README: clarify not affiliated with or endorsed by LocalSend

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

README.md

@@ -10,6 +10,10 @@ LocalSend mobile and desktop apps on the same LAN, including their default
 
 - **Discovery** — multicast announce/listen on `224.0.0.167:53317` plus the HTTP
   `/register` handshake, with peer aging.
+- **Remote devices** — reach boxes that aren't on your LAN (multicast can't find
+  them) by probing them directly over unicast. If [Tailscale](https://tailscale.com)
+  is running, online tailnet peers are discovered automatically; you can also add
+  a device by host/IP/name with the `+` key, saved for next time.
 - **Receive** — incoming files are accepted via a prompt (or auto-accepted) and
   written to the receive directory, with live progress.
 - **Send** — pick a peer, then find what to send with a built-in **recursive
@@ -47,9 +51,26 @@ curl -fsSL https://raw.githubusercontent.com/28allday/omarchy-send/main/install.
 ```
 
 This downloads the right binary for your architecture into `~/.local/bin`, and on
-Omarchy also adds a floating Walker entry (search **Omarchy-Send**). Override the
-location with `BIN_DIR=/usr/local/bin`, or pin a version with
-`OMARCHY_SEND_VERSION=v0.1.0`.
+Omarchy also adds a floating Walker entry (search **Omarchy-Send**) and the
+Nautilus right-click integration. Override the location with `BIN_DIR=/usr/local/bin`,
+or pin a version with `OMARCHY_SEND_VERSION=v0.1.0`.
+
+The installer also drops an **agent context file** so any AI agent on the machine
+(Claude, etc.) knows what omarchy-send is and where received files land: a canonical
+`~/.config/omarchy-send/AGENTS.md` (with a `CLAUDE.md` symlink) plus a short,
+idempotently-managed section appended to `~/.claude/CLAUDE.md`.
+
+**Local or remote?** When run interactively the installer asks whether this is a
+**local** machine (home/LAN) or a **remote server** (public IP). Local installs as
+above. For a remote server it additionally locks port `53317` to the Tailscale
+interface in the firewall (`ufw`), so the box is reachable over your tailnet only —
+not the open internet. Non-interactive installs (e.g. piped `curl | bash`) default
+to local; force a choice with `OMARCHY_SEND_MODE=local` or `OMARCHY_SEND_MODE=remote`.
+
+If you install in local mode but the box has a **public IP**, the installer detects
+it and prints a warning with the exact commands to lock the port down — it never
+changes your firewall without remote mode. See
+[Public-IP boxes](#public-ip-boxes-firewall-the-port) below.
 
 > The installer is a short shell script fetched over HTTPS; read it first if you
 > prefer — it lives at [`install.sh`](install.sh) in this repo.
@@ -80,21 +101,30 @@ omarchy-send --no-notify          # don't raise desktop notifications on incomin
 
 ### Headless send (no TUI)
 
-Send a one-off message to a peer by name, with no terminal UI — handy from
-scripts, cron, or an SSH session with no TTY:
+Send a one-off message, files, or folders to a peer by name, with no terminal
+UI — handy from scripts, cron, AI agents, or an SSH session with no TTY:
 
 ```sh
 omarchy-send --to "Strong Onion" --message "hello"
 omarchy-send --to "Strong Onion" --message "deploy finished" --wait 20s
 omarchy-send --to "Strong Onion" --message "hi" --send-pin 2468   # if the peer requires a PIN
+omarchy-send --to "Strong Onion" report.pdf photos/               # files and folders
+omarchy-send --to "Strong Onion" --message "build log attached" build.log
 ```
 
 The target is matched against the peer's display name, case-insensitively. The
-command discovers the peer over multicast (waiting up to `--wait`, default 15s),
-sends the message, prints a one-line result, and exits non-zero if the peer
-isn't found or the send fails. It starts discovery only — not the receiver — so
-it's safe to run while another `omarchy-send` instance is up. Both `--to` and
-`--message` are required; file sending stays in the TUI for now.
+command discovers the peer over multicast and, like the TUI, directly probes
+your known peers and online Tailscale peers (waiting up to `--wait`, default
+15s) — so a remote box added with `+` in the TUI, or any tailnet peer, is a
+valid `--to` target from a script too. It sends the message and/or files,
+prints a result line per file, and exits non-zero if the peer isn't found or
+the send fails. It starts discovery only — not the receiver — so it's safe to
+run while another `omarchy-send` instance is up.
