chrome-agent-0.15.0 is not a library.

chrome-agent

Disclaimer: This is an independent, community-driven project. It is not affiliated with, endorsed by, or sponsored by Google or the Chrome team.

You're not the user. Your LLM is.

You don't need to read this README. Your agent does. Install it, run chrome-agent --help, and let the LLM figure it out. The CLI embeds its own usage guide, every error comes with a hint for the next action, and --json gives an agent structured data without you writing an adapter. This page is here because GitHub expects one.

The one thing it does that others don't

Every browser tool can hand a page to a model. The question is what shape it arrives in.

chrome-agent goto news.ycombinator.com
chrome-agent --json extract --limit 30

{"ok":true,"count":30,"pattern":"TR.athing.submission","items":[
  {"title":"PGSimCity - How PostgreSQL Works",
   "url":"https://nikolays.github.io/PGSimCity/",
   "fields":["PGSimCity - How PostgreSQL Works (nikolays.github.io)"]},
  ...
]}

No selectors. No model call to find the rows. The pattern is detected structurally, with MDR/DEPTA-style heuristics that score sibling similarity, content heterogeneity and text-to-link ratio.

Measured on that page with scripts/measure.sh, which you can run yourself:

what you hand the model	tokens	what it gets
`extract --limit 30`	1,571	30 stories as records, with URLs
`inspect` (accessibility tree)	5,652	the tree, stories mixed into the surrounding page
raw HTML	8,727	everything, including markup nobody reads

All three contain the same 30 stories. Only the first hands them over as records. The others hand over the page and leave the model to find the stories in it, which you pay for twice: once in input tokens, again in the reasoning to parse them.

How wide that gap is depends on the page. On a blog archive that is nothing but a list, extract returns ~12,500 tokens against ~16,100 for the tree, because there is little surrounding markup to strip. The win comes from pages where the records sit inside a lot of other page furniture.

Every rival makes an agent either write per-site selectors, which break on the next deploy, or pay a model to read the DOM, which is the recurring cost this tooling exists to avoid.

How is this different from agent-browser?

agent-browser (Vercel) is the closest thing to this, it is also a Rust CLI built for agents, and it is well ahead: more features, more users, near-daily releases. If you want a platform, use it. Two honest differences:

	chrome-agent	agent-browser
Repeating-record extraction	`extract`, structural, no LLM call	not built in; `read` returns readable text
Bot detection	7 in-binary CDP patches, `--connect` to real Chrome	no stealth in core; delegated to paid cloud providers
Process model	one command, one connection, exits	background daemon
Element IDs	`backendNodeId`, still valid on the next inspect of the same page	sequential `@e1`, reassigned on every snapshot
Browser-native downloads	`download --uid/--selector` clicks and captures the file, and says so when none began	supported
MCP server	none	yes

Where it is genuinely behind: agent-browser has an encrypted credential vault, cloud provider integrations and an MCP mode. It also reuses your real Chrome profile, same as --copy-cookies here, so logged-in access is not a differentiator for either of us.

Why you shouldn't use chrome-agent

Borrowed from ripgrep, because the fastest way to waste your afternoon is a README that only lists strengths.

You need a test framework. Use Playwright. Assertions, retries, trace viewer, a test runner, and Microsoft maintaining it.
You want a supported product. This is one person's project. No SLA, no roadmap promises, no enterprise support.
You need MCP. There is no MCP server here. If your coding agent can't shell out, this is the wrong tool.
You need a browser fleet. No cloud, no proxy pool, no CAPTCHA solving. Browserbase, Steel and Browserless do that.
Your target is behind DataDome or Kasada. --stealth won't get you through. You'll need --connect to a real Chrome, and even then, no promises.
You need Firefox or Safari. This speaks CDP. Chrome only.

What it's built on

One binary, zero runtime. No Node, no npm, no Playwright download. Linux builds are static (musl), so they run on any distro without a glibc version to match.
Errors are instructions. Every failure carries a hint for the next action: {"ok":false,"error":"...","hint":"run inspect"}.
Stable element IDs. uids come from Chrome's backendNodeId, so n82 still points at the same node on the next inspect. They do change after a navigation, and diff will tell you when that happened instead of pretending to compare two different pages.
Sessions persist. Chrome stays alive between calls, so a command costs a connection, not a browser launch.
Parallel agents don't collide. --browser agent1, --browser agent2, separate Chrome instances and separate session state.

chrome-agent (3 MB Rust binary)
    | CDP over WebSocket
    v
Chrome (headless, no Node.js, no runtime)

Install

# For AI agents -- installs a SKILL.md your agent reads automatically
npx skills add sderosiaux/chrome-agent

# Or just the binary
npm install -g chrome-agent    # prebuilt
npx chrome-agent --help        # no install
cargo install chrome-agent     # from source

Quick start

# Navigate and see the page
chrome-agent goto https://example.com --inspect

# Click by uid
chrome-agent click n12 --inspect

# Fill a form
chrome-agent fill --uid n20 "user@test.com"

# CSS selectors work too
chrome-agent click --selector "button.submit"
chrome-agent fill --selector "input[name=email]" "hello@test.com"

# Article content (Readability -- like Firefox Reader Mode)
chrome-agent read

# Visible text, scoped and capped
chrome-agent text --selector "main" --truncate 500

# Run JS
chrome-agent eval "document.title"

# Screenshot (returns a file path, not binary)
chrome-agent screenshot

Commands

Navigation

Command	What it does
`goto <url> [--inspect] [--max-depth N] [--header "K: V"]`	Navigate. Auto-prefixes `https://`. `--header` (repeatable) sends extra HTTP headers.
`back`	History back.
`forward`	History forward.
`close [--purge]`	Stop browser. `--purge` deletes cookies/profile.
`close --orphans`	Close every running browser no session entry claims. `status` lists them; the profiles they leave are what `--purge-orphans` sweeps.

