15 KiB
Visual Brainstorming Companion Implementation Plan
For agentic workers: REQUIRED SUB-SKILL: Use superpowers:executing-plans to implement this plan task-by-task.
Goal: Give Claude a browser-based visual companion for brainstorming sessions - show mockups, prototypes, and interactive choices alongside terminal conversation.
Architecture: Claude writes HTML to a temp file. A local Node.js server watches that file and serves it with an auto-injected helper library. User interactions flow via WebSocket to server stdout, which Claude sees in background task output.
Tech Stack: Node.js, Express, ws (WebSocket), chokidar (file watching)
Task 1: Create the Server Foundation
Files:
- Create:
lib/brainstorm-server/index.js - Create:
lib/brainstorm-server/package.json
Step 1: Create package.json
{
"name": "brainstorm-server",
"version": "1.0.0",
"description": "Visual brainstorming companion server for Claude Code",
"main": "index.js",
"dependencies": {
"chokidar": "^3.5.3",
"express": "^4.18.2",
"ws": "^8.14.2"
}
}
Step 2: Create minimal server that starts
const express = require('express');
const http = require('http');
const WebSocket = require('ws');
const chokidar = require('chokidar');
const fs = require('fs');
const path = require('path');
const PORT = process.env.BRAINSTORM_PORT || 3333;
const SCREEN_FILE = process.env.BRAINSTORM_SCREEN || '/tmp/brainstorm/screen.html';
const SCREEN_DIR = path.dirname(SCREEN_FILE);
// Ensure screen directory exists
if (!fs.existsSync(SCREEN_DIR)) {
fs.mkdirSync(SCREEN_DIR, { recursive: true });
}
// Create default screen if none exists
if (!fs.existsSync(SCREEN_FILE)) {
fs.writeFileSync(SCREEN_FILE, `<!DOCTYPE html>
<html>
<head>
<title>Brainstorm Companion</title>
<style>
body { font-family: system-ui, sans-serif; padding: 2rem; max-width: 800px; margin: 0 auto; }
h1 { color: #333; }
p { color: #666; }
</style>
</head>
<body>
<h1>Brainstorm Companion</h1>
<p>Waiting for Claude to push a screen...</p>
</body>
</html>`);
}
const app = express();
const server = http.createServer(app);
const wss = new WebSocket.Server({ server });
// Track connected browsers for reload notifications
const clients = new Set();
wss.on('connection', (ws) => {
clients.add(ws);
ws.on('close', () => clients.delete(ws));
ws.on('message', (data) => {
// User interaction event - write to stdout for Claude
const event = JSON.parse(data.toString());
console.log(JSON.stringify({ type: 'user-event', ...event }));
});
});
// Serve current screen with helper.js injected
app.get('/', (req, res) => {
let html = fs.readFileSync(SCREEN_FILE, 'utf-8');
// Inject helper script before </body>
const helperScript = fs.readFileSync(path.join(__dirname, 'helper.js'), 'utf-8');
const injection = `<script>\n${helperScript}\n</script>`;
if (html.includes('</body>')) {
html = html.replace('</body>', `${injection}\n</body>`);
} else {
html += injection;
}
res.type('html').send(html);
});
// Watch for screen file changes
chokidar.watch(SCREEN_FILE).on('change', () => {
console.log(JSON.stringify({ type: 'screen-updated', file: SCREEN_FILE }));
// Notify all browsers to reload
clients.forEach(ws => {
if (ws.readyState === WebSocket.OPEN) {
ws.send(JSON.stringify({ type: 'reload' }));
}
});
});
server.listen(PORT, '127.0.0.1', () => {
console.log(JSON.stringify({ type: 'server-started', port: PORT, url: `http://localhost:${PORT}` }));
});
Step 3: Run npm install
Run: cd lib/brainstorm-server && npm install
Expected: Dependencies installed
Step 4: Test server starts
Run: cd lib/brainstorm-server && timeout 3 node index.js || true
Expected: See JSON with server-started and port info
Step 5: Commit
git add lib/brainstorm-server/
git commit -m "feat: add brainstorm server foundation"
Task 2: Create the Helper Library
Files:
- Create:
lib/brainstorm-server/helper.js
Step 1: Create helper.js with event auto-capture
(function() {
const WS_URL = 'ws://' + window.location.host;
let ws = null;
let eventQueue = [];
function connect() {
ws = new WebSocket(WS_URL);
ws.onopen = () => {
// Send any queued events
eventQueue.forEach(e => ws.send(JSON.stringify(e)));
eventQueue = [];
};
ws.onmessage = (msg) => {
const data = JSON.parse(msg.data);
if (data.type === 'reload') {
window.location.reload();
}
};
ws.onclose = () => {
// Reconnect after 1 second
setTimeout(connect, 1000);
};
}
function send(event) {
event.timestamp = Date.now();
if (ws && ws.readyState === WebSocket.OPEN) {
ws.send(JSON.stringify(event));
} else {
eventQueue.push(event);
}
}
// Auto-capture clicks on interactive elements
document.addEventListener('click', (e) => {