+
+`--to` requires a `--message`, file/folder paths, or both (flags must come
+before the paths). A folder is sent whole and its structure recreated on the
+receiver. Paths *without* `--to` instead open the TUI with them pre-staged
+(quick-send) — that form needs a TTY.
 
 ### Sending files
 
@@ -111,6 +141,92 @@ Staging a folder sends it whole (its structure is recreated on the receiver).
 Matching is case-insensitive, and noisy directories (`.git`, `node_modules`,
 caches, dotfiles…) are skipped to keep the index fast.
 
+### Remote devices (over Tailscale)
+
+Multicast discovery only finds peers on the same LAN. To send to / receive from a
+box elsewhere, omarchy-send probes it directly over unicast — which works over
+anything routable, [Tailscale](https://tailscale.com) being the easy, secure choice
+(stable addresses, end-to-end encryption, no port-forwarding):
+
+1. `tailscale up` on both devices (one-time).
+2. Either let omarchy-send **auto-discover** online tailnet peers (it probes them
+   every few seconds; any running omarchy-send/LocalSend appears in Devices), or
+   press **`+`** on the Devices tab and enter a host, IP, or Tailscale name (e.g.
+   `colossus`). Added devices are saved to `knownPeers` in the config and re-probed
+   on every launch.
+
+The receiver already listens on all interfaces, so it's reachable at its Tailscale
+IP with nothing else to configure. Sending and receiving both work, because the
+probe is a two-way handshake (each side learns the other).
+
+#### Containers / userspace-networking tailscaled
+
+When tailscaled runs with `--tun=userspace-networking` (typical in unprivileged
+containers — no TUN device), processes cannot dial tailnet addresses directly;
+outbound tailnet traffic only works through tailscaled's built-in SOCKS5 proxy.
+omarchy-send handles this automatically: when the box has no tailnet address on
+a local interface but a proxy answers at `localhost:1055`, connections to
+`100.64.0.0/10` destinations are routed through it — LAN traffic is never
+proxied, and explicit `HTTPS_PROXY`/`HTTP_PROXY`/`NO_PROXY` variables override
+the auto-detection. The one thing the box must provide is the proxy itself:
+
+```sh
+tailscaled --tun=userspace-networking --socks5-server=localhost:1055 …
+```
+
+The installer detects this situation and **offers to apply the fix** ([y/N]):
+it adds the flag to the launcher script that starts tailscaled (a container
+entrypoint, say) and restarts the daemon — or, when it lacks the rights to
+restart it, patches the launcher and tells you to restart the container/box.
+Non-interactive installs never touch the daemon; pre-answer with
+`OMARCHY_SEND_FIX_TAILSCALE=yes` (or `no`) to skip the prompt.
+
+Note that inbound connections on such boxes appear to come from `127.0.0.1`
+(tailscaled re-dials loopback); omarchy-send keeps a peer's routable address
+rather than letting those registers overwrite it.
+
+#### Public-IP boxes: firewall the port
+
+The receiver binds **all interfaces**, so on a box with a public IP, port `53317`
+is reachable from the open internet while the TUI is running. Don't leave it that
+way. Three ways to handle it:
+
+- **Easiest:** install in **remote** mode — `OMARCHY_SEND_MODE=remote bash install.sh`
+  — and the installer applies the `ufw` rules for you (when a real `tailscale0`
+  interface is present).
+- **Manually**, restrict the port to the tailnet:
+
+  ```sh
+  ufw allow in on tailscale0 to any port 53317   # tailnet only
+  ufw deny 53317                                 # everything else
+  ```
+
+  Or the `nftables` equivalent (inet filter, input chain):
+
+  ```
+  iifname "tailscale0" tcp dport 53317 accept
+  tcp dport 53317 drop
+  ```
+
+- **Inside a container** (e.g. Docker `--network host` with userspace-networking
+  Tailscale, where there's no `tailscale0` and no `CAP_NET_ADMIN`): you can't
+  firewall from in there — apply it on the **host**. If the host already
+  default-denies inbound (only opens e.g. 22/80/443), `53317` is already blocked
+  from the internet yet still reachable over the tailnet (tailscaled delivers it
+  via loopback) — nothing more to do.
