Void round

Live

POST{base}/api/void

Some providers use VOID instead of a cancel. The round is cancelled for good and is not expected to reopen. The round's net is bet_amount minus payout_amount, already computed for you in amount and direction. Apply it as given.

Process the whole txns[] batch in one DB transaction (atomic) — if any txn fails, roll back the batch and reply an error with balance_before == balance_after

If the same txn_id arrives again, do not apply it a second time; reply the current balance with code 0, or reply 20002. The only exception is a transaction that follows a /rollback of that round: it carries a corrected result and must be applied (see "re-settle after rollback" on the Contract page).

A 0 amount is real — a feature spin, a bought feature, a tip, or a stake the provider could not supply. Do not reject it: process it as a zero-value transaction and reply code 0 without moving the balance.

BY_TRANSACTION acts on this txn_id only. BY_ROUND acts on every bet in the same round_id at once, and amount is the round's combined total.

Always reply HTTP 200 even for business errors

⚠ Net semantics: one txn covers the whole round (stake returned + payout clawed back together) — best-system computes the direction: an un-settled round → payout 0 → net = stake back (CREDIT); an already-won round → usually DEBIT. Only apply amount in the given direction.

Headers

Field	Type	Required	Description
X-Api-Key	string	Yes	The API key best-system issued to you (verify it matches)
X-Signature	string	Yes	hex(HMAC-SHA256(secret, raw body)) — verify against the raw bytes, never re-serialize. Mismatch → code 30002

Request bodyapplication/json

Field	Type	Required	Description
request_id	string	Yes	Id of this request
player_username	string	Yes	The player's username on your system
currency	string	Yes	The player's currency code in ISO 4217, e.g. THB
product_code	string	—	Game-provider code (e.g. PGSOFT)
timestamp	number	Yes	Send time in unix milliseconds
txns	object[]	Yes	Void txns — amount = \|bet_amount − payout_amount\| (the round's net effect); the sign lives in direction
└ txn_id	string	Yes	Transaction ID. Used as the idempotency key (see the notes)
└ round_id	string	Yes	Round ID
└ amount	number	Yes	Amount for this transaction, never negative and may be 0 (see the notes). Direction comes from the endpoint or the direction field
└ game_code	string	—	Game code
└ is_feature	boolean	—	Whether this is a free or feature spin. Absent means false
└ status	string	—	Vendor bet status. Always VOIDOPEN \| WAITING \| SETTLED \| REFUND \| REJECT \| ROLLBACK \| VOID \| TIPS
└ play_info	string	—	The player's position or choice, e.g. player/banker, or the game name. `UNKNOWN` means the provider could not identify it — display only
└ transaction_type	string	—	Either BY_TRANSACTION or BY_ROUND (see the notes)BY_TRANSACTION \| BY_ROUND
└ ref_txn_id	string	Yes	txn_id of the source txn of the round being voided — not found → reply 20001
└ direction	string	Yes	The net direction best-system already computed (bet_amount − payout_amount ≥ 0 → CREDIT, negative → DEBIT) — just apply it, never recomputeDEBIT \| CREDIT
└ bet_amount	number	—	Net component: the round's stake (informational — the value to apply is amount)
└ payout_amount	number	—	Net component: the round's previously paid payout (informational)

Request example

{
  "request_id": "3b2a1908-c7d6-4e5f-8a9b-0c1d2e3f4a5b",
  "player_username": "foobar",
  "currency": "THB",
  "timestamp": 1783236605000,
  "txns": [
    {
      "txn_id": "T-003",
      "round_id": "R-1",
      "amount": 300,
      "is_feature": false,
      "ref_txn_id": "T-002",
      "direction": "DEBIT",
      "bet_amount": 200,
      "payout_amount": 500
    }
  ]
}

Expected Response

Fields in data

Field	Type	Required	Description
code	number	Yes	0 = success · see the Seamless codes page
request_id	string	Yes	Echoed from the request
username	string	Yes	Echo of player_username (defensive)
currency	string	Yes	Echoed from the request
balance_before	number	Yes	Balance before processing the whole txns[] batch
balance_after	number	Yes	Balance after processing the whole batch
timestamp	number	Yes	When you processed it (unix ms)

Response example

{
  "code": 0,
  "request_id": "3b2a1908-c7d6-4e5f-8a9b-0c1d2e3f4a5b",
  "username": "foobar",
  "currency": "THB",
  "balance_before": 1300,
  "balance_after": 1000,
  "timestamp": 1783236605097
}

Possible error codes

code	Name	HTTP	Message
10001	SEAMLESS_USER_NOT_FOUND	200	Player not found on the agent system
10002	SEAMLESS_INSUFFICIENT_BALANCE	200	Insufficient balance for the debitWhen direction = DEBIT and the balance cannot cover it
20001	SEAMLESS_TXN_NOT_FOUND	200	Referenced transaction (ref_txn_id) not found
20002	SEAMLESS_DUPLICATE_TXN	200	Duplicate transaction (txn_id already processed)
30002	SEAMLESS_INVALID_SIGNATURE	401	Invalid X-Signature
40003	SEAMLESS_FORBIDDEN	200	Forbidden (api-key/IP)
50001	SEAMLESS_INTERNAL_ERROR	200	Internal error on the agent system