Prepare a token mint
curl --request POST \
--url https://api.sandbox.brickken.com/prepare-transactions \
--header 'Content-Type: application/json' \
--header 'x-api-key: <api-key>' \
--data '
{
"method": "mintToken",
"chainId": "aa36a7",
"signerAddress": "0x742d35Cc6634C0532925a3b844Bc454e4438f44e",
"tokenSymbol": "EXMPL",
"userToMint": [
{
"investorEmail": "investor@example.com",
"investorAddress": "0x1111111111111111111111111111111111111111",
"amount": "100",
"needWhitelist": true
}
]
}
'import requests
url = "https://api.sandbox.brickken.com/prepare-transactions"
payload = {
"method": "mintToken",
"chainId": "aa36a7",
"signerAddress": "0x742d35Cc6634C0532925a3b844Bc454e4438f44e",
"tokenSymbol": "EXMPL",
"userToMint": [
{
"investorEmail": "investor@example.com",
"investorAddress": "0x1111111111111111111111111111111111111111",
"amount": "100",
"needWhitelist": True
}
]
}
headers = {
"x-api-key": "<api-key>",
"Content-Type": "application/json"
}
response = requests.post(url, json=payload, headers=headers)
print(response.text)const options = {
method: 'POST',
headers: {'x-api-key': '<api-key>', 'Content-Type': 'application/json'},
body: JSON.stringify({
method: 'mintToken',
chainId: 'aa36a7',
signerAddress: '0x742d35Cc6634C0532925a3b844Bc454e4438f44e',
tokenSymbol: 'EXMPL',
userToMint: [
{
investorEmail: 'investor@example.com',
investorAddress: '0x1111111111111111111111111111111111111111',
amount: '100',
needWhitelist: true
}
]
})
};
fetch('https://api.sandbox.brickken.com/prepare-transactions', options)
.then(res => res.json())
.then(res => console.log(res))
.catch(err => console.error(err));<?php
$curl = curl_init();
curl_setopt_array($curl, [
CURLOPT_URL => "https://api.sandbox.brickken.com/prepare-transactions",
CURLOPT_RETURNTRANSFER => true,
CURLOPT_ENCODING => "",
CURLOPT_MAXREDIRS => 10,
CURLOPT_TIMEOUT => 30,
CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
CURLOPT_CUSTOMREQUEST => "POST",
CURLOPT_POSTFIELDS => json_encode([
'method' => 'mintToken',
'chainId' => 'aa36a7',
'signerAddress' => '0x742d35Cc6634C0532925a3b844Bc454e4438f44e',
'tokenSymbol' => 'EXMPL',
'userToMint' => [
[
'investorEmail' => 'investor@example.com',
'investorAddress' => '0x1111111111111111111111111111111111111111',
'amount' => '100',
'needWhitelist' => true
]
]
]),
CURLOPT_HTTPHEADER => [
"Content-Type: application/json",
"x-api-key: <api-key>"
],
]);
$response = curl_exec($curl);
$err = curl_error($curl);
curl_close($curl);
if ($err) {
echo "cURL Error #:" . $err;
} else {
echo $response;
}package main
import (
"fmt"
"strings"
"net/http"
"io"
)
func main() {
url := "https://api.sandbox.brickken.com/prepare-transactions"
payload := strings.NewReader("{\n \"method\": \"mintToken\",\n \"chainId\": \"aa36a7\",\n \"signerAddress\": \"0x742d35Cc6634C0532925a3b844Bc454e4438f44e\",\n \"tokenSymbol\": \"EXMPL\",\n \"userToMint\": [\n {\n \"investorEmail\": \"investor@example.com\",\n \"investorAddress\": \"0x1111111111111111111111111111111111111111\",\n \"amount\": \"100\",\n \"needWhitelist\": true\n }\n ]\n}")
req, _ := http.NewRequest("POST", url, payload)
req.Header.Add("x-api-key", "<api-key>")
req.Header.Add("Content-Type", "application/json")
res, _ := http.DefaultClient.Do(req)
defer res.Body.Close()
body, _ := io.ReadAll(res.Body)
fmt.Println(string(body))
}HttpResponse<String> response = Unirest.post("https://api.sandbox.brickken.com/prepare-transactions")
.header("x-api-key", "<api-key>")
.header("Content-Type", "application/json")
