opera-browser-cli is a fork of chrome-devtools-axi. It wraps opera-devtools-mcp with an AXI-compliant CLI.

• Token-efficient — TOON-encoded output cuts token usage ~40% vs raw JSON
• Combined operations — one command navigates, captures, and suggests next steps
• Contextual suggestions — every response includes actionable next-step hints

Quick Start

npm install -g opera-browser-cli
opera-browser-cli setup   # interactive wizard — run in a terminal where you can answer prompts
opera-browser-cli open https://example.com

Once installed, open navigates to a URL and returns a structured snapshot you can act on:

$ opera-browser-cli open https://example.com
page: {title: "Example Domain", url: "https://example.com", refs: 1}
snapshot:
RootWebArea "Example Domain"
  heading "Example Domain"
  paragraph "This domain is for use in illustrative examples..."
  uid=1 link "More information..."
help[1]:
  Run `opera-browser-cli click @1` to click the "More information..." link

$ opera-browser-cli click @1
page: {title: "IANA — IANA-Managed Reserved Domains", refs: 12}
snapshot:
...

Opera Neon AI features

With Opera Neon and an active Opera account, you get four AI-powered commands:

opera-browser-cli chat "summarise this page"       # ask the built-in AI about the current page
opera-browser-cli invoke-do "book a table for 2"   # let the AI perform a multi-step browsing task
opera-browser-cli make "a todo app in vanilla JS"  # generate and open a webpage or mini-app
opera-browser-cli research "solid-state batteries" # in-depth research across multiple sources

Run opera-browser-cli setup to connect Neon, or opera-browser-cli doctor to check your configuration.

Install

Prerequisites: Node.js >= 20, Opera browser (Opera Neon recommended for AI features).

npm (recommended)

npm install -g opera-browser-cli

Run first-time setup — this is an interactive wizard, so run it in a terminal where you can answer prompts:

opera-browser-cli setup

This detects Opera installations, lets you pick one, saves configuration to ~/.opera-browser-cli/config, and installs the Claude Code skill to ~/.claude/skills/opera-browser-cli/SKILL.md.

Verify:

opera-browser-cli --version
opera-browser-cli open https://example.com

From source

# in this repo
npm install && npm run build && npm link

Then run opera-browser-cli setup as above.

Usage examples

# Basic navigation
opera-browser-cli open https://example.com

# Use Opera as the browser
OPERA_CLI_EXECUTABLE_PATH="/Applications/Opera.app/Contents/MacOS/Opera" \
  opera-browser-cli open https://example.com

# Headed mode (visible browser window)
OPERA_CLI_HEADED=1 opera-browser-cli open https://example.com

# Persistent profile (stay logged in across sessions)
OPERA_CLI_USER_DATA_DIR=~/.opera-profile opera-browser-cli open https://example.com

# Connect to already-running browser
OPERA_CLI_BROWSER_URL=http://127.0.0.1:9222 opera-browser-cli open https://example.com

How It Works

┌───────────────────────┐
│  opera-browser-cli  │  CLI — parse args, format output
└──────────┬────────────┘
           │ HTTP (localhost:9224)
           ▼
┌───────────────────────┐
│     Bridge Server     │  Persistent process, manages MCP session
└──────────┬────────────┘
           │ stdio
           ▼
┌───────────────────────┐
│  opera-devtools-mcp  │  Headless Chrome via DevTools Protocol
└───────────────────────┘

• Persistent bridge — a detached process keeps the MCP session alive across commands, so Chrome doesn't restart every invocation
• Auto-lifecycle — the bridge starts on first command and writes a PID file to ~/.opera-browser-cli/bridge.pid
• Snapshot parsing — accessibility tree snapshots are extracted and analyzed for interactive elements (uid= refs)
• TOON encoding — structured metadata uses TOON format for compact, token-efficient output

CLI Reference

Navigation

| Command | Description | | ----------------- | -------------------------------------------- | | open <url> | Navigate to URL and snapshot | | snapshot | Capture current page state | | screenshot <p> | Save a screenshot to a file | | scroll <dir> | Scroll: up, down, top, bottom | | back | Navigate back | | wait <ms\|text> | Wait for time or text to appear | | eval <js> | Evaluate a JavaScript expression or function | | run | Execute a multi-step script from stdin |

eval wraps plain input as () => (<expr>) before sending it to DevTools. For multi-statement logic, pass an arrow function, function, or IIFE yourself.

opera-browser-cli eval "document.title"
opera-browser-cli eval "(() => { const rows = [...document.querySelectorAll('tr')]; return rows.map((row) => row.textContent) })()"

Interaction

| Command | Description | | -------------------------- | ------------------------------ | | click @<uid> | Click an element by ref | | fill @<uid> <text> | Fill a form field | | type <text> | Type text at current focus | | press <key> | Press a keyboard key | | hover @<uid> | Hover over an element | | drag @<from> @<to> | Drag an element onto another | | fillform @<uid>=<val>... | Fill multiple form fields | | dialog <accept\|dismiss> | Handle a browser dialog | | upload @<uid> <path> | Upload a file through an input |

Page Management

| Command | Description | | ----------------- | --------------------------- | | pages | List all open tabs | | newpage <url> | Open a new tab | | selectpage <id> | Switch to a tab by ID | | closepage <id> | Close a tab by ID | | resize <w> <h> | Resize the browser viewport |

