Documentation

Learn how to integrate Japan Data API

Get API Key GitHub

Quick Start

Get started with Japan Data API in minutes.

Create an Account

Get Your API Key

Generate an API key from your dashboard. Keep it secret and secure.

Make Your First Request

Use your API key to authenticate requests and start fetching data.

Base URL

https://api.japandata.io/v1

Authentication

All API requests require authentication via an API key. Include your key in the Authorization header:

Authorization: Bearer YOUR_API_KEY

API Endpoints

Explore all available endpoints.

Regions

GET

/regions

List all regions

GET

/regions/{id}

Get a specific region

Prefectures

GET

/prefectures

List all prefectures

GET

/prefectures/{id}

Get a specific prefecture

GET

/regions/{id}/prefectures

List prefectures in a region

Cities

GET

/cities

List all cities (paginated)

GET

/cities/{id}

Get a specific city

GET

/prefectures/{id}/cities

List cities in a prefecture

Holidays

GET

/holidays

List holidays (current year)

GET

/holidays?year=2024

List holidays for a specific year

GET

/holidays/{id}

Get a specific holiday

Code Examples

Examples in popular programming languages.

curl -X GET "https://api.japandata.io/v1/prefectures" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Accept: application/json"

Response Format

All responses follow a consistent JSON structure:

{
  "success": true,
  "data": [
    {
      "id": 1,
      "name": "Hokkaido",
      "name_ja": "北海道",
      "name_en": "Hokkaido",
      "slug": "hokkaido",
      "iso_code": "JP-01",
      "region_id": 1,
      "capital": "Sapporo",
      "area_km2": 83424,
      "population": 5224614
    },
    {
      "id": 2,
      "name": "Aomori",
      "name_ja": "青森県",
      "name_en": "Aomori",
      "slug": "aomori",
      "iso_code": "JP-02",
      "region_id": 2,
      "capital": "Aomori",
      "area_km2": 9645,
      "population": 1237984
    }
  ],
  "meta": {
    "page": 1,
    "limit": 50,
    "total": 47
  },
  "error": null
}

Error Handling

When an error occurs, the API returns a structured error response:

{
  "success": false,
  "data": null,
  "meta": {},
  "error": {
    "code": "RATE_LIMIT_EXCEEDED",
    "message": "You have exceeded your rate limit. Please try again later."
  }
}

Common Error Codes

Code	HTTP Status	Description
UNAUTHORIZED	401	Missing or invalid API key
NOT_FOUND	404	Resource not found
RATE_LIMIT_EXCEEDED	429	Too many requests
SERVER_ERROR	500	Internal server error