GitHub Action

Any repository can use this action to lint its domain models and verify committed Markdown in CI. It supports Linux and macOS runners.

# .github/workflows/domain-model.yml
name: Domain Model
on: [pull_request]

jobs:
  domain-model:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: stacklok/modelith@v0.5.0
        with:
          files: "model.modelith.yaml"
          version: v0.5.0
          completeness: warn
          check-rendered: true

Inputs

Input	Default	Description
files	— (required)	YAML files or globs, space-, comma-, or newline-separated.
completeness	warn	Treat completeness gaps as warn or error.
check-rendered	true	Verify the committed *.md matches the YAML.
version	action-ref-dependent	Published modelith release to install; defaults to the release configured by the referenced action version. Set another published release to select it.

Multiple files / globs:

with:
  files: |
    docs/*.modelith.yaml
    services/**/model.modelith.yaml

How it works

The action downloads the prebuilt modelith release binary for the runner's OS and architecture, verifies it against the release's published checksums, and runs it. The example sets the version input explicitly to v0.5.0; set it to another published release when you need a different version. Pinning your uses: reference to a commit SHA keeps CI runs reproducible: a given action keeps CI runs reproducible: a given action commit installs the selected modelith version.

Vendored models in the glob

When the selected release supports vendored models, a glob can include a vendored model. A clean provenance header suppresses completeness findings for that copy and lets check-rendered skip a missing .md or a model this version cannot render. Structural and semantic findings, including a provenance-header defect or a changed copy, still fail the action.

The default v0.5.0 release supports this behavior. See Vendoring a model from another repository for provenance and render semantics.

Regenerating the Markdown

The action gates; it does not commit. When check-rendered fails, run modelith render <file> locally, commit the updated .md, and push — so the rendered output is reviewed in the PR like any other change.