Runtime APIs

Runtime APIs (aka Runtime calls in other frameworks) directly query the wasm runtime to get some information. In PAPI they're under typedApi.apis. Let's see its interface:

type CallOptions = Partial<{
  at: string
  signal: AbortSignal
}>
interface RuntimeCall<Args, Payload> {
  (...args: [...Args, options?: CallOptions]): Promise<Payload>
  isCompatible: IsCompatible
  getCompatibilityLevel: GetCompatibilityLevel
}

They're fairly straight-forward, let's see it with some examples:

With callOptions.at we can control which block to query. It can be a blockHash, "finalized" (the default), or "best"

// there are some APIs that do not take arguments!
const metadata = await typedApi.apis.Metadata.metadata()
 
// we can pass as well callOptions
const metadataAtBest = await typedApi.apis.Metadata.metadata({ at: "best" })
 
// this one takes a number as argument
const metadataV15 = await typedApi.apis.Metadata.metadata_at_version(15, {
  at: "best",
})