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vpzed-dev
vpzed-devOFFICIAL
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preview

Launches Windmill dev servers to preview flows, scripts, and apps visually.

1|Updated Aug 3, 2026
Search Tags:#dev server#preview#flow#visual verification#wmill#windmill#localhost proxy
One-click install
npx skills add https://github.com/vpzed-dev/smithy --skill preview-vpzed-dev
Or copy as Structured Prompt for Agent▼
Please help me install this Agent Skill.
Skill: preview
Source: https://github.com/vpzed-dev/smithy/tree/main/windmill/local-dev/.agents/skills/preview
Command: npx skills add https://github.com/vpzed-dev/smithy --skill preview-vpzed-dev

SYSTEM DOCUMENTATION & REQUIREMENTS

What problem does it solve? When developing Windmill flows, scripts, or apps, you often need to visually verify your work in the Windmill dev page, but choosing the right server mode (proxy vs direct), deciding who starts the server, and wiring up preview embedders correctly is error-prone and easy to get wrong. ## Core Features & Use Cases - Mode Selection Guidance: Decides between proxy mode (localhost URL for sandboxed embedders) and direct mode (remote HTTPS URL for regular browser tabs) based on what the preview consumer accepts. - Server Startup Handling: Starts wmill dev or wmill app dev in the background, captures the printed URL, and hands it to the user or an embedder without constructing URLs manually. - launch.json Integration: Writes per-target entries in .claude/launch.json for Claude Desktop / Code MCP preview tools, with unique ports per flow, script, or app so multiple previews coexist. - Use Case: After writing a new Windmill flow, ask for a preview and get a running dev server with the correct URL to open in your browser or IDE preview pane for live-reload visual verification. ## Quick Start Preview the flow at f/test/my_flow so I can visually verify it in the Windmill dev page.

Frequently Asked Questions about preview

High-intent search queries and answers about installing and using this skill.

FAQPage Schema
How do I preview a Windmill flow or script locally?▼

Run `wmill dev --path <wmill_path> --no-open` to start the dev server, which prints a URL to open in your browser. For a programmatic check instead, use `wmill flow preview <path> -d '<args>'` or `wmill script preview <path> -d '<args>'` to see the job result directly.

When should I use wmill dev proxy mode vs direct mode?▼

Use proxy mode (`--proxy-port <port>`) only when the preview embedder requires a localhost URL, such as sandboxed IDE or chat preview panes. Use direct mode for regular browser tabs, since the proxy adds an unnecessary localhost hop otherwise.

How do I preview a Windmill app instead of a flow?▼

Navigate into the app's `*__raw_app` directory and run `wmill app dev --no-open --port 4000`. It prints a local dev server URL that you can open in a browser or hand to a preview embedder.

Can I preview multiple Windmill flows at the same time?▼

Yes, by giving each flow, script, or app its own named entry in `.claude/launch.json` with a distinct port. Reusing a single generic entry causes previews to clobber each other.

Why is my Windmill preview URL broken or missing the workspace?▼

This happens when you construct the `/dev?path=...` URL yourself instead of using the proxy's root redirect. Always use `http://localhost:<port>/` so the proxy appends the workspace ID, auth token, and path automatically.

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