10 releases

0.1.11 Aug 10, 2021
0.1.10 Aug 5, 2020
0.1.7 Feb 13, 2020
0.1.5 Jan 30, 2020
0.1.1 Nov 29, 2019

#21 in #monorepo

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Oracle WebAssembly

Owasm (o-wah-some) is the standard library for writing and encoding oracle logic to be for deterministic execution on public ledgers that involve fetching data from external sources. Initially developed by Band Protocol, it is currently used as the go-to standard for writing oracle scripts in the Decentralized Data Delivery Network.


A D3N oracle script must allow the host to ask for the external data that the script wants (by invoking __prepare) and perform aggregation on data points collected from them (by invoking __execute).

Code Structure

Owasm library consists of two primary modules:

  • owasm/core is the backbone of the crate. It defines the methods to encode and decode both input commands and data outputs, with the Oracle trait to allow arbitrary data types, once implemented the trait, to be able to get converted to/from external data.
  • owasm/ext is the extension library providing convenient ways to write oracle scripts that connect to various public APIs. The library is growing to support more use cases and it open for public contribution!


~137K SLoC