npx skills add ...
npx skills add vercel-labs/dev3000 --skill d3k
npx skills add vercel-labs/dev3000 --skill d3k
Use when the user asks to use d3k, run/dev/test/debug a web project with d3k, or reproduce a browser issue. Own the runtime: reuse or background-start d3k non-interactively, wait for readiness, use its project-stable managed Chrome profile, and inspect unified browser/server evidence.
d3k is the local web runtime for this task. It starts the dev server behind a stable Portless URL, owns a project-stable Chrome profile, and records server logs, browser console output, network activity, interactions, and screenshots in one timeline.
When this skill triggers, operate d3k. Do not merely tell the user how to run it.
Run from the project root.
If it reports "running": true, reuse it. Do not start a second dev server or browser.
Use npm install -g dev3000 only when Bun is unavailable.
Do not wait for this long-running command to exit. Keep its process/session handle so you can monitor or stop it later. Prefer the execution tool's background/session support over shelling with &.
If the target URL is already known, pass it so the managed browser opens there:
Let d3k auto-detect the package manager, dev command, and port. Add --command, --script, or --port only when detection is wrong or the user specified them.
A successful status response is the readiness boundary. Prefer the reported Portless appUrl; the underlying app port may change between runs. If startup fails, inspect the retained process output and d3k logs --type server; do not launch a separate dev server.
When the user says "let me test":
"browserConnected": true.Do not replace the headed browser with automation while the user is testing.
Drive the exact browser d3k is monitoring:
Use --require-d3k-browser when opening a URL so failure cannot silently create another browser:
After every reproduction or code change, replay the relevant interaction and check d3k errors --context again.
Prefer these over ad-hoc log scraping:
Artifacts live under ~/.d3k/<project>/, including session.json, logs, screenshots, and the Chrome profile.
d3k must own browser startup by default. Its per-project Chrome profile preserves login state, cookies, and local storage.
For Google OAuth, Supabase auth, and other auth-sensitive flows, never substitute raw Chrome, Playwright, a browser MCP session, manual CDP attachment, or agent-browser --profile. Those paths use a different browser/profile and can trigger "This browser or app may not be secure."
If the managed browser is unavailable, stop or interrupt the retained d3k process and restart d3k cleanly. Do not work around it by creating another browser.
Use --headless only for CI or when explicitly requested. Use --servers-only only when browser monitoring is intentionally unwanted.
npm run dev, bun run dev, or another dev server alongside d3k.d3k status --json reports an active one.--no-portless or PORTLESS=0 only when direct localhost routing is explicitly required.d3k agent-browser snapshot -i
d3k agent-browser click @e2
d3k agent-browser fill @e3 "text"
d3k errors --contextd3k agent-browser --require-d3k-browser open "<url>"d3k status --json
d3k errors --context
d3k logs -n 200
d3k logs --type browser
d3k logs --type server