A3S Docs
A3S WebView

Usage

a3s-webview command-line flags, URL policy, size clamping, headers, install paths, and process behavior.

WebView Usage

a3s-webview is a one-window helper. It parses arguments, validates the URL, creates a native window, builds a WebView, and exits when the window is closed.

a3s-webview --url <http(s)://URL> [--width N] [--height N] [--title T]
            [--header 'Name: Value']... [--token-env NAME] [--no-auth]

a3s-webview --agent-island --snapshot <absolute-path>
            --lock-file <absolute-path>

Arguments

FlagRequiredBehavior
--urlYesMust start with http:// or https://. Other schemes are rejected before the window is created.
--widthNoLogical width; defaults to 900 and clamps to 240..4000.
--heightNoLogical height; defaults to 680 and clamps to 180..3000.
--titleNoNative window title; hosts should use a product-appropriate title.
--headerNoAdds a request header. Repeatable. Must use Name: Value syntax.
--token-envNoEnvironment variable name used for access-token auth seeding.
--no-authNoDisables all browser-storage auth seeding.
--helpNoPrints usage and exits.

The Agent Island mode is host-managed. Both paths must be absolute, and the snapshot must conform to the a3s.system_agent_snapshot.v1 contract.

Unknown arguments or missing flag values return a usage error and exit with status 2.

Example

a3s-webview \
  --url https://example.com/view \
  --width 960 \
  --height 720 \
  --title "A3S View" \
  --header "X-A3S-Source: tui"

Do not pass bearer credentials through --header unless the host process model already treats command-line arguments as protected. Prefer environment variables for session credentials.

Install

a3s install webview
brew install a3s-lab/tap/a3s-webview
cargo install --git https://github.com/A3S-Lab/WebView

On normal online a3s code startup, the CLI automatically prepares the verified release when the helper is missing. Offline mode and A3S_NO_AUTO_INSTALL=1 leave installation explicit. On macOS, the Homebrew a3s formula can install the helper alongside the umbrella CLI.

Process Model

The helper opens one focused window and waits in the native event loop. It does not manage multiple tabs, long-running background sessions, or a browser profile outside the embedded WebView process.

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