+
+Always set a **`--pin`** as a second layer regardless.
+
+> **Verifying** the port is closed: don't trust `nc -z`, `telnet`, or
+> `/dev/tcp` — some hosting providers (Hostinger, DigitalOcean, …) answer the TCP
+> handshake (SYN/ACK) for *every* port at their network edge, so those tools
+> report a firewalled port as "open". Only an **app-layer** probe is truthful:
+>
+> ```sh
+> curl -sk https://<public-ip>:53317/api/localsend/v2/info   # should time out / hang
+> curl -sk https://<tailnet-ip>:53317/api/localsend/v2/info  # returns device info
+> ```
+
 ### Right-click send (Nautilus)
 
 On an Omarchy desktop, the installer adds a **"Send via Omarchy-Send"** entry to
@@ -154,7 +270,7 @@ omarchy-send --auto-accept --pin 2468
 ### Keys
 
 - `1`–`5` or `tab` — switch between Devices / Transfers / Manage / Messages / Settings
-- Peers: `enter` send to the selected peer · `m` message · `v` send clipboard · `r` refresh · `/` filter
+- Peers: `enter` send to the selected peer · `m` message · `v` send clipboard · `+` add a remote device · `r` refresh · `/` filter
 - PIN-protected peers: messages prompt for the PIN and retry, just like file sends
 - Send finder: type to fuzzy-filter · `enter` stage file/folder · `ctrl+d` folders-only · `ctrl+s` send · `ctrl+u` up a dir · `esc` back
 - Incoming prompt: `y` accept · `n` reject
@@ -182,5 +298,5 @@ desktop client and are not controlled by the sender.
 
 MIT — see [LICENSE](LICENSE). Omarchy-Send is an independent implementation of
 the published [LocalSend protocol](https://github.com/localsend/protocol); it is
-not affiliated with the LocalSend project. The terminal UI is built on the
+not affiliated with or endorsed by the LocalSend project. The terminal UI is built on the
 [Charm](https://github.com/charmbracelet) libraries (also MIT).

cmd/omarchy-send/main.go

@@ -12,6 +12,7 @@ import (
 	"os"
 	"path/filepath"
 	"strings"
+	"sync"
 	"sync/atomic"
 	"time"
 
@@ -24,6 +25,7 @@ import (
 	"omarchy-send/internal/discovery"
 	"omarchy-send/internal/notify"
 	"omarchy-send/internal/server"
+	"omarchy-send/internal/tailscale"
 	"omarchy-send/internal/transfer"
 	"omarchy-send/internal/tui"
 )
@@ -34,6 +36,85 @@ type controller struct {
 	sender *client.Sender
 	srv    *server.Server
 	notify *atomic.Bool // live gate for desktop notifications (toggled from Settings)
+	rem    *remotes     // live set of directly-probed (known/remote) hosts
+}
+
+// remotes is the live set of hosts probed directly over unicast: known peers
+// loaded from config plus any added at runtime in the TUI. Guarded because the
+// watcher goroutine and the controller's AddKnownPeer both touch it.
+type remotes struct {
+	mu    sync.Mutex
+	hosts []string
+}
+
+func (r *remotes) list() []string {
+	r.mu.Lock()
+	defer r.mu.Unlock()
+	return append([]string(nil), r.hosts...)
+}
+
+// add appends host if not already present, returning true if it was new.
+func (r *remotes) add(host string) bool {
+	host = strings.TrimSpace(host)
+	if host == "" {
+		return false
+	}
+	r.mu.Lock()
+	defer r.mu.Unlock()
+	for _, h := range r.hosts {
+		if h == host {
+			return false
+		}
+	}
+	r.hosts = append(r.hosts, host)
+	return true
+}
+
+// AddKnownPeer registers a remote host and probes it immediately so it shows up
+// without waiting for the next watcher tick. Persisting it to config is the
+// TUI's job; this only updates the live set.
+func (c controller) AddKnownPeer(host string) {
+	if c.rem != nil {
+		c.rem.add(host)
+	}
+	go func() {
+		ctx, cancel := context.WithTimeout(context.Background(), 4*time.Second)
+		defer cancel()
+		_ = c.disc.Probe(ctx, host)
+	}()
+}
+
+// watchRemotes periodically probes the known-peer set plus any online Tailscale
+// peers, so devices that multicast can't reach (different subnet / over the
+// tailnet) still appear in the list — and age out when they stop answering.
