1. Status

The CoinPool idea was spawned in early 2020, and it was presented to the mailing list in June 2020.

After gathering some feedback, a thorough CoinPool design was proposed in the form of a whitepaper in February 2022.

A potential future of CoinPool may look as follows:

• activate SIGHASH_ANYPREVOUT or equivalent primitive enabling Eltoo-like update mechanism;
• activate SIGHASH_GROUP and malleability flags extensions (or an equivalent primitive) enabling transaction amounts introspection;
• update and maintain a Bitcoin Core fork with OP_MERKLESUB
• build a minimal CoinPool prototype, MERKLESUB-based running on the signet or bitcoin-inquisition;
• run a signet with OP_MERKLESUB;
• activate OP_MERKLESUB (or a modified OP_TLUV, or any other alternative);
• propose a specification to standardize CoinPool or other payment pools design.

This process should be accompanied by continiously researching the trade-offs and alternatives, as well as improving CoinPool itself.

Notably, while it is already possible to build a constrained form on CoinPool without changes to the base layer, we believe it is better to focus on the ground work research before proceeding to the implementation.