Buckets, Proofs & Vaults

Introduction

Buckets, Vaults, and Proofs are the three core asset containers in Scrypto, each serving a distinct purpose in Asset-Oriented Programming. Together they form the mechanism by which resources are stored, moved, and used for authorisation on the Radix network.

Vaults

A Vault is a permanent, on-ledger container that holds a single type of resource (fungible tokens or non-fungible tokens). Vaults are owned by Components — including Account components — and represent the resting state of all assets on the network.

At the end of every transaction, all resources must reside in Vaults. Any resources left outside a Vault cause the transaction to fail, preventing accidental token loss. A Component may hold multiple Vaults, but each Vault holds only one resource type.

Buckets

A Bucket is a temporary, in-transaction container for moving resources between Components. Buckets exist only during transaction execution — they are created when resources are withdrawn from a Vault and destroyed when deposited into another Vault.

The lifecycle of a Bucket within a Transaction Manifest:

1. Withdraw resources from an Account Vault → creates a Bucket
2. Pass the Bucket to a Component method → transfers ownership
3. The Component deposits the Bucket into its own Vault

The Radix Engine enforces that all Buckets must be empty or deposited by the end of the transaction. This guarantee — enforced at the platform level, not by application code — makes it impossible to accidentally lose tokens by sending them to the wrong address.

Proofs

A Proof is a non-transferable cryptographic attestation created from a Vault or Bucket, proving that the caller possesses a certain quantity or type of resource. Proofs do not move the underlying assets — they attest to their existence.

Proofs are placed onto an Auth Zone during transaction execution, where they are checked against Component Access Rules. This is how authorisation works on Radix: rather than checking msg.sender as on Ethereum, a Scrypto method requires a Proof of a specific badge resource.

Virtual Proofs are automatically created by the Radix Engine from transaction signatures. When a user signs a transaction with their wallet key, the engine creates a virtual Proof of the account's signature badge, linking traditional cryptographic signing to Radix's badge-based authorisation.

External Links

• Buckets and Vaults — Radix Documentation
• Resources — Radix Documentation
• Proofs and Auth — Radix Documentation