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
d3kcaptures server logs, browser console, network events, and screenshots in one timeline.d3kexposes a stable CDP endpoint so the agent can control the same browser session being monitored.- Running
npm run devorbun run devdirectly omits this unified telemetry and usually leads to weaker diagnoses.
Bootstrap Workflow
- Confirm whether
d3kis installed:
command -v d3k >/dev/null && d3k --version
- If
d3kis missing, install dev3000 globally (prefer Bun):
bun install -g dev3000
Fallback if Bun is unavailable:
npm install -g dev3000
- Start d3k as the runtime (preferred default in agent shells):
d3k --no-agent --no-tui -t
- 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.
-
Close any stale
agent-browserdaemon before launching with--profile. Otherwiseagent-browserwill reuse the existing daemon and print--profile ignored.d3k agent-browser close --all -
Start the app through d3k in
servers-onlymode 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-tuiAdjust the package-manager command and port for the project. Prefer
--commandover--scriptwhen passing framework flags. For npm scripts, put flags after--; otherwise tools like Next.js can interpret the port as a project directory. -
Verify the server before opening more browser windows:
curl -I http://127.0.0.1:3000 -
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 -
Sanity-check the opened page:
d3k agent-browser get title d3k agent-browser snapshot -i d3k errors
Practical rules:
- Prefer
127.0.0.1for this workflow. Iflocalhosthangs or flips between IPv4/IPv6 behavior, do not keep retrying browser launches. - If
curl -Ihangs, the server is wedged even if the port appears occupied; restart the d3k server process before opening a browser. - In
servers-onlymode there is no d3k-monitored CDP browser. Use regulard3k agent-browsercommands, notd3k cdp-port. - In sandboxed agent environments, rerun local-network checks and
agent-browseropens outside the sandbox when sandbox networking blocks access to127.0.0.1.
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-basedclick,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 accessibilitysnapshot, no ref-basedclick, and nofill. - 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
--headlessonly for CI or when explicitly requested. - Use
--servers-onlyonly when browser monitoring is intentionally disabled.