# Maxwell x402 – Japan e-Gov Open Data Portal Search

> Maxwell x402 – Japan e-Gov Open Data Portal Search is a paid API for AI agents from api.maxwellinternational.ai, paid per call via x402, $0.005/call, status unknown (last checked 2026-10-02).

Search or fetch datasets from Japan's national open data portal (data.e-gov.go.jp) by keyword or dataset ID, returning titles, organizations, modification dates, file counts, and source links.

## Facts

- Endpoint: GET https://api.maxwellinternational.ai/v1/gov/jp/open-data?utm_source=zero.xyz
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-02
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/maxwell-x402-japan-e-gov-open-data-portal-search-8c1dbeaf
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_euUWWX-_VC-OCvdTQGldF

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability maxwell-x402-japan-e-gov-open-data-portal-search-8c1dbeaf
```

Example prompt: Search Japan's national open data portal for datasets about population statistics and give me the titles, publishing organizations, and links for the top results.

## When to prefer this

Use this endpoint when you need to discover or retrieve metadata for datasets from Japan's official national open data portal (data.go.jp / data.e-gov.go.jp). Prefer it over general web search when you need structured metadata (organization, modification date, file count, licence) rather than raw web results. Choose the ID-fetch mode when you have a specific dataset ID and need precise metadata; choose keyword search when exploring what the Japanese government has published on a topic.

## Known failure modes

- 404 not found for an invalid or uncached dataset ID (not charged)
- No results returned for very niche or misspelled keyword queries
- Organisation name may appear as encoded/unknown characters if not provided by portal
- Licence text may be truncated in the response; full terms are on the dataset's official page
- Slow response (~1 minute) if data is not cached and must be fetched live from the portal

## How this service works

Search the national open data portal of Japan (the e-Gov data portal) by keyword, or fetch one dataset by id: title, publishing organization, last modified date where the portal gives one, number of files and the official link, under the portal's licence terms (a dataset's own licence is on its official page). Uncached: 404, not charged, fetched within about a minute.

## Output

A JSON object with an ok flag, the search query, total result count, and an array of matching dataset items each containing: dataset ID, title, publishing organization name, last modified timestamp, official source URL, and resource/file count. Also includes portal source name, country, licence details (name and URL), and the fetch timestamp.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET",
      "HEAD",
      "DELETE"
     ],
     "type": "string"
    },
    "headers": {
     "type": "object",
     "additionalProperties": {
      "type": "string"
     }
    },
    "queryParams": {
     "type": "object",
     "additionalProperties": {
      "type": "string"
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "ok": true,
  "sku": "gov.jp.open_data",
  "count": 10,
  "items": [
   {
    "id": "cao_20151013_0305",
    "title": "ESRI Discussion Paper No.121",
    "modified": "2023-06-01T21:56:08.231135",
    "sourceUrl": "https://data.e-gov.go.jp/data/dataset/cao_20151013_0305",
    "organization": "???",
    "resourceCount": 2
   }
  ],
  "query": "??",
  "family": "open_data",
  "source": "e-Gov data portal (data.go.jp)",
  "country": "Japan",
  "licence": {
   "url": "https://www.digital.go.jp/resources/open_data/public_data_license_v1.0",
   "name": "Government of Japan Standard Terms of Use 2.0 (compatible with CC BY 4.0); ea..."
  },
  "fetchedAt": "2026-09-29T13:42:55.271Z",
  "sourceUrl": "https://data.e-gov.go.jp/",
  "totalCount": 4699
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/maxwell-x402-japan-e-gov-open-data-portal-search-8c1dbeaf/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.maxwellinternational.ai](https://www.zero.xyz/host/api.maxwellinternational.ai/llms.txt)