+func watchRemotes(ctx context.Context, disc *discovery.Discoverer, rem *remotes) {
+	probeAll := func() {
+		seen := map[string]bool{}
+		hosts := rem.list()
+		hosts = append(hosts, tailscale.Peers(ctx)...)
+		for _, h := range hosts {
+			if h == "" || seen[h] {
+				continue
+			}
+			seen[h] = true
+			go func(host string) {
+				pctx, cancel := context.WithTimeout(ctx, 4*time.Second)
+				defer cancel()
+				_ = disc.Probe(pctx, host)
+			}(h)
+		}
+	}
+	probeAll() // immediate, so remotes appear without waiting a tick
+	t := time.NewTicker(10 * time.Second)
+	defer t.Stop()
+	for {
+		select {
+		case <-ctx.Done():
+			return
+		case <-t.C:
+			probeAll()
+		}
+	}
 }
 
 func (c controller) Announce()                                         { c.disc.Announce() }
@@ -81,7 +162,7 @@ func main() {
 		noNotify  = flag.Bool("no-notify", false, "don't raise desktop notifications on incoming messages/files")
 
 		// Headless one-shot send (no TUI): -to <alias> -message <text>.
-		toFlag      = flag.String("to", "", "headless send: target peer alias to send to (no TUI); requires -message")
+		toFlag      = flag.String("to", "", "headless send: target peer alias to send to (no TUI); combine with -message and/or file paths")
 		messageFlag = flag.String("message", "", "headless send: plain-text message to send to -to")
 		sendPINFlag = flag.String("send-pin", "", "headless send: PIN to present if the target peer requires one")
 		waitFlag    = flag.Duration("wait", 15*time.Second, "headless send: how long to wait for the target peer to be discovered")
@@ -106,7 +187,7 @@ func main() {
 		cfg.Port = *portFlag
 	}
 	if *dirFlag != "" {
-		cfg.ReceiveDir = *dirFlag
+		cfg.ReceiveDir = config.ExpandHome(*dirFlag)
 	}
 	if *pinFlag != "" {
 		cfg.PIN = *pinFlag
@@ -121,29 +202,27 @@ func main() {
 		cfg.NoNotify = true
 	}
 
-	// Headless one-shot send: resolve the target by alias over discovery, send,
-	// and exit — no TUI, no terminal required. Suitable for scripts and cron.
+	// Headless one-shot send: resolve the target by alias over discovery, send
+	// a message and/or positional file/folder paths, and exit — no TUI, no
+	// terminal required. Suitable for scripts, cron, and AI agents.
 	if *toFlag != "" || *messageFlag != "" {
-		if *toFlag == "" || *messageFlag == "" {
-			fmt.Fprintln(os.Stderr, "headless send needs both -to <alias> and -message <text>")
+		paths := absPaths(flag.Args())
+		if *toFlag == "" {
+			fmt.Fprintln(os.Stderr, "headless send needs -to <alias> (plus -message <text> and/or file paths)")
 			os.Exit(2)
 		}
-		os.Exit(runHeadlessSend(cfg, *toFlag, *messageFlag, *sendPINFlag, *waitFlag))
+		if *messageFlag == "" && len(paths) == 0 {
+			fmt.Fprintln(os.Stderr, "headless send needs -message <text>, file/folder paths, or both")
+			os.Exit(2)
+		}
+		os.Exit(runHeadlessSend(cfg, *toFlag, *messageFlag, *sendPINFlag, *waitFlag, paths))
 	}
 
 	// Quick-send: any positional arguments are file/folder paths to send (the
 	// Nautilus right-click integration calls `omarchy-send <paths…>`). Open the
 	// TUI with them pre-staged, on the device list.
 	if args := flag.Args(); len(args) > 0 {
-		paths := make([]string, 0, len(args))
-		for _, a := range args {
-			if abs, err := filepath.Abs(a); err == nil {
-				paths = append(paths, abs)
-			} else {
-				paths = append(paths, a)
-			}
-		}
-		os.Exit(runQuickSend(cfg, paths))
+		os.Exit(runQuickSend(cfg, absPaths(args)))
 	}
 
 	ctx, cancel := context.WithCancel(context.Background())
@@ -186,7 +265,9 @@ func main() {
 	// only carries the user preference here.
