What’s the max size and max cycles of a tx?
TLDR: The maximum size allowed for a transaction is 512,000 bytes, with a limit of 3.5 billion cycles.
The CKB consensus does not impose any restrictions on the size or cycles of a transaction. However, since a transaction will be included in a block, it is limited by the maximum block size and cycles (for more details, see What's the max size and max cycles of a block? - #2 by doitian )
The limit for block size includes the block header, transactions, proposals, and serialization overhead. Approximately 570,000 bytes are available for storing transactions, but each block also contains a cellbase transaction of unknown size. To prevent a scenario in which a transaction smaller than 570,000 bytes gets stuck in the pool because of its size plus cellbase exceeding that limit, the ckb node will reject transactions greater than 512,000 bytes in size.