Inspection

Command	What it does
`inspect [--verbose] [--max-depth N] [--uid nN] [--filter "role,role"] [--scroll] [--limit N] [--urls] [--max-chars N] [--offset K]`	a11y tree with UIDs. `--scroll --limit` for infinite scroll. `--urls` resolves href on links. `--max-chars`/`--offset` cap and page the output. Every one of these narrows what is PRINTED only: the snapshot stored for `diff` is the full tree, and every uid on the page stays actionable.
`diff`	What changed since last inspect. Compared against the FULL tree, whatever narrowing flags the inspect printed with — a `--filter`ed view is not a baseline, and using one reports every node the filter hid as an addition.
`screenshot [--filename name] [--format jpeg\|png] [--quality N] [--max-width N] [--uid nN\|--selector "css"]`	Screenshot to file. JPEG/quality/max-width shrink it; `--uid`/`--selector` clip to one element.
`pdf [--filename name] [--landscape] [--background]`	Print the current page to a PDF file.
`tabs`	List open tabs.

Interaction

Command	What it does
`click <uid> [--inspect]`	Click by uid. Falls back to JS `.click()` when no box model.
`click --selector "css" [--inspect]`	Click by CSS selector.
`click --xy 100,200`	Click by coordinates.
`dblclick <uid> [--inspect]`	Double-click by uid, `--selector`, or `--xy`.
`fill --uid <uid> <value> [--inspect]`	Fill input by uid.
`fill --selector "css" <value>`	Fill by selector.
`fill-form <uid=val>...`	Batch fill.
`select --uid <uid> <value>`	Select dropdown option by value or visible text.
`select --selector "css" <value>`	Select by CSS selector.
`check <uid>`	Ensure checkbox/radio is checked. Idempotent.
`uncheck <uid>`	Ensure checkbox/radio is unchecked. Idempotent.
`upload --uid <uid> <file>...`	Upload file(s) to a file input.
`upload --selector "css" <file>...`	Upload by CSS selector.
`drag <from-uid> <to-uid>`	Drag element to another element.
`type <text> [--selector "css"]`	Type into focused element.
`press <key>`	Enter, Tab, Escape, etc.
`scroll <down\|up\|uid>`	Scroll page or element into view.
`hover <uid>`	Hover.
`wait <text\|url\|selector> <pattern>`	Wait for a condition.
`wait network-idle [--idle-ms N] [--timeout N]`	Wait until the network is quiet for `--idle-ms` (default 500). Beats fixed sleeps for SPA/XHR settle.

Assertions

The exit code is the answer: 0 the claim held, 2 it did not, 1 it could not be checked (no browser, a selector matching nothing, an unparseable regex, a CDP timeout). No other command returns 2, and a bad flag exits 1 — so a CI job can tell "the page is wrong" from "the tool broke".

Command	What it does
`assert value (--selector "css"\|--uid <uid>) (--equals\|--contains\|--matches) <s>`	A form control's value. Secret fields are compared but never printed.
`assert text (--contains\|--matches) <s> [--selector "css"\|--uid <uid>]`	Visible text of the page, or of one element.
`assert url (--equals\|--matches) <s>`	The current URL.
`assert state (--selector "css"\|--uid <uid>) (--checked\|--unchecked\|--selected <opt>\|--enabled\|--disabled\|--visible)`	Checked (native or `aria-checked`), the `<select>`'s option, disabled (`:disabled` or `aria-disabled`), or rendered.
`assert exists --selector "css" [--count N\|--min N]`	How many elements match. `--count 0` asserts absence.

chrome-agent fill --selector "#coupon" "SAVE10"
chrome-agent assert value --selector "#coupon" --equals "SAVE10"; echo $?
# 0 if the field holds it. 2 if a mask or a controlled component rewrote it — and the
# response then names what the page kept: {"actual":"","held":false}

chrome-agent assert state --selector "#terms" --checked      # reads the same classification check/uncheck apply
chrome-agent assert exists --selector ".result" --min 1

assert is a read: no change report, no verdict, and it never clicks. --matches is a Rust regex (\d/\w/\s are ASCII-only, no \p{...}; (?i) works). In batch/pipe there is no exit code — a failed assertion is ok:false with the same assertion object.

Content extraction

Command	What it does
`read [--html] [--truncate N]`	Article extraction via Mozilla Readability.
`text [uid] [--selector "css"] [--truncate N]`	Visible text from page or element.
`eval <expression> [--selector "css"]`	JS in page context. `el` = matched element.
`extract [--selector "css"] [--limit N] [--scroll] [--a11y]`	Auto-detect repeating data. `--a11y` for React SPAs (X.com).
`download <url> [--out path] [--timeout N] [--max-bytes N]`	Download a URL fetched in-page, so cookies/auth carry over (login-gated files). Rejects responses over 64 MiB by default. Returns `{path,bytes,mime}`.
`download --uid n47 \| --selector "css"`	Click the element and capture the browser-native download it triggers — the only route to a file built in the page (`Blob`) or served by a POST no anchor names. Returns `{path,bytes,suggested_filename,source_url,delivery}`. A click that landed and produced nothing answers `ok:true` with `downloaded:false`.

