# Host a server on your Android phone Your phone becomes the server. Not a cloud service pretending to be yours - the actual device in your hand (or the spare one in a drawer) holds your group's data and serves it to everyone. Setup is a few taps. Works on: - **A spare/recycled Android phone** - the classic dedicated host. Keep it plugged in and the battery acts as a built-in UPS (see the battery note in step 5 before leaving it charging long-term). - **Your daily phone** - hosting runs as a foreground service alongside normal use. > [!note] 📷 Photo needed > Both host styles: a plugged-in spare phone, and the app hosting on a daily driver. Save as `_images/host-phones.jpg`. ## 1. Install Phlip Install the Phlip app on the Android phone that will host. That's the whole install - the host server is built into the app. > [!note] Open-source backend > The hosting backend - the server built into the app - is **open source under the Apache License 2.0**. You can read and audit exactly what your phone runs as a host, or build it yourself, on [GitHub](REPLACE_WITH_GITHUB_URL). ## 2. Create your server 1. Open **Settings → Hosting**. 2. Tap **New server**, give it a name and pick a server icon if you like. 3. Start hosting. The app takes wake and Wi-Fi locks so the server stays reachable, and shows a persistent notification while hosting. You can host **multiple servers** from one phone - each keeps its own data, members, invite code, and settings. > [!note] 📷 Photo needed > The Hosting settings screen with a server running. Save as `_images/host-settings.png`. ## 3. Share the join code Each server has a join code like <span class="dp-serial">9F2K4X</span>. Share it from the app (or just read it out). On your home network, friends' devices can also **discover the server automatically** - Phlip announces itself on the local network. New members pick a name and their own password, and appear in your **Approve / Deny** queue. You admit them; after that they sign in with their own credentials. Full member-side detail in [[3. Join a server|Join a server]]. ## 4. Approvals, roles and members As host you get: - **Approve/Deny** for every new join request. - A **member directory** - see everyone, edit roles, remove members. - **Roles**: host, admin, moderator, user, viewer. - Server settings such as whether members can create events, whether profile pictures are allowed, and the server's card theme. > [!note] 📷 Photo needed > The member directory with a couple of roles visible. Save as `_images/host-members.png`. ## 5. Battery and being a good host - **Spare phone:** keep it plugged in; that's it. - **Daily phone:** the foreground service keeps hosting alive, but aggressive manufacturer battery managers (Samsung "deep sleep" lists and similar) can interfere - exclude Phlip from battery optimisation. Stop/start hosting any time from Settings; while stopped, the server is simply offline and resumes intact. > [!warning] Leaving a phone on charge permanently isn't risk-free > Keeping any phone plugged in around the clock, indefinitely, holds its battery at or near 100% for long stretches - this accelerates lithium-ion battery wear and, on old or damaged hardware/cables, is a recognised (if rare) fire/overheating risk. It is **not officially advised** as a "set and forget forever" setup. To host more safely: > - Use a phone with a healthy, unswollen battery - retire anything old, damaged, or already degraded from daily use. > - Prefer a genuine or reputable charger/cable, and charge somewhere ventilated, not under bedding or in an enclosed cupboard. > - If your phone/charger supports it, enable a charge limit (e.g. 80-90%) or a "protect battery"/optimised-charging mode instead of a permanent 100% trickle charge. > - **No software charge limit on your phone?** Use a hardware workaround instead: a cheap **timed plug/smart plug** that cuts power for part of the day (e.g. off overnight, on for a couple of hours), so the phone isn't held at 100% continuously. Some smart plugs can even be scheduled or triggered by a battery-level automation (e.g. Home Assistant, Tasker) to switch off once charge is high and back on once it's dropped a bit. > - Check on the host phone occasionally - listen/feel for excess heat and check for battery swelling. > - Prefer this setup for a dedicated spare rather than a phone you also carry on you or leave near people while charging unattended. Your server's data lives on the device in a per-server data file. Back the phone up like you'd back up anything that matters. ## 6. Safer host setup (especially for Public) Phlip runs in Android's app sandbox. On a currently patched phone that is enough for most risks. On an old spare with no security updates for years, treat the host like a small appliance: - **Factory-reset** the host phone before you use it for groups. - Use a **throwaway Google account** for Play updates (no personal mail, photos, or payment methods) — or sideload and check for updates yourself. - Put the host on **guest Wi‑Fi**. Public still works (the tunnel is outbound-only); isolation stops a compromised phone reaching your router, NAS, or other devices. - Host from the spare; use your daily phone as a normal Phlip client. In the app, **Settings → Hosting** shows a short “Safer hosting setup” tip and a patch-age warning when the phone’s security update is old. --- **Next:** [[5. Go public with Cloudflare|Go public with Cloudflare]] so people can join from outside your Wi-Fi.