d3k

name	d3k
description	Bootstrap d3k in standalone AI apps (Codex, Cursor, Claude Code): detect/install dev3000, start d3k as the runtime, and use unified logs plus CDP browser control instead of running npm/bun dev directly.

d3k Standalone Bootstrap

Use this skill when working in a standalone AI app and you need reliable local web debugging with browser + server context.

Why d3k-first

• d3k captures server logs, browser console, network events, and screenshots in one timeline.
• d3k exposes a stable CDP endpoint so the agent can control the same browser session being monitored.
• Running npm run dev or bun run dev directly omits this unified telemetry and usually leads to weaker diagnoses.

Bootstrap Workflow

1. Confirm whether d3k is installed:

command -v d3k >/dev/null && d3k --version

2. If d3k is missing, install dev3000 globally (prefer Bun):

bun install -g dev3000

Fallback if Bun is unavailable:

npm install -g dev3000

3. Start d3k as the runtime (preferred default in agent shells):

d3k --no-agent --no-tui -t

4. Keep d3k running while editing code. Do not start a second dev server with npm/bun dev.

Codex Fresh Browser/Profile Startup

Use this workflow when the user asks Codex to start d3k with a fresh browser/profile.

1. Close any stale agent-browser daemon before launching with --profile. Otherwise agent-browser will reuse the existing daemon and print --profile ignored.

   d3k agent-browser close --all
   

2. Start the app through d3k in servers-only mode and keep that command running. In Codex, this is more reliable than asking d3k to launch the browser itself when a fresh profile is required.

   d3k --no-agent --no-skills --servers-only --command "npm run dev -- -H 127.0.0.1 -p 3000" --port 3000 --startup-timeout 90 --no-tui
   

   Adjust the package-manager command and port for the project. Prefer --command over --script when passing framework flags. For npm scripts, put flags after --; otherwise tools like Next.js can interpret the port as a project directory.

3. Verify the server before opening more browser windows:

   curl -I http://127.0.0.1:3000
   

4. Open the fresh profile as a separate browser step:

   d3k agent-browser --profile /tmp/d3k-fresh-profile --headed open http://127.0.0.1:3000
   

5. Sanity-check the opened page:

   d3k agent-browser get title
   d3k agent-browser snapshot -i
   d3k errors
   

Practical rules:

• Prefer 127.0.0.1 for this workflow. If localhost hangs or flips between IPv4/IPv6 behavior, do not keep retrying browser launches.
• If curl -I hangs, the server is wedged even if the port appears occupied; restart the d3k server process before opening a browser.
• In servers-only mode there is no d3k-monitored CDP browser. Use regular d3k agent-browser commands, not d3k cdp-port.
• In sandboxed agent environments, rerun local-network checks and agent-browser opens outside the sandbox when sandbox networking blocks access to 127.0.0.1.

Debugging Commands

Use these first before ad-hoc log scraping:

d3k errors --context
d3k logs -n 200
d3k logs --type browser
d3k logs --type server

CDP Browser Control

Use the already-monitored browser session instead of launching a separate automation browser.

d3k agent-browser open http://localhost:3000
d3k agent-browser snapshot -i
d3k agent-browser click @e2
d3k agent-browser screenshot /tmp/d3k-current.png

d3k agent-browser auto-connects to the active session's browser via CDP. To target a different browser, run d3k agent-browser connect <port> first.

Browser Tool Choice

Use the browser tool that matches the task instead of treating them as interchangeable:

• agent-browser
  • Default choice.
  • Best for generic web apps and for driving the exact headed browser session that d3k is already monitoring via CDP.
  • Use it when you need snapshot, ref-based click, fill, or to reproduce what the user sees in the monitored tab.
• next-browser
  • Next.js-specific tool.
  • Best for React/Next introspection: tree, errors, logs, routes, project, PPR inspection, and related Next dev-server signals.
  • It is not a drop-in replacement for agent-browser: no accessibility snapshot, no ref-based click, and no fill.
  • It launches its own daemon/browser flow and does not use the d3k session's CDP port.

Practical rule:

• Need to drive the same browser d3k is monitoring: use agent-browser.
• Need Next.js component tree or Next-specific diagnostics: use next-browser.

Examples:

# Same monitored browser session
d3k agent-browser snapshot -i
d3k agent-browser click @e2

# Next.js-specific inspection
d3k next-browser open http://localhost:3000
d3k next-browser tree
d3k next-browser errors
d3k next-browser logs

Artifacts to Read

• ~/.d3k/{project}/d3k.log
• ~/.d3k/{project}/logs/
• ~/.d3k/{project}/screenshots/
• ~/.d3k/{project}/session.json

Operating Rules

• Prefer headed mode for interactive debugging.
• Use --headless only for CI or when explicitly requested.
• Use --servers-only only when browser monitoring is intentionally disabled.