Monitoring

Command	What it does
`network [--filter "pattern"] [--body] [--live N] [--abort "pattern"]`	Network requests and API responses. `--abort` blocks matching requests.
`console [--level error] [--clear]`	console.log/warn/error + JS exceptions.

Advanced

Command	What it does
`frame <selector\|main>`	Switch `eval`/`inspect` into an iframe (or back to main). Persists only within a `pipe`/`batch` process.
`emulate device --width W --height H [--dpr N] [--mobile] [--touch] [--orientation portrait\|landscape] [--label name]`	Apply explicit device metrics to the current named page.
`emulate status\|reset`	Report requested and page-observed metrics, or clear that page's overrides.
`webmcp list`	List tools a page registered on `document.modelContext`. No `outputSchema` — the protocol defines none.
`webmcp call <name> [--args '{"k":"v"}'] [--inspect]`	Call a tool by name and report what it declared next to what the page's accessibility tree measurably did.
`batch`	Execute multiple commands from a JSON array on stdin.
`pipe`	Persistent JSON stdin/stdout connection.
`status`	Which browsers the session store knows, their pids, and the running ones no entry claims (`orphan=` lines).
`history`	The pages this browser visited.
`replay <file>`	Re-run a `pipe --record` file command by command. `macro` is the guarded, parameterised form of the same idea — see below.

Global flags

These are accepted on either side of the verb: fill --selector "#q" x --json works as well as --json fill --selector "#q" x. The exceptions are --timeout and --max-depth. A command that declares its own takes it after the verb (wait selector ".x" --timeout 5 keeps wait's 10 s default, not the global 30 s); everywhere else those two must come before it, and passing one where it is not declared is a usage error naming the invocation which works.

--browser <name>         Named browser profile (default: "default")
--page <name>            Named tab (default: "default")
--connect <auto|url>     Attach to a running Chrome (a value is required: "auto", or a
                         ws:// or http:// URL)
--proxy-server <url>     Proxy a managed Chrome (http(s), socks4/5; explicit port required)
--headed                 Show browser window (default: headless)
--stealth                Anti-detection patches. Clears a Cloudflare JS challenge
                         ("Just a moment..."); does NOT clear a managed Turnstile or
                         DataDome -- see the protection table below
--copy-cookies           Use cookies from your real Chrome profile
--chrome-arg <flag>      Extra flag for the Chrome chrome-agent launches (repeatable)
--timeout <seconds>      Command timeout (default: 30)
--max-depth <N>          Limit inspect depth
--verdict <mode>         auto (default): an action reports what changed. off: report the action only
--budget <chars>         Cap that change report (default 1200; 0 = uncapped)
--on-intercept <mode>    dispatch (default), guard, or refuse — see the table below
--ignore-https-errors    Accept self-signed certs
--json                   Structured JSON output
--dialog <mode>          JS dialog policy: accept (default), dismiss, or manual
--dialog-text <text>     Text to submit for prompt() dialogs when --dialog accept

--proxy-server is launch-only and is persisted with the named browser session. Close or purge a running named browser before changing its proxy. Attached browsers (--connect) must be configured with their proxy before ChromeAgent attaches. Proxy URLs containing credentials are rejected.

--chrome-arg passes an extra flag straight to the Chrome chrome-agent launches, repeatable:

chrome-agent --chrome-arg --enable-features=WebMCP,WebMCPTesting goto https://example.com

Like --proxy-server, it is launch-only (no effect under --connect — that Chrome is already running) and fixed for the life of a named browser: a follow-up command that omits it inherits whatever flags the browser already runs with, and one that names different flags is refused. Close or purge the browser to change them. A handful of flags are refused outright because chrome-agent depends on its own values for them to find and reconnect to the browser it launched: --user-data-dir, --remote-debugging-port, --remote-debugging-pipe, --proxy-server (use the dedicated flag above), and --headless (use --headed).

JS dialogs (alert/confirm/prompt/beforeunload) are auto-answered by default (--dialog accept). A native dialog otherwise blocks the page with no DOM signal and the agent's next command hangs. Use --dialog dismiss to cancel them, or --dialog manual to opt out.

The loop: inspect, act

chrome-agent goto https://app.com/login --inspect
# uid=n52 textbox "Email" focusable
# uid=n58 textbox "Password" focusable
# uid=n63 button "Sign In" focusable

chrome-agent fill --uid n52 "user@test.com"
# ~ uid=n52 textbox "Email" focusable value="" -> value="user@test.com"

chrome-agent fill --uid n58 "password123"
chrome-agent click n63
# Page navigated — previous uids are gone. New page:
# uid=n101 heading "Dashboard" level=1

An action says what it changed, so there is no second call to find out whether it landed. That is the whole point: an agent loop pays for turns, not just for tokens.

UIDs stay the same between inspects as long as the DOM node exists. After a navigation they are all reassigned, which is why the click above reports the page rather than a diff.

