Homebuyer.com - Happy Homebuying™ - Expert mortgage guidance and tools

Build With Mortgage Data

Public APIs, an MCP server for AI tools, and live data feeds. Free for non-commercial use. No sign-up required for most endpoints.

Quick Start

Every endpoint works without authentication. Add an API key to unlock HMDA queries and increase your rate limit from 20 to 100 requests per minute.

Terminal
# Get current mortgage rates for California
curl "https://homebuyer.com/api/v1/rates?state=CA&fico=1&ltv=1"

# Connect Claude Desktop or Cursor to 8 mortgage data tools
# Add this to your claude_desktop_config.json:
{
  "mcpServers": {
    "homebuyer": {
      "url": "https://homebuyer.com/api/mcp"
    }
  }
}

# Ask a natural language mortgage question (SSE stream)
curl -X POST "https://homebuyer.com/api/v1/ask" \
  -H "Content-Type: application/json" \
  -d '{"message": "What are FHA loan limits in Cook County?"}'

Try It Live

Pick a state and hit “Try it” to see live Opendoor mortgage rates returned from the API. No key needed.

GET /api/v1/rates?state=CA&fico=1&ltv=1

What You Can Build

Developers, researchers, and journalists use our data in production. Here are real use cases — each one is possible with the free tier.

Mortgage Comparison Chatbot

Connect MCP to Claude or build on the /ask API. Every response pulls from HMDA records, live rates, and loan limits.

Rate Alert Notifications

Poll /rates daily and alert users when their state drops below a threshold. Opendoor + Optimal Blue data.

County-Level Housing Research

Query HMDA for approval rates, denial reasons, and lending patterns. 121M+ records by county, race, age, income.

Economic Calendar Integration

Pull Fed meetings, CPI, and jobs reports into your app. Filter by impact level.

Example: check rates in a script

rate-checker.js
const res = await fetch(
  "https://homebuyer.com/api/v1/rates" +
  "?state=CA&fico=1&ltv=1",
  { headers: { "X-API-Key": key } }
);
const { rate, date } = await res.json();

if (rate < threshold) {
  notify(`CA rate dropped to ${rate}% on ${date}`);
}

Example: ask a question programmatically

ask.sh
curl -N -X POST \
  "https://homebuyer.com/api/v1/ask" \
  -H "Content-Type: application/json" \
  -d '{"message": "What credit score \
  do I need for an FHA loan?"}'

Connect Your AI Tools via MCP

The Model Context Protocol (MCP) lets AI assistants call external tools. Our MCP server gives Claude, Cursor, Windsurf, and other MCP clients access to 8 mortgage data tools. Here's how to set it up.

Step 1: Add the server to your config

Open your Claude Desktop config file (Settings → Developer → Edit Config) and add the Homebuyer.com server. No API key needed for 7 of the 8 tools.

claude_desktop_config.json
{
  "mcpServers": {
    "homebuyer": {
      "url": "https://homebuyer.com/api/mcp"
    }
  }
}

Step 2: Restart your client and ask a question

After restarting, Claude will automatically detect the 8 available tools. Try asking questions like these — Claude will call the right tool and return real data:

"What are FHA loan limits in Cook County?"
"Compare mortgage rates in Texas vs California"
"What's the average down payment for first-time buyers?"
"Show me approval rates by race in Florida"

Step 3 (optional): Add an API key for HMDA queries

The query_hmda tool queries 121M+ mortgage records via BigQuery. It requires a free API key. Generate one below, then add it to your config:

With API key
{
  "mcpServers": {
    "homebuyer": {
      "url": "https://homebuyer.com/api/mcp",
      "headers": {
        "X-API-Key": "mcp_your_key_here"
      }
    }
  }
}

Available Tools

get_mortgage_rates

Today's Opendoor mortgage rates by state, FICO tier, and LTV. Includes Optimal Blue and Freddie Mac national averages for comparison.

get_loan_limits

Conforming, FHA, VA, and USDA mortgage loan limits for all 3,200+ US counties. Data back to 1972.

lookup_glossary_term

Plain-language definitions for 131 mortgage and real estate terms, with FAQs and links to full glossary pages.

get_statistics

Pre-computed mortgage market statistics — originations, approval rates, average loan amounts, FHA market share, and more. Sourced from HMDA data.

get_economic_calendar

Upcoming economic events that affect mortgage rates — Fed meetings, CPI, jobs reports. Filter by impact level, category, or date range.

search_content

Full-text search across 250+ articles, 131 glossary terms, and research pages. Returns excerpts and URLs.

get_congress_bills

45 housing and mortgage bills tracked in Congress. Search by keyword or get bill status, sponsors, and analysis.

query_hmdaAPI key

121M+ HMDA mortgage records via BigQuery. Preset queries for rates, approvals, denials, demographics, and lender rankings — or run custom SQL.

