MELD Dev Diary 04

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MELD

2 min readOct 3, 2022

Lending and Borrowing

Formulated technical diagrams that express the execution flows and smart contracts’ validation logics for all transaction types in the protocol:

User interactions:

Batcher transaction:

Set up the Lending API server. The Lending API server is the gateway for MELDapp & users to interact with Lending services.

Implement bootstrap executable to export smart contract script to TextEnvelope format and deploy to UTXOs as reference scripts.

Avoid Nix-GHC bug related to loadArchive clang++ on macOS dev environment by replacing original GHC with haskell-nix patched GHC.

Update nixpkgs to newest version in order to use cabal-install-3.8.1.0 and ghc-9.2.4.

Separate smart contract build and application build which enables the ability to:

Use different GHC versions for the 2 builds, so that plutarch code for smart contracts can be compiled by ghc-9.2.4 while application code relying on cardano-api can keep being compiled by ghc-8.10.7
Pin smart contract dependency versions while being able to update the application dependencies to the newest versions in the future.

Successfully deployed the Cardano contract to pre-prod testnet after Plutus Script V2 cost model parameters were available.
Completed integration testing for 2-way wrapping & unwrapping on pre-prod testnet. All Akamon services are ready to be deployed on pre-prod testnet.

Configured VPCs for the new AWS dev accounts for the Cardano-based MVP and MELDApp.
Configured VPC peering between services: AWS account, root MELD AWS account, and the new dev accounts for Cardano-based MVP and MELDApp, enabling the ability to use a single Bastion host (jumphost) to access instances and databases in all other peered AWS accounts.
Installed and configured static code analysis tool server and integrated it to various MELD’s GitHub repos.

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