const target = e.target.closest('button, a, [data-choice], [role="button"], input[type="submit"]');
if (!target) return;
// Don't capture regular link navigation
if (target.tagName === 'A' && !target.dataset.choice) return;
e.preventDefault();
send({
type: 'click',
text: target.textContent.trim(),
choice: target.dataset.choice || null,
id: target.id || null,
className: target.className || null
});
});
// Auto-capture form submissions
document.addEventListener('submit', (e) => {
e.preventDefault();
const form = e.target;
const formData = new FormData(form);
const data = {};
formData.forEach((value, key) => { data[key] = value; });
send({
type: 'submit',
formId: form.id || null,
formName: form.name || null,
data: data
});
});
// Auto-capture input changes (debounced)
let inputTimeout = null;
document.addEventListener('input', (e) => {
const target = e.target;
if (!target.matches('input, textarea, select')) return;
clearTimeout(inputTimeout);
inputTimeout = setTimeout(() => {
send({
type: 'input',
name: target.name || null,
id: target.id || null,
value: target.value,
inputType: target.type || target.tagName.toLowerCase()
});
}, 500); // 500ms debounce
});
// Expose for explicit use if needed
window.brainstorm = {
send: send,
choice: (value, metadata = {}) => send({ type: 'choice', value, ...metadata })
};
connect();
})();
Step 2: Verify helper.js is syntactically valid
Run: node -c lib/brainstorm-server/helper.js
Expected: No syntax errors
Step 3: Commit
git add lib/brainstorm-server/helper.js
git commit -m "feat: add browser helper library for event capture"
Task 3: Write Tests for the Server
Files:
- Create:
tests/brainstorm-server/server.test.js - Create:
tests/brainstorm-server/package.json
Step 1: Create test package.json
{
"name": "brainstorm-server-tests",
"version": "1.0.0",
"scripts": {
"test": "node server.test.js"
}
}
Step 2: Write server tests
const { spawn } = require('child_process');
const http = require('http');
const WebSocket = require('ws');
const fs = require('fs');
const path = require('path');
const assert = require('assert');
const SERVER_PATH = path.join(__dirname, '../../lib/brainstorm-server/index.js');
const TEST_PORT = 3334;
const TEST_SCREEN = '/tmp/brainstorm-test/screen.html';
// Clean up test directory
function cleanup() {
if (fs.existsSync(path.dirname(TEST_SCREEN))) {
fs.rmSync(path.dirname(TEST_SCREEN), { recursive: true });
}
}
async function sleep(ms) {
return new Promise(resolve => setTimeout(resolve, ms));
}
async function fetch(url) {
return new Promise((resolve, reject) => {
http.get(url, (res) => {
let data = '';
res.on('data', chunk => data += chunk);
res.on('end', () => resolve({ status: res.statusCode, body: data }));
}).on('error', reject);
});
}
async function runTests() {
cleanup();
// Start server
const server = spawn('node', [SERVER_PATH], {
env: { ...process.env, BRAINSTORM_PORT: TEST_PORT, BRAINSTORM_SCREEN: TEST_SCREEN }
});
let stdout = '';
server.stdout.on('data', (data) => { stdout += data.toString(); });
server.stderr.on('data', (data) => { console.error('Server stderr:', data.toString()); });
await sleep(1000); // Wait for server to start
try {
// Test 1: Server starts and outputs JSON
console.log('Test 1: Server startup message');
assert(stdout.includes('server-started'), 'Should output server-started');
assert(stdout.includes(TEST_PORT.toString()), 'Should include port');
console.log(' PASS');
// Test 2: GET / returns HTML with helper injected
console.log('Test 2: Serves HTML with helper injected');
const res = await fetch(`http://localhost:${TEST_PORT}/`);
assert.strictEqual(res.status, 200);
assert(res.body.includes('brainstorm'), 'Should include brainstorm content');
assert(res.body.includes('WebSocket'), 'Should have helper.js injected');
console.log(' PASS');
// Test 3: WebSocket connection and event relay
console.log('Test 3: WebSocket relays events to stdout');
stdout = ''; // Reset stdout capture
const ws = new WebSocket(`ws://localhost:${TEST_PORT}`);
await new Promise(resolve => ws.on('open', resolve));
ws.send(JSON.stringify({ type: 'click', text: 'Test Button' }));
await sleep(100);
assert(stdout.includes('user-event'), 'Should relay user events');
assert(stdout.includes('Test Button'), 'Should include event data');
ws.close();
console.log(' PASS');
// Test 4: File change triggers reload notification
console.log('Test 4: File change notifies browsers');
const ws2 = new WebSocket(`ws://localhost:${TEST_PORT}`);
await new Promise(resolve => ws2.on('open', resolve));
let gotReload = false;
ws2.on('message', (data) => {
