nodecode-jet-browser

Jet Browser: its own acceptance check, run in a network-isolated container. A Nodecode rewrite of masakaai/jet-browser by masakaai.

Jet Browser is a browser built on WPE WebKit whose project publishes its runtime as one digest-pinned container. The check this cell runs is the project's own: the container starts, the built-in fixture page loads, the cell types into it through native pointer and text events, reads the two fields back out of the DOM, captures a PNG, and the container is removed. The answer is evidence — the title, the URL, the text that was typed, the PNG's octet count and sha256, the milliseconds it took — not a claim that a browser works.

Get it

Tell the agent "add the jet-browser cell", or run nodecode add nc://nodecode-jet-browser.

Then run /jetbrowser run, or ask for the check: the model calls the tool jet_browser_verify.

Set it up

The cell runs one container, so it asks which image, once. In /settings (or the page's Settings tab), under jet-browser:

image — required. The image to run, pinned by digest. The project publishes one; paste it from the cell's own guide or from config.example.jsonc:

ghcr.io/masakaai/jet-browser@sha256:540a1fec531bf71b62c2c2d030c033249955ffc192ab7e0e7a1ac8d8412a661b
docker — the CLI to run; docker by default, as PATH finds it.
screenshot_file — where to keep the PNG the check captures; empty keeps only its sha256.

Until image is set the folder is REFUSED, with the reason on the /cells line and in the model's notices: nothing of its tools is registered while it refuses.

Docker is required, and Docker access is root-equivalent on the host. That is the price of the check, and it is why the image is named by the operator rather than defaulted.

Use it

/jetbrowser typed alone shows what it would run and a row that runs it; /jetbrowser run runs the check and answers one line of evidence.
jet_browser_verify is the same as a tool. It takes no arguments: what it runs is the section's. Its answer is JSON — {"success":true,"network":"disabled","image":…,"title":…,"url":…,"input":…,"screenshot_bytes":…,"screenshot_sha256":…,"duration_ms":…,"screenshot_file":…} — or, for a check that failed, {"success":null,"error":"…"}.
(help :jet-browser) is the manual a model reads.

What runs, and what does not touch you

One docker run, a fixed argument vector, no shell and nothing mounted:

docker run --rm -i --name nodecode-jet-browser-<8 hex>
  --platform=linux/amd64 --network=none
  --cap-drop=ALL --cap-add=SETUID --cap-add=SETGID
  --security-opt=no-new-privileges --security-opt=systempaths=unconfined
  --security-opt=apparmor=unconfined
  --security-opt=seccomp=<the cell's seccomp_profile.json>
  --memory=1g --cpus=2 --pids-limit=256 --shm-size=256m
  --env=JET_BROWSER_SMOKE=1 <image>

The container has no network; only the page the image serves itself (http://127.0.0.1:8080/) is loaded. Docker itself reaches the registry the first time the image is not local.
AppArmor and systempaths are unconfined and the checked-in seccomp profile allows the user-namespace and mount syscalls WPE WebKit's own bubblewrap sandbox needs. The profile ships beside the cell (seccomp_profile.json, from the original repository); seccomp_profile names another, and an empty name falls back to Docker's own.
Nothing of yours is mounted: no home, no profile, no files, no conversation. The tool takes no arguments, so nothing of the turn's enters the container either.
On timeout, or when the client exits badly, only the uniquely named container this run created is force-removed. The docker client's own words are kept in a log file under the system temp directory, deleted when a run succeeds and named in the error when it does not.

Layout

cell.lisp — the section, the tool, the command, the manual and the transport.
seccomp_profile.json — the container's syscall profile, carried over from the original.
test/ — the slice: the lifecycle, the protocol through a scripted container, the command, a failed check, the screenshot file.

.github/test-cell.sh tools/nodecode-jet-browser runs it offline: no test needs Docker.

nc://jet-browser