| name | mpkl |
| description | Use mpkl to parse, typecheck, evaluate, or normalize Apple Pkl files and inline source in a WebAssembly command. Use when an agent needs to validate a local Pkl file tree with relative imports or cached package:// dependencies, inspect evaluated configuration as PCF, JSON, YAML, properties, plist, textproto, XML, or Jsonnet, or compare a small Pkl snippet without installing Apple Pkl. |
mpkl
Run mpkl through the MoonBit Skills Marketplace when a task needs a quick,
local check of Pkl source or a local Pkl file tree.
Run
Pass a file path to load it from the current working directory. Relative
import, expression-level import(), extends, and amends dependencies are
loaded recursively:
moon runwasm mizchi/pkl/cmd/mpkl -- check config.pkl
moon runwasm mizchi/pkl/cmd/mpkl -- eval --format json config.pkl
package:// dependencies are resolved from a pre-extracted mpkl package
cache. Pass a cache explicitly when it is not in the default location:
moon runwasm mizchi/pkl/cmd/mpkl -- eval --format json \
--package-cache .pkl-packages Taskfile.pkl
--package-cache is repeatable. Without it, mpkl checks
$PKL_MBT_PACKAGE_CACHE, $XDG_CACHE_HOME/pkl-mbt/package-2, then
$HOME/.cache/pkl-mbt/package-2. Populate the cache first with the native
mpkl CLI; the Wasm command does not download a cache miss.
For a small self-contained module, pass the complete text with --source:
moon runwasm mizchi/pkl/cmd/mpkl -- eval --format json --source 'answer = 6 * 7'
Use one of these commands:
parse: validate syntax and print ok.check: parse and typecheck the module, then print its inferred type.eval: evaluate the module and render its value. Select pcf, json,
yaml, properties, plist, textproto, xml, or jsonnet with
--format; the default is pcf.format: evaluate the module and emit canonical PCF. Treat this as value
normalization, not as a comment-preserving source formatter.
When using --source, preserve newlines and quote the argument so the shell
does not interpret Pkl interpolation or punctuation.
Constraints
File paths are host paths resolved from the process working directory. Without
a Moonrun policy, the command inherits Moonrun's legacy filesystem access. For
an agent or untrusted project, pass a deny-by-default policy that exposes only
the required tree:
[fs]
read = ["config"]
moon runwasm --experimental-policy moonrun-policy.toml \
mizchi/pkl/cmd/mpkl -- eval config/main.pkl
File mode resolves package:// and projectpackage:// URIs only from an
already extracted package cache. It does not fetch HTTP or a missing package,
and does not currently expand import globs or provide Pkl resource reads and
environment properties. Use the native mpkl CLI to populate a package cache
or when the task needs those capabilities.
Interpret exit codes as follows:
0: the requested operation succeeded.1: Pkl parsing, typechecking, or evaluation produced diagnostics.2: the command line is invalid or requests an unsupported operation.
