Overview
Get New Zealand mortgage, personal loan, car loan, and credit card interest rates as JSON. Use the free Rates API with curl, OpenAPI, or MCP.
Rates API gives the interest rates of New Zealand financial institutions. You can get the newest rates and snapshots of earlier rates. An API key is not necessary. All responses are JSON.
The data can be incorrect. For correct rates, refer to the financial institution. For the data source and the terms of use, read About.
Key Facts
Rates API is a free JSON API for New Zealand interest rates. It has four datasets: mortgage, personal loan, car loan, and credit card rates. Each dataset has more than 30 lenders or issuers. The API checks interest.co.nz each hour. It saves a maximum of one snapshot each day, when the data changes. The history starts on 8 March 2025.
Start Here
| Task | Page |
|---|---|
| Send your first request | Quickstart |
| Connect an AI agent or an assistant | AI Integration |
| Read about IDs, dates, and errors | Core Concepts |
| Find the base URL, the endpoints, and the response rules | API Reference |
| Find all parameters and response fields, and send requests from the browser | OpenAPI Reference |
| Run or deploy the project | Open Source |
| Read about the data source, the terms of use, and how to get help | About |
Example
curl https://www.ratesapi.nz/api/v1/mortgage-ratesThe response contains a list of institutions. Each institution has products, and each product has rates. Use the id of an institution in detail requests and time-series requests.
Made for AI Agents
AI agents can find the data, get it, and check it without special work.
| Item | How it helps an AI agent |
|---|---|
| Model Context Protocol (MCP) | POST /api/v1/mcp gives tools that an MCP client can find and use. |
| OpenAPI | /openapi/json gives a contract that tools can read. SDK generators can make clients from it. |
llms.txt | /llms.txt gives a short plain-text list of the documentation pages. |
| JSON | Responses and errors always have the same shape. An agent can easily check a result. |
| IDs | The ID of an institution or an issuer does not change. An agent can use it in the next request. |
| No API key | An agent can use the data without secrets. |
Data
| Category | List Endpoint | Get By ID | Time Series |
|---|---|---|---|
| Mortgage Rates | GET /api/v1/mortgage-rates | GET /api/v1/mortgage-rates/{institutionId} | GET /api/v1/mortgage-rates/time-series |
| Personal Loan Rates | GET /api/v1/personal-loan-rates | GET /api/v1/personal-loan-rates/{institutionId} | GET /api/v1/personal-loan-rates/time-series |
| Car Loan Rates | GET /api/v1/car-loan-rates | GET /api/v1/car-loan-rates/{institutionId} | GET /api/v1/car-loan-rates/time-series |
| Credit Card Rates | GET /api/v1/credit-card-rates | GET /api/v1/credit-card-rates/{issuerId} | GET /api/v1/credit-card-rates/time-series |
The mortgage data has fixed terms of 6 months to 5 years, and floating rates.
Use Cases
- Compare mortgages, personal loans, car loans, and credit cards.
- Calculate the cost of a loan with the newest rates.
- Show changes in the lending market on a dashboard.
- Make charts of rates over time. The API keeps a snapshot only for days on which the data changed.
- Examine rates over time with the same institution IDs.
- Let an AI assistant answer questions about rates with data from the API.
- Let an agent compare lenders or find rate changes.
Summary
| Item | Value |
|---|---|
| Base URL | https://www.ratesapi.nz |
| Local API URL | http://localhost:8787 |
| Authentication | None. An API key is not necessary. |
| Format | JSON |
| OpenAPI reference (Scalar) | /openapi |
| OpenAPI JSON | /openapi/json |
| MCP endpoint | POST /api/v1/mcp |
| Documentation list for LLMs | /llms.txt |
| Full documentation text for LLMs | /llms-full.txt |
| Source code | github.com/simonbetton/ratesapi.nz |
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