

| Field | Type | Description |
|--|--|--|
| programId |  publicKey | The program ID of the callback program being invoked. |
| accounts |  [AccountMetaZC](/idl/types/AccountMetaZC)[32] | The accounts being used in the callback instruction. |
| accountsLen |  u32 | The number of accounts in the accounts array. |
| ixData |  u8[1024] | The serialized instruction data. |
| ixDataLen |  u32 | The length of the instruction buffer. |
