---
title: "Public stateless invoice-date demonstration"
method: POST
path: "/api/v1/demo/calculate-deadline"
tags: ["calculations"]
---

# Public stateless invoice-date demonstration

`POST /api/v1/demo/calculate-deadline`

## Request

- Base URL: `https://secure-api-v1.liendeadline.com`
- URL: `https://secure-api-v1.liendeadline.com/api/v1/demo/calculate-deadline`
- Auth: none declared

Public calculator demonstration. Uses public rules, saves no calculation, sends no email, provides no account/API entitlement and charges no usage. Invoice dates are illustrative inputs; statutory triggering events require review. No key or browser session is required. Kansas invoice-only requests require event review.

## Request body

- CalculationRequest
  - `state` string, required: Supported two-letter US state code
  - `invoice_date` string, required: Legacy invoice-date projection in YYYY-MM-DD; not a verified statutory triggering event
  - `project_type` 'commercial' | 'residential'
  - `notice_date` string: Optional notice-of-completion date in YYYY-MM-DD
  - `role` 'supplier' | 'contractor' | 'subcontractor'

## Response `200`

Successful Response

- unknown

## Other responses

- `422`: Validation Error

---

[API](https://skmtc.dev/liendeadline/apis/lien-deadline-api.md) · [All operations](https://skmtc.dev/liendeadline/apis/lien-deadline-api/llms.txt) · [OpenAPI document](https://skmtc.dev/liendeadline/apis/lien-deadline-api/revisions/170b4d579b4b?raw)