Connect J-Quants to Claude Code
Query J-Quants directly from Claude Code. Arlet links the two through one MCP connection and takes care of API keys.
This server connects your AI client to J-Quants API V2, the official market data API operated by JPX Market Innovation & Research (Japan Exchange Group). It provides pro-grade Japanese equities data collected directly from the exchange.
Key features:
- Look up listed companies (name, sector, market segment) by issue code or by company-name keyword.
- Fetch daily OHLC bars (open/high/low/close, volume, turnover, and split-adjusted figures) for any listed stock, over a date range.
- Fetch quarterly financial summaries built from TDnet earnings reports (kessan tanshin).
- Check upcoming earnings announcement dates and the trading calendar (market holidays).
Using the API requires a J-Quants account and an API key issued from the J-Quants dashboard. A free plan is available (data is delayed; paid plans unlock fresher data, longer history, and higher rate limits - the free plan allows 5 requests per minute). Set the key as JQUANTS_API_KEY in your Arlet environment variables.
How to connect J-Quants to Claude Code
- 1
In the Arlet dashboard, open Data tools, find J-Quants, set the API key issued by J-Quants and switch it on.
- 2
In your terminal, run claude mcp add --transport http arlet https://mcp.arlet.dev/mcp/ to add Arlet as an MCP server.
- 3
Start Claude Code, run /mcp, select arlet and click Authenticate.
- 4
Your browser opens. Sign in with Google and click Allow on the consent screen. The connection is complete.
The connection is per user and works across every project on the same machine.