Quickstart

This guide walks through authenticating with the Lendiro API and submitting your first cash-flow decision request. Estimated time: 20–30 minutes for a backend engineer familiar with REST APIs.

Prerequisites

A Lendiro API key (contact [email protected] to request one)
Bank transaction data for a test applicant (24 months preferred; 6 months minimum)
An HTTP client (curl, Postman, or your LOS's HTTP library)

Step 1 — Verify authentication

Start by confirming your API key works against the sandbox environment.

# Test authentication with a GET to /v1/health
curl -X GET https://api-sandbox.lendirow.com/v1/health \
  -H "Authorization: Bearer lndr_sandbox_sk_xxxxxxxx" \
  -H "Content-Type: application/json"

# Expected response — 200 OK
{
  "status": "ok",
  "environment": "sandbox",
  "api_version": "v1"
}

Step 2 — Prepare your transaction payload

Build a transaction array with at least 6 months of bank transaction history. Each transaction requires:

date — ISO 8601 date string (YYYY-MM-DD)
amount — Signed decimal. Negative = outflow (debit), positive = inflow (credit)
category — Transaction category string (see Data Model for category taxonomy)
recurrence — Boolean. true if transaction is part of a recurring series

Step 3 — Submit your first decision

POST to /v1/decisions with the transaction payload and applicant reference:

# POST /v1/decisions — Submit for decisioning
curl -X POST https://api-sandbox.lendirow.com/v1/decisions \
  -H "Authorization: Bearer lndr_sandbox_sk_xxxxxxxx" \
  -H "Content-Type: application/json" \
  -d '{
    "applicant_ref": "test_applicant_001",
    "lookback_months": 24,
    "transactions": [
      {
        "date": "2024-05-01",
        "amount": 2450.00,
        "category": "payroll",
        "recurrence": true
      },
      {
        "date": "2024-05-03",
        "amount": -850.00,
        "category": "rent",
        "recurrence": true
      },
      {
        "date": "2024-05-08",
        "amount": -125.00,
        "category": "utilities",
        "recurrence": true
      }
    ],
    "requested_loan": {
      "amount": 5000,
      "term_months": 24
    }
  }'

Step 4 — Parse the decision response

A successful request returns HTTP 200 with the following structure:

{
  "decision_id": "dec_sandbox_abc123",
  "applicant_ref": "test_applicant_001",
  "score": 74,
  "recommendation": "approve",
  "reason_codes": ["CF-01"],
  "signals": {
    "income_consistency": 0.82,
    "expense_discipline": 0.71,
    "liquidity_cushion": 0.68,
    "payment_reliability": 0.91
  },
  "data_freshness": {
    "lookback_months_available": 24,
    "most_recent_transaction": "2024-05-08"
  },
  "model_version": "v1.4.2",
  "audit_log_ref": "audit_sandbox_xyz"
}

Step 5 — Generate adverse action notice (if needed)

If your underwriting policy results in an adverse action, POST to /v1/adverse-action with the decision ID to receive Reg B–mapped reason statements:

curl -X POST https://api-sandbox.lendirow.com/v1/adverse-action \
  -H "Authorization: Bearer lndr_sandbox_sk_xxxxxxxx" \
  -H "Content-Type: application/json" \
  -d '{
    "decision_id": "dec_sandbox_abc123",
    "applicant_ref": "test_applicant_001",
    "action_taken": "adverse"
  }'

Next steps

Review the full API Reference for all endpoint parameters and error codes
Read the Data Model for the complete transaction category taxonomy
Set up Webhooks for async decision delivery in high-volume workflows
Contact us to discuss your LOS integration and get production API keys