Yahoo! Finance Japan API integration & Yahoo! Finance Connect data extraction

Yahoo! Finance Connect bridge API

Authenticate the user, replay the consent dance with the linked broker (currently SBI Securities and partner channels), and stream holdings, cash_balance, and trade_history records into your backend. Use case: build a unified P/L panel that reconciles across multiple Japanese brokers in one call.

Portfolio & watchlist API

CRUD endpoints for the up-to-50-symbol portfolios — registering Japanese stocks, US stocks, ETFs, FX pairs, investment trusts, and indices. Use case: copy a customer's existing Yahoo!ファイナンス watchlist into your robo-advisor onboarding so they don't restart from zero.

Quote, chart & screener API

Pull intraday-through-all-time OHLC series, configurable moving averages, and the screener filter set (PER company forecast, PBR actual, dividend yield, market cap, shareholder benefits). Use case: feed a custom factor backtester or a Nikkei 225 dashboard.

Alerts & disclosure webhook

Subscribe to threshold alerts on price/FX/index moves and to corporate-event notifications: timely-disclosure (適時開示), 5-business-day earnings reminders, and shareholder-benefit ex-dates. Use case: route real-time signals into Slack, internal CRM, or trading-desk OMS.

Investment-trust search API

Query the fund universe by fee, dividend, trailing return, and the NAV ≥ ¥5 billion ranking pool. Use case: power a fund-comparison feature inside a fintech app or a fee-disclosure widget for advisor portals.

Bulletin-board sentiment feed

Optional ingest of public board posts per ticker for buy/sell sentiment aggregation, normalized into a tabular feed. Use case: a sentiment overlay on charts, or a narrative-risk filter for portfolio managers.

1. Multi-broker NAV reconciliation

Context: a wealth-management firm onboarding retail clients who hold accounts at SBI Securities, Rakuten Securities, and Monex Securities. Data & APIs: Yahoo! Finance Connect /holdings and /trade_history endpoints, broker-side OAuth re-authorization. OpenFinance mapping: equivalent to a regulated AISP "account information" call — we package the consent record, audit trail, and refresh logic so the firm can rebuild a unified position book nightly.

2. Tax-season transaction export

Context: a Japanese tax-prep SaaS needs annual realized-gain data per user. Data & APIs: /trade_history?from=2025-01-01&to=2025-12-31 with paging, plus per-symbol cost-basis from the portfolio module. OpenFinance mapping: mirrors a "statement download" use case — output is JSON + Excel, ready for the e-Tax filing flow and reconciled against broker-issued tokutei kouza (特定口座) summaries.

3. Real-time alert routing for an OMS

Context: a trading desk wants Yahoo!ファイナンス price alerts and timely-disclosure pings inside its OMS. Data & APIs: POST /alerts to register thresholds, plus a webhook receiver for disclosure events. OpenFinance mapping: equivalent to event-streaming patterns common in payment-initiation flows — we sign each webhook payload and provide replay endpoints for downtime catch-up.

4. Robo-advisor onboarding migration

Context: a new robo-advisor wants to bootstrap clients' watchlists from Yahoo!ファイナンス to reduce setup friction. Data & APIs: /portfolio?id=… to read existing 50-symbol lists with notes and cost basis, then map into the robo's instrument universe. OpenFinance mapping: consent-scoped read-only access; once migration completes, the consent token is revoked and a deletion log is filed.

5. Compliance & investor-education dashboards

Context: an FSA-supervised IFA monitoring suitability across client accounts. Data & APIs: /holdings + /screener (PER, PBR, yield) + corporate-event webhook to detect concentrated-position risk and material-event exposure. OpenFinance mapping: aligns with read-only "wealth aggregator" patterns that Japan's Financial Services Agency has been formalizing for electronic payment intermediary services.

