jquants-mcp

A Claude Code add-on for Japanese stock-market data through the J-Quants API. It covers shares, financial reports, indexes, derivatives, margin and short-selling data, market screeners, technical indicators, and chart data, with a local SQLite cache.

In plain words
What is it for?
Use it to query Japanese equities and financials, screen the market, inspect trading and derivatives data, calculate or retrieve technical indicators, and obtain chart-ready JSON.
Why use it?
It brings many Japanese-market datasets into the coding agent and can reuse locally cached data. J-Quants is the data service that supplies the Japanese market information.

Plugin for Claude Code

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Claude Code
/plugin marketplace add shigechika/jquants-mcp
agentmods
npx agentmods add plugins/shigechika/jquants-mcp/plugin
Clone the repo
git clone --depth 1 https://github.com/shigechika/jquants-mcp

Made for: Claude Code.

Per session not measured What this adds to a session before it is invoked.
When invoked not measured Not applicable: nothing here is loaded into a session.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Security

Grade A, and why

jquants-mcp scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured yesterday.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

plugin/.claude-plugin/plugin.json · 23 lines

What it actually says

{
  "$schema": "https://json.schemastore.org/claude-code-plugin-manifest.json",
  "name": "jquants-mcp",
  "displayName": "J-Quants MCP",
  "description": "Japanese stock market data via J-Quants API v2, for Claude Code. 55 tools covering equities, financials, indices, derivatives, margin/short-selling data, market-wide screeners, technical indicators, and JSON chart data, backed by a local SQLite cache. Zero-config on a machine that already runs jquants-api-client (auto-reads ~/.jquants-api/jquants-api.toml); otherwise run `jquants-mcp login` or set JQUANTS_API_KEY.",
  "author": {
    "name": "AIKAWA Shigechika",
    "url": "https://github.com/shigechika"
  },
  "homepage": "https://shigechika.github.io/jquants-mcp/",
  "repository": "https://github.com/shigechika/jquants-mcp",
  "license": "MIT",
  "keywords": [
    "jquants",
    "stocks",
    "japan",
    "market-data",
    "finance",
    "trading",
    "screener"
  ]
}
Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. yesterday First seen · 23 lines scan A ce3151653abb

Subscribe to this mod's changes

jquants-mcp is a plugin published in the GitHub repository shigechika/jquants-mcp (2 stars, last pushed 10d ago), licensed MIT. Its token cost is not measured: this kind of file is read by the harness, not the model. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.