Crate sp_api

Substrate runtime api

The Substrate runtime api is the crucial interface between the node and the runtime. Every call that goes into the runtime is done with a runtime api. The runtime apis are not fixed. Every Substrate user can define its own apis with decl_runtime_apis and implement them in the runtime with impl_runtime_apis.

Every Substrate runtime needs to implement the Core runtime api. This api provides the basic functionality that every runtime needs to export.

Besides the macros and the Core runtime api, this crates provides the Metadata runtime api, the ApiExt trait, the CallApiAt trait and the ConstructRuntimeApi trait.

On a meta level this implies, the client calls the generated API from the client perspective.

Macros

decl_runtime_apis	Declares given traits as runtime apis.
impl_runtime_apis	Tags given trait implementations as runtime apis.
mock_impl_runtime_apis	Mocks given trait implementations as runtime apis.

Structs

ApiRef	Auxiliary wrapper that holds an api instance and binds it to the given lifetime.
CallApiAtParams	Parameters for CallApiAt::call_api_at.
OldRuntimeVersion

Enums

InitializeBlock	Before calling any runtime api function, the runtime need to be initialized at the requested block. However, some functions like execute_block or initialize_block itself don’t require to have the runtime initialized at the requested block.
OffchainOverlayedChanges	In-memory storage for offchain workers recoding changes for the actual offchain storage implementation.

Constants

MAX_EXTRINSIC_DEPTH

Maximum nesting level for extrinsics.

Traits

ApiErrorExt	Extends the runtime api traits with an associated error type. This trait is given as super trait to every runtime api trait.
ApiExt	Extends the runtime api implementation with some common functionality.
CallApiAt	Something that can call into the an api at a given block.
ConstructRuntimeApi	Something that can be constructed to a runtime api.
Core	The Core runtime api that every Substrate runtime needs to implement.
Metadata	The Metadata api trait that returns metadata for the runtime.
ProvideRuntimeApi	Something that provides a runtime api.
RuntimeApiInfo	Something that provides information about a runtime api.

Type Definitions

ApiErrorFor	Extracts the Api::Error for a type that provides a runtime api.
ProofRecorder	A type that records all accessed trie nodes and generates a proof out of it.
StateBackendFor	Extract the state backend type for a type that implements ProvideRuntimeApi.
StorageChanges
StorageTransactionCache	A type that is used as cache for the storage transactions.
TransactionFor	Extract the state backend transaction type for a type that implements ProvideRuntimeApi.