Document RPC Calls

[wpank]

People looking through the documentation may notice that RPC documentation is missing from the knowledge base. I'm aware they are referenced here from the autogeneration, but at least referencing them somewhere in the knowledge base would be useful. (A step further would be giving examples of the inputs/outputs of these, as the above link doesn't make this too explicit and can be a point of confusion).

[joepetrowski]

We discussed this recently in chat. There should probably be an autogenerated set of RPC reference docs that we publish somewhere. For the KB, I think RPC documentation should perhaps have a basics page, but the primary content should really be across multiple areas:

• RPC Basics: basic curl examples, protocols supported, list of tools
• Node management
• Defining runtime RPC endpoints (e.g. TransactionPayment.queryInfo)
• Using RPC for storage (already in storage documentation)
• Decoding RPC data (already in SCALE)

[JoshOrndorff]

Defining runtime RPC endpoints (e.g. TransactionPayment.queryInfo)

For crosslinking purposes: https://substrate.dev/recipes/3-entrees/custom-rpc.html

Also, I recently had this conversation

Fred

runtime-specific RPCs was (and is) an anti-pattern

Me

Ah, I didn't realize that.

Fred

The thing is, maybe the framework isn't good enough to let people do things through the generic APIs, and people are resorting to runtime-specific RPCs because they have no better option then it's on us to provider a better option

[joepetrowski]

Yeah, I agree with Fred here, especially given the recent weights issue where the host couldn't talk to the runtime. So we might not document "how to create it" but perhaps "how to troubleshoot it".

[danforbes]

Ref: w3f/PSPs#6, https://github.com/w3f/PSPs/blob/psp-rpc-api/psp-002.md