What a response tells you

ok:true means the command ran, not that the page complied. Every mutating action carries a verdict, a verdict_reason and a next — one token from a closed set of six, so an empty change report is never ambiguous and a caller can branch without parsing prose.

`verdict`	`verdict_reason`	`next`	What it means
`changed`	`tree_delta`, `nodes_moved`, `focus_only`	`proceed`	The page moved; `delta` says how. On `focus_only` the move was focus alone, onto a real element — `focus.to` names what RECEIVED focus, which is often a focusable ancestor of the node clicked (a span inside a link focuses the link). Focus landing on the document is not counted: it is what a click on nothing focusable leaves behind, so it answers `identical_tree` instead.
`changed`	`value_kept`	`proceed` / `inspect`	The state was confirmed by the read-back on the element itself, and the tree could not show it — a secret field renders as a fixed marker, so re-filling one leaves no delta to point at, and on a fresh session there is no tree to compare at all. `fill`, `select` and `check`/`uncheck` all reach it, through the same `value.verbatim`. The only row whose `next` is not a function of the reason alone: when the page read failed too, the verdict still stands (it is about the element) and `next` becomes `inspect` (nothing else was seen).
`changed`	`values_lost`	`confirm`	It moved and emptied a field that held a value — `values_lost` names each one. A form that submitted and cleared itself looks identical to one that threw the input away.
`navigated`	`document_replaced`	`inspect`	New document; every stored uid is dead.
`intercepted`	`hit_test_receiver`, `modal_dialog`	`dismiss`	Another element occupied the point aimed at and received the event. `intercepted_by` names it (tag, id, class, uid, z-index, whether it is a modal). Nothing is known about the target. `hit_test_receiver` is the one that fires in practice — 8 interceptions over 61 real sites, all of them it. `modal_dialog` needs the top layer (`:modal`: a `<dialog>` opened with `showModal()`, or fullscreen), is covered by a fixture and has not been seen in the wild: the `<div role="dialog">` overlays most sites ship never enter the top layer. Read `tag`/`id`/`class` rather than `z_index`, which was `auto` on 7 of those 8 and on both fixtures — scrims usually stack by DOM order and `position`.
`not_kept`	`value_reverted`, `value_rewritten`	`stop`	The write reached the element and it does not hold it: empty on the first, rewritten by a mask or normaliser on the second. Read `value.actual`; a second fill produces the same answer.
`no_effect`	`delivered_no_change`	`confirm`	Delivery proven by a hit test and the tree stayed still inside `observed_after_ms`.
`unchanged`	`identical_tree`	`confirm`	The tree was identical while the tool watched — delivery not proven.
`unknown`	`no_baseline`, `read_failed`, `identity_unreadable`	`inspect`	Nothing could be compared. Never "nothing happened".
`unknown`	`aim_point_off_target`	`inspect`	Nothing was dispatched, and the readings agreed — so a repeat aims at the same point and refuses again.
`unknown`	`scroll_not_settled`	`retry`	Nothing was dispatched at all and the readings disagreed, so a repeat duplicates nothing and can succeed.
`not_checked`	`reporting_disabled`	`proceed`	You passed `--verdict off`.

Two of those rungs report that nothing was dispatched and only one asks for a retry, because what separates them is whether two readings of the aim point agreed: scroll_not_settled is transient (they disagreed — the point was still moving, so the next attempt aims at a settled box and works), while aim_point_off_target is stable (they agreed and the point still could not be aimed at, so an identical retry misses identically). The stable rung covers two shapes, and aim tells them apart: a coordinate on screen means the element has no box a pointer can reach (a wrapped inline box, a clipped container), and a coordinate outside the viewport means the page is holding it there — a consent wall in position: fixed over a document whose scroll is locked, where scroll reports success and moves nothing.

unchanged means the page did not change while the tool watched — not "the action had no effect", which it cannot know: an unchanged tree is also what a click swallowed by an overlay looks like. That is why pointer-targeted actions also report delivery (target_hit, intercepted, off_target, not_settled, js, not_probed) from a hit test at the coordinate about to be dispatched: no_effect is only ever emitted behind target_hit, and not_settled/off_target mean nothing was sent. --on-intercept refuse turns an interception into an error instead of sending the event anyway — ok:false, exit 1, and the same fields the dispatch would have carried (delivery, intercepted_by, verdict, next, verdict_hint, hint) plus dispatched:false, because the mode that refuses to act is the one whose caller has the most re-planning to do.

