How do I install dev-browser?

Run these in Claude Code: /plugin marketplace add SawyerHood/dev-browser then /plugin install dev-browser@dev-browser-marketplace. Then prompt normally.

Does dev-browser auto-invoke its skills?

Not yet. It is indexed on Flowy as a plain plugin. Request auto-invocation on its page and Flowy will route its skills for you as you prompt.

Yes. Flowy is free and open source, with nothing gated. You can read every skill in full before you install.

Automation

Plugin

dev-browser

A Claude Skill to give your agent the ability to use a web browser

Boost this plugin

sawyerhood@sawyerhood

GitHub

Plugin Signal64/100Solid

maintained92

capable14

documented75

adopted81

Install on Claude Code

> /plugin marketplace add SawyerHood/dev-browser
> /plugin install dev-browser@dev-browser-marketplace

Stats

TypeScript JavaScript Node CSS Bash

+6 tags

Linux GitHub Playwright Anthropic MCP Bun

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Stars

433

Forks

Active

Maintenance

TypeScript

Language

MIT

License

16d ago

Last commit

9mo ago

Created

Repo: SawyerHood/dev-browser

In this plugin

1 skill

- dev-browser

See everything inside

What's inside

Skill(1 skill)

/dev-browserBrowser automation with persistent named pages via the dev-browser CLI. Use when users ask to navigate websites, fill forms, take screenshots, extract web data, test web apps, log into sites, or automate browser workflows. Trigger phrases include "go to [url]", "click on", "fill

README

Read on GitHub

Brought to you by Do Browser.

dev-browser lets coding agents control Chrome with short JavaScript scripts. The browser stays open between calls, so an agent can navigate once, inspect the page, act, and verify the result without starting over each time.

Key features:

Persistent pages. Named tabs carry state across scripts.
Compact snapshots. Accessibility trees give agents readable output and stable element refs.
Real Puppeteer. Scripts use the Puppeteer Page API plus a small set of agent-focused helpers.
Launch or attach. Start an isolated Chrome profile or connect to a browser you already have open.

Demo

https://github.com/user-attachments/assets/c6cf7fb9-b1dc-46ed-93b9-6e7240990c53

CLI installation

npm install -g dev-browser
dev-browser install    # only needed if dev-browser cannot find Chrome

The release binary includes Bun and Puppeteer. Node is not required after installation. macOS and glibc Linux are supported; Windows and musl Linux are not yet supported.

Snap-packaged Chromium cannot read the default ~/.dev-browser/v1 directory. On Ubuntu, use dev-browser install or point DEV_BROWSER_CHROME at another Chrome binary.

If your package manager blocks lifecycle scripts, run npm rebuild -g dev-browser, pnpm approve-builds -g dev-browser, or bun pm -g trust dev-browser. The CLI will also try to download its binary on first use. For a private mirror, set DEV_BROWSER_DOWNLOAD_BASE; set DEV_BROWSER_SKIP_DOWNLOAD=1 if you install the binary yourself.

Quick start

# Launch a headless browser and run a script
dev-browser --headless <<'EOF'
const page = await browser.getPage("main");
await page.goto("https://example.com");
console.log(await page.title());
EOF

# Attach to Chrome started with `dev-browser chrome`
dev-browser chrome
dev-browser --connect <<'EOF'
console.log(await browser.listPages());
EOF

Chrome 136 and newer ignore remote-debugging flags on the default profile. dev-browser chrome handles this by using a dedicated profile and checking that Chrome actually started.

Using it with coding agents

Tell the agent to run dev-browser --help. The built-in guide covers the current API and the preferred look → act → verify workflow.

Agents that discover local skills can install the bundled skill explicitly:

dev-browser install-skill --codex   # ~/.codex/skills/dev-browser/SKILL.md
dev-browser install-skill --claude  # ~/.claude/skills/dev-browser/SKILL.md
dev-browser install-skill --agents  # ~/.agents/skills/dev-browser/SKILL.md

Run dev-browser install-skill without flags to update all three locations.

Idle browser cleanup

Launched browsers close after 30 minutes without a script by default. Change that per command, in the environment, or in ~/.dev-browser/v1/config.json:

dev-browser --idle-timeout 5m < script.js
DEV_BROWSER_IDLE_TIMEOUT=1h dev-browser -e 'await browser.listPages()'

{
  "idleTimeout": "5m"
}

Durations accept 30s, 5m, 1h, or raw milliseconds. Set the value to 0 to keep a launched browser open until dev-browser stop. Attached browsers are never closed by idle cleanup. Profiles, cookies, and login state remain on disk when a launched browser closes.

Add dev-browser to the allow list in .claude/settings.json for one project or ~/.claude/settings.json for every project:

{
  "permissions": {
    "allow": ["Bash(dev-browser *)"]
  }
}

This allows any matching command without another prompt. Only do this where you trust the scripts being run: node:vm gives each script fresh globals, but it is not a security sandbox.

/plugin marketplace add sawyerhood/dev-browser
/plugin install dev-browser@sawyerhood/dev-browser

Restart Claude Code after installation.

Script API

Scripts get these globals:

// Browser control
browser.getPage(nameOrId)    // Get/create a named page, or attach by target ID
browser.newPage()            // Create an anonymous page; close it yourself
browser.listPages()          // [{ id, url, title, name }]
browser.closePage(name)      // Close a named page

// File I/O, restricted to ~/.dev-browser/v1/tmp
saveFile(name, data)
readFile(name)

// Output
console.log()
console.warn()
console.error()

Top-level await works, and the last expression becomes the command result. Pages are real Puppeteer Page objects with a few additions:

await page.snapshot({ interactive: true }) // Accessibility tree with refs such as e12
await page.click("ref/e12")                 // Refs work in Puppeteer selector methods
await page.ref("e12")                       // ElementHandle for a ref
await page.shot()                           // JPEG path and CSS-pixel dimensions
await page.waitForLoad()                    // Wait for navigation, requests, and DOM activity to settle
await page.fill("#email", "me@example.com")

Each command runs in a fresh node:vm context inside the daemon. This keeps script globals separate, but it is not a security boundary. When a command finishes or times out, its page, locator, browser-context, and registry operations are closed so detached work cannot interfere with the next command.

