ledger_last_hash

Summary. Write the 32-byte hash of the last closed ledger into hook memory.

Signature.

int64_t ledger_last_hash(uint32_t write_ptr, uint32_t write_len);

Parameters.

Name	Type	Description
write_ptr	uint32_t	Destination buffer.
write_len	uint32_t	Must be at least 32.

Return value. Returns 32 (bytes written) on success. Errors: OUT_OF_BOUNDS (-1) for a bad buffer; TOO_SMALL (-4) if write_len < 32.

Common failure patterns.

• A buffer shorter than 32 bytes → TOO_SMALL.

Caveats / notes.

• This is view().info().parentHash — the hash of the most recently closed ledger.

Minimal example.

uint8_t h[32];
ledger_last_hash((uint32_t)h, 32);

Related APIs. ledger_seq, ledger_nonce.