Use the CLI

Getting started covers installation, running a module, and compiling an executable. This page contains the module operations that go beyond that path.

Invoke an export

Select a function and pass its arguments after the module path:

wago run --invoke fib fib.wasm 30

Use 30:i32, 30:i64, 30:f32, or 30:f64 when the type must be explicit. Put Wago flags before the module path.

Inspect and validate

Inspect a module without executing it:

wago module imports fib.wasm
wago module exports fib.wasm
wago module capabilities fib.wasm
wago validate fib.wasm

Add --json when another program needs the output.

Develop

Rerun when the module changes or parallelize work on a large module:

wago run --watch --invoke fib fib.wasm 20
wago run --parallel=4 --invoke fib fib.wasm 20

Parallelism adds overhead to small modules. Measure before keeping it enabled.

Debug a trap

Reproduce the exact export and arguments outside watch mode. If validation passes, Wago reports the trap reason and any Wasm frames:

wago run --invoke process module.wasm 42

context.Canceled and context.DeadlineExceeded are host cancellation, not guest traps.

Cache native code

Build a host-specific .wago artifact when startup compilation matters:

wago build fib.wasm -o fib.wago
wago run --allow-native-artifact fib.wago 20

A .wago file contains native code. Run only artifacts you trust, retain the original Wasm, and rebuild for each architecture or incompatible Wago release.