Modules and calls

Decode or validation failure

Separate validation from execution:

wago validate module.wasm

Common causes are malformed bytes, a disabled proposal, a module built for Core 3 while Wago uses the Core 2 default, or a feature unavailable on the selected platform.

Try Core 3 only when the producer intentionally emits it:

wago run --core 3 module.wasm

Do not use feature flags to force malformed Wasm through.

Missing import

wago module imports module.wasm
wago module capabilities module.wasm

An unresolved import means the module needs another plugin scope, an uninstalled plugin, an application host function, or a corrected name and signature.

For a local project:

wago init --run
wago add <plugin>
wago plugin list

For the Go API:

wago.WithImports(wago.Imports{
	"host.log": logFunc,
})

Missing export

Command modules normally export _start. Select a library function explicitly:

wago run --invoke add math.wasm 20 22

A source-language function name does not necessarily survive compilation as a Wasm export.

Rejected arguments

Wago follows the Wasm signature. Add explicit scalar suffixes where needed:

wago run --invoke convert math.wasm 42:i64 3.5:f64

In Go, use matching typed values:

out, err := inst.Call(ctx, "add", wago.ValueI32(20), wago.ValueI32(22))

Next

• Inspect and validate modules
• Troubleshoot plugin resolution
• Return to Troubleshooting