Contract Artifacts

Compiling an Aztec contract produces a contract artifact file (.json) containing everything needed to interact with that contract: its name, functions, their interfaces, and compiled bytecode. Since private function bytecode is never published to the network, you need this artifact file to call private functions.

Most developers don't need this

When you compile a contract and use aztec codegen, you get type-safe TypeScript classes that handle artifacts automatically. This page is useful if you're:

• Building custom tooling around Aztec contracts
• Debugging compilation or deployment issues
• Understanding what data is available in artifacts

Where to Find Artifacts

After running aztec compile, artifacts are output to the target/ directory:

target/
└── my_contract-MyContract.json    # Contract artifact

Use aztec codegen to generate TypeScript bindings from these artifacts for type-safe contract interaction.

Contract Artifact Structure

A contract artifact contains:

• name: The contract name as defined in Noir
• functions: Array of function artifacts (private, public dispatch, and utility functions)
• nonDispatchPublicFunctions: Public function ABIs (excluding the dispatch function)
• outputs: Exported structs and globals from the contract
• storageLayout: Storage slot mappings for contract state
• fileMap: Source file mappings for debugging

Function Properties

Each function in the artifact includes:

Property	Description
name	Function name as defined in Noir
functionType	One of private, public, or utility
isOnlySelf	If true, function can only be called from within the same contract
isStatic	If true, function cannot alter state
isInitializer	If true, function can be used as a constructor
parameters	Array of input parameters with name, type, and visibility
returnTypes	Array of return value types
errorTypes	Custom error types the function can throw
bytecode	Compiled ACIR bytecode (base64 encoded)
verificationKey	Verification key for private functions (optional)
debugSymbols	Compressed debug information linking to source code

Function Types

• private: Executed and proved locally by the client. Bytecode is not published to the network.
• public: Executed and proved by the sequencer. Bytecode is published to the network.
• utility: Executed locally to compute information (e.g., view functions). Cannot be called in transactions.

Parameter and Return Types

Parameters and return values use these type definitions:

Type	Description
field	A field element in the BN254 curve's scalar field
boolean	True/false value
integer	Whole number with sign (signed/unsigned) and width (bits)
array	Collection of elements with length and element type
string	Character sequence with fixed length
struct	Composite type with named fields and a path identifier
tuple	Unnamed composite type with ordered fields

Parameter visibility can be public, private, or databus.

Next Steps

• Compile contracts to generate artifacts
• Deploy contracts using generated TypeScript bindings
• Send transactions to interact with deployed contracts