As a Substrate builder, I don't see any reason of still implementing custom RPCs as runtime API seems superior to me. So I was wondering about any arguments for still adding custom RPCs to the client.
Runtime APIs come with many upsides:
- Versioning support
- Soon™️ part of metadata
- Part of the runtime per definition, does not require node upgrades
- Does not require applying a plurality of
serdeattribute rewiring to all RPC associated types such as
#[cfg_attr(feature = "std", derive(serde::Serialize, serde::Deserialize))] #[cfg_attr(feature = "std", serde(bound = ""))] #[cfg_attr(feature = "std", serde(rename_all = "camelCase"))]`
https://github.com/polkadot-js/api/issues/5529#issuecomment-1465271895 sums up my wariness about RPCs:
TL:DR It seems you are missing the #[serde(rename_all = "camelCase")] attribute in your type - sadly this is just a standard that needs to be followed, since encoding enums different would make the world break (aka it is applied everywhere in Substrate, so the base JS API encoding for any enums follows that de-facto standard)
PS: You are actually better off not doing RPCs and doing all via
decl_runtime- lots of reasons, but basically the former cannot be supported on light clients and the former will never appear in the metadata, so it will always be manual (for the latter, both are on the radar for Substrate) and they are actually versioned, unlike RPCs where changing params is a nightmare.