Switchwon (스위치원) API integration & OpenFinance services

Authorized login & session bridge

We mirror the Switchwon authorization handshake — device pairing, OTP confirmation, and the app-to-bank linkage used for KRW transfers. The bridge refreshes tokens, rotates device fingerprints, and exposes a single /auth/session endpoint for downstream services. A concrete use case: an accounting SaaS can use one endpoint to keep a ledger sync running for 500 corporate users without re-prompting OTP.

FX transaction history API

Every executed FX order is surfaced with the interbank reference rate, the 환율우대 100% preferential-rate margin, cut-off timestamps (Asia/Seoul), and the internal 체결번호 settlement id. This supports reconciliation against Woori, KEB Hana, and KB Kookmin settlement files on T+1.

Auto-exchange rule export

Read each target-rate rule (trigger currency pair, threshold, max notional, expiry) and its lifecycle events — ARMED, FIRED, EXPIRED, CANCELLED. A treasury desk can feed these into risk dashboards to compare intended rate triggers against realized mid-market at fill time.

Metal holdings & withdrawal state

Gold, silver, and copper positions are exposed with the gram-level unit cost basis, KRX quote at fill, and the current custody state (held vs withdrawn). Because Korean tax rules only levy 10% VAT on physical withdrawal, the withdrawal flag drives the downstream tax-lot engine directly.

Widget & mission events

The home-screen FX-rate widget issues a refresh ping; we expose those snapshots as a rate time series. The daily-mission flow that accrues USD rewards is exposed as a reward-event stream with mission id, accrual amount, and credit timestamp — useful for loyalty analytics and anti-abuse rule engines.

SwitchFlow corporate feed

For enterprise clients of Switchwon's B2B product SwitchFlow, we mirror the 50+ currency dashboard, AI market commentary digest, and the corporate hedging plan. This lets a CFO's ERP receive a daily AI forex briefing as a structured JSON payload rather than a screenshot.

1. Treasury reconciliation for an import-export SME

Business context: A Seoul-based importer runs USD invoicing and wants to tie every Switchwon KRW→USD conversion to the matching supplier PO in ERP.

Data involved: FX transaction history API, auto-exchange rule export, and the bank-linkage settlement id.

OpenData / OpenFinance mapping: The Switchwon ledger becomes another aggregated data source in the MyData 2.0 batch-inquiry flow, joined with Woori or KEB Hana corporate banking data for end-to-end trace.

2. Unified investor dashboard across FX and metals

Business context: A Korean robo-advisor wants a single portfolio view that merges Switchwon currency holdings, Switchwon gold/silver/copper lots, and a user's domestic brokerage positions.

Data involved: Portfolio snapshot API, metal custody flag (to split taxable vs deferred lots), and KRX price feed.

Mapping: The integration surfaces a normalized positions[] array aligned with the MyData financial investment category, so other Open Finance dashboards can render Switchwon alongside NH, Mirae Asset, or Samsung Securities data.

3. Compliance & audit pipeline

Business context: A mid-sized exporter must produce a monthly foreign-exchange declaration under Korea's Foreign Exchange Transactions Act.

Data involved: FX ledger export with 체결번호, counterparty bank, transferred currency, and notional.

Mapping: The exporter-side system joins Switchwon's per-order ledger with internal approvals and emits a signed declaration file — the data minimization and retention rules we apply line up with Korea's Personal Information Protection Act (PIPA).

4. AI forex research on top of SwitchFlow

Business context: A corporate treasury team subscribes to SwitchFlow's AI market briefings and wants them ingested into an internal LLM research agent.

Data involved: SwitchFlow corporate feed (50+ currency quotes, AI commentary, hedge plan recommendations).

Mapping: We turn the daily briefing into a machine-readable payload with indicators[], narrative, and hedging_actions[] so it can be consumed by vector search and scheduled agent runs.

5. Tax-aware metals withdrawal flow

Business context: A precious-metal investor plans to physically withdraw 50g of gold and needs to know the VAT exposure before confirming.

Data involved: Metal holdings API with per-lot cost basis, custody flag, and the current KRX bid.

