Trading APIs — Underlying (Stocks)

Place, amend, and cancel stock orders. Every call requires the access_token from B1 (Authentication — Underlying). POST, PUT, and DELETE calls additionally require x-otp-token, x-lang, and x-via headers.

Authentication: Requires Authorization: Bearer <access_token> from B1. POST/PUT/DELETE also require x-otp-token: 552066a35eb30a9815afc952b14287a8 (sandbox fixture), x-lang: vi, x-via: K.

C1. Place Order (Underlying)

Submits a new stock order for a sub-trading account. POST /accounts/:accountId/orders/underlying

Sandbox URL

https://flashapi.phs.vn/sandbox/oapi/accounts/:accountId/orders/underlying

Parameters

Location	Name	Required	Description
path	accountId	Yes	Sub trading account ID.
body	instrument	Yes	Instrument code. Example: ACB
body	qty	Yes	Order quantity. Example: 1
body	side	Yes	Order side. Example: buy
body	type	Yes	Order type. Example: LO
body	limitPrice	Yes	Limit price. Example: 23000
body	timetype	Yes	Time-in-force. Example: T

Example Request (cURL against Sandbox)

curl -X POST "https://flashapi.phs.vn/sandbox/oapi/accounts/$ACCOUNT_ID/orders/underlying" \
  -H "Authorization: Bearer $ACCESS_TOKEN" \
  -H "Content-Type: application/json" \
  -H "x-lang: vi" -H "x-via: K" \
  -H "x-otp-token: 552066a35eb30a9815afc952b14287a8" \
  -d '{ "instrument": "ACB", "qty": 1, "side": "buy", "type": "LO",
        "limitPrice": 23000, "timetype": "T" }'

Example Sandbox Response

{ "s": "ok", "d": { "orderid": "8000180326000219" } }

Sandbox behavior: Sandbox validates that all required fields are present and correctly typed, and requires the same headers as Production, but no real order reaches the exchange. Every successful call returns a fixed example order ID. In place of a one-time password sent to your phone, sandbox accepts the fixed fixture OTP token documented on this page — send that exact string in x-otp-token.

C2. Update Order (Underlying)

Amends quantity and/or limit price on an existing, still-eligible stock order. PUT /accounts/:accountId/orders/underlying/:orderId

Sandbox URL

https://flashapi.phs.vn/sandbox/oapi/accounts/:accountId/orders/underlying/:orderId

Parameters

Location	Name	Required	Description
path	accountId	Yes	Sub trading account ID.
path	orderId	Yes	Order ID to update.
body	qty	Yes	Updated order quantity.
body	limitPrice	Yes	Updated limit price.

Example Request (cURL against Sandbox)

curl -X PUT "https://flashapi.phs.vn/sandbox/oapi/accounts/$ACCOUNT_ID/orders/underlying/$ORDER_ID" \
  -H "Authorization: Bearer $ACCESS_TOKEN" \
  -H "Content-Type: application/json" \
  -H "x-lang: vi" -H "x-via: K" \
  -H "x-otp-token: 552066a35eb30a9815afc952b14287a8" \
  -d '{ "qty": 1, "limitPrice": 23000 }'

Example Sandbox Response

{ "s": "ok" }

Sandbox behavior: Sandbox validates that all required fields are present and correctly typed, and requires the same headers as Production, but no real order reaches the exchange. Every successful call returns a fixed example order ID. In place of a one-time password sent to your phone, sandbox accepts the fixed fixture OTP token documented on this page — send that exact string in x-otp-token.

