GitHub - simonw/rodney: CLI tool for interacting with the web
Extracto
CLI tool for interacting with the web. Contribute to simonw/rodney development by creating an account on GitHub.
Resumen
Resumen Principal
"Rodney" es una potente herramienta CLI escrita en Go, diseñada para la automatización de Chrome desde la línea de comandos. Su característica central es la capacidad de operar con una instancia persistente de Chrome headless, permitiendo que cada comando se conecte al mismo proceso de navegador de larga duración. Esta arquitectura simplifica significativamente el scripting de inter
Contenido
Rodney: Chrome automation from the command line
A Go CLI tool that drives a persistent headless Chrome instance using the rod browser automation library. Each command connects to the same long-running Chrome process, making it easy to script multi-step browser interactions from shell scripts or interactive use.
Architecture
rodney start → launches Chrome (headless, persists after CLI exits)
saves WebSocket debug URL to ~/.rodney/state.json
rodney connect H:P → connects to an existing Chrome on a remote debug port
saves WebSocket debug URL to ~/.rodney/state.json
rodney open URL → connects to running Chrome via WebSocket
navigates the active tab, disconnects
rodney js EXPR → connects, evaluates JS, prints result, disconnects
rodney stop → connects and shuts down Chrome, cleans up state
Each CLI invocation is a short-lived process. Chrome runs independently and tabs persist between commands.
Building
Requires:
- Go 1.21+
- Google Chrome or Chromium installed (or set
ROD_CHROME_BIN=/path/to/chrome)
Usage
Start/stop the browser
rodney start # Launch headless Chrome rodney start --show # Launch with visible browser window rodney start --insecure # Launch with TLS errors ignored (-k shorthand) rodney connect host:9222 # Connect to existing Chrome on remote debug port rodney status # Show browser info and active page rodney stop # Shut down Chrome
Navigate
rodney open https://example.com # Navigate to URL rodney open example.com # http:// prefix added automatically rodney back # Go back rodney forward # Go forward rodney reload # Reload page rodney reload --hard # Reload bypassing cache rodney clear-cache # Clear the browser cache
Extract information
rodney url # Print current URL rodney title # Print page title rodney text "h1" # Print text content of element rodney html "div.content" # Print outer HTML of element rodney html # Print full page HTML rodney attr "a#link" href # Print attribute value rodney pdf output.pdf # Save page as PDF
Run JavaScript
rodney js document.title # Evaluate expression rodney js "1 + 2" # Math rodney js 'document.querySelector("h1").textContent' # DOM queries rodney js '[1,2,3].map(x => x * 2)' # Returns pretty-printed JSON rodney js 'document.querySelectorAll("a").length' # Count elements
The expression is automatically wrapped in () => { return (expr); }.
Interact with elements
rodney click "button#submit" # Click element rodney input "#search" "query" # Type into input field rodney clear "#search" # Clear input field rodney file "#upload" photo.png # Set file on a file input rodney file "#upload" - # Set file from stdin rodney download "a.pdf-link" # Download href/src target to file rodney download "a.pdf-link" - # Download to stdout rodney select "#dropdown" "value" # Select dropdown by value rodney submit "form#login" # Submit a form rodney hover ".menu-item" # Hover over element rodney focus "#email" # Focus element
Wait for conditions
rodney wait ".loaded" # Wait for element to appear and be visible rodney waitload # Wait for page load event rodney waitstable # Wait for DOM to stop changing rodney waitidle # Wait for network to be idle rodney sleep 2.5 # Sleep for N seconds
Screenshots
rodney screenshot # Save as screenshot.png rodney screenshot page.png # Save to specific file rodney screenshot -w 1280 -h 720 out.png # Set viewport width/height rodney screenshot-el ".chart" chart.png # Screenshot specific element
Manage tabs
rodney pages # List all tabs (* marks active) rodney newpage https://... # Open URL in new tab rodney page 1 # Switch to tab by index rodney closepage 1 # Close tab by index rodney closepage # Close active tab
Query elements
rodney exists ".loading" # Exit 0 if exists, exit 1 if not rodney count "li.item" # Print number of matching elements rodney visible "#modal" # Exit 0 if visible, exit 1 if not rodney assert 'document.title' 'Home' # Exit 0 if equal, exit 1 if not rodney assert 'document.querySelector("h1") !== null' # Exit 0 if truthy
Accessibility testing
rodney ax-tree # Dump full accessibility tree rodney ax-tree --depth 3 # Limit tree depth rodney ax-tree --json # Output as JSON rodney ax-find --role button # Find all buttons rodney ax-find --name "Submit" # Find by accessible name rodney ax-find --role link --name "Home" # Combine filters rodney ax-find --role button --json # Output as JSON rodney ax-node "#submit-btn" # Inspect element's a11y properties rodney ax-node "h1" --json # Output as JSON
These commands use Chrome's Accessibility CDP domain to expose what assistive technologies see. ax-tree uses getFullAXTree, ax-find uses queryAXTree, and ax-node uses getPartialAXTree.