`--on-intercept`	Sends through the receiver when it looks...	Refuses when it looks...
`dispatch` (default)	anything	never — always sends
`guard`	inert (no interactive tag/role, not focusable, no `cursor: pointer`)	actionable, or an `<iframe>` (opaque — see below), or unidentified
`refuse`	never — always refuses	anything

guard is the middle ground: neither extreme was right for an interception measured during a site audit, where a click aimed at unrelated navigation landed on a consent wall's own "accept" button and dispatch sent the click through it, accepting the wall on the caller's behalf. Five of eight interceptions measured that day were inert (a HEADER, plain text, an image, a search <iframe>) and would have been wrongly refused by a blanket refuse; three could act (that consent button, a CMP <iframe>, a country-selector cell) and were wrongly sent through by dispatch. guard reads intercepted_by.actionable — a native interactive tag, an ARIA interactive role, explicit keyboard focusability, or a cursor: pointer computed style, whichever the receiver has — computed inside the same probe call, so it costs no extra round trip. It is deliberately not a keyword match against the receiver's text or class name ("accept", "agree", "j'accepte", a CMP vendor's own class fragment): those carried the information to a person reading the field data, but a wordlist is never complete and never will be, in every language a consent wall might use. An <iframe> receiver refuses under guard regardless — its content is opaque from outside, so "inert" would be assumed, not measured, and between a false refusal on an inert search box and a false dispatch into an unseen consent wall this project accepts the former. The default stays dispatch: guard's predicate has not been measured at the scale that justifies dispatch's own default (12/12 on the design fixtures, and separately checked across dozens of real sites), and flipping the default would change outcomes for every overlapping-button case, not only consent walls. A refusal under guard carries the exact same payload a refusal under refuse does (delivery, intercepted_by — now with actionable — verdict, next, verdict_hint, hint, dispatched:false); the two differ only in the words explaining why nothing was dispatched.

waited_ms rides on a mutating response when the action waited for the page to load after it, and only then — a click that navigates carries it, a click that did not does not, and it is what answers "why did that take so long" without the caller guessing. A pointer event that Chrome does not acknowledge within 8 s fails instead of waiting out --timeout, and says the event may already have reached the page: the one thing not to do there is send it again. Pointer actions also bring their page to the foreground first, because a background tab answers them on a fixed five-second timer — with several pages open in one browser, clicking on one makes it the active one, which is what clicking means.

Macros

A macro is a path that already worked once, kept under a name with the postconditions observed on that success. macro record distils a recorded session — the exploration and the dead ends do not survive — and macro run replays it, checking every step's guards and stopping at the first that does not hold.

chrome-agent macro record cancel --from-recording session.jsonl
chrome-agent macro run cancel --var email=ada@example.com

What becomes a guard is the whole point: delivery: target_hit, the verdict WORD (never the reason), value.verbatim, and a url_matches built from the path. Never the changed counters, never a uid, never a duration — a macro that pins those breaks on a page that still works. A step aimed by a uid is recorded by role and accessible name or refused outright; a secret field becomes a declared parameter and is never written to the file. A guard that does not hold stops the run and reports the step, the guard, what was observed and the action's own next. There is no repair and no retry: that line is deliberate.

Two blind spots, both stated rather than papered over: the read-back window is a fixed 60 ms (reported as observed_after_ms, so a validator firing at 400 ms is outside it — wait then assert value), and canvas, WebGL and CSS-only effects are invisible to the accessibility tree.

--verdict off restores the older behaviour: the action is reported, the page is not read back. Faster, quieter, and you find out what happened on your next call — the response says not_checked so you know that is what happened.

Content extraction

From least to most tokens:

# Articles (Readability, like Firefox Reader Mode)
chrome-agent read

# Repeating data -- products, search results, feeds. No selectors.
chrome-agent extract
# Uses MDR/DEPTA heuristics. Finds the pattern automatically.

# React SPAs (X.com, etc.) -- uses a11y tree instead of DOM
chrome-agent extract --a11y --scroll --limit 20

# Scoped visible text
chrome-agent text --selector "[role=main]" --truncate 1000

# API responses -- skip the DOM
chrome-agent network --filter "api" --body

Forms: dropdowns, checkboxes, file uploads

# Select dropdown by value or visible text
chrome-agent select --uid n15 "California"

# Idempotent checkbox control
chrome-agent check n20     # no-op if already checked
chrome-agent uncheck n20   # no-op if already unchecked

# File upload
chrome-agent upload --uid n30 /path/to/document.pdf

# Double-click (text selection, special controls)
chrome-agent dblclick n42

Device emulation

chrome-agent --page mobile emulate device --label "checkout phone" \
  --width 412 --height 915 --dpr 2.625 --mobile --touch
chrome-agent --page mobile emulate status
chrome-agent --page mobile emulate reset

Metrics are attached to one named page. Chrome reverts every override the moment the CDP session that set it detaches, so the configuration is persisted and reapplied at the start of each connection — which also means that between commands on a headed or --connect browser the page briefly shows its real metrics. Sibling pages keep their own metrics, with one visibility caveat: Chromium exposes an orientation override only for its active target, so commands on an emulated page activate that tab first, backgrounding its siblings the way switching tabs does. Closing or restarting Chrome discards the configuration. Values are explicit because device preset catalogs belong to the DevTools frontend, not CDP; the binary does not ship a copy that can drift from Chromium. Under --touch, click and check dispatch touch taps instead of mouse events (dblclick, hover and drag stay mouse — pages that only listen to touch will not see them); Chrome's own mouse-to-touch conversion was measured to leave Input.dispatchMouseEvent unanswered, which is why the taps are synthesized. screenshot --max-width counts CSS pixels, so a --dpr 2.625 capture is that factor larger. If Chromium rejects one of the override calls, the command attempts every cleanup call and does not persist the incomplete configuration.

