Overview
Whisky is a free, open-source code library that lets developers build, sign, and test blockchain transactions from code written in Rust, a programming language designed for fast, reliable software1. It suits teams running the server side of a DApp (an app that runs on a blockchain), the part that prepares a transaction before a user's wallet approves it. Whisky can also check a finished transaction in automated tests, so developers can confirm that funds and tokens go where they intended2.
Whisky works on Cardano and sits among the directory's transaction builders. SIDAN Lab, a Hong Kong-based development studio, builds it3, and the same team runs the DeltaDeFi trading platform4. The library started life as sidan-csl-rs before being renamed Whisky5. Project Catalyst, Cardano's community-voted grant program, funded the original library in Fund 116 and a second version built on TxPipe's Pallas, a pure-Rust Cardano library, in Fund 147.
Key Features
- Transactions assembled one step at a time. Whisky's builder follows the pattern of cardano-cli, Cardano's standard command-line tool, so developers add payments, token mints, and a change address (where leftover funds return) in a chain of calls and let the library pick which coins to spend8.
- Script costs worked out without running a node. A built-in evaluator uses TxPipe's uplc to calculate how much computing work each step of a smart contract (a program that runs on the blockchain) needs, then updates the transaction to match, with no Cardano node (the software that runs the network) required1.
- Checks on finished transactions for unit tests. Whisky's tester lets developers check which addresses a parsed transaction pays, which tokens it mints or burns, which keys it requires as signers, and its valid time window, and it names any check that fails2.
- Existing transactions that can be edited and rebuilt. Whisky decodes a raw transaction back into editable parts, so a developer can remove or add outputs and rebuild it with a fresh change output8.
- A choice of two encoding engines. Developers can pick cardano-serialization-lib or a pure-Rust engine built on TxPipe's Pallas to turn transactions into the exact bytes the network accepts, and switching leaves the transaction-building code unchanged9.
What to Expect
Whisky is a building block for developers, not an app with screens to click through. Rust developers add it to a project with one command in Cargo, Rust's package manager. JavaScript and TypeScript developers can install ready-made packages from npm, JavaScript's package registry, for Node.js servers or web browsers instead1.
The Whisky guide walks through installation, a quick first transaction, simple sends, smart contract spending, minting, staking, and editing existing transactions, and it links a full reference of the library's functions10. By default Whisky builds transactions offline. When a backend needs live blockchain data or wants to submit transactions, developers can plug in hosted data services such as Maestro or Blockfrost11.
JavaScript developers can rely on Whisky without touching Rust. Mesh, a JavaScript toolkit for Cardano apps, builds its @meshsdk/core-csl package on whisky-js, the library's JavaScript package12.
The library's own test suite covers everyday payments, token minting, stake withdrawals, and governance actions such as registering as a DRep (a voting representative) and casting votes8. The code is public under the Apache 2.0 license, which allows free use, changes, and commercial reuse8. SIDAN Lab posts project updates on its Discord server, and the project's GitHub repository has a public issue tracker8.