# CI check: verify all buttons have accessible names rodney ax-find --role button --json | python3 -c " import json, sys buttons = json.load(sys.stdin) unnamed = [b for b in buttons if not b.get('name', {}).get('value')] if unnamed: print(f'FAIL: {len(unnamed)} button(s) missing accessible name') sys.exit(1) print(f'PASS: all {len(buttons)} buttons have accessible names') "
Directory-scoped sessions
By default, Rodney stores state globally in ~/.rodney/. You can instead create a session scoped to the current directory with --local:
rodney start --local # State stored in ./.rodney/state.json # Chrome data in ./.rodney/chrome-data/ rodney open https://example.com # Auto-detects local session rodney stop # Cleans up local session
This is useful when you want isolated browser sessions per project — each directory gets its own Chrome instance, cookies, and state.
Auto-detection: When neither --local nor --global is specified, Rodney checks for ./.rodney/state.json in the current directory. If found, it uses the local session; otherwise it falls back to the global ~/.rodney/ session.
# Force global even when a local session exists rodney --global open https://example.com # Force local (errors if no local session) rodney --local status
The --local and --global flags can appear anywhere in the command:
rodney --local start
rodney start --local # Same effect
rodney open --global https://example.comAdd .rodney/ to your .gitignore to keep session state out of version control.
Shell scripting examples
# Wait for page to load and extract data rodney start rodney open https://example.com rodney waitstable title=$(rodney title) echo "Page: $title" # Conditional logic based on element presence if rodney exists ".error-message"; then rodney text ".error-message" fi # Loop through pages for url in page1 page2 page3; do rodney open "https://example.com/$url" rodney waitstable rodney screenshot "${url}.png" done rodney stop
Exit codes
Rodney uses distinct exit codes to separate check failures from errors:
| Exit code | Meaning |
|---|---|
0 |
Success |
1 |
Check failed — the command ran successfully but the condition/assertion was not met |
2 |
Error — something went wrong (bad arguments, no browser session, timeout, etc.) |
This makes it easy to distinguish between "the assertion is false" and "the command couldn't run" in scripts and CI pipelines.
Using Rodney for checks
Several commands return exit code 1 when a condition is not met, making them useful as assertions in shell scripts and CI pipelines. All of these print their result to stdout and exit cleanly — no error message is written to stderr.
exists — check if an element exists in the DOM
rodney exists "h1" # Prints "true", exits 0 rodney exists ".nonexistent" # Prints "false", exits 1
visible — check if an element is visible
rodney visible "#modal" # Prints "true" and exits 0 if the element exists and is visible rodney visible "#hidden-div" # Prints "false" and exits 1 if the element is hidden or doesn't exist
ax-find — check for accessibility nodes
rodney ax-find --role button --name "Submit" # Prints the matching node(s), exits 0 rodney ax-find --role banner --name "Nonexistent" # Prints "No matching nodes" to stderr, exits 1
assert — assert a JavaScript expression
With one argument, checks that the expression is truthy. With two arguments, checks that the expression's value equals the expected string. Use --message / -m to set a custom failure message.
# Truthy mode — check that expression evaluates to a truthy value rodney assert 'document.querySelector(".logged-in") !== null' # Prints "pass", exits 0 rodney assert 'document.querySelector(".nonexistent")' # Prints "fail: got null", exits 1 # Equality mode — check that expression result matches expected value rodney assert 'document.title' 'Dashboard' # Prints "pass" if title is "Dashboard", exits 0 rodney assert 'document.querySelectorAll(".item").length' '3' # Prints "pass" if there are exactly 3 items, exits 0 rodney assert 'document.title' 'Wrong Title' # Prints 'fail: got "Dashboard", expected "Wrong Title"', exits 1
The expression is evaluated the same way as rodney js — the result is converted to its string representation before comparison. This means rodney assert 'document.title' 'Dashboard' compares the unquoted string, and rodney assert '1 + 2' '3' compares the number as a string.
Use --message (or -m) to add a human-readable description to the failure output:
rodney assert 'document.querySelector(".logged-in")' -m "User should be logged in" # On failure: "fail: User should be logged in (got null)" rodney assert 'document.title' 'Dashboard' --message "Wrong page loaded" # On failure: 'fail: Wrong page loaded (got "Home", expected "Dashboard")'
Combining checks in a shell script
You can chain these together in a single script to run multiple assertions. Because check failures use exit code 1 while real errors use exit code 2, you can use set -e to abort on errors while handling check failures explicitly:
#!/bin/bash set -euo pipefail FAIL=0 check() { if ! "$@"; then echo "FAIL: $*" FAIL=1 fi } rodney start rodney open "https://example.com" rodney waitstable # Assert elements exist check rodney exists "h1" check rodney exists "nav" check rodney exists "footer" # Assert key elements are visible check rodney visible "h1" check rodney visible "#main-content" # Assert JS expressions check rodney assert 'document.title' 'Example Domain' check rodney assert 'document.querySelectorAll("p").length' '2' check rodney assert 'document.querySelector("h1") !== null' # Assert accessibility requirements check rodney ax-find --role navigation check rodney ax-find --role heading --name "Example Domain" rodney stop if [ "$FAIL" -ne 0 ]; then echo "Some checks failed" exit 1 fi echo "All checks passed"
This pattern is useful in CI — run Rodney as a post-deploy check, an accessibility audit, or a smoke test against a staging environment. Because exit code 2 signals an actual error (e.g. Chrome didn't start), set -e will abort the script immediately if something is broken rather than reporting a misleading test failure.
