Glass

Glass is a lightweight browser control tool written in Rust. It drives Chrome or Chromium directly through the Chrome DevTools Protocol (CDP), without Playwright, WebDriver, or an embedded browser runtime.

Glass executes explicit browser commands. It does not choose a workflow or silently retarget an action.

Status

Glass 0.1.17 is published as the glass-browser crate. Release binaries are provided for Linux x86-64 and macOS x86-64/arm64. Windows is not a supported target.

The command-line interface, terminal UI, MCP server, and Rust library share the same session runtime.

Install

Install the published command with Cargo:

cargo install glass-browser --locked
glass --help

Or build from a checkout:

cargo install --path . --locked

Prebuilt Linux and macOS binaries are available from the 0.1.17 GitHub release. The assets include SHA-256 checksum files. For example:

GLASS_VERSION=v0.1.17
curl -fL "https://github.com/wanazhar/glass/releases/download/${GLASS_VERSION}/glass-linux-x86_64" -o glass
curl -fL "https://github.com/wanazhar/glass/releases/download/${GLASS_VERSION}/glass-linux-x86_64.sha256" -o glass.sha256
sha256sum -c glass.sha256
chmod +x glass

Use glass-macos-x86_64 on Intel Macs or glass-macos-aarch64 on Apple Silicon. The binary must be able to find Chrome, Chromium, or Chrome for Testing. Use glass install-chromium to install the release-pinned Chrome for Testing build when a system browser is not available.

See installation and operations for browser discovery, profiles, attach mode, logging, policy presets, and deployment guidance.

First run

The terminal UI keeps one browser session open for a sequence of commands:

glass tui

Inside the UI:

navigate https://example.com
observe

For a single explicit operation, use a CLI subcommand. Results are JSON on stdout and diagnostics are written to stderr:

glass navigate https://example.com
glass --incognito --headed navigate https://example.com

Use --profile NAME for persistent cookies and storage, or --incognito for a disposable browser profile.

Interfaces

Surface	Use it for	Entry point
CLI	Scripts and one-shot commands	`glass <command>`
Terminal UI	A visible, interactive session	`glass tui`
MCP	A long-lived stdio session from an MCP-compatible client	`glass --mcp`
Rust library	Embedding the session runtime	`glass-browser` crate, imported as `glass`

Configure an MCP client to launch the binary directly:

{
  "mcpServers": {
    "glass": {
      "command": "/absolute/path/to/glass",
      "args": ["--mcp"]
    }
  }
}

Keep stdout reserved for MCP frames. Use an absolute binary path when the client does not inherit the shell's PATH. The MCP guide lists the tools, framing limits, lifecycle, and security rules.

Command surface

The main browser operations are available from the CLI and MCP:

navigate, click, double-click, hover, drag, type, clear, check, uncheck, and select;
scroll, wait, inspect visible text, inspect DOM, evaluate JavaScript, and capture screenshots or PDFs;
upload files, handle JavaScript dialogs, dismiss recognized consent walls, and verify a popup opened from a click;
list and select page targets and frames;
inspect cookies and web storage;
export/import cookies and bounded session checkpoints; and
run bounded typed batches and reconcile revisioned references.

Use glass --help for the complete CLI surface. Detailed command syntax is in the CLI reference, and the corresponding MCP names and arguments are in the MCP guide.

Targets and revisions

Observations publish bounded accessibility data and revisioned element references such as r7:b42. Locators can also use an accessible name, an explicit role and name, text, CSS, or an ordinal:

glass click 'name=Save'
glass click 'role=button;name=Save'
glass click 'css=button.primary'

For an action tied to a specific observation, pass its revision:

glass click r7:b42 --expected-revision 7
glass type 'hello' --target r7:b43 --expected-revision 7

The guarded click, type, fill, and navigation APIs return a structured status, the previous and current revisions, and bounded verification metadata. A stale revision is rejected before the browser action runs. Legacy commands without an expected revision remain available. See the action contract for result fields, failure kinds, and recovery examples.

Rust library

Add the published crate as glass in Cargo.toml:

[dependencies]
glass = { package = "glass-browser", version = "0.1" }

The library exposes BrowserSession, typed session options and policies, compact observations, revision-safe actions, target/frame management, storage, downloads, screenshots, PDFs, and the MCP server implementation.

Small optional MCP clients are included for TypeScript and Python. They launch a local Glass binary and do not include a browser runtime.

Scope and safety

Glass currently supports Linux x86-64 and macOS x86-64/arm64. It requires a local Chrome, Chromium, or Chrome for Testing process and a local CDP connection. It does not provide a browser runtime, a hosted browser service, or cross-platform Windows support.

Use a dedicated browser profile, keep the CDP endpoint local, and treat profiles, screenshots, DOM output, cookies, and logs as sensitive. Review SECURITY.md before using authenticated sessions or attach mode.

Documentation

Development

cargo fmt --all -- --check
cargo test --all-targets --locked
cargo clippy --all-targets --all-features --locked -- -D warnings

The opt-in browser smoke test requires a detectable Chrome or Chromium:

GLASS_E2E=1 cargo test --test browser_smoke -- --nocapture

License

Glass is licensed under the MIT License.

glass-browser 0.1.17