App Runner

Obsidian desktop plugin (macOS): register local apps with a start command, open them in Obsidian tabs, and stop them when the last tab closes.

Under construction. So far: the project registry (Settings, App Runner), the Open <name> and Stop <name> commands per project, a global "Pop out current App Runner tab to browser" command, the webview tab, and starting and stopping the app itself.

How an app is run

• Open <name> runs the project's command as /bin/zsh -lic '<command>' in the project folder, in its own process group. Your login shell's PATH applies (nvm node, for example). stdin is ignored and there is no terminal.
• The plugin looks for the TCP ports the group listens on (lsof), waits until one answers GET / over loopback (any status counts; 2 s per try, retried every 1 s, 60 s in all), then opens the tab. If several ports serve a page it asks once and remembers the choice as the project's URL override. Only 127.0.0.1, localhost and [::1] are ever probed or shown; a listener on any other address, or a URL override that is not loopback, is ignored.
• If every process exits first, or 60 s pass, the group is stopped, no tab opens and a notice shows the last 10 log lines.
• Stop <name> sends SIGTERM to the group, then SIGKILL after 5 s if anything is still alive. It only signals a group the plugin started: the pid and start time of each member are recorded in running.json, and a group with no live recorded member is left alone. If the signal cannot be sent (for example a permission error), a notice says why and the app stays listed as running; the Kill-when-all-tabs-closed timer does not retry it, so Stop (or opening it again) is up to you. Until adoption at relaunch lands, apps are also stopped when the plugin unloads.
• Output (stdout and stderr) goes to logs/<slug>.log, truncated at each start. Runtime files live in ~/Library/Application Support/Obsidian App Runner/<vault key>/, outside the vault. Show log in the project's settings row opens the file in the system app, or reveals it in Finder.

Known limit

Stop kills the process group, nothing more. A child that daemonises and leaves the group (a new session, for example setsid or Node's detached: true) survives Stop. The plugin does not hunt for it and does not claim it is stopped. Members started after the app was ready are recorded by a 5 s poll while the app runs, and again when the leader exits, so a worker that outlives its leader keeps the app running and Stop still signals it; the app is reported as stopped on its own only once no recorded member is left. A worker that leaves the group within one poll interval of starting is not seen.

The webview and microphone spike is recorded in docs/webview-spike.md.

Development

npm install
npm run typecheck
npm test
npm run build     # writes main.js
npm run dev       # rebuilds main.js on change