CPU Payer (WAX only)

On WAX, Alcor pays the CPU of transactions that interact with its contracts. The transaction starts with a liquid.alcor::noop action authorized by liquid.alcor@bw; with ONLY_BILL_FIRST_AUTHORIZER, the chain bills the CPU to that first authorizer instead of the user. The service only cosigns: the user still signs the transaction, and the client pushes it.

How it worksCopy Anchor Link

1. Call Status to see whether the service is signing.
2. Build the transaction with liquid.alcor::noop as the first action, authorized by liquid.alcor@bw, followed by the user's actions.
3. The user signs the transaction.
4. Send the serialized transaction to Cosign. The service checks it and returns its signature.
5. Push the transaction with both signatures. The CPU is billed to liquid.alcor.

StatusCopy Anchor Link

Whether the service is up and signing, and how much of its CPU is used.

POST https://wax.alcor.exchange/api/v2/cpu/status

Example

curl -X POST https://wax.alcor.exchange/api/v2/cpu/status

{
  "available": true,
  "signing": true,
  "throttled": false,
  "cpu": {
    "used": 2988810,
    "max": "13859878911",
    "percent": 0.0215
  },
  "lastCheck": 1792068283798
}

Response fields

cpu and lastCheck are null until the first check.

CosignCopy Anchor Link

Checks a transaction and signs it as liquid.alcor@bw.

POST https://wax.alcor.exchange/api/v2/cpu/cosign

Request body

Example

curl -X POST https://wax.alcor.exchange/api/v2/cpu/cosign \
  -H "Content-Type: application/json" \
  -d '{"serializedTransaction": "<hex>"}'

Answers HTTP 201:

{
  "signature": "SIG_K1_..."
}

Checks

• The first action is liquid.alcor::noop, authorized by liquid.alcor@bw.
• Every other action is either an action of an allowed contract, or a transfer to one: alcordexmain (spot DEX), swap.alcor (AMM), otc.alcor and alcorotcswap (OTC), liquid.alcor.
• The user is the first authorizer of the second action. Rate limits count per user account and per IP.

A transaction that fails a check, or goes over a limit, answers HTTP 400 with {"error": "<message>"}, for example:

• First action must be noop from payer
• Contract <account> is not allowed
• Transfer recipient <account> is not allowed
• Hourly IP limit exceeded
• Daily account limit exceeded

Rate limitsCopy Anchor Link