Iframes

The frame switch binds eval and inspect to the iframe, but only within one process, so drive it through pipe (or batch), never as separate CLI calls:

printf '%s\n' \
  '{"cmd":"frame","target":"#payment-iframe"}' \
  '{"cmd":"inspect"}' \
  '{"cmd":"fill","uid":"n42","value":"4242424242424242"}' \
  '{"cmd":"frame","target":"main"}' | chrome-agent pipe

Target the intended iframe precisely (e.g. iframe[src*="checkout"]); a bare iframe matches the first one in DOM order, often an ad about:blank slot.
frame scopes eval/inspect; it does not scope --selector targeting. Run inspect after the switch to get iframe uids, then act by uid (uids resolve across frames).
Each standalone chrome-agent <cmd> opens a fresh connection, so chrome-agent frame … followed by a separate chrome-agent inspect loses the switch. Use pipe/batch.

WebMCP tools

Pages can register tools on document.modelContext (W3C WICG WebMCP). webmcp list discovers them; webmcp call calls one and reports what it declared next to what the page measurably did — because the protocol defines no outputSchema. A tool's return is a freeform string with no contract to check it against, so {"success":true} and nothing having moved is not a protocol violation, it looks exactly like a correct call:

chrome-agent webmcp list
# tool=add_to_cart "Add a product to the cart."
# note: no tool here carries an outputSchema — the protocol defines none...

chrome-agent inspect   # establish a baseline first, like any other action
chrome-agent webmcp call add_to_cart --args '{"item":"Espresso Blend"}'
# declared_result: {"success":true,"item":"Espresso Blend","price":"$18.00"}
# verdict: changed (tree_delta) — added=3 removed=2 changed=1: a real cart line appeared

chrome-agent webmcp call add_to_cart_broken --args '{"item":"Espresso Blend"}'
# declared_result: {"success":true,"item":"Espresso Blend","price":"$18.00"}   <- byte-identical
# verdict: unchanged (identical_tree) — nothing moved. Not "no effect": a canvas
# repaint, a CSS-only change, or a handler that runs after the window all look like this too.

webmcp call is reported exactly like any other action command — verdict, delta, next — because that machinery is the only corroboration the protocol leaves available. It never invents a stronger claim than the tree can support: a call that declares success and moves nothing reads as unchanged, not as a lie, for the same reason no_effect elsewhere requires proof of delivery before it is used.

Two of the spec's own sharp edges are handled rather than surfaced: executeTool requires the actual RegisteredTool object from getTools() (a bare name throws TypeError: The provided value is not of type 'RegisteredTool'.) and a JSON string second argument (an object throws Failed to parse input arguments) — webmcp call <name> resolves the tool and validates --args as JSON before either can happen.

Under a frame binding, webmcp hits the same isolated-world blindness eval already has: a tool a frame's own main-world script registered is invisible from there (measured, not assumed — see tests/fixtures/webmcp_iframe_host.html). The response carries frame_scoped: true so an empty list reads as unproven, not as "this frame has none".

Most installed Chrome builds have no native WebMCP yet. Test against the real API with --chrome-arg --enable-features=WebMCP,WebMCPTesting (see --chrome-arg above), or against a page that ships its own polyfill.

Batch mode

Execute a sequence of commands from stdin without per-command process startup:

echo '[
  {"cmd":"goto","url":"https://example.com"},
  {"cmd":"inspect","filter":"button"},
  {"cmd":"click","uid":"n42"}
]' | chrome-agent batch

Each command produces one JSON line. About 10x faster than spawning a process per command.

Stealth

--stealth patches 7 automation fingerprints via CDP:

navigator.webdriver set to undefined
chrome.runtime mocked
Permissions API fixed
WebGL renderer masked
User-Agent cleaned
Input coordinate leak patched
Runtime.enable never called

These are CDP-level patches (Page.addScriptToEvaluateOnNewDocument), not Chrome flags.

For sites with heavier protection (DataDome, Kasada) that fingerprint the Chromium binary itself, connect to your real Chrome:

google-chrome --remote-debugging-port=9222 &
chrome-agent --connect http://127.0.0.1:9222 goto https://www.leboncoin.fr --inspect

Protection	Solution	Measured
None	`chrome-agent goto ...`	—
Cloudflare JS challenge ("Just a moment…")	`chrome-agent --stealth goto ...`	`shop.app`: 403 and 6 nodes without it, 200 and the real page with it
Cloudflare managed Turnstile	`--stealth` does not help	`nowsecure.nl`: 10 nodes with it and without it, no difference
Logged-in sites	`chrome-agent --stealth --copy-cookies goto ...`	—
DataDome/Kasada	`chrome-agent --connect` to real Chrome	`leboncoin.fr`: 403 with `--stealth` and without

The two Cloudflare rows are not the same product. The interstitial that says "Just a moment…" runs a JS challenge that the seven patches satisfy; a managed Turnstile widget fingerprints the browser itself, and no in-binary patch moves it. --connect to a real Chrome is the only route this tool has for the second row and for DataDome. Each measurement above was taken three times, with and without the flag, on the dates in the commit.

Logged-in sites

--copy-cookies copies the cookie database from your Chrome profile. Both Chrome instances use the same macOS Keychain, so encrypted cookies just work.

chrome-agent --stealth --copy-cookies goto x.com/home --inspect
# Your timeline. Your DMs. No login flow.

chrome-agent --copy-cookies goto mail.google.com --inspect
chrome-agent --copy-cookies goto github.com/notifications --inspect

Your real Chrome is not affected.

