The PR diagrams Action posts one comment on a pull request that changes a diagram file. It runs in your CI with the openflowkit CLI, git and gh: no server and no hosting.

on:
  pull_request:
    paths: ['**/*.openflow.json', '**/*.ofk']
permissions:
  contents: write        # only to push refreshed SVGs
  pull-requests: write   # the comment
jobs:
  diagrams:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
        with: { fetch-depth: 0 }
      - uses: openflowkit/openflowkit/[email protected]

Use a release tag (v2.1.0 or later) or a commit SHA. A branch name also works but moves under you. Inside the OpenFlowKit repository itself, uses: ./action works.

The default CLI is the version pinned in that tag’s action.yml: 0.2.3 in v2.1.0, 0.3.0 in v2.2.0. A CLI you point the cli input at must be 0.2.0 or newer: older versions have no render, convert or op.

One comment per pull request, updated in place. For each changed diagram: its status, node and connector counts before and after, the DSL diff (first 300 lines) and, for .ofk architecture models, drift (gone, new, changed). A file that fails to render gets a line, not a failed job. When no diagram changed, there is no comment.

A committed SVG beside a diagram (x.openflow.json or x.ofk next to x.svg) that differs from a fresh render is listed as stale. With refresh-svg: true on a same-repo PR, the Action commits the fresh SVG to the PR branch instead, and still lists it if the push is rejected.

Fork and Dependabot PRs get a read-only token, so the Action can’t comment or push there. It writes the same text to the job summary and exits 0. It does the same if the comment call returns 403.

A push made with GITHUB_TOKEN doesn’t trigger workflows, so a refreshed commit has no checks and required checks block the merge. That is why refresh-svg is off by default. To use it under branch protection, pass an App or PAT token as github-token, and its login as comment-author.

• No inline images. GitHub can’t show an SVG from CI without hosting it. The before and after SVGs are uploaded as the run’s diagram-svgs artifact (kept 14 days), and the comment links to it.
• No PNG. Pictures are SVG, like the CLI’s.

• The openflowkit CLI: the commands the Action runs.
• Architecture workspace: .ofk models and drift.