Agent Skills: WordPress Playground

WordPress Playground

When to use

• Spin up a disposable WordPress to test a plugin/theme without full stack setup.
• Run or iterate on Playground Blueprints (JSON) locally.
• Build a reproducible snapshot of a site for sharing or CI.
• Switch WP/PHP versions quickly to reproduce issues.
• Debug plugin/theme code with Xdebug in an isolated Playground.

Inputs required

• Host machine readiness: Node.js ≥ 20.18, npm/npx available.
• Project path to mount (--auto-mount or explicit mount mapping).
• Desired WP version/PHP version (optional; defaults to latest WP, PHP 8.3).
• Blueprint location/URL if running a blueprint.
• Port preference if 9400 conflicts.
• Whether Xdebug is needed.

Procedure

0) Guardrails

• Playground instances are ephemeral and SQLite-backed; never point at production data.
• Confirm Node ≥ 20.18 (node -v) before running CLI.
• If mounting local code, ensure it is clean of secrets; Playground copies files into an in-memory FS.

1) Quick local spin-up (auto-mount)

cd <plugin-or-theme-root>
npx @wp-playground/cli@latest server --auto-mount

• Opens on http://localhost:9400 by default. Auto-detects plugin/theme and installs it.
• Add --wp=<version> / --php=<version> as needed.
• For classic full installs already present, add --skip-wordpress-setup and mount the whole tree.

2) Manual mounts or multiple mounts

• Use --mount=/host/path:/vfs/path (repeatable) when auto-mount is insufficient (multi-plugin, mu-plugins, custom content).
• Mount before install with --mount-before-install for bootstrapping installer flows.
• Reference: references/cli-commands.md

3) Run a Blueprint (no server needed)

npx @wp-playground/cli@latest run-blueprint --blueprint=<file-or-url>

• Use for scripted setup/CI validation. Supports remote URLs and local files.
• Allow bundled assets in local blueprints with --blueprint-may-read-adjacent-files when required.
• See references/blueprints.md for structure and common flags.

4) Build a snapshot for sharing

npx @wp-playground/cli@latest build-snapshot --blueprint=<file> --outfile=./site.zip

• Produces a ZIP you can load in Playground or attach to bug reports.

5) Debugging with Xdebug

• Start with --xdebug (or --enable-xdebug depending on CLI release) to expose an IDE key, then connect VS Code/PhpStorm to the host/port shown in CLI output.
• Combine with --auto-mount for plugin/theme debugging.
• Checklist: references/debugging.md

6) Version switching

• Use --wp= to pin WP (e.g., 6.9.0) and --php= to test compatibility.
• If feature depends on Gutenberg trunk, prefer the latest WP release plus plugin if available; Playground images track stable WP plus bundled Gutenberg.

7) Browser-only workflows (no CLI)

• Launch quick previews with URL fragments or query params:
  • Fragment: https://playground.wordpress.net/#<base64-or-json-blueprint>
  • Query: https://playground.wordpress.net/?blueprint-url=<public-url-or-zip>
• Use the live Blueprint Editor (playground.wordpress.net) to author blueprints with schema help; paste JSON and copy a shareable link.

Verification

• Verify mounted code is active (plugin listed/active; theme selected).
• For blueprints/snapshots, re-run with --verbosity=debug to confirm steps executed.
• Run targeted smoke (e.g., wp plugin list inside Playground shell via browser terminal if exposed) or UI click-path.

Failure modes / debugging

• CLI exits complaining about Node: upgrade to ≥ 20.18.
• Mount not applied: check path, use absolute path, add --verbosity=debug.
• Blueprint cannot read local assets: add --blueprint-may-read-adjacent-files.
• Port already used: --port=<free-port>.
• Slow/locked UI: disable --experimental-multi-worker if enabled; or enable it to improve throughput on CPU-bound runs.

Escalation

• If PHP extensions or native DB access are required, Playground may be unsuitable; fall back to full WP stack or wp-env/Docker.
• For browser-only embedding or VS Code extension specifics, consult the upstream docs: https://wordpress.github.io/wordpress-playground/