leo build

To compile your program into Aleo instructions and verify that it builds properly, run:

leo build

On invoking the build command, Leo automatically creates a build/⁠ folder in the project directory - or, when the package is inside a workspace, at the workspace root, shared across every member. Inside it, every program - your own program and each dependency - gets its own build/{program}/ directory containing its compiled .aleo bytecode and ABI.

console output:

  Leo     2 statements before dead code elimination.
  Leo     2 statements after dead code elimination.
  Leo ✅ Compiled '{PROGRAM_NAME}.aleo' into Aleo instructions.
  Leo ✅ Generated ABI for program '{PROGRAM_NAME}.aleo'.

The build also generates an ABI file at build/{PROGRAM_NAME}/abi.json describing your program's public interface (transitions, mappings, and types). See the ABI Generation guide for details on the format and type lowering specification.

Checksums

The program checksum and the checksum of each entry and view function are the values that the Program::function_checksum intrinsic targets, so they are useful when writing a constructor that pins specific functions across upgrades. To print them, pass --checksums:

leo build --checksums

console output:

  Leo     The program checksum is: '[141u8, 87u8, ...]'.
  Leo       `main` function checksum is: '[140u8, 56u8, ...]'.
  Leo       `peek` function checksum is: '[239u8, 16u8, ...]'.

Each checksum is the SHA3-256 of the component's Aleo source, as 32 bytes. The same checksums are written to the --json-output build JSON (as integer arrays under program_checksum and function_checksums), so leo build --json-output is a convenient way to consume them programmatically.

Flags

--build-tests
    Build tests along with the main program and dependencies.
--checksums
    Print the program checksum and the checksum of each entry and view function
    (the `Program::function_checksum` targets).
--no-cache
    Don't use the dependency cache.
--no-local
    Don't use the local source code.
--network <NETWORK>
    The network to build for. Overrides the `NETWORK` environment variable.
--endpoint <ENDPOINT>
    The endpoint to resolve network dependencies from. Overrides the `ENDPOINT` environment variable.
--network-retries <N>
    Number of times to retry a network request on transient transport failure, with
    exponential backoff (1 s, 2 s, 4 s, … capped at 64 s). Overrides the
    NETWORK_RETRIES environment variable. Defaults to 2. HTTP errors and broadcast
    calls are not retried.

Workspace Behavior

When run inside a workspace:

• From workspace root: Builds all members in dependency order.
• From a member directory: Builds only that member.
• With --package <NAME>: Builds only the specified member.

# Build all workspace members
leo build

# Build only the swap member
leo build -p swap