The REIzer deal-analysis API

Underwrite any residential investment deal over JSON: send a strategy and your assumptions — get back cash flow, cap rate, DSCR, stress tests, and a 0–100 strategy-aware deal score. The core analysis endpoints are live in beta — free, no API key, no account. Keyed data endpoints (comps, records, market data) and a remote MCP server are in development; their sections below are the draft contract.

Try it now

The analysis endpoints are live. Inputs use the engine's camelCase keys; all rates and percents are fractions (0.0675, not 6.75). Omit any operating input and REIzer fills a documented default and lists it under assumptions.estimated_fields. Discover each strategy's inputs at GET /api/v1/strategies.

# No API key, no account — try it from your terminal
curl -X POST https://reizer.io/api/v1/analyze \
  -H "Content-Type: application/json" \
  -d '{
    "strategy": "ltr",
    "inputs": {
      "price": 285000, "marketRent": 3100,
      "downPct": 0.25, "rate": 0.0675, "term": 30,
      "closing": 6000, "taxes": 3200, "insurance": 1500
    }
  }'

{
  "strategy": "ltr",
  "score": 96,
  "verdict": "Strong",
  "metrics": {
    "monthly_cash_flow": 636.85,
    "cash_on_cash": 0.0989,
    "cap_rate": 0.0852,
    "dscr": 1.4594,
    "gross_yield": 0.1305,
    "cash_invested": 77250
  },
  "stress": [ /* 7 scenarios with verdicts */ ],
  "thresholds": { "break_even_rent": 2282.53, "max_rate": 0.0878, "max_vacancy": 0.3005 },
  "assumptions": { "estimated_fields": ["vacancyPct", "mgmtPct", "maintPct", "capexPct"] },
  "summary": "Strong (96/100). $637/mo cash flow, DSCR 1.46, 8.5% cap rate, 9.9% cash-on-cash on $77,250 invested. Some inputs are estimates.",
  "report_url": "https://reizer.io/report.html?id=…", /* shareable 30-day report */
  "access_level": "anonymous",
  "assumptions_source": "caller_supplied",
  "available_with_key": ["comps", "str_comps", "public_records", "market_data", "pdf_export"],
  "upgrade_url": "https://reizer.io/pricing.html?utm_source=api"
}

Free vs keyed access

The line sits exactly where it sits in the web app: everything computed by REIzer's own engine is free; everything backed by licensed third-party data requires an API key tied to a paid account.

Anonymous calls to a keyed endpoint return HTTP 402 (not 401) with the plan that unlocks it and a signup link — an upgrade path, not a broken credential. API usage draws from the same monthly allowances as the web app, shown on the same usage meters.

Endpoints

Two are live today; the rest are the draft contract for the keyed tier.

Authentication & keys

• Analysis endpoints need no authentication at all.
• Keyed endpoints use an API key created on your account's settings page, sent as a header. Keys look like rz_live_… (and rz_test_… for testing); the raw key is shown once at creation and stored only as a hash.
• Your key's entitlements always reflect your live subscription — a plan change applies to the very next request.

Rate limits

Every tier has a per-minute ceiling as a runaway guard (draft figures, tuned at launch). Exceeding it returns HTTP 429 with a retry_after value agents can honor.

Remote MCP server LIVE

The same capabilities are exposed as a remote MCP (Model Context Protocol) server at https://reizer.io/mcp — Claude, Cursor, and other agent hosts call REIzer as native tools. Free tools: analyze_deal, best_use, solve_max_offer, list_strategies; pull_comps and str_market_data are listed but key-gated until the keyed tier ships. Responses are compact JSON plus a deterministic summary — no server-side LLM narration.

claude mcp add --transport http reizer https://reizer.io/mcp

{
  "mcpServers": {
    "reizer": { "type": "http", "url": "https://reizer.io/mcp" }
  }
}

What you could build

FAQ

In the meantime: the full methodology is at reizer.io/docs, and machine-readable summaries live at /llms.txt and /llms-full.txt.