casper-contract 1.4.4

A library for developing Casper network smart contracts.


LOGO Documentation License

A library for developing Casper network smart contracts.


The crate is no_std, but uses the core and alloc crates. It is recommended to build Wasm smart contracts in a no_std environment as this generally yields smaller, and hence cheaper, binaries.

Compile-time features


Enabled by default.

Given that the library is intended to be consumed by smart-contract binaries, and that in a no_std environment these will all require to provide an alloc error handler and an eh_personality, then this crate provides these when no-std-helpers is enabled. This unfortunately requires the use of nightly Rust.

For further convenience, enabling this feature also provides a global allocator suitable for use in a no_std environment.

If you wish to use a different global allocator, or provide different panic/out-of-memory handlers, then add the following to your Cargo.toml:

casper-contract = { version = "1", default-features = false }


Disabled by default.

To help support smart contract debugging, enabling the test-support feature makes the function contract_api::runtime::print(text: &str) available. If the contract is being tested offchain using the casper-engine-test-support crate, then the contract can output text to the console for debugging.

casper-contract = { version = "1", features = ["test-support"] }


Licensed under the Apache License Version 2.0.