How do I get an Underlytix API key?

API access is currently in early access. Email api@underlytix.com with your use case to request an API key. Developers building real estate tools, AI agents, or platforms that need deal analysis and lender matching are prioritized.

What can I build with the Underlytix API?

You can build AI assistants that analyze real estate deals, investor portals with built-in fundability scoring, lender intake tools with automatic deal pre-screening, realtor client qualification workflows, and ChatGPT or Claude integrations for deal intelligence.

Is the Underlytix API RESTful?

Yes. The Underlytix API is a REST API using JSON request and response bodies. Authentication uses bearer token API keys. All endpoints support HTTPS.

Underlytix API Documentation — Deal Analysis & Lender Matching API

Authentication

Getting started

The Underlytix API uses bearer token authentication. Include your API key in every request header.

# Base URL
https://api.underlytix.com/v1

# Authentication header (required on all requests)
Authorization: Bearer your_api_key_here
Content-Type: application/json

# Test your connection
curl -X GET https://api.underlytix.com/v1/ping   -H "Authorization: Bearer your_api_key_here"

# Response
{ "status": "ok", "version": "1.0" }

Endpoints

Available API endpoints

POST /v1/deal-analysis

Analyzes a real estate deal and returns DSCR, LTV, cash-on-cash return, NOI projection, Capital Readiness Score, fundability verdict, and lender type match.

// Request body
{
  "purchase_price":   680000,       // required
  "loan_amount":      510000,       // required
  "monthly_rent":     5200,         // required
  "property_type":    "multifamily", // sfr | multifamily | mixed_use
  "units":            4,            // optional
  "interest_rate":    7.25,         // optional, uses market rate if omitted
  "monthly_expenses": 1100          // optional
}

// Response
{
  "capital_readiness_score": 84,
  "dscr":                  1.31,
  "ltv":                   0.75,
  "cash_on_cash_return":   0.074,
  "monthly_noi":          2840,
  "verdict":              "FUNDABLE",
  "recommended_loan_type": "DSCR_RENTAL",
  "risk_flags":           []
}

POST /v1/capital-readiness-score

Returns a single 0–100 Capital Readiness Score for a deal, with weighted component breakdown.

// Response
{
  "score": 84,
  "components": {
    "dscr_score":        88,
    "ltv_score":         82,
    "cash_flow_score":   79,
    "lender_fit_score":  90
  },
  "band": "STRONG"
}

POST /v1/lender-match

Matches a deal profile to appropriate lender types and products, ranked by fit score.

// Response
{
  "primary_match": {
    "loan_type":   "DSCR_RENTAL",
    "fit_score":   92,
    "requirements": { "min_dscr": 1.0, "max_ltv": 0.80 }
  },
  "alternatives": [
    { "loan_type": "PORTFOLIO", "fit_score": 74 }
  ]
}

POST /v1/risk-analysis

Returns identified risk factors for a deal with severity ratings and suggested remediations.

// Response (deal with DSCR issue)
{
  "risk_count": 1,
  "risks": [{
    "factor":    "DSCR_SHORTFALL",
    "severity": "HIGH",
    "current":  0.87,
    "minimum":  1.0,
    "fix":     "Increase down payment by $34K"
  }],
  "overall_risk": "MEDIUM"
}

What You Can Build

Use cases for the API

🤖

AI Assistants

Build ChatGPT, Claude, or Gemini integrations that can answer "can this deal get funded?" with a real Capital Readiness Score backed by Underlytix.

🏘️

Investor Portals

Embed deal scoring natively in your own investor portal or real estate marketplace — every listing shows a fundability score automatically.

🏦

Lender Intake Tools

Pre-screen incoming loan applications before they reach your underwriting team — score deals automatically at submission.

Underlytix API