Japanese stock data APIs compared
If you want Japanese company financials in code or in an AI assistant, there are four main options: Hachiquant, J-Quants from Japan Exchange Group, IR BANK’s IRBANK Connect and the Buffett Code API. They differ a lot in what’s free, how far back the data goes and what you have to sign up for. Everything below about the other three comes from their own sites, checked on October 17, 2026.
Side by side
| API | Free tier | Sign-up | Rate limit (free) | Financial data | Stock prices |
|---|---|---|---|---|---|
| Hachiquant | Everything is free | None. No key | 60 requests a minute for REST, 300 for MCP | Full statements for about 4,000 companies, about 10 years | No |
| J-Quants (Japan Exchange Group) | Free plan: 2 years of data, excluding the latest 12 weeks | Registration and an API key | 5 calls a minute | Summary financials on Free, Light and Standard. Full statements on Premium (¥16,500 a month) | Yes. Daily prices on every plan |
| IRBANK Connect | Free during the beta. Free members get 200 requests a day after it | Registration with name and address | 4,000 requests a day during the beta | Results, dividends and more. Same data range on every plan | Yes |
| Buffett Code API | A free test API key for trying it | Paid contract on individual request | Not published on its pricing page | Quarterly statements and price-based ratios | Price-based ratios |
Hachiquant
Hachiquant’s REST API and MCP server are free and open: no account and no key, just a per-minute rate limit. It returns full income statements, balance sheets and cash flow statements, with each series kept on one accounting standard and each figure traceable to its source filing. The docs and an OpenAPI schema are at /docs. It has no prices, forecasts or dividend data.
J-Quants
J-Quants is run by Japan Exchange Group, so it’s the official source for exchange data such as prices. Its free plan covers 2 years of data, excluding the latest 12 weeks, at 5 calls a minute, with listed companies, daily prices and summary financials. Paid plans were ¥1,650 (Light, 5 years), ¥3,300 (Standard, 10 years) and ¥16,500 a month (Premium, 20 years and full financial statements). It also has an MCP option and CSV downloads on paid plans. If you need prices with your fundamentals, start here.
IRBANK Connect
IR BANK added an API and an MCP server in 2026. During the beta they are free for users who register with their name and address, with 4,000 requests a day shared between the two. Its documentation lists 200 requests a day for free members after the beta, 1,000 for Standard and 4,000 for the top plan, with the same data range on every plan. Its guide says commercial use isn’t allowed for now.
Buffett Code API
Buffett Code’s Web API is a paid feature offered to members who ask for it individually. It covers quarterly statements and daily price-based ratios. A free test API key is available for trying it.
Which one should you use?
- Free full statements with no sign-up, or an MCP server for an AI assistant: Hachiquant.
- Official prices along with fundamentals: J-Quants.
- Dividends through an API, for non-commercial use: IRBANK Connect.
- A commercial contract with long history and support: the Buffett Code API.
FAQ
Is there a free API for Japanese company financial statements?
Yes. Hachiquant’s API is free with no key. J-Quants has a free plan with summary financials and 2 years of data, excluding the latest 12 weeks. IRBANK Connect is free during its beta for registered users.
Which API has Japanese stock prices?
J-Quants, run by Japan Exchange Group, has daily prices on every plan, including the free one. Hachiquant doesn’t have prices.
Can I use these APIs with ChatGPT or Claude?
Hachiquant has a free remote MCP server at https://hachiquant.com/mcp that needs no key. J-Quants and IRBANK Connect also offer MCP access. Check each one’s terms for what you may do with the data.
J-Quants https://jpx-jquants.com/ ; IRBANK Connect https://irbank.net/article/irbank/irbankconnect-release/ and https://docs.irbank.net/getting-started/plans ; Buffett Code https://www.buffett-code.com/pricing. Checked October 17, 2026. Plans change, so check each site before you build on it.