- BIP draft: https://github.com/bitcoin/bips/pull/1793

- bitcoin-core concept implementation: https://github.com/bitcoin/bitcoin/pull/32080

- Delving post: https://delvingbitcoin.org/t/op-checkcontractverify-and-its-amount-semantic/1527

In the new post on delving, I delve into the amount logic of CCV, something that has somewhat evolved since the initial posts.

I argue that while scriptPubKey checks are just equality checks this transaction-wide logic is preferable, and it's difficult to replicate it otherwise.

However, while the amount logic is not difficult, transaction-wide checks present some implementation challenges, because of multi-threaded Script validation in core.

Solving this seems to be necessary for several possible soft forks (CCV, VAULT, TXHASH, CISA), but even just to implement batch validation for Schnorr signatures, which is an optimization available today.

More details in the PR.

As usual, you'll find all the links at https://merkle.fun.

I look forward to your comment and ideas.