Transactions — HCS‑15 Builders

Note

• These builders are for direct transaction construction (e.g., Standards Agent Kit, custom pipelines).
• For most apps, prefer the higher‑level Node or Browser clients which wrap these builders.

Sources

• TypeScript: GitHub
• Go: GitHub

Base Account

Creates a base account with ECDSA key and EVM alias suitable for HCS‑15 usage.

TypeScript

import { Client, PrivateKey, Hbar } from '@hashgraph/sdk';
import { buildHcs15BaseAccountCreateTx } from '@hashgraphonline/standards-sdk';

const key = PrivateKey.generateECDSA();
const tx = buildHcs15BaseAccountCreateTx({
  publicKey: key.publicKey,
  initialBalance: new Hbar(1),
  accountMemo: 'HCS‑15 Base',
});
const receipt = await (await tx.execute(client)).getReceipt(client);

Notes

• Uses the SDK's "ECDSA + alias" setter so an immutable EVM alias is assigned on creation.
• Set maxAutomaticTokenAssociations if you expect many token airdrops.

Go

import "github.com/hashgraph-online/standards-sdk-go/pkg/hcs15"

key, _ := hedera.PrivateKeyGenerateEcdsa()
tx, err := hcs15.BuildBaseAccountCreateTx(hcs15.BaseAccountCreateTxParams{
	PublicKey:      key.PublicKey(),
	InitialBalance: 1.0,       // HBAR
	AccountMemo:    "HCS-15 Base",
})
if err != nil {
	log.Fatal(err)
}

response, _ := tx.Execute(hederaClient)
receipt, _ := response.GetReceipt(hederaClient)

Python

key = hedera.private_key_generate_ecdsa()
tx = hcs15.build_base_account_create_tx(public_key=public_key, initial_balance=1.0,"HCS-15 Base")

response = tx.execute(hederaClient)
receipt = response.get_receipt(hederaClient)

Petal Account

Creates a Petal (shadow) account that reuses the base account's public key and does not set an alias.

TypeScript

import { buildHcs15PetalAccountCreateTx } from '@hashgraphonline/standards-sdk';

const tx = buildHcs15PetalAccountCreateTx({
  publicKey: baseKey.publicKey,
  initialBalance: 0.5,
  accountMemo: 'HCS‑15 Petal',
});
const receipt = await (await tx.execute(client)).getReceipt(client);

Go

tx, err := hcs15.BuildPetalAccountCreateTx(hcs15.PetalAccountCreateTxParams{
	PublicKey:      baseKey.PublicKey(),
	InitialBalance: 0.5,
	AccountMemo:    "HCS-15 Petal",
})
if err != nil {
	log.Fatal(err)
}

response, _ := tx.Execute(hederaClient)
receipt, _ := response.GetReceipt(hederaClient)

Python

tx = hcs15.build_petal_account_create_tx(public_key=baseKey.PublicKey(), initial_balance=0.5, account_memo="HCS-15 Petal")

response = tx.execute(hederaClient)
receipt = response.get_receipt(hederaClient)

Notes

• Petal accounts are meant to be controlled by the same private key as the base—do not set an alias.
• Combine with HCS‑11 to inscribe per‑Petal profiles and HCS‑10 to create per‑Petal communication topics.