Configuration
| Environment Variable | Default | Description |
|---|---|---|
RODNEY_HOME |
~/.rodney |
Data directory for state and Chrome profile |
ROD_CHROME_BIN |
/usr/bin/google-chrome |
Path to Chrome/Chromium binary |
ROD_TIMEOUT |
30 |
Default timeout in seconds for element queries |
HTTPS_PROXY / HTTP_PROXY |
(none) | Authenticated proxy auto-detected on start |
Global state is stored in ~/.rodney/state.json with Chrome user data in ~/.rodney/chrome-data/. When using --local, state is stored in ./.rodney/state.json and ./.rodney/chrome-data/ in the current directory instead. Set RODNEY_HOME to override the default global directory.
Proxy support
In environments with authenticated HTTP proxies (e.g., HTTPS_PROXY=http://user:pass@host:port), rodney start automatically:
- Detects the proxy credentials from environment variables
- Launches a local forwarding proxy that injects
Proxy-Authorizationheaders into CONNECT requests - Configures Chrome to use the local proxy
This is necessary because Chrome cannot natively authenticate to proxies during HTTPS tunnel (CONNECT) establishment. The local proxy runs as a background process and is automatically cleaned up by rodney stop.
See claude-code-chrome-proxy.md for detailed technical notes.
How it works
The tool uses the rod Go library which communicates with Chrome via the DevTools Protocol (CDP) over WebSocket. Key implementation details:
startuses rod'slauncherpackage to start Chrome withLeakless(false)so Chrome survives after the CLI exits- Proxy auth handled via a local forwarding proxy that bridges Chrome to authenticated upstream proxies
- State persistence via a JSON file containing the WebSocket debug URL and Chrome PID
- Each command creates a new rod
Browserconnection to the same Chrome instance, executes the operation, and disconnects - Element queries use rod's built-in auto-wait with a configurable timeout (default 30s)
- JS evaluation wraps user expressions in arrow functions as required by rod's
Eval - Accessibility commands call CDP's Accessibility domain directly via rod's
protopackage (getFullAXTree,queryAXTree,getPartialAXTree)
Dependencies
- github.com/go-rod/rod v0.116.2 - Chrome DevTools Protocol automation
Commands reference
| Command | Arguments | Description |
|---|---|---|
start |
[--show] [--insecure|-k] |
Launch Chrome (headless by default, --show for visible) |
connect |
<host:port> |
Connect to existing Chrome on remote debug port |
stop |
Shut down Chrome | |
status |
Show browser status | |
open |
<url> |
Navigate to URL |
back |
Go back in history | |
forward |
Go forward in history | |
reload |
[--hard] |
Reload page (--hard bypasses cache) |
clear-cache |
Clear the browser cache | |
url |
Print current URL | |
title |
Print page title | |
html |
[selector] |
Print HTML (page or element) |
text |
<selector> |
Print element text content |
attr |
<selector> <name> |
Print attribute value |
pdf |
[file] |
Save page as PDF |
js |
<expression> |
Evaluate JavaScript |
click |
<selector> |
Click element |
input |
<selector> <text> |
Type into input |
clear |
<selector> |
Clear input |
file |
<selector> <path|-> |
Set file on a file input (- for stdin) |
download |
<selector> [file|-] |
Download href/src target (- for stdout) |
select |
<selector> <value> |
Select dropdown value |
submit |
<selector> |
Submit form |
hover |
<selector> |
Hover over element |
focus |
<selector> |
Focus element |
wait |
<selector> |
Wait for element to appear |
waitload |
Wait for page load | |
waitstable |
Wait for DOM stability | |
waitidle |
Wait for network idle | |
sleep |
<seconds> |
Sleep N seconds |
screenshot |
[-w N] [-h N] [file] |
Page screenshot (optional viewport size) |
screenshot-el |
<selector> [file] |
Element screenshot |
pages |
List tabs | |
page |
<index> |
Switch tab |
newpage |
[url] |
Open new tab |
closepage |
[index] |
Close tab |
exists |
<selector> |
Check element exists (exit 1 if not) |
count |
<selector> |
Count matching elements |
visible |
<selector> |
Check element visible (exit 1 if not) |
assert |
<expr> [expected] [-m msg] |
Assert JS expression is truthy or equals expected (exit 1 if not) |
ax-tree |
[--depth N] [--json] |
Dump accessibility tree |
ax-find |
[--name N] [--role R] [--json] |
Find accessible nodes |
ax-node |
<selector> [--json] |
Show element accessibility info |
Global flags
| Flag | Description |
|---|---|
--local |
Use directory-scoped session (./.rodney/) |
--global |
Use global session (~/.rodney/) |
--version |
Print version and exit |
--help, -h, help |
Show help message |
Fuente: GitHub