Build an AI Lease Analyzer App with the AI Pass SDK
Build an AI Lease Analyzer App with the AI Pass SDK
Document analysis is one of the highest-value AI applications — people will pay to have complex contracts explained in plain language. A lease analyzer is particularly in-demand: millions of people sign leases every year without fully understanding what they're agreeing to.
This tutorial builds a complete AI lease analyzer web app with the AI Pass SDK.
Prerequisites
- HTML/JavaScript basics
- AI Pass account (sign up at aipass.one)
- Client ID from Developer Dashboard
Step 1: Get Your Client ID
- Log in at aipass.one
- Go to Developer Dashboard → OAuth2 Clients
- Create a new client called "Lease Analyzer"
- Copy your
client_XXXX...ID
Step 2: Build the App
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>AI Lease Analyzer</title>
<script src="https://aipass.one/aipass-sdk.js"></script>
<style>
* { box-sizing: border-box; margin: 0; padding: 0; }
body {
font-family: 'Segoe UI', sans-serif;
background: #f0f4ff;
max-width: 860px;
margin: 0 auto;
padding: 2rem;
color: #1e293b;
}
h1 { color: #1e40af; margin-bottom: 0.25rem; }
.subtitle { color: #64748b; margin-bottom: 2rem; }
.input-section {
background: white;
border-radius: 12px;
padding: 1.5rem;
box-shadow: 0 1px 4px rgba(0,0,0,0.08);
}
label { font-weight: 600; font-size: 0.875rem; color: #374151; display: block; margin-bottom: 0.5rem; }
textarea {
width: 100%;
min-height: 200px;
padding: 1rem;
border: 1px solid #d1d5db;
border-radius: 8px;
font-family: monospace;
font-size: 0.875rem;
resize: vertical;
color: #1e293b;
}
.options-row { display: flex; gap: 1rem; margin: 1rem 0; flex-wrap: wrap; }
select {
padding: 0.5rem 1rem;
border: 1px solid #d1d5db;
border-radius: 8px;
font-size: 0.9rem;
background: white;
}
button {
background: #1e40af;
color: white;
border: none;
padding: 0.875rem 2rem;
border-radius: 8px;
font-size: 1rem;
font-weight: 600;
cursor: pointer;
width: 100%;
margin-top: 0.75rem;
}
button:disabled { background: #93c5fd; cursor: not-allowed; }
#status { text-align: center; margin: 1rem 0; color: #6b7280; }
.results {
margin-top: 1.5rem;
display: none;
}
.card {
background: white;
border-radius: 12px;
padding: 1.5rem;
margin-bottom: 1rem;
box-shadow: 0 1px 4px rgba(0,0,0,0.08);
}
.card h2 { font-size: 1rem; color: #1e40af; margin-bottom: 0.75rem; padding-bottom: 0.5rem; border-bottom: 2px solid #dbeafe; }
.card-content { line-height: 1.7; color: #374151; white-space: pre-wrap; }
.red-flag { background: #fff1f2; border-left: 4px solid #ef4444; padding: 0.75rem 1rem; border-radius: 0 8px 8px 0; margin: 0.5rem 0; }
.green-flag { background: #f0fdf4; border-left: 4px solid #22c55e; padding: 0.75rem 1rem; border-radius: 0 8px 8px 0; margin: 0.5rem 0; }
</style>
</head>
<body>
<h1>📋 AI Lease Analyzer</h1>
<p class="subtitle">Understand every clause before you sign</p>
<div class="input-section">
<label>Paste Your Lease Text *</label>
<textarea id="leaseText" placeholder="Paste your full lease agreement here. The more text you provide, the more thorough the analysis."></textarea>
<div class="options-row">
<div>
<label style="margin-bottom:0.3rem">Lease Type</label>
<select id="leaseType">
<option>Residential Rental</option>
<option>Commercial / Office</option>
<option>Month-to-Month</option>
<option>Student Housing</option>
<option>Commercial Retail</option>
</select>
</div>
<div>
<label style="margin-bottom:0.3rem">Focus</label>
<select id="focusArea">
<option>Full Analysis</option>
<option>Red Flags Only</option>
<option>Financial Terms</option>
<option>Termination & Exit</option>
<option>Landlord Rights & Access</option>
</select>
</div>
</div>
<button id="analyzeBtn" onclick="analyzeLease()">🔍 Analyze Lease</button>
</div>
<p id="status"></p>
<div class="results" id="results">
<div class="card">
<h2>📌 Summary</h2>
<div class="card-content" id="summary"></div>
</div>
<div class="card">
<h2>🚩 Red Flags</h2>
<div id="redFlags"></div>
</div>
<div class="card">
<h2>📖 Clause-by-Clause Breakdown</h2>
<div class="card-content" id="clauses"></div>
</div>
<div class="card">
<h2>❓ Questions to Ask Before Signing</h2>
<div class="card-content" id="questions"></div>
</div>
</div>
<script>
AiPass.initialize({
clientId: 'YOUR_CLIENT_ID',
requireLogin: true,
darkMode: false
});
async function analyzeLease() {
const text = document.getElementById('leaseText').value.trim();
if (!text || text.length < 100) {
alert('Please paste your lease text (at least a few paragraphs).');
return;
}
const btn = document.getElementById('analyzeBtn');
const status = document.getElementById('status');
btn.disabled = true;
status.textContent = '⏳ Analyzing your lease... (30-60 seconds)';
document.getElementById('results').style.display = 'none';
const leaseType = document.getElementById('leaseType').value;
const focusArea = document.getElementById('focusArea').value;
const prompt = `Analyze this ${leaseType} lease agreement with focus on: ${focusArea}.