C3. Cancel Order (Underlying)

Cancels an existing, unfilled stock order. DELETE /accounts/:accountId/orders/underlying/:orderId?timeType=T&isbuyin=N

Sandbox URL

https://flashapi.phs.vn/sandbox/oapi/accounts/:accountId/orders/underlying/:orderId?timeType=T&isbuyin=N

Parameters

Location	Name	Required	Description
path	accountId	Yes	Sub trading account ID.
path	orderId	Yes	Order ID to cancel.
query	timetype	Yes	Time-in-force. Example: T
query	isbuyin	Yes	Buy-in flag. Example: N

Example Request (cURL against Sandbox)

curl -X DELETE "https://flashapi.phs.vn/sandbox/oapi/accounts/$ACCOUNT_ID/orders/underlying/$ORDER_ID?timeType=T&isbuyin=N" \
  -H "Authorization: Bearer $ACCESS_TOKEN" \
  -H "x-lang: vi" -H "x-via: K" \
  -H "x-otp-token: 552066a35eb30a9815afc952b14287a8"

Example Sandbox Response

{ "s": "ok" }

Sandbox behavior: Sandbox validates that all required fields are present and correctly typed, and requires the same headers as Production, but no real order reaches the exchange. Every successful call returns a fixed example order ID. In place of a one-time password sent to your phone, sandbox accepts the fixed fixture OTP token documented on this page — send that exact string in x-otp-token.

C4. Get Underlying Buying Power

Returns available buying power for a stock, given a proposed order price. GET-only — no x-otp-token needed. GET /accounts/:accountId/underlying/buyingPower

Sandbox URL

https://flashapi.phs.vn/sandbox/oapi/accounts/:accountId/underlying/buyingPower

Parameters

Location	Name	Required	Description
path	accountId	Yes	Trading account ID.
query	symbol	Yes	Stock symbol. Example: VIC
query	quotePrice	Yes	Order price used to calculate buying power. Example: 222000

Example Request (cURL against Sandbox)

curl "https://flashapi.phs.vn/sandbox/oapi/accounts/$ACCOUNT_ID/underlying/buyingPower?symbol=VIC&quotePrice=222000" \
  -H "Authorization: Bearer $ACCESS_TOKEN"

Example Sandbox Response

{ "s": "ok", "d": [ { "ppse": 0, "maxqty": -1, "allowance": 16, "blocked": 0 } ] }

Sandbox behavior: Sandbox returns one fixed example record for any accountId you pass, so you can validate field names and data types before pointing your integration at Production, where the data reflects the real account.

API documentation

Terms and conditions

Trading APIs — Underlying (Stocks)

C1. Place Order (Underlying)

Sandbox URL

Parameters

Example Request (cURL against Sandbox)

Example Sandbox Response

C2. Update Order (Underlying)

Sandbox URL

Parameters

Example Request (cURL against Sandbox)

Example Sandbox Response

C3. Cancel Order (Underlying)

Sandbox URL

Parameters

Example Request (cURL against Sandbox)

Example Sandbox Response

C4. Get Underlying Buying Power

Sandbox URL

Parameters

Example Request (cURL against Sandbox)

Example Sandbox Response

​C1. Place Order (Underlying)

​Sandbox URL

​Parameters

​Example Request (cURL against Sandbox)

​Example Sandbox Response

​C2. Update Order (Underlying)

​Sandbox URL

​Parameters

​Example Request (cURL against Sandbox)

​Example Sandbox Response

​C3. Cancel Order (Underlying)

​Sandbox URL

​Parameters

​Example Request (cURL against Sandbox)

​Example Sandbox Response

​C4. Get Underlying Buying Power

​Sandbox URL

​Parameters

​Example Request (cURL against Sandbox)

​Example Sandbox Response

C1. Place Order (Underlying)

Sandbox URL

Parameters

Example Request (cURL against Sandbox)

Example Sandbox Response

C2. Update Order (Underlying)

Sandbox URL

Parameters

Example Request (cURL against Sandbox)

Example Sandbox Response

C3. Cancel Order (Underlying)

Sandbox URL

Parameters

Example Request (cURL against Sandbox)

Example Sandbox Response

C4. Get Underlying Buying Power

Sandbox URL

Parameters

Example Request (cURL against Sandbox)

Example Sandbox Response