 	notifyOn := &atomic.Bool{}
 	notifyOn.Store(!cfg.NoNotify)
-	ctrl := controller{disc: disc, sender: sender, srv: srv, notify: notifyOn}
+	rem := &remotes{hosts: cfg.KnownPeers}
+	ctrl := controller{disc: disc, sender: sender, srv: srv, notify: notifyOn, rem: rem}
+	go watchRemotes(ctx, disc, rem)
 
 	p := tea.NewProgram(tui.New(cfg, ctrl), tea.WithAltScreen())
 	app.BridgeDiscovery(ctx, disc.Events(), p.Send)
@@ -222,7 +303,9 @@ func runQuickSend(cfg config.Config, paths []string) int {
 
 	// No receiver in quick-send mode, so nothing to notify about.
 	notifyOff := &atomic.Bool{}
-	ctrl := controller{disc: disc, sender: sender, srv: nil, notify: notifyOff}
+	rem := &remotes{hosts: cfg.KnownPeers}
+	ctrl := controller{disc: disc, sender: sender, srv: nil, notify: notifyOff, rem: rem}
+	go watchRemotes(ctx, disc, rem) // so a remote box is a valid quick-send target too
 
 	p := tea.NewProgram(tui.New(cfg, ctrl, tui.WithStagedFiles(paths)), tea.WithAltScreen())
 	app.BridgeDiscovery(ctx, disc.Events(), p.Send)
@@ -236,12 +319,27 @@ func runQuickSend(cfg config.Config, paths []string) int {
 	return 0
 }
 
+// absPaths resolves each path to absolute (best-effort; a path that fails to
+// resolve is passed through as-is and will fail with a clear error later).
+func absPaths(args []string) []string {
+	paths := make([]string, 0, len(args))
+	for _, a := range args {
+		if abs, err := filepath.Abs(a); err == nil {
+			paths = append(paths, abs)
+		} else {
+			paths = append(paths, a)
+		}
+	}
+	return paths
+}
+
 // runHeadlessSend discovers the peer whose alias matches target (case-
-// insensitively), sends it a plain-text message, and returns a process exit
-// code. It deliberately starts only discovery — not the HTTP receiver — so it
-// can run alongside an already-running instance without fighting over the
-// listen port. Status goes to stderr; the success line goes to stdout.
-func runHeadlessSend(cfg config.Config, target, message, sendPIN string, wait time.Duration) int {
+// insensitively), sends it the given file/folder paths and/or a plain-text
+// message, and returns a process exit code. It deliberately starts only
+// discovery — not the HTTP receiver — so it can run alongside an
+// already-running instance without fighting over the listen port. Status goes
+// to stderr; the success lines go to stdout.
+func runHeadlessSend(cfg config.Config, target, message, sendPIN string, wait time.Duration, paths []string) int {
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
 
@@ -252,6 +350,11 @@ func runHeadlessSend(cfg config.Config, target, message, sendPIN string, wait ti
 	}
 	disc.Announce() // solicit replies immediately rather than waiting a tick
 
+	// Multicast can't cross subnets or the tailnet, so also probe known peers
+	// and online Tailscale peers directly — same as the TUI's device list.
+	rem := &remotes{hosts: cfg.KnownPeers}
+	go watchRemotes(ctx, disc, rem)
+
 	want := strings.TrimSpace(target)
 	fmt.Fprintf(os.Stderr, "Looking for %q on the network (up to %s)…\n", want, wait)
 
@@ -268,22 +371,56 @@ func runHeadlessSend(cfg config.Config, target, message, sendPIN string, wait ti
 				fmt.Fprintf(os.Stderr, "  - %q (%s)\n", p.Info.Alias, p.IP)
 			}
 		} else {
-			fmt.Fprintln(os.Stderr, "No peers were seen at all — check you're on the same LAN and the target is running omarchy-send / LocalSend.")
+			fmt.Fprintln(os.Stderr, "No peers were seen at all — check the target is running omarchy-send / LocalSend on the same LAN, or is reachable as a known peer / over Tailscale.")
