Install
bunx skills add vercel-labs/dev3000 --skill d3k --agent '*' -g -yWho it's for
d3k is for people debugging a Web app locally who want a coding assistant to see the full timeline. It starts your development server, opens a monitored browser with a project-stable Chrome profile, and folds server logs, browser errors, network activity, interactions, and screenshots into one timeline.
The main interface is the d3k skill: tell the assistant what you want to test or inspect, and let it take over the runtime. It is not a generic “open another browser” script, and it is not for starting your own extra development server and asking the assistant to guess logs.
You need Node.js 24 or newer. Skill install and runtime install are two commands; do not merge them into one line. In an environment without skill support, do not apply the skill-install command.
First try in 3 minutes
The official skill command is bunx skills add vercel-labs/dev3000 --skill d3k --agent '*' -g -y. The repository is https://github.com/vercel-labs/dev3000 Follow only that page. The official runtime command is bun install -g dev3000. The docs also say npm install -g dev3000 works, but the main path follows bun; do not invent a third installer.
Prerequisites: this machine has Node.js ≥ 24, a Web project that can start locally, and you accept the assistant launching a monitored browser. The skill installs on the assistant side (the command includes -g); the runtime installs as the global dev3000 package. After install, first confirm the assistant can talk about d3k, then decide whether to start it.
Low-risk first task: use a disposable local app. Tell the assistant clearly: start d3k non-interactively, keep the background process, reuse the browser it manages, and only look at the unified evidence. Before start, confirm the port and project directory; do not point it at production. Success signal: a timestamped timeline appears (logs, errors, network, or screenshots), and the assistant did not separately open another development server or another browser.
If you only want to confirm install first, ask the assistant “how to start d3k non-interactively” and approve only after you see the command it is about to run. The docs do not write a default port number or how to stop the process; on the first try, ask about stopping before you start.
Use cases
Case 1: Hand debugging to the d3k skill. After installing the skill, describe the page problem to reproduce and let the assistant own the runtime. This fits when you can already say in one sentence which page, which action, and which error you saw. The docs do not write a fixed slash command, so natural language is enough. If the assistant starts npm run dev itself and opens the system browser, tell it to switch to d3k. The comparison page is https://github.com/vercel-labs/dev3000
Case 2: After the global runtime is in, let the assistant start non-interactively and only read the timeline. The skill teaches the assistant: start non-interactively, keep the background process, reuse the hosted browser, inspect unified evidence — not open another server or browser. This fits when you are regressing a known interaction and need network and screenshots together. The docs do not list a timeline file path or UI address; you can only go as far as “after start, look at evidence in the entry the assistant gives.” Until you see the unified timeline, do not open a second monitor at the same time.
Limits
Version limit: Node.js 24 or newer. Install limit: the skill uses bunx skills add vercel-labs/dev3000 --skill d3k --agent '*' -g -y; the runtime uses bun install -g dev3000 (npm works too). Without skill support, do not apply the first command. Usage limit: the main interface is telling the assistant the goal and letting it take over the runtime; reuse the hosted browser and the unified timeline, do not open another server or browser. Scope limit: it covers the local development server, the monitored browser, logs, errors, network, interactions, and screenshots; the docs do not write remote environments or production probing. Stop and port details are not expanded; ask clearly on the first try before you start.