#wasm #parity #webassembly #blockchain

nightly no-std pwasm-std

Parity WebAssembly standard library for contract development

17 releases (9 breaking)

0.10.0 Jul 25, 2018
0.9.0 Jun 11, 2018
0.6.0 Mar 15, 2018
0.3.0 Dec 18, 2017
0.2.0 Nov 22, 2017

#20 in No standard library

Download history 126/week @ 2018-07-20 176/week @ 2018-07-27 125/week @ 2018-08-03 295/week @ 2018-08-10 147/week @ 2018-08-17 149/week @ 2018-08-24 89/week @ 2018-08-31 113/week @ 2018-09-07 80/week @ 2018-09-14 63/week @ 2018-09-21 80/week @ 2018-09-28 90/week @ 2018-10-05 108/week @ 2018-10-12

500 downloads per month
Used in 2 crates


197 lines


Parity WASM contracts standard library for Rust

Build Status


Parity Wasm Tutorial - a full fledged tutorial on how to write contracts in Webassembly for Kovan and other Wasm-enabled networks.

pwasm-std is a limited subset of the Rust standard library, along with a custom allocator which delegates the allocation to the runtime-defined externs.


Just add a dependency

pwasm-std = "0.9"

The crate is supposed to be used on nightly Rust only, until the custom allocator api stablizes in Rust.


pwasm-std is itself compiled with no_std and expected to be used within no_std-crates/binaries, since it defines lang_item-s on it's own, which will conflict with standard library.

But for test scenarios it can be compiled with feature "std" and auxiliary crate "pwasm-test" to support testing of contracts' internal logic.


pwasm-std is primarily distributed under the terms of both the MIT license and the Apache License (Version 2.0), at your choice.

See LICENSE-APACHE, and LICENSE-MIT for details.


Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in pwasm-std by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.