Lib.rs

Version module for the Substrate runtime; Provides a function that returns the runtime version.

License: Apache-2.0

lib.rs:

Substrate runtime version

Each runtime that should be executed by a Substrate based node needs to have a runtime version. The runtime version is defined by [RuntimeVersion]. The runtime version is used to distinguish different runtimes. The most important field is the spec_version. The spec_version should be increased in a runtime when a new runtime build includes breaking changes that would make other runtimes unable to import blocks built by this runtime or vice-versa, where the new runtime could not import blocks built by the old runtime. The runtime version also carries other version information about the runtime, see [RuntimeVersion] for more information on this.

Substrate will fetch the runtime version from a wasm blob by first checking the runtime_version link section or calling the Core::version runtime api. The link section can be generated in the runtime using the [runtime_version] attribute. The Core runtime api also needs to be implemented for the runtime using impl_runtime_apis!.