Rate Limits

Without API key (7 tools)20 requests/min
With API key (all 8 tools)100 requests/min

API Key

Sign in with Google to get a free API key. Unlocks the query_hmda tool and increases your rate limit to 100 requests per minute. Up to 3 keys per account.

REST API

Standard REST endpoints returning JSON. Pass your API key as a header or query parameter:

# Option 1: X-API-Key header
curl -H "X-API-Key: mcp_your_key" "https://homebuyer.com/api/v1/rates?state=CA"

# Option 2: Authorization Bearer
curl -H "Authorization: Bearer mcp_your_key" "https://homebuyer.com/api/v1/rates?state=CA"

# Option 3: Query parameter
curl "https://homebuyer.com/api/v1/rates?state=CA&api_key=mcp_your_key"
GET/api/v1/rates

Current Opendoor mortgage rates by state, FICO tier (780+ through 680-699), and LTV tier (75% and 95%). Returns rate, date, and state. Updated daily.

Response
{
  "rate": 5.125,
  "date": "2026-03-01",
  "state": "CA",
  "fico_tier": "780+",
  "ltv_tier": "75%",
  "source": "opendoor"
}
GET/api/v1/statistics

Mortgage market statistics with context. Filter by category (market_overview, rates, loan_types, down_payment, borrower_profile, lenders, affordability). Includes source URLs and data year.

Response
{
  "stat": {
    "id": "avg_down_payment_pct",
    "value": "14.1",
    "label": "Average Down Payment",
    "headline": "The average down payment is 14.1%",
    "category": "down_payment",
    "data_year": 2024,
    "source_url": "https://..."
  }
}
GET/api/v1/calendar

Economic calendar events that move mortgage rates. Filter by impact (high, medium, low), category (fed, inflation, employment, housing), or date range.

Response
{
  "events": [
    {
      "name": "FOMC Meeting",
      "date": "2026-03-18",
      "impact": "high",
      "category": "fed",
      "description": "Federal Reserve rate decision"
    }
  ]
}
POST/api/v1/ask

Natural language mortgage Q&A with streaming SSE responses. Backed by HMDA data, loan limits, live rates, and educational content. Responses cite sources.

Response
// SSE stream
data: {"type":"chunk","text":"FHA loan limits in Cook County..."}
data: {"type":"chunk","text":" for 2026 are $524,225..."}
data: {"type":"sources","urls":["homebuyer.com/mortgage-loan-limits/..."]}
data: {"type":"done"}
View full API documentation

Data Sources

The data behind our APIs and tools. Browse it on the site or access it programmatically.

HMDA Mortgage Data

121+ million mortgage applications from the Home Mortgage Disclosure Act. Originations, approvals, denials by state, county, demographics, loan type, and lender. 2018-2024 data available via BigQuery.

View research

Loan Limits by County

Conforming, FHA, VA, and USDA loan limits for all 3,200+ US counties. Covers 1-4 unit properties with historical data back to 1972. Updated annually when FHFA publishes new limits.

Browse limits

Live Mortgage Rates

Opendoor rates benchmarked against Optimal Blue market rates (via FRED). By state, FICO tier, and LTV tier. Updated daily on business days. $0 lender fees, no discount points.

See rates

Congressional Bills

45 housing-related bills tracked with status, sponsors, cosponsors, committee assignments, and analysis. Updated as bills progress through Congress.

Track bills

Feeds

Subscribe to content updates via RSS.

Main Feed/feed.xml

All articles and learn content

News Feed/news-feed.xml

Mortgage news and market updates

Machine-Readable Data

Structured data for AI agents, crawlers, and automated systems.

Brand Facts/.well-known/brand-facts.json

Company info, data sources, API endpoints, and tools in a machine-parseable format

AI Info Page/ai-info-page

Context page for AI models — who we are, what data we have, how to cite us

Homebuyer.com is operated by Opendoor Home Loans LLC (NMLS #2810193). APIs are free for non-commercial use. For commercial licensing or high-volume access, contact us.

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