mcp-estat-japan

# @pipeworx/estat-japan

e-Stat (Japan) MCP — Japanese government statistics aggregator (~5000 tables across population, economy, labor, trade, prices, agriculture, environment). Free with an app ID.

Part of [Pipeworx](https://pipeworx.io) — an MCP gateway connecting AI agents to 1684+ live data sources.

## Tools

- `search_stats(query, limit?, start_position?, lang?)` — find stats tables
- `get_metadata(stats_data_id, lang?)` — dimensions + code lists for a table
- `get_data(stats_data_id, limit?, start_position?, lang?, filters?)` — observations
- `list_data_catalog(query?, limit?, start_position?, lang?, data_type?, survey_years?, stats_code?, stats_field?)` — browse catalog

## Auth

- **Platform key:** gateway env `PLATFORM_ESTAT_KEY` (an `appId` issued by e-stat.go.jp)
- **BYO:** `?_apiKey=<appId>` after registering at https://www.e-stat.go.jp/api/

## Data source

`https://api.e-stat.go.jp/rest/3.0/app/json/` — `appId` as query param.

Default language is Japanese (`J`); pass `lang: "E"` for English where available.

## Timeouts

e-Stat is slow and sets no timeout of its own. Measured 2026-08-27: `/getStatsList`
takes ~26s uncached, and `/getDataCatalog` ran past the gateway's 75s request deadline
at page sizes 1, 5 and 20 alike — page size is not what makes it slow.

Each request therefore carries its own budget — 55s (about 20s under the gateway's
own 75s deadline), and 35s for `list_data_catalog`, which is the endpoint that does
not finish at all rather than one that finishes late. Exceeding the budget returns a
soft failure rather than hanging:

```json
{ "found": false, "reason": "upstream_timeout", "endpoint": "...", "timeout_ms": 35000,
  "hint": "... use search_stats ..." }
```

`limit` defaults to 20 on `list_data_catalog` (100 on `get_data`, 20 on `search_stats`),
so a bare call is already bounded — page size was never what made the catalog slow.
The catalog accepts e-Stat's own narrowing params (`query`, `data_type`, `stats_code`,
`survey_years`); during the 2026-08-27 stall none of them shortened it, so treat them
as filters rather than as a fix. `search_stats` searches the same tables and answered
in seconds throughout.

## Quick Start

Add to your MCP client (Claude Desktop, Cursor, Windsurf, etc.):

```json
{
  "mcpServers": {
    "estat-japan": {
      "url": "https://gateway.pipeworx.io/estat-japan/mcp"
    }
  }
}
```

### What this endpoint actually serves

`tools/list` at `https://gateway.pipeworx.io/estat-japan/mcp` returns the tools in the table
above **plus the shared Pipeworx meta-tools** — `ask_pipeworx`,
`discover_tools`, `search_within`, `remember`/`recall` and the rest of the
gateway-wide set. So the tool count you see is larger than this table: a
single-pack endpoint currently lists roughly 30 shared tools alongside the
pack's own. The connection's `initialize` response states its exact scope, and
is the authoritative answer for a given day.

This is deliberate, not multiplexing by accident. The meta-tools are what let a
scoped connection answer a question this pack does not cover — via
`ask_pipeworx`, which routes across the whole catalog — without you adding a
second MCP server. There is currently no way to mount a pack endpoint without
them; if the extra schemas cost you more context than the routing is worth,
connect to the full gateway once rather than to several pack endpoints.

Or connect to the full Pipeworx gateway to get every pack's tools listed
directly, instead of just this one's:

```json
{
  "mcpServers": {
    "pipeworx": {
      "url": "https://gateway.pipeworx.io/mcp"
    }
  }
}
```

Both URLs reach the same gateway and the same 1684+ data sources. The
only difference is which pack's tools are listed **directly**; `ask_pipeworx`
reaches all of them from either one.

## No MCP client? Call it over HTTP

```bash
curl -X POST https://gateway.pipeworx.io/v1/tools/search_stats \
  -H 'Content-Type: application/json' \
  -d '{"query":"失業率"}'
```

No account needed for the first calls. Inspect any tool: `GET https://gateway.pipeworx.io/v1/tools/search_stats`. Find one: `POST https://gateway.pipeworx.io/v1/tools/search_packs` with `{"query":"..."}`.

## Standalone (no gateway account)

This package also runs as a local stdio MCP server — no Pipeworx account, no
gateway round-trip:

```json
{
  "mcpServers": {
    "estat-japan": {
      "command": "npx",
      "args": ["-y", "@pipeworx/mcp-estat-japan"]
    }
  }
}
```

Or run it directly to confirm it starts:

```bash
npx -y @pipeworx/mcp-estat-japan
```

It speaks MCP over stdin/stdout and answers `initialize`/`tools/list`/`tools/call`
for **only** this pack's tools — none of the shared meta-tools the gateway
connection above adds. Same source, same tools, no ask_pipeworx routing.

## Using with ask_pipeworx

Instead of calling tools directly, you can ask questions in plain English —
this works on the pack endpoint above as well as on the full gateway:

```
ask_pipeworx({ question: "your question about Estat Japan data" })
```

The gateway picks the right tool and fills the arguments automatically.

## More

- [Docs and guides](https://pipeworx.io/docs)
- [pipeworx.io](https://pipeworx.io)

## License

MIT