.body("{\n \"method\": \"mintToken\",\n \"chainId\": \"aa36a7\",\n \"signerAddress\": \"0x742d35Cc6634C0532925a3b844Bc454e4438f44e\",\n \"tokenSymbol\": \"EXMPL\",\n \"userToMint\": [\n {\n \"investorEmail\": \"investor@example.com\",\n \"investorAddress\": \"0x1111111111111111111111111111111111111111\",\n \"amount\": \"100\",\n \"needWhitelist\": true\n }\n ]\n}")
.asString();require 'uri'
require 'net/http'
url = URI("https://api.sandbox.brickken.com/prepare-transactions")
http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true
request = Net::HTTP::Post.new(url)
request["x-api-key"] = '<api-key>'
request["Content-Type"] = 'application/json'
request.body = "{\n \"method\": \"mintToken\",\n \"chainId\": \"aa36a7\",\n \"signerAddress\": \"0x742d35Cc6634C0532925a3b844Bc454e4438f44e\",\n \"tokenSymbol\": \"EXMPL\",\n \"userToMint\": [\n {\n \"investorEmail\": \"investor@example.com\",\n \"investorAddress\": \"0x1111111111111111111111111111111111111111\",\n \"amount\": \"100\",\n \"needWhitelist\": true\n }\n ]\n}"
response = http.request(request)
puts response.read_body{
"transactions": [
{
"from": "0x1234567890abcdef1234567890abcdef12345678",
"to": "0xabcdef1234567890abcdef1234567890abcdef12",
"value": "0x00",
"nonce": 3792,
"chainId": 11155111,
"data": "0xd362e8a70000000000000000000000000000000000000000000000000000000000000040...",
"type": 2,
"maxPriorityFeePerGas": "1150000",
"maxFeePerGas": "1156037",
"gasLimit": "0xccef"
}
],
"txId": "0x46adea7bdf49c576a760102e0d6bc9ecd650b3998588cd3d7f576a7973426aad",
"info": {
"tokenizerEmail": "tokenizer@example.com",
"tokenSymbol": "EXMPL",
"investorEmail": "investor@example.com"
}
}Prepare Transactions
mintToken
Issue tokens directly to investors, optionally whitelisting them in the same call.
POST
/
prepare-transactions
Prepare a token mint
curl --request POST \
--url https://api.sandbox.brickken.com/prepare-transactions \
--header 'Content-Type: application/json' \
--header 'x-api-key: <api-key>' \
--data '
{
"method": "mintToken",
"chainId": "aa36a7",
"signerAddress": "0x742d35Cc6634C0532925a3b844Bc454e4438f44e",
"tokenSymbol": "EXMPL",
"userToMint": [
{
"investorEmail": "investor@example.com",
"investorAddress": "0x1111111111111111111111111111111111111111",
"amount": "100",
"needWhitelist": true
}
]
}
'import requests
url = "https://api.sandbox.brickken.com/prepare-transactions"
payload = {
"method": "mintToken",
"chainId": "aa36a7",
"signerAddress": "0x742d35Cc6634C0532925a3b844Bc454e4438f44e",
"tokenSymbol": "EXMPL",
"userToMint": [
{
"investorEmail": "investor@example.com",
"investorAddress": "0x1111111111111111111111111111111111111111",
"amount": "100",
"needWhitelist": True
}
]
}
headers = {
"x-api-key": "<api-key>",
"Content-Type": "application/json"
}
response = requests.post(url, json=payload, headers=headers)
print(response.text)const options = {
method: 'POST',
headers: {'x-api-key': '<api-key>', 'Content-Type': 'application/json'},
body: JSON.stringify({
method: 'mintToken',
chainId: 'aa36a7',
signerAddress: '0x742d35Cc6634C0532925a3b844Bc454e4438f44e',
tokenSymbol: 'EXMPL',
userToMint: [
{
investorEmail: 'investor@example.com',
investorAddress: '0x1111111111111111111111111111111111111111',
amount: '100',
needWhitelist: true
}
]
})
};
fetch('https://api.sandbox.brickken.com/prepare-transactions', options)
.then(res => res.json())
.then(res => console.log(res))
.catch(err => console.error(err));<?php
$curl = curl_init();
curl_setopt_array($curl, [
CURLOPT_URL => "https://api.sandbox.brickken.com/prepare-transactions",
CURLOPT_RETURNTRANSFER => true,
CURLOPT_ENCODING => "",
CURLOPT_MAXREDIRS => 10,
CURLOPT_TIMEOUT => 30,
CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
CURLOPT_CUSTOMREQUEST => "POST",
