Crystallize shared understanding into a reviewable spec, or update an existing one. Use when the problem needs a written specification, when assumptions or decisions have changed, or when the user says 'write a spec'.
Lightweight triage for the ln-* skill set. Use when unsure which ln skill to use next, starting work on something new, or when the user asks for guidance on their development process.
Explore radically different module shapes before committing to one. Use when choosing an API surface, deciding what a module hides vs exposes, or when the user says 'design it twice'.
Collapse meaningful ambiguity with contrastive examples. Use when a plan/design has several plausible meanings, requirements feel vague, examples would clarify intent faster than grilling, or the user asks to disambiguate, find ambiguity, use behavioral kernels, or ask contrastive questions.
Audit code quality focusing on deep modules, naming, model hygiene, and architectural clarity. Use after a burst of development, when codebase structure needs assessment, or to make code more agent-navigable.
Refresh `memory/SPEC.md` and `memory/PLAN.md` in mature mode — restore canonical truth, archive retired plan history, delete stale derivative artifacts, and flag drift against code.
| name | d3k |
| description | d3k assistant for debugging web apps |
d3k captures browser and server logs in a unified log file. Use these commands:
d3k errors # Show recent errors (browser + server combined)
d3k errors --context # Show errors + user actions that preceded them
d3k errors -n 20 # Show last 20 errors
d3k logs # Show recent logs (browser + server combined)
d3k logs --type browser # Browser logs only
d3k logs --type server # Server logs only
d3k fix # Deep analysis of application errors
d3k fix --focus build # Focus on build errors
d3k crawl # Discover app URLs
d3k crawl --depth all # Exhaustive crawl
d3k agent-browser auto-connects to the active session's browser via CDP:
d3k agent-browser open http://localhost:3000/page
d3k agent-browser snapshot -i # Get element refs (@e1, @e2)
d3k agent-browser click @e2
d3k agent-browser fill @e3 "text"
d3k agent-browser screenshot /tmp/shot.png
To target a different browser, run d3k agent-browser connect <port> first.
Use this workflow when the user asks Codex to start d3k with a fresh browser/profile.
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
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.
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:
127.0.0.1 for this workflow. If localhost hangs or flips between IPv4/IPv6 behavior, do not keep retrying browser launches.curl -I hangs, the server is wedged even if the port appears occupied; restart the d3k server process before opening a browser.servers-only mode there is no d3k-monitored CDP browser. Use regular d3k agent-browser commands, not d3k cdp-port.agent-browser opens outside the sandbox when sandbox networking blocks access to 127.0.0.1.Use agent-browser for browser work.
Practical rule:
agent-browser.d3k agent-browser snapshot -i
d3k agent-browser click @e2
To make d3k prefer one locally when it launches helper browser commands, use:
d3k --browser-tool agent-browser
d3k errors --context - See errors and what triggered themd3k agent-browser open <url> then d3k agent-browser click @e1 to replayd3k errors - Verify fix workedWhen creating a PR for visual changes, always capture before/after screenshots to show the impact:
Before making changes, screenshot the production site:
d3k agent-browser open https://production-url.com/affected-page
d3k agent-browser screenshot /tmp/before.png
After making changes, screenshot localhost:
d3k agent-browser open http://localhost:3000/affected-page
d3k agent-browser screenshot /tmp/after.png
Or use the tooling API to capture multiple routes at once:
capture_before_after_screenshots(
productionUrl: "https://myapp.vercel.app",
routes: ["/", "/about", "/contact"]
)
Include in PR description using markdown:
### Visual Comparison
| Route | Before | After |
|-------|--------|-------|
| `/` |  |  |
Upload screenshots by dragging them into the GitHub PR description.