API Reference

Complete reference for the Lendiro v1 REST API. Base URL: https://api.lendirow.com

Endpoints

Submit a normalized transaction payload to receive a cash-flow decision score, signal breakdown, and adverse action reason codes.

Request body

{
  "applicant_ref": "string",         // Required. Your internal applicant ID
  "lookback_months": 24,              // Optional. 6–24. Default 24
  "transactions": [...array],        // Required. See Data Model
  "requested_loan": {               // Optional. For DTI context
    "amount": number,
    "term_months": number
  }
}

Response — 200 OK

{
  "decision_id": "dec_xxxxxxxx",
  "score": 0-100,                  // 0 = weakest, 100 = strongest
  "recommendation": "approve|review|decline",
  "reason_codes": ["CF-01", ...],  // Reg B–mapped codes
  "signals": {
    "income_consistency": 0.0-1.0,
    "expense_discipline": 0.0-1.0,
    "liquidity_cushion": 0.0-1.0,
    "payment_reliability": 0.0-1.0
  },
  "data_freshness": { ... },
  "model_version": "string",
  "audit_log_ref": "string"
}

Retrieve any previously made decision by its ID. Useful for display in underwriter queues or audit log retrieval.

Path parameters

decision_id — Required. The decision ID returned from POST /v1/decisions.

Response — 200 OK

Same structure as POST /v1/decisions response, plus "created_at" timestamp.

Given a decision ID and an adverse action flag, returns plain-English reason statements mapped to Regulation B adverse action notice categories. Use these statements in your consumer adverse action notices.

Request body

{
  "decision_id": "dec_xxxxxxxx",  // Required
  "applicant_ref": "string",       // Required
  "action_taken": "adverse"        // Required. Currently: "adverse"
}

Response — 200 OK

{
  "notice_id": "notice_xxxxxxxx",
  "action_taken": "Credit denied",
  "reason_statements": [
    "Insufficient length of income history",
    "Insufficient evidence of recurring income"
  ],
  "reg_b_codes": ["CF-01", "CF-04"],
  "generated_at": "ISO 8601 timestamp"
}

Webhooks

Register a webhook URL to receive decision results asynchronously. Suitable for high-volume origination pipelines where synchronous waiting is impractical.

Registering a webhook

curl -X POST https://api.lendirow.com/v1/webhooks \
  -H "Authorization: Bearer lndr_live_sk_xxxxxxxx" \
  -d '{
    "url": "https://your-los.example.com/webhooks/lendiro",
    "events": ["decision.complete", "decision.failed"]
  }'

Payload verification

All webhook deliveries include an X-Lendiro-Signature header containing an HMAC-SHA256 signature of the payload body using your webhook signing secret. Verify this signature before processing the payload.

Compliance Integration Guide

See Compliance page for the full regulatory context. Technical notes:

Reason codes in the reason_codes array follow the CF-XX naming convention where the number maps to a Reg B adverse action category.
The /v1/adverse-action endpoint generates consumer-facing language — review and adapt to your institution's adverse action notice template before sending to applicants.
Decision audit logs are exportable via GET /v1/decisions with date range parameters for regulatory examination.

Error codes

HTTP Status	Code	Description
400	`invalid_payload`	Malformed request body or missing required fields
400	`insufficient_data`	Transaction history below 6-month minimum
401	`unauthorized`	Missing or invalid API key
403	`forbidden`	IP not on allowlist (if configured)
404	`not_found`	Decision ID not found in your account
429	`rate_limited`	Rate limit exceeded — retry after `X-RateLimit-Reset`
500	`processing_error`	Internal processing error — not billed, safe to retry