CURLOPT_POSTFIELDS => json_encode([
'method' => 'mintToken',
'chainId' => 'aa36a7',
'signerAddress' => '0x742d35Cc6634C0532925a3b844Bc454e4438f44e',
'tokenSymbol' => 'EXMPL',
'userToMint' => [
[
'investorEmail' => 'investor@example.com',
'investorAddress' => '0x1111111111111111111111111111111111111111',
'amount' => '100',
'needWhitelist' => true
]
]
]),
CURLOPT_HTTPHEADER => [
"Content-Type: application/json",
"x-api-key: <api-key>"
],
]);
$response = curl_exec($curl);
$err = curl_error($curl);
curl_close($curl);
if ($err) {
echo "cURL Error #:" . $err;
} else {
echo $response;
}package main
import (
"fmt"
"strings"
"net/http"
"io"
)
func main() {
url := "https://api.sandbox.brickken.com/prepare-transactions"
payload := strings.NewReader("{\n \"method\": \"mintToken\",\n \"chainId\": \"aa36a7\",\n \"signerAddress\": \"0x742d35Cc6634C0532925a3b844Bc454e4438f44e\",\n \"tokenSymbol\": \"EXMPL\",\n \"userToMint\": [\n {\n \"investorEmail\": \"investor@example.com\",\n \"investorAddress\": \"0x1111111111111111111111111111111111111111\",\n \"amount\": \"100\",\n \"needWhitelist\": true\n }\n ]\n}")
req, _ := http.NewRequest("POST", url, payload)
req.Header.Add("x-api-key", "<api-key>")
req.Header.Add("Content-Type", "application/json")
res, _ := http.DefaultClient.Do(req)
defer res.Body.Close()
body, _ := io.ReadAll(res.Body)
fmt.Println(string(body))
}HttpResponse<String> response = Unirest.post("https://api.sandbox.brickken.com/prepare-transactions")
.header("x-api-key", "<api-key>")
.header("Content-Type", "application/json")
.body("{\n \"method\": \"mintToken\",\n \"chainId\": \"aa36a7\",\n \"signerAddress\": \"0x742d35Cc6634C0532925a3b844Bc454e4438f44e\",\n \"tokenSymbol\": \"EXMPL\",\n \"userToMint\": [\n {\n \"investorEmail\": \"investor@example.com\",\n \"investorAddress\": \"0x1111111111111111111111111111111111111111\",\n \"amount\": \"100\",\n \"needWhitelist\": true\n }\n ]\n}")
.asString();require 'uri'
require 'net/http'
url = URI("https://api.sandbox.brickken.com/prepare-transactions")
http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true
request = Net::HTTP::Post.new(url)
request["x-api-key"] = '<api-key>'
request["Content-Type"] = 'application/json'
request.body = "{\n \"method\": \"mintToken\",\n \"chainId\": \"aa36a7\",\n \"signerAddress\": \"0x742d35Cc6634C0532925a3b844Bc454e4438f44e\",\n \"tokenSymbol\": \"EXMPL\",\n \"userToMint\": [\n {\n \"investorEmail\": \"investor@example.com\",\n \"investorAddress\": \"0x1111111111111111111111111111111111111111\",\n \"amount\": \"100\",\n \"needWhitelist\": true\n }\n ]\n}"
response = http.request(request)
puts response.read_body{
"transactions": [
{
"from": "0x1234567890abcdef1234567890abcdef12345678",
"to": "0xabcdef1234567890abcdef1234567890abcdef12",
"value": "0x00",
"nonce": 3792,
"chainId": 11155111,
"data": "0xd362e8a70000000000000000000000000000000000000000000000000000000000000040...",
"type": 2,
"maxPriorityFeePerGas": "1150000",
"maxFeePerGas": "1156037",
"gasLimit": "0xccef"
}
],
"txId": "0x46adea7bdf49c576a760102e0d6bc9ecd650b3998588cd3d7f576a7973426aad",
"info": {
"tokenizerEmail": "tokenizer@example.com",
"tokenSymbol": "EXMPL",
"investorEmail": "investor@example.com"
}
}Prepares unsigned transactions for minting tokens to specified users. Use
When at least one recipient still needs whitelisting, the whitelist transaction comes first and
Full walkthrough: Tokenize an asset and run an STO.
POST /prepare-transactions with method=mintToken.
Minting increases the token’s current totalSupply and the recipient’s balance. It does not change the configured maximum supply.
