Blueprints & Packages

Introduction

In the Radix ecosystem, a Blueprint is a reusable template — analogous to a class in object-oriented programming — from which Components (on-ledger smart contract instances) are created. One or more Blueprints are bundled into a Package, which is the deployable unit on the Radix network.

This model separates code deployment from instantiation. A developer publishes a Package once, and anyone on the network can then instantiate Components from its Blueprints — each with its own on-ledger address, state, and Vaults holding resources.

Architecture

Blueprints

A Blueprint defines:

• State fields — typed data the Component stores (e.g., a Vault for collected fees, a u64 counter)
• Functions — stateless methods callable without a Component instance (including constructors like instantiate_*)
• Methods — stateful methods that operate on a specific Component instance
• Events — typed events emitted during execution for off-chain indexing

Blueprints can also declare access rules, royalties, and metadata at both the Blueprint and Component level.

Packages

Scrypto source code is compiled into WebAssembly and bundled into a Package. Once published to the ledger, the Package receives a unique on-ledger address (e.g., package_rdx1...). All Blueprints within the Package share the same address namespace.

The Radix network includes several native Packages — system-provided Blueprints for Accounts, Validators, Access Controllers, and Resources — that form the platform's built-in functionality.

Component Lifecycle

1. Develop — write Scrypto Blueprints using Rust tooling
2. Test — use the Scrypto test framework with the ledger simulator
3. Publish — deploy the compiled Package to the Radix ledger via a Transaction Manifest
4. Instantiate — call a Blueprint's constructor function to create a Component
5. Interact — call the Component's methods via Transaction Manifests

External Links

• Blueprints and Components — Radix Documentation
• Your First Scrypto Project — Radix Documentation
• radixdlt-scrypto — GitHub Repository