 15.786 0 0 0-4.402 1.935l-71.67 45.674a14.898 14.898 0 0 0-6.73 9.975a15.9 15.9 0 0 0 2.709 12.012a17.156 17.156 0 0 0 18.404 6.832a15.841 15.841 0 0 0 4.402-1.935l27.345-17.427a52.147 52.147 0 0 1 14.552-6.397c23.101-6.006 47.497 3.037 61.102 22.65a52.681 52.681 0 0 1 9.003 39.848a49.453 49.453 0 0 1-22.34 33.12l-71.664 45.673a52.218 52.218 0 0 1-14.563 6.398"></path></svg>