Emulation

| Command | Description | | --------- | ------------------------------- | | emulate | Emulate device/network/viewport |

DevTools Debugging

| Command | Description | | ------------------ | ------------------------------ | | console | List console messages | | console-get <id> | Get a specific console message | | network | List network requests | | network-get [id] | Get a specific network request |

Performance

| Command | Description | | --------------------------- | ----------------------------- | | lighthouse | Run a Lighthouse audit | | perf-start | Start a performance trace | | perf-stop | Stop the performance trace | | perf-insight <set> <name> | Analyze a performance insight | | heap <path> | Capture a heap snapshot |

Opera AI

Requires Opera Neon with an active Opera account.

| Command | Description | | ------------------- | --------------------------------------------- | | chat <prompt> | Send a chat message to Opera's built-in AI | | invoke-do <prompt>| Ask the AI to perform a complex browsing task | | make <prompt> | Ask the AI to build a webpage or app | | research <prompt> | Ask the AI to research a topic in depth |

research accepts --type local (default), --type one-minute, or --type deep.

Configuration

| Command | Description | | -------- | ------------------------------------------------ | | setup | Interactive first-time setup (browser path, etc) | | doctor | Check configuration and environment | | logs | Show bridge server logs |

Bridge

| Command | Description | | ------- | ----------------------- | | start | Start the bridge server | | stop | Stop the bridge server |

Running with no command shows the CLI home view. It prepends bin and description metadata, then includes the current snapshot when a browser session is active or the no-session status/help block when one is not.

Flags

| Flag | Description | | --------------------------- | ------------------------------------------- | | --help | Show usage information | | -v, -V, --version | Show the installed CLI version | | --full | Show complete output without truncation | | --background | Open new page in background (newpage) | | --uid @<uid> | Target a specific element (screenshot) | | --full-page | Capture entire scrollable page (screenshot) | | --format <fmt> | Image format: png, jpeg, webp (screenshot) | | --viewport <spec> | Viewport like "390x844x3,mobile" (emulate) | | --color-scheme <value> | dark, light, or auto (emulate) | | --network <condition> | Network throttle: Slow 3G, etc. (emulate) | | --cpu <rate> | CPU throttling rate 1-20 (emulate) | | --geolocation <lat>x<lon> | Set geolocation (emulate) | | --user-agent <string> | Custom user agent (emulate) | | --type <type> | Filter by type (console, network) | | --limit <n> | Max items to return (console, network) | | --page <n> | Pagination (console, network) | | --device <device> | desktop or mobile (lighthouse) | | --mode <mode> | navigation or snapshot (lighthouse) | | --output-dir <path> | Directory for reports (lighthouse) | | --no-reload | Skip page reload (perf-start) | | --no-auto-stop | Disable auto-stop (perf-start) | | --file <path> | Save trace data to file (perf-start/stop) | | --response-file <path> | Save response body (network-get) | | --request-file <path> | Save request body (network-get) |

Configuration

| Variable | Default | Purpose | | --- | --- | --- | | OPERA_CLI_PORT | 9224 | Bridge server port | | OPERA_CLI_MCP_BIN | (bundled opera-devtools-mcp) | Override the MCP server binary | | OPERA_CLI_EXECUTABLE_PATH | (system Chrome) | Custom browser binary | | OPERA_CLI_BROWSER_URL | — | Connect to an existing browser instance instead of launching one | | OPERA_CLI_USER_DATA_DIR | — | Persistent Chrome profile directory (skips isolated mode) | | OPERA_CLI_HEADED | — | Set to 1 to run in headed (visible) mode | | OPERA_CLI_CHROME_ARGS | — | Extra Chrome flags, space-separated | | OPERA_CLI_DISABLE_HOOKS | — | Set to 1 to skip auto-installing session hooks |

State is stored in ~/.opera-browser-cli/:

| File | Purpose | | ------------ | ---------------------------------- | | bridge.pid | PID and port of the running bridge |

Session Hooks

On supported agents, the packaged CLI also installs a SessionStart hook in ~/.claude/settings.json and ~/.codex/hooks.json, and enables codex_hooks in ~/.codex/config.toml.

Set OPERA_CLI_DISABLE_HOOKS=1 to skip that auto-install behavior.

Development entrypoints such as npm run dev and bin/opera-browser-cli.ts do not modify those hook files.

Local Setup (Full Stack)

Both opera-devtools-mcp and opera-browser-cli need to be built and linked so they're available in PATH.

1. Build and link opera-devtools-mcp:

# in the opera-devtools-mcp repo
npm install
npm run build
npm link

2. Build and link opera-browser-cli:

# in this repo
npm install
npm run build
npm link

3. Set the browser executable path:

export OPERA_CLI_EXECUTABLE_PATH="/Applications/Opera Neon.app/Contents/MacOS/Opera"

Tip: Set OPERA_CLI_MCP_BIN to point to the locally linked opera-devtools-mcp:

export OPERA_CLI_MCP_BIN=opera-devtools-mcp

Tip: Set OPERA_CLI_HEADED=1 to launch the browser in headed (visible) mode — useful during development to watch what's happening:

export OPERA_CLI_HEADED=1

Development

npm run build      # Compile TypeScript to dist/
npm run dev        # Run CLI directly with tsx
npm test           # Run tests with vitest
npm run test:watch # Run tests in watch mode