Clarify how ApiId is being generated (#9519)

* Clarify how `ApiId` is being generated * Clarify more
paritytech · Aug 9, 2021 · d7babec · d7babec
1 parent f2b3997
commit d7babec
Showing 1 changed file with 5 additions and 0 deletions.
diff --git a/primitives/version/src/lib.rs b/primitives/version/src/lib.rs
@@ -98,6 +98,11 @@ pub mod embed;
 pub use sp_version_proc_macro::runtime_version;
 
 /// The identity of a particular API interface that the runtime might provide.
+///
+/// The id is generated by hashing the name of the runtime api with BLAKE2 using a hash size
+/// of 8 bytes.
+///
+/// The name of the runtime api is the name of the trait when using `decl_runtime_apis!` macro.
 pub type ApiId = [u8; 8];
 
 /// A vector of pairs of `ApiId` and a `u32` for version.