---
title: Runtime
description: Transaction execution environment for the Thru blockchain
source_url:
  html: https://thru.org/docs/spec/runtime/overview/
  md: https://thru.org/docs/spec/runtime/overview.md
---

# Runtime

The Thru Runtime is the execution environment that processes transactions on the Thru blockchain. It manages the complete transaction lifecycle from validation through execution to state commitment.

## Key Components

### [Transaction Execution](https://thru.org/docs/spec/runtime/transaction-execution.md)

Covers the multi-phase transaction processing pipeline including pre-execution validation, VM execution, and post-execution rules.

### [Resource Management](https://thru.org/docs/spec/runtime/resources.md)

Defines the resource metering system with Compute Units (CUs) for instruction execution, Memory Units (MUs) for scratch space allocation, and resource consumption patterns.

### [Error Handling](https://thru.org/docs/spec/runtime/errors.md)

Comprehensive error codes organized by transaction lifecycle stage, from validation errors to execution failures and system-level issues.