Mapping: The integration computes the 10% VAT trigger instant and returns a pre-trade cost breakdown — this mirrors the KRX gold spot market's tax-free-until-withdrawal rule and keeps the downstream finance team compliant with Korean tax law.

Deliverables checklist

• OpenAPI 3.1 specification for every Switchwon endpoint we surface
• Protocol & auth-flow report (device pairing, OTP, token rotation, bank linkage)
• Runnable Python / Node.js / Go source with retries, pagination, and idempotency keys
• Postman collection, pytest or jest suite, and sample fixtures
• Compliance appendix (Korea PIPA, MyData 2.0, KRX rules, foreign-exchange declaration)
• Deployment notes for Docker and typical Korean cloud setups (NHN, Naver Cloud, AWS Seoul)

API example — FX ledger query

POST /api/v1/switchwon/fx/transactions
Content-Type: application/json
Authorization: Bearer <ACCESS_TOKEN>
X-Idempotency-Key: 2026-04-24T09:00-acct-87a2

{
  "account_id": "swon_usr_8f21",
  "base": "KRW",
  "quotes": ["USD","JPY","EUR","CNY"],
  "from": "2026-03-01",
  "to":   "2026-03-31",
  "page_size": 200
}

200 OK
{
  "items": [{
    "order_id": "swon_fx_0001823",
    "settlement_id": "20260312-KRW-USD-00927",
    "pair": "KRW/USD",
    "executed_rate": 1367.12,
    "reference_rate": 1367.80,
    "preferential_margin_bps": 50,
    "notional_krw": 2000000,
    "executed_at": "2026-03-12T04:11:28+09:00"
  }],
  "next_cursor": "eyJwYWdlIjoyfQ=="
}

API example — auto-exchange rule stream

GET /api/v1/switchwon/auto_exchange/rules?state=FIRED
Authorization: Bearer <ACCESS_TOKEN>

200 OK
{
  "rules": [{
    "rule_id": "swon_rule_1142",
    "pair": "KRW/JPY",
    "threshold": 9.12,
    "direction": "AT_OR_BELOW",
    "max_notional_krw": 3000000,
    "state": "FIRED",
    "armed_at":  "2026-04-14T20:05:00+09:00",
    "fired_at":  "2026-04-22T11:42:19+09:00",
    "fill": { "rate": 9.11, "notional_krw": 3000000 }
  }]
}

API example — metals holdings webhook

POST https://your-endpoint/hooks/switchwon/metals
X-Switchwon-Signature: sha256=...

{
  "event": "metal.position.updated",
  "account_id": "swon_usr_8f21",
  "metal": "GOLD",
  "lot_id": "swon_lot_g_0451",
  "grams": 12.5,
  "unit_cost_krw": 109230,
  "krx_reference_krw": 110040,
  "custody_state": "HELD",
  "vat_trigger": false,
  "occurred_at": "2026-04-23T15:02:10+09:00"
}

// On ack the downstream tax-lot engine updates its cost basis and
// recomputes the VAT exposure if custody_state transitions to WITHDRAWN.

Compliance & privacy

Every Switchwon integration we build is scoped to explicit end-user authorization and to data categories covered under Korea's Personal Information Protection Act (PIPA) and the Credit Information Use and Protection Act. For 2024 and 2025 projects we also align with MyData 2.0, announced by the Financial Services Commission in April 2024, which introduces batch-inquiry semantics, extended subscription validity, and clearer rules for data integration across financial institutions.

On the precious-metals side, custody and VAT handling follow the KRX gold spot market rules: positions are tax-free while held on-exchange and a 10% VAT is triggered on physical withdrawal. Our integrations propagate the custody flag so downstream systems can never under-report the event. Cross-border USD/JPY/EUR/CNY flows are logged in line with the Foreign Exchange Transactions Act, and for European connectivity we follow the PSD2 SCA posture when needed.

We apply data minimization, purpose binding, and retention limits. No screenshot scraping, no unauthorized reverse engineering; our work is explicit protocol analysis under a written scope agreement, and we sign NDAs when requested.

