PAB as client

[ch1bo]

What & Why

Several DApp projects on Cardano use the Plutus Application Backend (PAB) for constructing & submitting transactions including Plutus scripts, as well as observing the chain and execute off-chain code.

Currently the PAB only supports connecting to the cardano-node and balance/sign transactions via the wallet backend (TBD: what's the actual status here?)

Within this feature we want to enable the PAB to connect to the hydra-node, submit transactions to it when the Head is open, as well as observe the "chain" by subscribing to transactions inside a Hydra Head using the hydra-node.

[pradeepp88]

At Charli3 oracles, we have designed our oracle scripts to aggregate node values from multiple node UTXOs produced by node operators in a decentralized way. The aggregation is coded using the Plutus OffChain code, which is run by the PAB integrated with the wallet-backend for balancing/signing the transactions and the plutus-chain-Index for reading the data related to UTXOs along with the cardano-node. We also conducted a short survery with our partner projects and about 85% of them replied that they use a similar architecture. So we would like to have support to integrate all these components into a hydra-node so that our oracles can be run in hydra heads.