Japan Jepx MCP

What japan-jepx-mcp does

The japan-jepx-mcp MCP server exposes Japanese wholesale electricity spot prices from JEPX through Model Context Protocol tools. Coverage includes the nationwide system price and nine regional areas: Hokkaido, Tohoku, Tokyo, Chubu, Hokuriku, Kinki, Chugoku, Shikoku, and Kyushu. The area catalogue accepts both romanized names and kanji, including tokyo and 東京.

Prices are reported in JPY/kWh at 30-minute resolution, with 48 periods in a trading day. The available data supports current-price checks, complete day-level curves, daily-average history, low-price slot searches, area comparisons, and metadata lookup.

How it works

The server attempts to retrieve current settlement data from JEPX.org. If that site cannot be reached because of IP restrictions, responses can fall back to the bundled data/jepx_spot.json seed cache. The cache contains approximately 400 days of data with 48 periods per day, providing offline or fallback coverage.

Regional price deltas use OCCTO area-price forecast data. Source attribution identifies JEPX settlement prices and OCCTO forecasts, and the README states that the data is available under Government Standard Terms of Use with attribution.

The same data functions are also available through REST endpoints when the OpenAPI gateway is used. These include routes for the latest value, a date-specific curve, history, cheapest results, area metadata, and the OpenAPI document.

Setup and configuration

Run the local stdio server with:

uv run --directory . src/stdio_main.py

The documented local command is suitable for MCP clients such as Claude Desktop and Cursor. A REST-only smoke test can use the seed data by setting JEPX_DATA_DIR:

JEPX_DATA_DIR=/tmp/jepx-smoke python3 smoke_rest.py

The project also documents Smithery installation for Claude, Cursor, VS Code, and Cline. The command uses the Smithery CLI and accepts the relevant client name. A managed deployment is available as an Apify Actor in Standby mode, with the MCP path configured as /mcp.

Tools and capabilities

The japan-jepx-mcp MCP server provides five tools:

• get_latest_spot_price returns the latest price for an area and defaults to Tokyo.
• get_spot_price_by_day returns all 48 half-hour periods for a date, plus minimum, maximum, and average values.
• get_spot_price_history returns daily minimum, maximum, and average statistics over a requested window.
• get_cheapest_spot finds the least expensive half-hour slots or ranks areas by price.
• list_spot_areas lists supported areas, the unit, and the latest available date.

REST clients can use /rest/latest, /rest/date, /rest/history, /rest/cheapest, and /rest/areas. The /openapi.json route provides the API description.

Limitations and notes

Prices represent JEPX spot settlement data rather than retail electricity tariffs. The server uses 30-minute periods and reports JPY/kWh, so applications should account for their own contract terms, charges, and scheduling constraints. Live retrieval is not guaranteed when the source site restricts access; in that case, answers may come from the bundled seed cache. The README does not specify a required environment variable for the stdio server.