Laytime Calculator Pro — API & MCP Server

AI-powered laytime, demurrage and despatch calculation for dry-bulk and tanker chartering. Send a Charter Party, Fixture Recap, Notice of Readiness (NOR) or Statement of Facts (SoF) — get back a full, auditable laytime statement with the demurrage / despatch settlement.

Built for software teams in shipping: integrate it into your own systems over a plain REST API, or plug it into an AI assistant via the Model Context Protocol (MCP). Same key, same quota, same engine.

• 🌐 Product: https://navitt.com/web
• 🔑 API access & pricing: https://navitt-mcp.marine-356.workers.dev/authorize
• 📇 MCP Registry: io.github.shipping-ship-it/laytime-calculator-pro
• ✉️ Contact: [email protected]

What it does

Laytime calculation requires holding every charter-party term in mind at once — laycan, NOR validity, turn time, SHINC/SHEX, weather working days, exceptions, half-rate periods, reversible vs non-reversible time. Miss one clause and the settlement is wrong. This service reads the documents, applies the terms and returns a day-by-day calculation you can audit, with the final demurrage or despatch figure.

• Accepts Charter Party, Fixture Recap, NOR, Statement of Facts, Bills of Lading
• Input as plain text and/or files (PDF, image, Excel)
• Returns a full, line-by-line laytime statement plus the settlement
• Works with any language or platform over REST — no AI required on your side

Quick start (REST)

curl -X POST https://navitt-mcp.marine-356.workers.dev/api/calculate \
  -H "x-api-key: YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "text": "NOR tendered 01 Jun 08:00. Loading 01 Jun 12:00 to 03 Jun 18:00. Laytime allowed 3 days SHINC. Demurrage USD 10000/day. Despatch half demurrage."
  }'

Response:

{
  "result": "… full day-by-day laytime statement and demurrage/despatch settlement …",
  "remaining": 92
}

remaining is the number of calculations left on your plan.

Authentication

Every request must include your API key in the `x-api-key` header. Keys are issued after sign-up on the access & pricing page.

x-api-key: YOUR_API_KEY

REST API reference

POST /api/calculate

Base URL: https://navitt-mcp.marine-356.workers.dev

Headers

Body (JSON) — provide text, documents, or both:

\* At least one of text or documents must be supplied.

`documents[]` item

Response 200 OK

Errors

Each successful request consumes one calculation from your plan.

Example: sending a document (Node.js)

import { readFileSync } from "node:fs";

const data = readFileSync("charter_party.pdf").toString("base64");

const res = await fetch("https://navitt-mcp.marine-356.workers.dev/api/calculate", {
  method: "POST",
  headers: {
    "x-api-key": process.env.LAYTIME_API_KEY,
    "Content-Type": "application/json",
  },
  body: JSON.stringify({
    documents: [{ mimeType: "application/pdf", data }],
    instructions: "SHINC. Demurrage USD 12,000/day, despatch half demurrage.",
  }),
});

const { result, remaining } = await res.json();
console.log(result);
console.log("Calculations left:", remaining);

Example: Python

import base64, requests

with open("statement_of_facts.pdf", "rb") as f:
    data = base64.b64encode(f.read()).decode()

r = requests.post(
    "https://navitt-mcp.marine-356.workers.dev/api/calculate",
    headers={"x-api-key": "YOUR_API_KEY"},
    json={"documents": [{"mimeType": "application/pdf", "data": data}]},
)
print(r.json()["result"])

MCP server

The same calculator is available as a Model Context Protocol server, so an AI assistant can call it directly as a tool.

• Endpoint: https://navitt-mcp.marine-356.workers.dev/mcp (streamable HTTP, OAuth-protected)
• Registry name: io.github.shipping-ship-it/laytime-calculator-pro
• Tool: calculate_laytime

Tool input

Authorize and obtain access on the access & pricing page.

Pricing

Pay-as-you-go: USD 1,000 for 500 calculations (USD 2 per calculation), by card or by invoice to a corporate account. Corporate rates available for teams. See the access & pricing page or contact [email protected].

About

Built by AGRIX / Navitt — modern tools for shipping. BIMCO member 181628.

• https://agrix.world
• https://navitt.com