Toss Invest | emulate

Emulates all 41 operations of the Toss Invest Open API. Accounts, holdings, orders, and conditional orders are stateful; market and reference data are generated deterministically from the seeded prices.

Included now:

POST /oauth2/token (client credentials; form body or HTTP Basic). Issuing a new token revokes the previous one (token-revoked).
Market data: /api/v1/prices, /orderbook, /trades, /price-limits, /candles
Stock info: /api/v1/stocks, /stocks/all, warnings, and KR investor trends
Market info: exchange rate, KR/US market calendars, rankings, market indicators
Sectors: list, rankings, detail, member stocks and ETFs
Accounts: /api/v1/accounts, /api/v1/holdings
Orders: create, modify, cancel, list (OPEN / CLOSED with cursor), detail
Conditional orders (SINGLE / OCO / OTO): create, list, detail, modify, delete
Buying power, sellable quantity, commissions
Emulator control: POST /_emulator/prices moves a price, filling resting limit orders and firing conditional orders

Account-scoped endpoints need the X-Tossinvest-Account: <accountSeq> header. Responses are wrapped in { "result": ... }; errors are { "error": { "requestId", "code", "message", "data"? } }. The exception is POST /oauth2/token, which answers in the plain OAuth2 shape ({ "access_token", "token_type", "expires_in" }, or { "error", "error_description" }).

Start

# From this repo (after `bun install && bun run build`)
bun packages/emulate/dist/index.js --service tossinvest

# Or from the published package
npx @pleaseai/emulate --service tossinvest

A single service starts on the base port (default 4000). Use -p <port> to change it. When started alongside other services, ports are assigned sequentially from the base port.

Auth

curl -X POST http://localhost:4000/oauth2/token \
  -d grant_type=client_credentials \
  -d client_id=tsck_example_client_id \
  -d client_secret=tsck_example_client_secret

Trading Example

# Current price
curl "http://localhost:4000/api/v1/prices?symbols=005930" \
  -H "Authorization: Bearer <access_token>"

# Market buy; fills immediately at the current price
curl -X POST http://localhost:4000/api/v1/orders \
  -H "Authorization: Bearer <access_token>" \
  -H "X-Tossinvest-Account: 1" \
  -H "content-type: application/json" \
  -d '{"symbol":"005930","side":"BUY","orderType":"MARKET","quantity":"10"}'

# Move the price to fill a resting limit order
curl -X POST http://localhost:4000/_emulator/prices \
  -H "content-type: application/json" \
  -d '{"symbol":"005930","price":70000}'

Seed Config

Add a tossinvest: section to emulate.config.yaml (or pass --seed <file>):

tossinvest:
  holidays: # optional; a listed country (KR or US) replaces its built-in 2026 holiday set; null or [] clears it
    KR: [2026-05-05, 2026-10-09]
    US: [2026-07-03]
  clients:
    - client_id: tsck_example_client_id
      client_secret: tsck_example_client_secret
      name: Demo App
  stocks:
    - symbol: '005930'
      name: 삼성전자
      market: KOSPI
      price: 72000
  accounts:
    - account_seq: 1
      cash:
        krw: 10000000
        usd: 10000
      commission:
        kr: '0.00015'
        us: '0.001'
        kr_start_date: 2026-01-01 # KR startDate in GET /commissions
      holdings:
        - symbol: '005930'
          quantity: 100
          average_price: 65000