Deprecation noticeWebhooks v1 has been in soft deprecation since June 15, 2026: it receives no fixes or enhancements, and issue resolution is not guaranteed. Starting October 5, 2026, v1 is being shut down permanently in phases, with all workspaces affected by October 28, 2026. Once shut down, v1 stops delivering notifications and cannot be restored. Fireblocks is not responsible for missed or delayed notifications or any disruption resulting from continued use of Webhooks v1. Upgrade to Webhooks v2 now via the Developer Center in the Fireblocks Console. For upgrade steps and event mapping, see the Webhooks v2 Migration Guide.
Webhook payload
type: string, // NFT_BALANCE_CHANGED
tenantId: string,
timestamp: number,
data: {
id: string, // unique web-hook id
transaction?: TransactionObject, // when WH is from refresh call, this will be empty
token: TokenObject,
balance: BalanceObject, // current balance
}
Data Objects
TransactionObject
| Name | Type | Description |
|---|---|---|
| id | string | The Fireblocks transaction ID. |
| hash | string | The hash of the transaction for the on-chain NFT transfer. |
| blockNumber | number | The transaction’s block number. |
TokenObject
| Name | Type | Description |
|---|---|---|
| assetId | string | The identifier of the NFT asset. |
| blockchainDescriptor | string | The descriptor for the specific blockchain network. |
| tokenId | string | The ID of the transferred token. |
| contractAddress | string [Optional] | The address of the NFT contract. |
| standard | string [Optional] | The NFT standard for the token. |
BalanceObject
| Name | Type | Description |
|---|---|---|
| owner | OwnerObject | The owner of the NFT with the changed balance. |
| outgoing | boolean [Optional] | Indicates whether the transfer is outgoing from the vault. |
| amount | string [Optional] | The amount of the NFT transferred in the balance change. |
| total | string | The token balance. Represented as a decimal string. |
| blockNumber | number | The block number of the NFT when its token balance was last queried. |
OwnerObject
| Name | Type | Description |
|---|---|---|
| type | PeerType | The source of the transfer (e.g., VAULT_ACCOUNT, INTERNAL_WALLET). |
| accountId | string | The vault account ID. |
| walletId | string [Optional] | The Non-Custodial Wallet (NCW) ID. |
| address | string | The owner’s wallet address (i.e., the vault account ID or the NCW ID). |