Scripts may run concurrently. Browser and page creation are serialized, as are input operations on different tabs through a bring-to-front lock. Two scripts using the same named page can still interleave.

See dev-browser --help for the full API, error behavior, configuration, JSON output, MCP tools, and examples.

Connecting to an existing browser

--connect accepts auto-discovery, a port, an HTTP URL, a WebSocket URL, or a raw CDP Unix socket:

dev-browser chrome --profile work
dev-browser --connect -e 'await browser.listPages()'
dev-browser --connect 9222 -e 'await browser.listPages()'
dev-browser --connect 'wss://provider.example?token=…' -e 'await browser.listPages()'

Attached browsers belong to the user. dev-browser extends only the tabs a script asks for and never closes the browser because of an idle timeout. Credentials are redacted from logs and status output, while differently authenticated endpoints remain separate sessions.

MCP

claude mcp add dev-browser -- dev-browser mcp --headless

The server exposes dev_browser_run, dev_browser_pages, dev_browser_browsers, dev_browser_stop, and dev_browser_help over the same warm daemon as the CLI.

Upgrading to 1.0

Version 1.0 replaces the Playwright/QuickJS implementation from dev-browser 0.2 with the Puppeteer/Bun implementation developed as doobie. Its state lives under ~/.dev-browser/v1, separate from both older installations.

To copy durable doobie state:

doobie stop
dev-browser migrate-from-doobie

migrate-from-doobie leaves ~/.doobie untouched. Scripts written for dev-browser 0.2 need to replace helpers such as snapshotForAI() and getByRef() with snapshot() and ref/eN. Computer-use helpers under page.cua and page.domCua are not part of 1.0.

Benchmarks

Measured on Linux with a headless browser and warm daemon, medians of 9 runs:

Scenario	Time
Empty script	~13 ms
`getPage("x")` + `page.title()`	~14 ms
`page.snapshot()` on a SERP-like page	~18 ms
`page.shot()`	~36 ms
Cold daemon and Chrome launch	~280 ms

Run them with bun run build && bun run bench/run.ts --runs 9. The older end-to-end comparison is in dev-browser-eval.

Development

bun install
bun run dev -- -e '1+1'
bun test
bun run build

Design notes live in docs/design-decisions.md.

Releasing

See RELEASING.md for release-candidate testing, npm trusted publishing, and post-release verification.

License

MIT

Author

Sawyer Hood

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FAQ

dev-browser is a Claude Code plugin with 1 hand-picked skill for automation work, indexed on Flowy. Install it with the command on its page. It includes dev-browser. Its skills do not fire on their own yet. Request auto-invocation to have Flowy route them as you prompt. Free and open source.

What is dev-browser?: A Claude Skill to give your agent the ability to use a web browser
How do I install dev-browser?: Run these in Claude Code: /plugin marketplace add SawyerHood/dev-browser then /plugin install dev-browser@dev-browser-marketplace. Then prompt normally.
Does dev-browser auto-invoke its skills?: Not yet. It is indexed on Flowy as a plain plugin. Request auto-invocation on its page and Flowy will route its skills for you as you prompt.
Is dev-browser free?: Yes. Flowy is free and open source, with nothing gated. You can read every skill in full before you install.

Is this plugin yours?

Claim it with GitHub Submit a plugin Promote it

# Launch a headless browser and run a script dev-browser --headless <<'EOF' const page = await browser.getPage("main"); await page.goto("https://example.com"); console.log(await page.title()); EOF # Attach to Chrome started with `dev-browser chrome` dev-browser chrome dev-browser --connect <<'EOF' console.log(await browser.listPages()); EOF

dev-browser install-skill --codex # ~/.codex/skills/dev-browser/SKILL.md dev-browser install-skill --claude # ~/.claude/skills/dev-browser/SKILL.md dev-browser install-skill --agents # ~/.agents/skills/dev-browser/SKILL.md

// Browser control browser.getPage(nameOrId) // Get/create a named page, or attach by target ID browser.newPage() // Create an anonymous page; close it yourself browser.listPages() // [{ id, url, title, name }] browser.closePage(name) // Close a named page // File I/O, restricted to ~/.dev-browser/v1/tmp saveFile(name, data) readFile(name) // Output console.log() console.warn() console.error()

await page.snapshot({ interactive: true }) // Accessibility tree with refs such as e12 await page.click("ref/e12") // Refs work in Puppeteer selector methods await page.ref("e12") // ElementHandle for a ref await page.shot() // JPEG path and CSS-pixel dimensions await page.waitForLoad() // Wait for navigation, requests, and DOM activity to settle await page.fill("#email", "me@example.com")

dev-browser chrome --profile work dev-browser --connect -e 'await browser.listPages()' dev-browser --connect 9222 -e 'await browser.listPages()' dev-browser --connect 'wss://provider.example?token=…' -e 'await browser.listPages()'

Scenario

Time

Empty script

~13 ms

getPage("x") + page.title()

~14 ms

page.snapshot() on a SERP-like page

~18 ms

page.shot()

~36 ms

Cold daemon and Chrome launch

~280 ms