navette — the browser for agents

navette — v1.4.0

[navette — the browser for agents]

The browser for agents. One tiny Rust binary driving the WebView your OS already ships — no Chromium, no download, no RAM bonfire.

Navette is French for shuttle — the small vessel that carries your agent from page to page. Always fueled (the engine ships with your OS), light enough to ignore, and it skips the human web's garbage so your agent doesn't have to.

Single Rust binary, three modes:

$ ls -lh target/release/navette-rwxr-xr-x  1 user  staff   626K  navette

626 KB installed on macOS (release binaries: 658 KB darwin-arm64, ~1.2 MB windows-x64 / linux-x64 — the wry backends carry their bindings). Playwright ships 218 MB. Lightpanda ships 96 MB (and cannot screenshot). Measured claims, reproducible with one command (BENCHMARKS.md):

• Faster than Playwright + Chromium on every metric we measured — install, cold start, navigate→read (8 ms), act (1 ms), peak RAM, 100-page crawl (0.9–2.8 s, parity with Lightpanda within variance and ~2–3x faster than Playwright), real-web success rate (95–100% vs 85%).
• Crawls at Lightpanda's speed while rendering (parity within variance through the zero-bias raw-CDP probe, where Lightpanda is the fastest page-reader at 3.3–3.4 ms — it parses a partial DOM and cannot render — and navette is the fastest full-rendering reader: 17.9–19.4 ms vs Chromium's 28–34 ms through the identical client).
• The two rows Lightpanda wins — fresh-process boot and peak RAM — are the price of rendering. If your agent only reads static pages, use fetch + readability; if it needs JS, sessions, actions and vision, that price is the product.

FAQ

Why not Apple's Safari MCP server (2026)? Same thesis, different scope: navette is agent-first (8 primitives, ghost windows, resident daemon), open source, and cross-platform by design (WebView2 on Windows is Chromium — preinstalled). Apple's is macOS-and-Safari-shaped.

Why not just fetch + readability? For static pages, do that — it beats everyone. navette exists for what fetch can't do: JS-built pages, logins, sessions, forms, screenshots, acting like a human.

Security? The server binds 127.0.0.1 only, has no auth (do not expose it), and sessions use a non-persistent store — no cookies leak between runs. The agent's JS executes in the OS WebKit sandbox, not in your terminal.

Build & run

brew install slabbdev/navette/navette   # macOS arm64cargo install navette-browser   # any platform, from sourcenavette serve --port 8765       # HTTP API on loopbacknavette mcp                     # MCP stdio for agent hostsnavette install-daemon          # resident: warm from login

Or build from source:

cargo build --release          # rustup; macOS fully shipped — Windows (WebView2) / Linux (WebKitGTK) backends aboard./target/release/navette serve --port 8765   # HTTP API on loopback./target/release/navette mcp                 # MCP stdio for agent hosts./target/release/navette install-daemon      # resident: warm from login, 24 ms first page./target/release/navette uninstall-daemon

The mcp mode auto-starts serve if nothing is listening (it idles politely if the port is already served by another navette). The resident daemon is a LaunchAgent with KeepAlive — the cold start an agent feels drops to 24–37 ms, forever.

HTTP API (127.0.0.1 only, JSON)

Sessions are created lazily; ghost windows are attached only when a screenshot needs them.

JS dialogs (alert/confirm/prompt) are auto-handled in-page: alert logs and no-ops, confirm accepts, prompt returns its default — agents never deadlock on a hidden modal.

MCP for agent hosts

Register once (ZCode example, workspace .zcode/config.json):

{ "mcp": { "servers": { "navette": {    "command": "/abs/path/to/navette/target/release/navette",    "args": ["mcp"]} } } }

The host gets 16 tools: navigate, read, screenshot (returned as MCP image content — the agent sees the page), click, hover, type, key, evaluate, wait, scroll, upload, viewport, sessions, session_close, state_export / state_import (cookies — the Playwright storageState equivalent).

Architecture

src/main.rs          HTTP server (std::net), routes, agent-first JS snippetssrc/mcp.rs           MCP stdio adapter + serve auto-startsrc/backend_macos.rs WKWebView via raw objc2 — ghost windows, lazy attach,                     measured cold-start ordering (AppKit -> listener -> pre-warm)src/backend_wry.rs   Windows (WebView2) / Linux (WebKitGTK) via wry + tao —                     same surface, IPC-shim results, URL-matched navigationsrc/backend_stub.rs  fallback for other targets (placeholder)

The 8 primitives are engine-agnostic; each platform backend is a thin layer over the system WebView behind this exact surface. Engine strategy: system-first, embedded fallback (WebView2 Fixed Version / WebKitGTK via apt / WPE) — see ONEPAGER.md.

Status

v1.4.0 (2026-10-04) — current. 16 MCP tools including file upload (page-side DataTransfer — no OS dialog) and scroll; published on crates.io as navette-browser (cargo install navette-browser → navette); a bench workflow measures navigate/read/screenshot on all three engines. CI green on all three OSes: macOS (WKWebView), Windows (WebView2), Linux (WebKitGTK).

Recent releases: v1.3.0 — full platform parity (native screenshots per engine, cookie state export/import, viewport control, resident daemon everywhere, hover + key, auto-handled dialogs) · v1.2.1 — hardening (five root-cause fixes, boot-time session pre-warm: first navigate 38 s → 83 ms on a cold CI VM).

Known gaps, stated plainly: real (OS-level) keyboard/mouse input, request/response network interception, OS file-dialog automation. MIT.