Agent Browser changelog: what's new each month
Every stable Agent Browser release summarised by month: the highlights, new features, improvements, fixes and anything you need to act on. 3 months covered; the current month updates daily.
October 2026 · so far
2 releases: 0.38.2 → 0.39.0
October brought stability improvements across authentication, browser launching, and sandbox environments, along with an experimental new rendering engine and better support for secure network configurations.
Highlights
- Fixed Chrome freezing on startup by properly handling stderr output.
- Added experimental Obscura engine as an alternative to Chrome with local lifecycle management.
- Fixed authentication vault to correctly handle duplicate controls and prevent form submission errors.
- Added private CA trust for CLI HTTPS requests across all platforms.
- Fixed chat mode to properly use WebMCP tools instead of falling back to eval.
New
- Experimental Obscura engine (--engine obscura) with local launch, cleanup, and MCP support.
- Private CA trust for CLI HTTPS requests with --ca-cert applying across all platforms.
- System CA option (--use-system-ca) for HTTPS requests behind TLS inspection.
Improved
- Kernel profiles now send profile as an object and support KERNELPROFILESAVECHANGES to persist changes.
- Browser Use switched to Cloud V4 for more reliable browser creation, attachment, and cleanup with bounded timeouts.
- Auto-connect now waits up to 30 seconds for Chrome 144+ remote-debugging prompt instead of opening repeated prompts.
- Daemon responsiveness during long commands improved to keep accepting connections including close requests.
- Vercel Sandbox shared memory detection now measures /dev/shm capacity and disables dev-shm usage when undersized.
- Eve integration upgraded from 0.47.3 to 0.57.0 for compatibility with eve 0.50 and later.
- Selector-scoped snapshots fixed to avoid printing elements twice and preserve shadow root content.
- Contact sheet example updated with loading-flash demo output.
Fixed
- Auth vault login now picks usable controls when hidden duplicates exist and binds credential entry to selected field.
- Chat mode now allows webmcp, skills, and other top-level browser commands instead of falling back to eval.
- Chrome freezing after launch resolved by draining stderr for the browser's lifetime.
- Vercel Sandbox Chrome renderer termination on undersized shared memory mount.
- Auto-connect repeated prompts and failures with Chrome 144+.
- Daemon losing SIGTERM signals sent while a command holds the state lock.
September 2026
5 releases: 0.36.0 → 0.38.1
September brought major enhancements to Agent Browser's recording and page automation capabilities, including experimental WebMCP support for discovering tools on web pages and higher-quality video recording at configurable frame rates. Session management and interactive features also saw significant improvements.
Action needed
- Removed obsolete Lightpanda session timeout argument; launches now use current supported server options only.
Highlights
- Experimental WebMCP support lets agents discover and invoke tools exposed by the current page, with frame-aware selection and safety constraints.
- Video recording now captures at 30 fps by default with support for 1-60 fps, using Page.startScreencast for smoother motion.
- Sessions opened in new tabs now inherit headers, credentials, user agent, locale, timezone, and geolocation from the active session.
- Conditional screenshots skip unchanged captures and tolerate small pixel differences with configurable thresholds.
- Human-like pointer movement adds realistic curved mouse paths with per-action control and reproducible behavior.
New
- WebMCP generation skill to expose existing page workflows as validated page tools with safety constraints and fallback behavior.
- Recording presentation tools including animated cursor rendering and click ripples, plus contact sheets showing timestamped visual changes.
- Snapshot deltas with automatic baselines and compact structural change reporting for unchanged revisions.
- Persistent snapshot refs that survive DOM element changes within the same document.
- Stateful auth vault login with auth login --no-navigate to fill prepared login pages.
- WebMCP catalog updates in browser responses with content-bounded summaries on discovery and changes.
- Screenshot history scoped per tab with --if-changed and --threshold options.
- Recording frame timing improvements to synchronize output duration with requested frame rates.
Improved
- Recording startup validation now fails early for missing ffmpeg, invalid paths, or bad options before changing browser state.
- Recording navigation clears stale element references, frame scope, and page WebMCP state during URL navigation.
- Recording cursor and mouse movement timing stays synchronized with page content during drags and timed moves.
- Session setup inheritance now applies to tabs opened via tab new or page clicks.
- WebMCP availability output advertises allowed tools in navigation responses for CLI, JSON, and MCP clients.
- Eve integration updated to 0.47.3 with raised compatibility floor.
Fixed
- Windows headless Chrome desktop artifacts by isolating owned headless Chrome on a private desktop with proper process cleanup.
- Recording startup validation to prevent state changes on configuration errors.
- Recording navigation state to properly clear stale references when URL changes during recording.
- Recording cursor and mouse movement timing synchronization during interactive actions.
August 2026
5 releases: 0.33.2 → 0.35.2
August brought major improvements to streaming performance and session management, along with enhanced security hardening and better support for remote deployments. The month focused on fixing latency issues, adding configuration options, and improving reliability across different platforms.
Highlights
- Fixed keyboard and click input latency over the stream, which was blocked by waiting for Chrome's replies before processing the next message.
- Added persistent session-to-tab binding for shared Chrome sessions, so named sessions now remember their target across commands and restarts.
- Introduced configurable stream encoding quality to give users bandwidth control beyond just frame rate.
- Added private proxy CA trust for locally launched Chromium on Linux with certificate configuration support.
- Hardened dashboard security with same-origin provenance enforcement against DNS rebinding and cross-origin attacks.
New
- Per-client delivery settings in the stream server with separate reader and writer tasks for input dispatch.
- Configurable stream encoding quality via AGENTBROWSERSTREAMQUALITY environment variable and config file.
- Persistent session-to-tab binding for shared Chrome sessions across commands and daemon restarts.
- Remote Agent Browser provider guide covering Vercel authentication, disposable and stable sessions, and live-view URLs.
- Bundled protected Vercel deployments skill for agents to handle Trusted Sources OIDC authentication and handoffs.
- Private proxy CA trust for Chromium on Linux via --ca-cert flag, AGENTBROWSERCACERT variable, or config file.
Improved
- Frame delivery now uses latest-wins strategy, holding only the newest frame to skip frames produced while earlier ones are being sent.
- metadata.timestamp now carries real epoch millisecond values instead of always being zero.
- Agent Browser doctor no longer hangs on Chrome version detection with optimized detection for Windows.
- Stream URL tracking now emits active main-frame URL updates for full-document, History API, and fragment navigation.
- Windows ARM64 launcher now prefers native ARM64 executable and falls back to x64 with emulation when needed.
- Snapshot diff element references now reset numbering per diff and invalidate across URL navigations.
Fixed
- Keyboard input over the stream which failed when key, code, or text fields were absent by handling explicit nulls correctly.
- Click latency behind mouse movement by allowing input dispatch to continue without waiting for Chrome's reply.
- Parallel sessions sharing one Chrome hijacking each other's tabs by preventing event-discovered targets from stealing pinned session tabs.
- Stream disable returning while a slow client's input reader was still running.
- Root remote CDP WebSocket URLs with query strings by inserting required slash before query parameters.
- Snapshot diff element reference invalidation across URL navigations and after diff failures.
Summaries are written automatically from the official release notes (full changelog ↗); check the original notes before relying on a detail. Agent Browser: pricing, features and alternatives · All changelogs