Add module doc for handler
* limitations under the License.
* -----------------------------------------------------------------------------
*/
+
+//! Traits for handling the execution of a transaction.
+//!
+//! The TransactionHandler trait provides the interface for implementing smart contract engines.
+//! These handlers must be stateless and deterministic. They are provided, along with the
+//! transaction itself, a TransactonContext implementation which provides access to reading and
+//! writing from state, as well appending events and other opaque data to the receipt.
+
mod error;
pub use crate::handler::error::{ApplyError, ContextError};