Provide your analysis in exactly this format:
SUMMARY:
[2-3 sentence overview: lease type, duration, rent amount, key dates]
RED FLAGS:
[List each red flag as: 🚩 [Clause Name]: [What it means and why it's concerning]]
[If no red flags, write "No major red flags identified."]
CLAUSE BREAKDOWN:
[For each major section: Section Name — Plain English explanation of what the tenant is agreeing to]
QUESTIONS TO ASK:
[5-7 specific questions the tenant should ask the landlord before signing]
LEASE TEXT:
${text.substring(0, 8000)}`;
try {
const result = await AiPass.generateCompletion({
model: 'gpt-5',
temperature: 1,
max_tokens: 16000,
messages: [
{
role: 'system',
content: 'You are a tenant rights expert who explains legal documents in plain, accessible language. You identify clauses that are unusual, one-sided, or potentially harmful to tenants. You do not provide legal advice but help people understand what they are reading.'
},
{ role: 'user', content: prompt }
]
});
const content = result.choices[0].message.content;
// Parse sections
const summaryMatch = content.match(/SUMMARY[:\s]+([\s\S]*?)(?=RED FLAGS:|$)/i);
const flagsMatch = content.match(/RED FLAGS[:\s]+([\s\S]*?)(?=CLAUSE BREAKDOWN:|$)/i);
const clausesMatch = content.match(/CLAUSE BREAKDOWN[:\s]+([\s\S]*?)(?=QUESTIONS TO ASK:|$)/i);
const questionsMatch = content.match(/QUESTIONS TO ASK[:\s]+([\s\S]*?)$/i);
document.getElementById('summary').textContent = summaryMatch ? summaryMatch[1].trim() : '';
// Format red flags
const flagsText = flagsMatch ? flagsMatch[1].trim() : '';
const flagsContainer = document.getElementById('redFlags');
flagsContainer.innerHTML = '';
if (flagsText && !flagsText.toLowerCase().includes('no major red flags')) {
flagsText.split('\n').filter(l => l.trim()).forEach(flag => {
const div = document.createElement('div');
div.className = flag.includes('🚩') ? 'red-flag' : '';
div.textContent = flag;
flagsContainer.appendChild(div);
});
} else {
const ok = document.createElement('div');
ok.className = 'green-flag';
ok.textContent = '✅ No major red flags identified in this lease.';
flagsContainer.appendChild(ok);
}
document.getElementById('clauses').textContent = clausesMatch ? clausesMatch[1].trim() : '';
document.getElementById('questions').textContent = questionsMatch ? questionsMatch[1].trim() : '';
document.getElementById('results').style.display = 'block';
status.textContent = '✅ Analysis complete. Review your results below.';
} catch (err) {
status.textContent = '❌ Error: ' + err.message;
}
btn.disabled = false;
}
</script>
</body>
</html>
Key Notes
temperature: 1andmax_tokens: 16000are required for GPT-5- Lease text is truncated to 8,000 characters — for longer leases, process in chunks
- The
gpt-5model provides the best document understanding quality
Deploy & Earn
Self-host: Single HTML file, works on any static host.
Publish on AI Pass: Submit at Developer Dashboard → Apps. Earn 50% commission on every lease analysis. This is a high-value, recurring use case — people analyze leases before every move.