agent-browser Updates & Release Notes

New Features

Added persistent session-to-tab binding for shared Chrome sessions. Named sessions connected through --cdp or --auto-connect now remember their CDP target across commands and daemon restarts, and CDP target ids can be used directly as tab references. Start each session with --pin-tab to make the binding strict, so a tab closed externally returns a stable tab_gone error instead of silently adopting a neighboring tab. JSON output includes data.targetId and an optional sanitized data.lastUrl; batch exposes the same recovery data under result (#1589)

Improvements

Added a Remote Agent Browser provider guide covering Vercel authentication, disposable and stable sessions, custom VCR images, snapshots, and live-view URLs (#1648)

Bug Fixes

Fixed parallel sessions sharing one Chrome hijacking each other's tabs. Event-discovered targets no longer steal a pinned session's active tab, re-attach restores the persisted target instead of selecting index 0, and preliminary plus existing-daemon --cdp and --auto-connect paths preserve explicit pin enable and disable. Agent skill guidance now requires a named --session before the first command (#1589)

Fixed agent-browser doctor hanging on Chrome version detection. Windows reads the version from the executable resource table without spawning Chrome; other platforms bound the version subprocess with a deadline, kill, and reap so inherited output handles cannot block forever or leave an orphan browser (#1641)

Contributors

@Railly

@huozhi

@soichisumi

@dandaka

@mvanhorn

New Features

Added input priority and per-client delivery settings to the stream server: each WebSocket connection now splits into a reader task and a writer loop, so clicks and keystrokes dispatch to the browser without queueing behind a frame write. Adds a per-client {"type":"config","maxFps":N} cap (1 to 120, 0 uncapped) and opt-in ack pacing via {"type":"config","pacing":"ack"} with {"type":"ack","seq":N}, which keeps one frame in flight so a stalled client never drains a backlog. Both settings can also be declared on the connection URL (?pacing=ack&maxFps=10), the only way to cover the opening frame. Every frame now carries a monotonic seq (#1594)

Added configurable stream encoding: frames were hardcoded to jpeg quality 80 at the session viewport, so frame rate was the only bandwidth lever. AGENT_BROWSER_STREAM_QUALITY, AGENT_BROWSER_STREAM_MAX_WIDTH and AGENT_BROWSER_STREAM_MAX_HEIGHT are read once per daemon and cut bytes without dropping frames: on a busy page at 1280x720, quality 20 takes a frame from 54 KB to 25 KB, and quality 20 at 640x360 takes it to 9 KB, frame rate unchanged in both. Width and height default to the session viewport, so a larger viewport is never downscaled unless both are set (#1626)

Behavior Changes

Frame delivery is now latest-wins. The stream server holds only the newest frame and reads it at send time, so frames produced while an earlier one is still being written are skipped. A client that assumed it received every frame from the WebSocket now receives fewer. Nothing in this repo consumes the stream that way, since record captures through CDP and the dashboard is a viewer, so this affects external consumers only (#1594)

metadata.timestamp now carries a real value. It was always 0, because CDP sends the capture time as a float in seconds and the code read it as an integer. It is now epoch milliseconds, so a client can measure how stale the frame it is drawing is. A client that treated 0 as unknown is unaffected (#1594)

Bug Fixes

Fixed keyboard input over the stream, which worked in none of the three shapes the docs publish: an absent key, code, or text reached CDP as an explicit null, which rejects the whole command, so every key release and every non-printable key was silently dropped, the dashboard's own payloads included (#1594)

Fixed click latency behind mouse movement: input dispatch awaited Chrome's reply before reading the next message, so a click sat one round trip behind every queued mouse move. After a 300-event sweep a click landed 2471ms late; it now lands in 6ms (#1627)

Fixed stream disable returning while a slow client's input reader was still running (#1594)

Contributors

@Railly

@kevingatera

@WebCloud

Behavior Changes

The daemon now ships a default idle timeout of 1 hour: after an hour with no commands or dashboard input it saves configured restore state, closes the browser, and exits, so integrations that die without calling close no longer leak the daemon and its Chrome tree indefinitely. Sessions without --restore or another restore key discard transient browser state and open tabs when they shut down. Set AGENT_BROWSER_IDLE_TIMEOUT_MS=0 to restore the old always-persist behavior, or any other value to tune it. Dashboard mouse, keyboard, and touch input reset the timer. The default never closes headed browsers, including Safari and iOS WebDriver sessions, or user-attached browsers that may be in direct human use. Provider-owned cloud browsers remain eligible for cleanup, and an explicitly configured timeout applies to all browsers, as before (#1605)

Bug Fixes

Fixed tab recovery and selection to avoid daemon hangs on Memory Saver-discarded tabs by selecting a live renderer on CDP connect, reviving tabs on switch or after close, treating dialog-blocked tabs as live, preserving refs on rejected operations, and surfacing recovery state across CLI, JSON, and MCP output (#1543)

Fixed a11y selector errors to report invalid CSS selectors cleanly instead of exposing raw browser evaluation stack traces in text and JSON output (#1604)

Contributors

@ctate

@Railly

@joelhooks

@jadenfix

Bug Fixes

Fixed find role to match implicit ARIA roles and browser-computed accessible names through the accessibility tree, so semantic elements like <h2> (heading) and <ul> (list) resolve, with case-insensitive substring name matching that mirrors Playwright's getByRole (#1552)

Fixed element-not-found errors to preserve the locator detail (selector, role, name, or index) instead of flattening every miss into one generic message, and aligned the advertised find actions with the set the dispatcher actually accepts (#1553)

Contributors

@Railly

@cooleryu

New Features

Eve extension - Added @agent-browser/eve, an Eve extension that mounts the agent-browser tool set with namespaced browser tools, sandbox bootstrap helpers, docs, examples, CI, and release packaging (#1547)

Security

Hardened domain allowlists by blocking WebRTC bypasses, applying network containment across launch modes, workers, popups, restored state, and reused daemon sessions, rejecting unsafe startup arguments, and adding Chrome regression coverage (#1546)

Bug Fixes

Fixed completed-page waits so load and DOMContentLoaded waits resolve immediately when the current document is already ready, with structured Eve wait timeout handling and focused coverage (#1554)

Contributors

@ctate

@dnukumamras

New Features

WebGPU launch preset - Added --webgpu across the CLI, config, environment, and MCP surfaces, with hardware backends on macOS and Windows, software Vulkan on Linux, automatic Xvfb for displayless headed sessions, and a doctor --webgpu render and screenshot probe (#1529)

Improvements

Added periodic restore-state autosaves while the browser remains open, preserving recent state after a browser window is closed by hand and capturing background page changes while honoring the restore save policy. The interval is configurable with AGENT_BROWSER_AUTOSAVE_INTERVAL_MS (#1509)

Contributors

@ctate

New Features

Restore workflow - Added --restore, --restore-save, restore validation flags, worktree-scoped session id, session info, and --namespace so agent runs can use stable, isolated, automatically restored browser state without managing state files by hand (#1486)

Improvements

Hardened session lifecycle handling with explicit daemon and browser compatibility checks, lifecycle status output, MCP support for restore options, and safer auto-save behavior that avoids overwriting good state after a failed restore or failed validation (#1486)

Bug Fixes

Fixed restore lifecycle edge cases around switching restore keys with a live browser, daemon configuration startup races, launch mode validation, and clearing restore failures after an explicit state load (#1486)

Contributors

@ctate