# Executive Module
The Executive module acts as the orchestration layer for the runtime. It dispatches incoming
extrinsic calls to the respective modules in the runtime.
## Overview
The executive module is not a typical noble providing functionality around a specific feature.
It is a cross-cutting framework component for the FABRIC. It works in conjunction with the
[FABRIC System module](https://docs.rs/fabric-system/latest/fabric_system/) to perform these cross-cutting functions.
The Executive module provides functions to:
- Check transaction validity.
- Initialize a block.
- Apply extrinsics.
- Execute a block.
- Finalize a block.
- Start an off-chain worker.
### Implementations
The Executive module provides the following implementations:
- `ExecuteBlock`: Trait that can be used to execute a block.
- `Executive`: Type that can be used to make the FABRIC available from the runtime.
## Usage
The default Tetcore node template declares the [`Executive`](https://docs.rs/fabric-executive/latest/fabric_executive/struct.Executive.html) type in its library.
### Example
`Executive` type declaration from the node template.
```rust
#
/// Executive: handles dispatch to the various modules.
pub type Executive = executive::Executive<Runtime, Block, Context, Runtime, AllModules>;
```
### Custom `OnRuntimeUpgrade` logic
You can add custom logic that should be called in your runtime on a runtime upgrade. This is
done by setting an optional generic parameter. The custom logic will be called before
the on runtime upgrade logic of all modules is called.
```rust
#
struct CustomOnRuntimeUpgrade;
impl fabric_support::traits::OnRuntimeUpgrade for CustomOnRuntimeUpgrade {
fn on_runtime_upgrade() -> fabric_support::weights::Weight {
// Do whatever you want.
0
}
}
pub type Executive = executive::Executive<Runtime, Block, Context, Runtime, AllModules, CustomOnRuntimeUpgrade>;
```
License: Apache-2.0