Data flow / architecture

The reference pipeline is straightforward:

• Client App — Switchwon iOS / Android with user-granted authorization
• Integration gateway — our managed API bridge handles session refresh, retries, and rate limiting
• Normalized storage — PostgreSQL or BigQuery with the MyData-compatible schema (accounts, positions, transactions, events)
• Downstream output — REST API, webhooks, scheduled CSV drops, or a direct push into customer ERP / BI (Tableau, Looker, Metabase)

Average end-to-end latency for a single statement query is under 2 seconds, and webhook delivery is retried with exponential backoff and a dead-letter queue.

Travel Wallet

A Korean mobile-first multi-currency prepaid card that solved offline exchange fees. Users combining Travel Wallet and Switchwon often want a single travel-vs-investment split in one dashboard.

Cashmallow

An inbound / outbound currency-exchange app popular with travelers in Asia. Treasury teams integrating both platforms usually look for a unified per-user conversion history across travel and savings flows.

Toss

The flagship Korean super-app for transfers, investing, and MyData. Switchwon FX transactions are a natural complement to Toss account balances and cards when building a consolidated PFM view.

Kakao Pay

A payments and overseas-remittance wallet embedded in Kakao. Users often pair Kakao Pay remittance receipts with Switchwon currency conversions to trace inbound FX end-to-end.

Naver Pay

Korea's other dominant fintech wallet. Merchants reconciling KRW settlements with imported inventory bought in USD often combine Naver Pay flows with Switchwon's USD ledger.

Wise

A global cross-border transfer leader with transparent mid-market rates. Switchwon users sending funds abroad frequently need Wise + Switchwon conversion trails reconciled in one report.

Revolut

A multi-currency neobank serving EU, UK, and parts of APAC. Korean residents with a Revolut account alongside Switchwon often request a single wallet snapshot across both platforms.

Monzo

A UK neobank with strong spending analytics. Integration teams sometimes join Monzo category-tagged spend with Switchwon FX rates to get a true-cost view of overseas purchases.

한국금거래소 (Korea Gold Exchange)

A long-established Korean precious-metals operator and KRX-member app. Investors tracking gold lots in both 한국금거래소 and Switchwon frequently want a combined grams-held view.

Hana Bank

A top-tier Korean commercial bank offering FX services. Treasury desks often join Hana's bank-side transfer records with Switchwon's preferential-rate conversions for audit and reporting.

About our studio

We are an independent technical services studio focused on authorized App interface integration and OpenData-style protocol analysis. Our engineers come from Korean and international banks, payment gateways, and cloud infra teams, so we can move quickly across Korean fintech ecosystems such as Switchwon, Toss, Kakao Pay, and Naver Pay.

• Retail and corporate FX, digital wallets, metals, and investment platforms
• Enterprise API gateways, webhook fan-out, and security reviews
• Python / Node.js / Go SDKs with typed models and fixture-based tests
• Full pipeline: scope → protocol analysis → implementation → QA → compliance sign-off
• Source code delivery from $300 — runnable API source code plus documentation; you pay after delivery upon satisfaction.
• Pay-per-call API billing — access our hosted endpoints and pay only per call, no upfront cost; ideal for usage-based pricing.

Contact

To request a quote or submit your target app and requirements, open our contact page. Share the data scope (e.g. FX ledger + metals holdings), the expected monthly call volume, and any existing sandbox credentials you can provide.

Contact page

For Switchwon engagements specifically, we recommend sending over the exact data points you need (e.g. 환율우대 margin, auto-exchange rule lifecycle, metals custody flag) so we can quote turnaround and pricing accurately.

Engagement workflow

1. Scope confirmation — integration scenarios, data points, auth posture, compliance frame.
2. Protocol analysis & API design — usually 2–5 business days depending on depth.
3. Implementation & internal validation — typically 3–8 business days for a Switchwon scope.
4. Docs, sample code, Postman collection, and automated test suite — 1–2 business days.
5. Handover, walk-through, and optional on-call support window.
6. Typical first delivery: 5–15 business days; regulated approvals or multi-platform scopes can extend this.

FAQ

What do you need from me?

How long does a Switchwon-style delivery take?

How do you handle compliance for Korean financial data?

Can you deliver only the API, not the source?