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POST
/
prepare-transactions
/
approve
approve
curl --request POST \
  --url https://api.sandbox.brickken.com/prepare-transactions/approve \
  --header 'Content-Type: application/json' \
  --header 'x-api-key: <api-key>' \
  --data '
{
  "method": "approve",
  "signerAddress": "0x742d35Cc6634C0532925a3b8D4C9db96c4b4d8b",
  "chainId": "aa36a7",
  "tokenSymbol": "USDT",
  "spenderAddress": "0x3333333333333333333333333333333333333333",
  "amount": "100",
  "tokenizerAddress": "0x4444444444444444444444444444444444444444"
}
'
{
  "transactions": [
    {}
  ],
  "txId": "<string>"
}
Prepares unsigned transactions for approving a spender to use tokens on behalf of the signer. This endpoint is equivalent to calling /prepare-transactions with method=approve.

Authorizations

​
x-api-key
string
header
required

Body

application/json

Request body for approve.

​
method
enum<string>
required

Required. Must be approve.

Available options:
approve
​
signerAddress
string
required

Required. Wallet address that will sign the prepared transaction.

​
chainId
string
required

Required. Blockchain network identifier. Hex format is recommended, for example Sepolia aa36a7.

​
tokenSymbol
string
required

Required. Token symbol to approve. Can be a tokenized asset symbol or a payment token symbol such as BKN, USDT, USDC, USDt, or HAI.

​
spenderAddress
string
required

Required. Address being approved to spend tokens.

Pattern: ^0x[a-fA-F0-9]{40}$
​
amount
string
required

Required. Allowance amount to approve.

​
investorAddress
string

Optional. Token owner address for payment-token approvals. Defaults to signerAddress.

Pattern: ^0x[a-fA-F0-9]{40}$
​
tokenizerAddress
string

Optional. Conditionally required when approving payment tokens (BKN, USDT, USDC, USDt, or HAI) so the API can resolve the tokenizer scope.

Pattern: ^0x[a-fA-F0-9]{40}$
​
tokenizerEmail
string<email>

Optional. Tokenizer email override for payment-token approvals.

​
investmentId
string

Optional. Investment identifier to associate with this approval.

​
gasLimit
string

Optional. Gas limit override. If omitted, the API estimates gas automatically.

​
privateRpcUrl
string

Optional. Private RPC URL override. If omitted, the API uses the configured RPC for chainId.

​
nonce
integer

Optional. Nonce override. If omitted, the API reads the pending nonce from the RPC.

Response

200 - application/json

Successful response

​
transactions
object[]
required
​
txId
string
required