1) Authorization handshake (Yahoo! JAPAN ID + broker)

POST /api/v1/yahoofinance-jp/auth/start
Content-Type: application/json

{
  "yid_session": "<encrypted YJ session token>",
  "broker": "sbi",          // sbi | rakuten | monex (deeplink)
  "scope": ["holdings","trade_history","alerts"]
}

200 OK
{
  "consent_id": "cnst_8f2a91…",
  "expires_at": "2026-07-28T09:15:00+09:00",
  "refresh_token": "rtk_…",
  "broker_link_status": "linked"
}

2) Trade-history pull (paged, JPY-normalized)

GET /api/v1/yahoofinance-jp/trade_history
  ?consent_id=cnst_8f2a91
  &from=2025-01-01&to=2025-12-31
  &page=1&page_size=200
Authorization: Bearer <ACCESS_TOKEN>

200 OK
{
  "items": [
    {
      "trade_id": "T-20251104-0001",
      "symbol": "7203.T",        // Toyota Motor
      "side": "buy",
      "qty": 100,
      "price_jpy": 2845.5,
      "fee_jpy": 99,
      "executed_at": "2025-11-04T09:00:11+09:00",
      "account_type": "tokutei"  // 特定口座
    }
  ],
  "next_cursor": "eyJwYWdlIjoyfQ=="
}

3) Price-alert webhook (signed delivery)

POST https://your-domain/webhooks/yahoofinance-jp
X-Signature: sha256=…
Content-Type: application/json

{
  "event": "price_alert.fired",
  "alert_id": "al_9921",
  "symbol": "9984.T",            // SoftBank Group
  "rule": { "op": ">=", "value": 12000 },
  "fired_at": "2026-04-28T10:02:33+09:00",
  "context": { "last": 12015, "change_pct": 1.42 }
}

// Reply 2xx within 5s; we retry with exponential backoff for 24h.

4) Screener query (factor filter)

POST /api/v1/yahoofinance-jp/screener
{
  "market": ["TSE_PRIME"],
  "per_forecast": { "max": 12 },
  "pbr_actual":   { "max": 1.0 },
  "dividend_yield_forecast": { "min": 3.5 },
  "shareholder_benefit": true,
  "min_buy_jpy":  { "max": 200000 },
  "order_by": "dividend_yield_forecast.desc",
  "limit": 50
}

200 OK
{ "items": [ { "symbol":"8316.T","name":"SMFG","yield":4.6,"per":9.2 }, … ] }

About our studio

We are an independent technical service studio specializing in App interface integration and authorized API integration, with deep hands-on experience across Japanese and international fintech. Our engineers come from banks, brokerages, payment gateways, mobile-app reverse engineering, and cloud infrastructure backgrounds, which means we can move fluently from protocol analysis to OpenAPI specification to a hardened production deployment.

• Mobile-app protocol analysis (Android & iOS), authorization-flow reverse engineering, and SDK refactoring
• OpenData, OpenFinance, OpenBanking, and Japan-specific FSA-aligned integrations
• Custom Python / Node.js / Go SDKs, OpenAPI specs, and CI test harnesses
• Two pricing models: source-code delivery from $300 (pay after delivery upon satisfaction) and pay-per-call hosted API (no upfront fee)

Contact

Ready to extract Yahoo!ファイナンス holdings, trade history, watchlists, or screener results into your stack? Send us the target app name and your concrete requirements, and we'll quote scope, timeline, and the right pricing model.

Open contact page

Engagement workflow

1. Scope confirmation: which Yahoo!ファイナンス surfaces (Connect, portfolio, screener, alerts) you need and which downstream system consumes them.
2. Authorization model: agree on Yahoo! JAPAN ID consent flow, retention rules, and the broker linkage scope (SBI / Rakuten / Monex / others).
3. Protocol analysis & API design — typically 2–5 business days.
4. Build & internal validation against fixture data — typically 3–8 business days.
5. Documentation, OpenAPI spec, sample clients, test cases — 1–2 business days.
6. First delivery in 5–15 business days; complex flows or third-party approvals can extend the timeline.

FAQ

What do you need from me to start?

How is delivery handled?

How is consent and data retention managed?