Skip to main content

mops check

Check Motoko files for syntax errors and type issues

mops check <files...>

Runs the Motoko compiler in check-only mode (moc --check) on the specified files. All package sources from the project are automatically included.

Exits with a non-zero code if any file has errors, making it suitable for CI pipelines. Warnings do not cause a failure by default.

Examples

Check a single file

mops check src/main.mo

Check multiple files

mops check src/main.mo src/types.mo

Check with verbose output (shows the compiler command being run)

mops check src/main.mo --verbose

Treat warnings as errors

mops check src/main.mo -- -Werror

Arguments

<files...>

One or more paths to Motoko files to check. At least one file is required.

Options

--verbose

Print the full moc invocation before running it.

Passing flags to the Motoko compiler

Any arguments after -- are forwarded directly to moc. For example, to treat all warnings as errors:

mops check src/main.mo -- -Werror
info

mops check only type-checks files — it does not produce any compiled output. To compile canisters, use mops build.