Recipient Requirements
- Every entry in
userToMintneeds a validinvestorEmailand a positive whole-tokenamount. investorEmailmust be different from the token’stokenizerEmail. Issuer and investor are separate email identities, even when they use the same wallet for sandbox testing. A collision returnsinvestorEmail cannot be the tokenizer email (index N), whereNis the position inuserToMint.- Use the exact symbol from a successfully confirmed
newTokenization. A symbol that does not resolve on the supplied chain returnsNo company found with this token symbol. needWhitelistonly determines whether the recipient is whitelisted with the mint. It does not change the identity requirement. It defaults totrueunless explicitly set tofalse.needKycon auserToMintentry works the same way it does onwhitelist, andfalseis accepted in Sandbox only.
Testing in Sandbox? Pass
needKyc: false and skip identity verification entirely. The KYC flow
is a Sumsub verification with document upload, not something you need to prove your integration
works, and every test investor you create without it is one less manual step in your loop.Rehearse the real KYC flow once before you go live, since needKyc: false is rejected in
production with needKyc=false is only available in the sandbox environment.This method is an issuance-to-investors flow. It cannot mint to the tokenizer’s own identity, so
there is no supported payload for minting into a company treasury.
Response shape
transactions is an array, as it is for every other prepare method. Iterate it rather than assuming
a single entry: when a recipient still needs whitelisting, the response carries two transactions.
When no recipient needs whitelisting:
{
"transactions": [ { "…unsigned mint transaction…" } ],
"info": { "…" },
"txId": "0x…"
}
txId carries the matching identifiers in the same order:
{
"transactions": [
{ "…unsigned whitelist transaction…" },
{ "…unsigned mint transaction…" }
],
"info": { "…" },
"txId": ["0x…", "0x…"]
}
Sign and send all of them, in order, and wait for each to succeed before the next. The
transactions carry sequential nonces, so broadcasting only the mint leaves it on a nonce that will
never be used: it never mines, and the tokens never exist. A later
burnToken or balance read then
correctly reports no balance, which looks like an indexing lag but is not one.Credits
Two independent counters can block a mint:- API-key mint credits, consumed once per mint operation at send time. Exhausting them returns
Out of credits for minting. - License mint-recipient credits, counted per distinct recipient. Exhausting them returns
Mint credit limit exceeded.
Invitation credit limit exceeded. When more than one counter is exhausted the message lists them, for example Insufficient license credits: mint, invitation.
None of these have a public reset endpoint. Contact support@brickken.com to review an account’s balances.
The first mint to a new recipient sends both a new-shareholder invitation and a token-received
notification. Later mints to the same recipient send only the token-received notification.
Next step
Preparing does not touch the chain. The response gives youtxId and an array of unsigned transactions — you still have to sign and submit them.
1
Sign every returned transaction
Sign each entry locally with the wallet that sends the transaction —
signerAddress, or investorAddress for newInvest and claimTokens. It must be whitelisted by Brickken, and it needs native gas on the target chain.2
Submit the signed payloads
POST them to /send-transactions as { txId, signedTransactions } and Brickken broadcasts for you.If you would rather broadcast yourself, prepare with executionMode: "client-broadcast" and confirm afterwards with { txId, txHash } instead.3
Poll until it confirms
Call
GET /get-transaction-status with the txId. A pending status means it is broadcast but not yet mined — do not resubmit.Authorizations
Body
application/json
Required. Operation to prepare. Must be mintToken for this endpoint.
Available options:
mintToken Example:
"mintToken"
Required. Blockchain network identifier. Hex format is recommended, for example Sepolia aa36a7.
Example:
"aa36a7"
Required. Tokenizer wallet that signs the mint transaction, and the whitelist transaction when recipients still need whitelisting.
Example:
"0x742d35Cc6634C0532925a3b844Bc454e4438f44e"
Required. Symbol of the token to mint. Its chainId must match the one in this request.
Example:
"EXMPL"
Required. Users to mint tokens to.
Minimum array length:
1Show child attributes
Show child attributes
Example:
[
{
"investorEmail": "investor@example.com",
"investorAddress": "0x1111111111111111111111111111111111111111",
"amount": "100",
"needWhitelist": true
}
]
Response
200 - application/json
Successful response
Unsigned transactions ready for signing, in the order they must be broadcast. Contains two entries when a recipient still needs whitelisting: the whitelist transaction first, then the mint.
Show child attributes
Show child attributes
Identifier for this prepared transaction, required by /send-transactions. When transactions holds more than one entry this is an array of identifiers in the same order. This is NOT a blockchain transaction hash.
Example:
"0x46adea7bdf49c576a760102e0d6bc9ecd650b3998588cd3d7f576a7973426aad"
Metadata about the operation
Show child attributes
Show child attributes