Pi Web POC

Small web wrapper around @mariozechner/pi-coding-agent.

What it does

• Add/list projects.
• Discover workspaces from git worktree list --porcelain.
• For non-git projects, show the project folder as the only workspace.
• List Pi sessions for a workspace using Pi's default session storage.
• Start Pi sessions, chat over WebSocket events, and stop individual session runtimes.

State

This POC intentionally keeps state minimal:

• Projects: ~/.pi-web/projects.json
• Workspaces: discovered from git, not stored
• Sessions/chat history: Pi default JSONL session storage
• Active session runtimes/WebSockets: memory only in pi-web-sessiond

Run

npm install
npm run dev

Open the Vite URL, usually http://localhost:5173.

The session runtime owner is split into a tiny long-lived daemon. To iterate on only the web/API/UI process while keeping active Pi sessions alive, run these in separate terminals:

npm run dev:sessiond
npm run dev:web
npm run dev:client

Then restart dev:web or dev:client freely; active Pi sessions continue in dev:sessiond.

systemd user services for local development

This repository is commonly run as two systemd user services:

• pi-web-sessiond.service: runs npm run start:sessiond without autoreload or automatic restart.
• pi-web-ui-dev.service: runs npm run dev:web and npm run dev:client together, giving backend autoreload via tsx watch and Vite UI HMR.

Example units live in ~/.config/systemd/user/ on the development host:

# ~/.config/systemd/user/pi-web-sessiond.service
[Unit]
Description=Pi Web session daemon

[Service]
Type=simple
WorkingDirectory=/srv/dev/pi-web
ExecStart=/bin/bash -lc 'exec npm run start:sessiond'
Restart=no

[Install]
WantedBy=default.target

# ~/.config/systemd/user/pi-web-ui-dev.service
[Unit]
Description=Pi Web UI dev server
After=pi-web-sessiond.service
Wants=pi-web-sessiond.service

[Service]
Type=simple
WorkingDirectory=/srv/dev/pi-web
ExecStart=/bin/bash -lc 'trap "kill 0" EXIT; npm run dev:web & npm run dev:client & wait'
Restart=no

[Install]
WantedBy=default.target

After creating or changing units:

systemctl --user daemon-reload
systemctl --user enable --now pi-web-sessiond.service
systemctl --user enable --now pi-web-ui-dev.service

Useful logs:

journalctl --user -u pi-web-sessiond.service -f
journalctl --user -u pi-web-ui-dev.service -f

Because sessiond is intentionally not watched or restarted automatically, code changes that affect src/server/sessiond.ts or session runtime ownership require manually restarting pi-web-sessiond.service:

systemctl --user restart pi-web-sessiond.service

Restarting only the UI dev service is enough for changes in the web/API/UI processes.

For deployment:

npm run build
npm run start:sessiond
PI_WEB_PORT=3000 npm start

Then proxy Traefik to http://127.0.0.1:3000.

The web server defaults to 127.0.0.1:3000. Use PI_WEB_HOST=0.0.0.0 only if you want to bind directly on all interfaces. The session daemon defaults to a private Unix socket at ~/.pi-web/sessiond.sock; override with PI_WEB_SESSIOND_SOCKET or use TCP with PI_WEB_SESSIOND_PORT plus PI_WEB_SESSIOND_URL for the web process.

Notes

• The backend uses your normal Pi auth/model settings from ~/.pi/agent.
• Slash commands that belong to Pi's interactive TUI, such as /model, are not implemented in this POC UI yet. Plain prompts and extension/prompt-template handling go through the SDK path.
• Browser disconnects and web-server restarts do not stop active Pi sessions. Only the explicit Stop session action aborts/disposes that one session runtime.