Jet Browser for Hermes

This Hermes plugin registers one model-callable tool, jet_browser_verify. It runs Jet Browser's real standalone acceptance check in a short-lived Docker container and returns structured evidence for browser startup, native input, DOM agreement, PNG capture, and cleanup.

This first integration is intentionally narrow. It verifies the runtime; it does not replace Hermes' CDP browser backend, browse public sites, attach to a personal Chrome profile, or keep a browser daemon running. Jet Browser uses WPE WebKit and ordered JSONL rather than Chromium CDP, so presenting it as a native Hermes browser provider would be misleading.

Install

Requirements: Linux, Docker, and Hermes Agent 0.21.6 or newer.

hermes plugins install masakaai/jet-browser/integrations/hermes
hermes plugins enable jet-browser

Start Hermes and ask:

Verify the Jet Browser runtime and report the evidence.

The tool returns JSON shaped like:

{
  "success": true,
  "network": "disabled",
  "title": "Jet Browser Ready",
  "input": "open-source runtime",
  "screenshot_bytes": 12345,
  "screenshot_sha256": "...",
  "duration_ms": 1450
}

Security and operational boundaries

The OCI image is pinned to an immutable digest and currently targets linux/amd64.
Docker may contact GitHub Container Registry the first time it needs the pinned image. The browser container itself runs with networking disabled.
The container drops all capabilities before selectively restoring only SETUID and SETGID, sets no-new-privileges, uses the checked-in seccomp profile, and has CPU, memory, PID, and shared-memory limits.
The plugin invokes Docker with a fixed argument vector and never opens a shell. On timeout or failure it terminates the client and force-removes only the uniquely named container it created.
No credentials, browser profiles, telemetry, accounts, API keys, or hosted Jet Browser service are used.

Validate the plugin

From a Hermes Agent checkout:

hermes plugins validate /path/to/jet-browser/integrations/hermes --install-deps

The plugin's stdlib-only contract tests can also run directly:

python -m unittest discover -s integrations/hermes/tests -v

Jet Browser source, benchmark method, raw samples, and the broader standalone quick start live at https://github.com/masakaai/jet-browser.

jet-browser

What it adds

Tools 1

README