Network capture and blocking

# Resources already loaded (stealth-safe, uses Performance API)
chrome-agent network --filter "api"

# Live traffic with response bodies
chrome-agent network --live 5 --body --filter "graphql"

# Block tracking/ads (uses Fetch domain interception)
chrome-agent network --abort "*tracking*" --live 30

# Console output
chrome-agent console --level error    # errors + exceptions only

Console capture uses an injected interceptor, not Runtime.enable.

Downloads, PDF, and token-safe screenshots

Files are written under ~/.chrome-agent/tmp (or your --out path) with 0600 perms; the path is printed on stdout. Binary bytes never hit stdout.

# Download a file, fetched inside the page so cookies/auth carry over.
# Ideal for login-gated exports (invoices, CSVs, PDFs behind an auth wall).
chrome-agent download https://app.com/reports/2024.csv --out ./2024.csv
# {"ok":true,"path":"./2024.csv","bytes":48213,"mime":"text/csv"}

# Print the current page to PDF.
chrome-agent pdf --filename invoice.pdf --background

# Screenshots that don't blow up your context window.
chrome-agent screenshot --format jpeg --quality 60 --max-width 1024
chrome-agent screenshot --uid n42            # capture a single element (or --selector "css")

# Click-triggered downloads: an "Export CSV" button that builds the file in the page has no
# URL to fetch, so the only way to the bytes is to click it.
chrome-agent download --selector "#export" --out ./export.csv
# {"ok":true,"downloaded":true,"via":"click","path":"./export.csv","bytes":48213,
#  "suggested_filename":"report.csv","delivery":"target_hit","uid":"n42"}

# The click landed and nothing downloaded. Exit 0, because the click is not undoable and an
# error here invites a second real one.
chrome-agent download --selector "#maybe" --timeout 5 --json
# {"ok":true,"downloaded":false,"observed_after_ms":5002,
#  "message":"Clicked selector '#maybe' and no download began in the 5s that followed…",
#  "hint":"…Do not click again: the first click reached the page…"}

Two mechanisms, one verb, one contract: a file at a named path, 0600, with its size and the name the server proposed. download <url> uses an in-page fetch with credentials:'include', so the request inherits the page's session. download --uid/--selector runs the same click as click — same hit test, same --on-intercept, so a covered button reports its receiver — and arms Browser.setDownloadBehavior around it.

Read downloaded, not ok. A click that was delivered is never an error, whatever it failed to produce, for the reason a lost connection is never a retry: the page cannot tell a second click from a second deliberate action. --timeout bounds the whole window (the transfer must begin and finish inside it) and --max-bytes cancels a transfer that goes past it, removing the partial file.

The arming lives on the connection that clicks because Chrome's download override does not outlive the CDP session that set it — measured: a fresh connection clicking the same link with nothing armed produces no file. That is why this is a flag on download and not a separate wait --download verb, which would work in pipe mode and silently capture nothing from the CLI.

Waiting for the network to settle

# Resolve once no requests are in flight for 500ms (tunable), bounded by --timeout.
# Replaces fragile fixed sleeps on SPAs / XHR-heavy pages.
chrome-agent wait network-idle
chrome-agent wait network-idle --idle-ms 800 --timeout 20

Opt-in (enables the Network domain), so it stays off the stealth hot path.

Pipe mode

For agents that send many commands in sequence, pipe mode keeps a single connection open:

echo '{"cmd":"goto","url":"https://example.com","inspect":true}
{"cmd":"click","uid":"n12","inspect":true}
{"cmd":"read"}' | chrome-agent pipe

One JSON line per response. About 10x faster than spawning a process per command.

JSON mode

chrome-agent --json goto https://example.com --inspect
# {"ok":true,"url":"...","title":"...","landed":{"requested":"...","final":"...","redirected":false,"http_status":200,"serving":"page"},"snapshot":"uid=n1 heading..."}

# `landed` is where you aimed vs where you ended up. An expired session redirecting to a
# login wall used to be indistinguishable from a successful load:
chrome-agent --json goto https://app.example.com/orders
# {"ok":true,"url":"https://app.example.com/login?next=/orders","title":"Sign in",
#  "landed":{"requested":"https://app.example.com/orders",
#            "final":"https://app.example.com/login?next=/orders",
#            "redirected":true,"http_status":200,"serving":"page"},
#  "hint":"The redirect landed on a path containing 'login', which often means the session expired. ..."}
# A fragment-only or trailing-slash change is not a redirect. `http_status` is the final
# hop's status (a followed 302 reports 200), read from the Navigation Timing API so
# --stealth is untouched, and absent — never 0 — when the page reports none.

