Kitewright

Kitewright

Browser automation for AI agents as a single small binary. An MCP server (Streamable HTTP + stdio) that gives LLM clients navigate / screenshot / extract — without carrying the Node.js + Playwright stack.

Install in one line:

claude mcp add kitewright -- npx -y @kitewright/mcp

Why — measured, not claimed

Head-to-head vs @playwright/mcp 0.0.78, same machine, same Chromium headless-shell build, same page (full methodology):

The browser itself (Chromium) costs the same in any language — warm latency is a tie because both speak CDP to the same browser. The wins are everything around it: startup, distribution, idle footprint, and lifecycle management. The honest gap: playwright-mcp ships ~25 tools today, we ship 21 — closing that is the roadmap.

Reliability — actionability auto-waiting

click / type / fill_form / select_option / hover don't fire blindly. Before acting, the engine polls (100 ms, up to a 5 s per-op budget) until the target element is present, visible (not display:none / visibility:hidden / zero-size), enabled (no disabled / aria-disabled), not covered by another element at its click point, and geometrically stable across two consecutive frames. A settled element passes on the first poll, so this is invisible when things are fine — but when an action can't happen, you get a cause-specific error (not found / not visible / disabled / covered / unstable) instead of a silent misclick or a generic timeout. Transient CDP errors are retried twice. Pass timeout_ms on any interaction tool to override the 5 s per-op budget (e.g. a short timeout to fail fast when you expect an element to already be there).

Performance

External-site latency is network-bound — DNS + TLS + TTFB (~400–600 ms) is a floor no tool beats, and Kitewright does not claim to. What it does attack is every controllable cost around the network:

• Prewarm + warm-context pool. The moment an MCP session initializes, the server launches the browser and fills a small pool of pre-created blank browser contexts (MCP_CONTEXT_POOL, default 2) in the background. A new session is then handed a ready context+page, so its first navigate pays zero browser-launch and zero context-creation cost. Measured localhost first-navigate: ~31 ms prewarmed vs ~709 ms cold (Apple Silicon; details). The pool drains with the browser on idle-reap and refills lazily on next demand, so idle footprint stays at the ~8 MB baseline.
• Lite mode. browser_navigate {lite:true} (and the default for extract / extract_markdown) blocks images/media/fonts + ad/analytics hosts before the load — 30–70 % faster DOM-ready on heavy pages by skipping the bulk of the bytes. Screenshots/PDF never block resources.
• Shared disk cache + connection pre-warm. A stable --disk-cache-dir (KITE_CACHE_DIR) lets repeat asset fetches hit cache across runs; KITE_PREWARM_URL establishes DNS+TLS to a known origin during prewarm.

The honest framing: the wins are browser launch, page weight, session start, and connection setup — not the network round-trip to a remote origin.

Architecture

crates/
├── engine/    kitewright-engine — CDP core (chromiumoxide): lazy launch, idle reaper,
│              per-session browser contexts, capped text extraction + AX snapshots.
│              Shared by all frontends.
└── server/    kitewright — rmcp Streamable HTTP server exposing the engine as MCP tools.
bindings/
└── node/      @kitewright/node — napi-rs bindings exposing a Puppeteer-compatible
               (experimental) API over the same engine (built separately; kept out
               of the core cargo workspace). See "@kitewright/node" below.

Each MCP session owns one persistent page inside its own Chromium browser context (cookie isolation between agents): log in once, keep clicking. The page and context are closed when the session ends; the browser itself is still reaped after the idle TTL and transparently relaunched on the next call.

Install

The zero-install way — run it straight from npx, like @playwright/mcp:

claude mcp add kitewright -- npx -y @kitewright/mcp

npx @kitewright/mcp resolves the prebuilt kite binary for your platform (an optional per-platform dependency, esbuild-style) and starts a stdio MCP server — no Rust toolchain, no build. See npm/kitewright-mcp.

Prefer the raw kite binary? (npx above is the easy path; these need a Rust toolchain.)

# From the public repo — builds + installs the `kite` binary:
cargo install --git https://github.com/kitewright/kitewright kitewright   # → ~/.cargo/bin/kite

# From a local checkout:
cargo install --path crates/server

# Docker (headless Chromium bundled in the image):
docker run --rm -p 8090:8090 kitewright   # build locally: docker build -t kitewright .

Not yet published to crates.io or Homebrew — cargo binstall/brew aren't wired up. Use npx @kitewright/mcp (no toolchain) or the cargo install --git line above.

Get a browser

Kitewright drives Chromium over CDP but does not embed one. It uses a system Chrome/Chromium when present, honors BROWSER_EXECUTABLE, and — if neither is found — falls back to a browser downloaded by kite install:

kite install    # fetch the latest stable chrome-headless-shell into the kite cache

kite install downloads the current Chrome-for-Testing chrome-headless-shell build for your platform into $KITE_CACHE_DIR (or the OS cache dir) and the engine picks it up automatically — no BROWSER_EXECUTABLE needed. Re-running is a no-op once a build is present. The Docker image already ships Chromium.

Run & connect

kite with no arguments serves MCP over Streamable HTTP (networked, default, supports auth + many sessions); kite --stdio serves a single session over stdio for local clients.

kite
# → kitewright listening on http://0.0.0.0:8090/mcp

HTTP transport — connect from Claude Code:

claude mcp add kite --transport http http://localhost:8090/mcp

stdio transport — MCP client config (Claude Desktop, Cursor, …):

{
  "mcpServers": {
    "kite": {
      "command": "kite",
      "args": ["--stdio"]
    }
  }
}

Configuration

Security

Kitewright drives a real browser, so treat the endpoint as privileged. The defaults are safe for local use; harden before exposing it.