const msg = JSON.parse(data.toString());
if (msg.type === 'reload') gotReload = true;
});
// Modify the screen file
fs.writeFileSync(TEST_SCREEN, '<html><body>Updated</body></html>');
await sleep(500);
assert(gotReload, 'Should send reload message on file change');
ws2.close();
console.log(' PASS');
console.log('\nAll tests passed!');
} finally {
server.kill();
cleanup();
}
}
runTests().catch(err => {
console.error('Test failed:', err);
process.exit(1);
});
Step 3: Run tests
Run: cd tests/brainstorm-server && npm install ws && node server.test.js
Expected: All tests pass
Step 4: Commit
git add tests/brainstorm-server/
git commit -m "test: add brainstorm server integration tests"
Task 4: Add Visual Companion to Brainstorming Skill
Files:
- Modify:
skills/brainstorming/SKILL.md - Create:
skills/brainstorming/visual-companion.md(supporting doc)
Step 1: Create the supporting documentation
Create skills/brainstorming/visual-companion.md:
# Visual Companion Reference
## Starting the Server
Run as a background job:
```bash
node ${PLUGIN_ROOT}/lib/brainstorm-server/index.js
Tell the user: "I've started a visual companion at http://localhost:3333 - open it in a browser."
Pushing Screens
Write HTML to /tmp/brainstorm/screen.html. The server watches this file and auto-refreshes the browser.
Reading User Responses
Check the background task output for JSON events:
{"type":"user-event","type":"click","text":"Option A","choice":"optionA","timestamp":1234567890}
{"type":"user-event","type":"submit","data":{"notes":"My feedback"},"timestamp":1234567891}
Event types:
- click: User clicked button or
data-choiceelement - submit: User submitted form (includes all form data)
- input: User typed in field (debounced 500ms)
HTML Patterns
Choice Cards
<div class="options">
<button data-choice="optionA">
<h3>Option A</h3>
<p>Description</p>
</button>
<button data-choice="optionB">
<h3>Option B</h3>
<p>Description</p>
</button>
</div>
Interactive Mockup
<div class="mockup">
<header data-choice="header">App Header</header>
<nav data-choice="nav">Navigation</nav>
<main data-choice="main">Content</main>
</div>
Form with Notes
<form>
<label>Priority: <input type="range" name="priority" min="1" max="5"></label>
<textarea name="notes" placeholder="Additional thoughts..."></textarea>
<button type="submit">Submit</button>
</form>
Explicit JavaScript
<button onclick="brainstorm.choice('custom', {extra: 'data'})">Custom</button>
**Step 2: Add visual companion section to brainstorming skill**
Add after "Key Principles" in `skills/brainstorming/SKILL.md`:
```markdown
## Visual Companion (Optional)
When brainstorming involves visual elements - UI mockups, wireframes, interactive prototypes - use the browser-based visual companion.
**When to use:**
- Presenting UI/UX options that benefit from visual comparison
- Showing wireframes or layout options
- Gathering structured feedback (ratings, forms)
- Prototyping click interactions
**How it works:**
1. Start the server as a background job
2. Tell user to open http://localhost:3333
3. Write HTML to `/tmp/brainstorm/screen.html` (auto-refreshes)
4. Check background task output for user interactions
The terminal remains the primary conversation interface. The browser is a visual aid.
**Reference:** See `visual-companion.md` in this skill directory for HTML patterns and API details.
Step 3: Verify the edits
Run: grep -A5 "Visual Companion" skills/brainstorming/SKILL.md
Expected: Shows the new section
Step 4: Commit
git add skills/brainstorming/
git commit -m "feat: add visual companion to brainstorming skill"
Task 5: Add Server to Plugin Ignore (Optional Cleanup)
Files:
- Check if
.gitignoreneeds node_modules exclusion for lib/brainstorm-server
Step 1: Check current gitignore
Run: cat .gitignore 2>/dev/null || echo "No .gitignore"
Step 2: Add node_modules if needed
If not already present, add:
lib/brainstorm-server/node_modules/
Step 3: Commit if changed
git add .gitignore
git commit -m "chore: ignore brainstorm-server node_modules"
Summary
After completing all tasks:
- Server at
lib/brainstorm-server/- Node.js server that watches HTML file and relays events - Helper library auto-injected - captures clicks, forms, inputs
- Tests at
tests/brainstorm-server/- verifies server behavior - Brainstorming skill updated with visual companion section and
visual-companion.mdreference doc
To use:
- Start server as background job:
node lib/brainstorm-server/index.js & - Tell user to open
http://localhost:3333 - Write HTML to
/tmp/brainstorm/screen.html - Check task output for user events