# `serving` is what answered. `ok:true` only says the navigation happened — a WAF refusal
# served with a 200, a captcha interstitial and a 403 all used to look like a load:
chrome-agent --json goto https://www.leboncoin.fr
# {"ok":true,"title":"leboncoin",
#  "landed":{...,"http_status":403,"serving":"challenge",
#            "challenge_from":"geo.captcha-delivery.com"},
#  "hint":"A challenge frame from geo.captcha-delivery.com is the only thing here to act on..."}
#
#   page                nothing measured contradicts the load — an absence of evidence,
#                       not a certificate (a paywall reads as `page` too)
#   challenge           an anti-bot vendor's frame or script, and no form of the site's own;
#                       `challenge_from` names the host. Use --connect, not --stealth
#   error               the server answered 4xx/5xx — `http_status` says which
#   nothing_actionable  no link, no form control, no script, almost no text. What an
#                       edge-served refusal looks like, and what a page that had not
#                       rendered yet looks like. Run `inspect` before giving up
#   unreadable          the shape probe did not run

chrome-agent --json eval "1+1"
# {"ok":true,"result":2}

# Errors exit 1 but JSON is still on stdout (parseable):
chrome-agent --json click n99
# {"ok":false,"error":"Element uid=n99 not found.","hint":"Run 'chrome-agent inspect'"}

# An assertion that did not hold exits 2 — a page fact, not a tool failure:
chrome-agent --json assert value --selector "#coupon" --equals "SAVE10"
# {"ok":false,"assertion":{"kind":"value","expected":"SAVE10","actual":"","held":false},"hint":"..."}

Exit codes: 0 success · 1 error (including a bad flag) · 2 an assertion did not hold · 130 Ctrl+C.

Inspect with link URLs

When deciding which link to click, the agent often needs the URL, not just the text:

chrome-agent inspect --urls --filter link
# uid=n82 link "Pricing" url="https://example.com/pricing"
# uid=n97 link "Docs" url="https://docs.example.com"

Multi-tab and parallel agents

# Multiple tabs in one browser
chrome-agent --page main goto https://app.com
chrome-agent --page docs goto https://docs.app.com
chrome-agent --page main eval "document.title"   # "App"

# Multiple agents, each with their own Chrome
chrome-agent --browser agent1 goto https://example.com
chrome-agent --browser agent2 goto https://other.com

Using with AI agents

# Install the skill (Claude Code, Cursor, Copilot, etc.)
npx skills add sderosiaux/chrome-agent

# Or tell your agent to run:
chrome-agent --help
# The help output includes a full LLM usage guide.

Claude Code permissions:

{
  "permissions": {
    "allow": ["Bash(chrome-agent *)"]
  }
}

Comparison

	chrome-agent	agent-browser (Vercel)	Playwright MCP
Language	Rust	Rust	TypeScript
Binary	3 MB, zero runtime	3 MB CLI + dashboard + cloud providers	Node + Playwright
Startup	~10ms (session reuse)	daemon (fast after first)	cold start
Page cost, HN front page	5,652 tokens (`inspect`), 1,571 (`extract`, all 30 records)	not measured here	not measured here
UID stability	`backendNodeId` (stable across inspects)	sequential `@e1, @e2` (reassigned per snapshot)	N/A (selectors)
Action + observe	`--inspect` flag (1 call)	separate snapshot call	separate call
Stealth	7 native CDP patches	delegated to cloud providers	none
Reader mode	`read` (Readability.js)	none	none
Data extraction	`extract` (auto-detect repeating data)	none	none
Link URL resolution	`inspect --urls`	`snapshot -u`	N/A
Dropdowns	`select`	`select`	via selectors
Checkboxes	`check`/`uncheck` (idempotent)	`check`/`uncheck`	via selectors
File upload	`upload`	`upload`	via selectors
Drag and drop	`drag`	`drag`	via selectors
Annotated screenshots	not yet	`screenshot --annotate`	not yet
Element/token-safe screenshots	`screenshot --uid/--selector`, `--format jpeg`, `--max-width`	via options	via options
PDF export	`pdf` (`Page.printToPDF`)	none	none
File download	`download <url>` (in-page fetch, auth-preserving) and `download --uid/--selector` (click-triggered)	`download`	via events
Extra request headers	`goto --header`	yes	via context
Network-idle wait	`wait network-idle`	yes	`browser_wait_for`
JS dialog handling	auto (`--dialog accept/dismiss/manual`)	yes	`browser_handle_dialog`
Live dashboard	no (lean)	yes (Next.js)	no
Cloud providers	no (`--connect` to anything)	5 built-in	no
iOS/Safari	no	yes (WebDriver)	no
Network blocking	`network --abort`	`network route --abort`	no
Iframe switching	`frame`	`frame`	via selectors
Batch execution	`batch` (JSON stdin)	`batch` (JSON or quoted)	N/A
AI chat built-in	no (the agent IS the LLM)	yes (AI Gateway)	N/A
Codebase	~22.2K lines of Rust in `src/` (blank and comment-only lines excluded; a test re-measures it)	~40K lines (their figure, unverified here)	Playwright
Design goal	minimal tokens, maximal autonomy	feature-complete platform	browser testing

License

MIT

chrome-agent 0.15.0

chrome-agent

The one thing it does that others don't

How is this different from agent-browser?

Why you shouldn't use chrome-agent

What it's built on

Install

Quick start

Commands

Navigation

Inspection

Interaction

Assertions

Content extraction

Monitoring

Advanced

Global flags

The loop: inspect, act

What a response tells you

Macros

Content extraction

Forms: dropdowns, checkboxes, file uploads

Device emulation

Iframes

WebMCP tools

Batch mode

Stealth

Logged-in sites

Network capture and blocking

Downloads, PDF, and token-safe screenshots

Waiting for the network to settle

Pipe mode

JSON mode

Inspect with link URLs

Multi-tab and parallel agents

Using with AI agents

Comparison

License