Playtest

A build that compiles proves nothing. A game that renders proves almost nothing. Playtesting proves it plays — that the loop runs, input moves the player, the objective is reachable, and nothing throws along the way.

The Tool: vg playtest

Everything here runs through one command. vg playtest is a passthrough to agent-browser, a native browser-automation CLI built for agents — vg installs it and its browser on first use, so there is nothing to add to the game's package.json to drive it. No test runner, no devDependencies, no MCP server to configure. (The one optional dependency is on the game's side: @vibedgames/playtest types and publishes the diagnostics contract below.)

vg playtest open http://localhost:5173   # launch + navigate (headless by default)
vg playtest snapshot -i                  # interactive elements, with @eN refs
vg playtest click @e2                    # act on a ref from that snapshot
vg playtest eval "window.__GAME_DIAGNOSTICS__" --json
vg playtest screenshot /tmp/frame.png
vg playtest close

A daemon persists between invocations, so one-call-per-step is cheap and the page stays open across commands.