Gemini Argon Bridge

Experimental local CLI and MCP bridge for asking the Argon selection in Gemini Web through browser CDP. The bridge sends the prompt and context you provide to the signed-in Gemini Web tab and returns a newly completed assistant turn.

This package currently supports only https://gemini.google.com/. Before it submits anything, it requires one unambiguous Gemini Web tab, a visible model control containing Argon and Cao/High, an idle page, and an empty prompt box. It accepts a response only from a new top-level model-response whose Markdown content and model announcer report aria-busy="false", whose .response-footer.complete.gap marker is present, and while no Stop control is visible.

The model label is evidence read from the page UI. It does not verify the backend model. Google AI Studio and LM Arena are not supported by this adapter. The package and the harness examples below are experimental; they have not been tested as integrations in Claude Code, Cursor, Codex, or Antigravity.

Requirements and install

• Node.js 20 or newer.

• npm install in a local checkout, or npm install --global "<absolute-path-to-this-package>" to expose ask-argon and argon-mcp outside the checkout.

• Chrome or Edge launched with CDP enabled, with a Gemini Web tab open and the expected Argon setting selected.

Use a browser profile that you intend to expose through CDP. Anyone who can reach that CDP endpoint may be able to control the browser. When a launcher starts a new browser, it uses a separate ArgonProfile; if the configured CDP port is already open, the launcher reuses that existing browser without checking its profile. Review the active profile and account before sending anything.

Start Chrome/Edge with the supplied launcher, or start your own Chromium browser with --remote-debugging-port=9222. Then list eligible tabs and copy the target ID:

ask-argon --list-tabs

The list operation only reads open Gemini Web tabs. If more than one is listed, pass the selected target ID with --tab.

Related MCP server: Gemini MCP Bridge

CLI

ask-argon --prompt "Review this failure" --context "Relevant, approved context" --tab "<CDP_TARGET_ID>"
ask-argon --file ./prompt.txt --json

The CLI also accepts a positional prompt or UTF-8 input on stdin. --json writes one JSON object to stdout; progress goes to stderr. Use --help for all options. ARGON_CDP_ENDPOINT sets the CDP endpoint and ARGON_TIMEOUT_SEC sets the total deadline in seconds; explicit flags take precedence. --timeout covers connection, tab selection, lock wait, validation, submit, and response completion.

MCP

The package exposes one stdio tool, ask_gemini_argon. Its arguments are prompt, optional context, optional positive timeoutSeconds (default 600), and optional tabId. The server reads ARGON_CDP_ENDPOINT from its process environment. It supports JSON-RPC cancellation notifications; callers should set their own tool timeout above the requested bridge deadline.

After installing this package globally, use argon-mcp as the command in your MCP host. Adapter files under adapters/ are starting-point examples. Replace values only as needed for your host and verify the host can discover and call the tool before relying on it. The Antigravity package manifest and MCP configuration are in plugin.json and mcp_config.json; the plugin host itself has not been tested here.

Safety and limits

• Only provide prompt and context that you are authorized to send to the Google account active in the browser. The bridge does not upload project files automatically, but supplied context goes to Gemini Web.

• A CDP target lock serializes this package's own processes for the same browser tab. It cannot prevent manual interaction or other software from changing the page.

• An observed UI label is not backend attestation. The response is returned with modelLabelObserved, thinkingLabelObserved, and completionEvidence; it never sets modelVerified.

• Browser DOM changes, account state, quotas, localization, network failures, and host-specific MCP behavior can prevent use. Unsupported or ambiguous states fail closed.

• No support claim is made for all operating systems, browser versions, languages, or agent harnesses.

Checks

Read the Vietnamese guide or the validation scope and results.

npm ci
npm test
npm run pack:check

An optional real-browser fixture uses an installed Chrome/Edge, a temporary profile, a random CDP port, and an intercept that serves only synthetic local HTML:

npm run test:browser

It does not call Gemini or contact provider sites. Live checks require an explicit user decision and should use only synthetic prompts. See docs/USAGE.md for the current scope and setup.

License

MIT. See LICENSE.