Sweef 0.1.0-alpha.5 (alpha)

Sweef 0.1.0-alpha.5 (ALPHA)

This is an alpha release. Sweef is a young independent browser engine. Expect missing features,
sites that do not render correctly, and rough edges. Sweef offers to open such pages in your system
browser. Please do not rely on it for banking or other sensitive browsing yet.

Commit: 55791d0ab705

Install

Platform	File	Notes
Linux (Debian/Ubuntu)	sweef_0.1.0-alpha.5_linux_<arch>.deb	sudo apt install ./sweef_...deb
Linux (Fedora/openSUSE)	sweef_0.1.0-alpha.5_linux_<arch>.rpm	sudo dnf install ./sweef_...rpm
Linux (any)	sweef_0.1.0-alpha.5_linux_<arch>.AppImage	chmod +x and run
Linux (any)	sweef_0.1.0-alpha.5_linux_<arch>.tar.gz, or install.sh	user-level install, no root
macOS 12+	sweef_0.1.0-alpha.5_darwin_universal.dmg	unsigned alpha: Gatekeeper will block it, see docs/install.md
Windows 10/11	sweef_0.1.0-alpha.5_windows_<arch>_setup.exe or .zip	unsigned alpha: SmartScreen will warn (see docs/install.md)

<arch> is amd64 or arm64. Full instructions, uninstall steps and the unsigned-binary
workarounds are in docs/install.md.

Verify your download

sha256sum -c SHA256SUMS --ignore-missing
gh attestation verify <file> --repo sweefbrowser/sweef    # build provenance (SLSA)

Known alpha limitations

• Installers are unsigned: macOS Gatekeeper and Windows SmartScreen will show warnings, and Linux packages are not GPG-signed.
• No automatic updates yet: download the new version to update.
• See the README for rendering-fidelity numbers and known gaps.

Changes

• sdk: regression tests for the tester's failures (title, first/last/nth, click then type, rewriting select) (ce22448)
• engine: free pages on navigation; an enforced memory budget; honest numbers (c1172e9)
• docs: install from releases, the SDKs or a clone; go install @latest cannot work (db270d1)
• engine: inline style numbers serialize like browsers; Optimizely Cleanse regression test (d7c7eff)
• engine: click then type reaches the focused field on every surface (ad9c52a)
• engine: Page.title follows document.title; no control characters in tab state (01a4a3a)
• engine: Playwright-style selector chaining (A >> B, nth=N, visible=, has-text=) (df02180)
• engine: keep option selectedness apart from script-written selected attributes (d47a7c7)
• sdk 0.2.1: install the sweef engine automatically (verified download into a per-user cache, sweef command, sweef-install) (93c7f1d)
• fix(engine): browser UI pages measure from script on the finished layout; agentbridge tests read the starting page from the task (2188be7)
• ci: publish-sdks workflow (npm @sweef/browser, PyPI sweef-browser); manual, dry run by default (ad0eff3)
• bench, README: Mode B on the new build (Sweef 119/120 at 5.2 s and $0.0009 per success; Chromium agent 119/120 at 5.0 s) (deedc84)
• bench: Mode B 2026-10-16 progress (in progress) (958feef)
• bench: Mode B 2026-10-16 progress (in progress) (57804db)
• bench: Mode B 2026-10-16 recovered parts (198 runs) (8160a5a)
• bench: Mode B 2026-10-16 recovered parts (162 runs); supervisor restarted for the remaining tasks (c3b5056)
• bench: Mode B 2026-10-16 progress (in progress) (4a912c0)
• bench: Mode B 2026-10-16 progress (in progress) (43a25bd)
• bench: Mode B 2026-10-16 part1b (72 runs recovered from the last snapshot) (8b619ec)
• bench: Mode B 2026-10-16 progress (in progress) (584dbae)
• bench: Mode B 2026-10-16 progress (new build, in progress) (6544166)
• engine: decode early-prefetched images as they arrive (99fc492)
• README, CHANGELOG: the gap work and its measured results (6321309)
• bench/realsites: owner-site report after the gap work (1a5d879)
• bench/surfaces: re-run after the gap work, with sweef-cli in the CLI rows (0caaed7)
• bench/realsites: owner-site screenshot fidelity re-run after the gap work (2e484cc)
• bench/realsites: replay table (5 runs, median and spread) and resource use through bench/replay (397eea0)
• bench/realsites: Mode A after the gap work (47 tasks x 3 fresh runs, live network) (e183bac)
• engine: a frame whose load is about to start counts as loading (828e02b)
• cmd/sweef: run the session CLI smoke test on Windows (c31a28e)
• engine: screenshots encode PNG with one row filter, RGB when opaque (02f46a2)
• engine: agent mode also blocks self-hosted analytics and developer-site ad networks (53a8074)
• bench/replay: record pages with their subresources once, serve them from localhost (a233dbd)
• sweef-cli: the session commands without the engine, in half the start time (98e4457)
• agent, mcp: build regexps and the MCP tool table on first use, not at init (34f82f5)
• engine: the compiled prelude is embedded; the first VM waits for a pool build in progress (4c58221)
• agent: pages keep running between model turns in sweef agent (89b17c7)
• engine: a headless load settles for 600 ms, not the 1.5 s action budget (7ebc9bc)
• engine: test that precompiled modules and scripts run from their bytecode (84eabd1)
• render: the first layout of a container-query page keeps its first pass when a second could not differ (a4b3dd3)
• engine: compile scripts and modules on other cores as they arrive (d8d3be6)
• bench/realsites: Mode B report shows uncached, cache-read and cache-write tokens per agent (47c330e)
• engine: input actions drain what they started instead of a full settle (f0a07ba)
• agent: starting page rides with the task; system prompt and tool schema cut to a quarter (3ee6ce3)
• engine, rpc: pushState moves the tab URL; batch waits honour their timeouts (2b5de02)
• engine: a layout forced by page script does not wait for the network (16902bc)
• engine: prefetch only module-like import specifiers; SWEEF_CPUPROFILE for the daemon (4918703)
• bench: Mode B re-run on the merged build, real Haiku 5.5, 40 tasks x 3 runs (Sweef 119/120, Chromium agent 119/120) (63ebb09)
• engine: style-only mutations do not keep a headless settle from going quiet (ec8867d)
• bench: Mode B re-run part 2 (in progress) (966e9d6)
• engine: headless loads start image downloads when the document is parsed (5df58ee)
• engine: a headless settle does not wait for router prefetches (09c6d16)
• render, style: cheaper SVG scenes and stylesheet reuse across layout passes (82364f4)
• engine: scan module sources for static imports without regexp (d50a1f0)
• style, render: ancestor bloom filter for selector matching (9526230)
• bench: Mode B re-run part 1 (5 tasks; run restarted under a supervisor) (22b3cca)
• bench: Mode B re-run progress (merged build, in progress) (dca9bbf)
• bench/surfaces: Sweef MCP/SDK/CLI vs @playwright/mcp, playwright-core, agent-browser; docs (9a7d705)
• engine: warm VM pool builds in parallel; mcp and serve keep two VMs ready (2c2d803)
• font: cache the system font index in the engine cache directory (b574eff)