 		}
 		return 1
 	}
 
 	sender := client.New(cfg.DeviceInfo())
-	if err := sender.SendMessageSync(peer, message, sendPIN); err != nil {
+
+	reportErr := func(err error) {
 		switch {
 		case errors.Is(err, transfer.ErrPinRequired):
 			fmt.Fprintf(os.Stderr, "%q requires a PIN — pass it with -send-pin.\n", peer.Info.Alias)
 		default:
 			fmt.Fprintf(os.Stderr, "send to %q (%s) failed: %v\n", peer.Info.Alias, peer.IP, err)
 		}
-		return 1
 	}
 
-	fmt.Printf("Message sent to %q (%s).\n", peer.Info.Alias, peer.IP)
+	if len(paths) > 0 {
+		fmt.Fprintf(os.Stderr, "Sending to %q (%s)… (waiting for the peer to accept)\n", peer.Info.Alias, peer.IP)
+		sent := 0
+		err := sender.SendFilesSync(ctx, peer, paths, sendPIN, func(name string, size int64) {
+			sent++
+			fmt.Printf("  sent %s (%s)\n", name, humanBytes(size))
+		})
+		if err != nil {
+			reportErr(err)
+			return 1
+		}
+		fmt.Printf("%d file(s) sent to %q (%s).\n", sent, peer.Info.Alias, peer.IP)
+	}
+
+	if message != "" {
+		if err := sender.SendMessageSync(peer, message, sendPIN); err != nil {
+			reportErr(err)
+			return 1
+		}
+		fmt.Printf("Message sent to %q (%s).\n", peer.Info.Alias, peer.IP)
+	}
 	return 0
 }
+
+// humanBytes renders a byte count as a short human-readable size.
+func humanBytes(n int64) string {
+	const unit = 1024
+	if n < unit {
+		return fmt.Sprintf("%d B", n)
+	}
+	div, exp := int64(unit), 0
+	for x := n / unit; x >= unit; x /= unit {
+		div *= unit
+		exp++
+	}
+	return fmt.Sprintf("%.1f %ciB", float64(n)/float64(div), "KMGTPE"[exp])
+}

install.sh

@@ -14,11 +14,15 @@
 # Environment overrides:
 #   BIN_DIR=/usr/local/bin           install location (default ~/.local/bin)
 #   OMARCHY_SEND_VERSION=v0.1.0       pin a release (default: latest)
+#   OMARCHY_SEND_MODE=local|remote    skip the local/remote prompt (default: ask,
+#                                     or local when non-interactive)
 #
 # Behaviour:
-#   - Headless system: installs the plain `omarchy-send` TUI binary.
-#   - Omarchy desktop:  additionally adds a Walker entry that launches it as a
-#     floating TUI (via the stock TUI.float app-id), like the Wi-Fi TUI.
+#   - Local machine (home/LAN): installs the TUI; on Omarchy also adds a Walker
+#     entry + the Nautilus right-click integration.
+#   - Remote server (public IP): same install, then restricts port 53317 to the
+#     Tailscale interface in the firewall, so it's reachable over the tailnet
+#     only — not the open internet.
 
 set -euo pipefail
 
@@ -27,6 +31,7 @@ BIN_DIR="${BIN_DIR:-$HOME/.local/bin}"
 APP_DIR="$HOME/.local/share/applications"
 BIN="$BIN_DIR/omarchy-send"
 VERSION="${OMARCHY_SEND_VERSION:-latest}"
+PORT=53317
 
 mkdir -p "$BIN_DIR"
 
@@ -36,6 +41,30 @@ if [ -n "${BASH_SOURCE[0]:-}" ] && [ -f "${BASH_SOURCE[0]}" ]; then
   SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
 fi
 
+# ---- local vs remote -----------------------------------------------------
+# A remote (public-IP) server should not expose the transfer port to the
+# internet. Ask once; default to "local" when non-interactive (e.g. piped
+# `curl | bash` with no terminal) so a firewall is never changed without intent.
+# Reads /dev/tty so the prompt still works under curl|bash.
+MODE="${OMARCHY_SEND_MODE:-}"
+case "$MODE" in
+  local | remote) : ;; # explicit override, don't ask
+  *)
+    MODE="local"
+    # Try to open the controlling terminal read-write on fd 3. A bare -r test
+    # isn't enough: /dev/tty can exist yet fail to open (no controlling tty —
+    # cron/CI/piped). Only prompt when the open actually succeeds.
+    if { exec 3<>/dev/tty; } 2>/dev/null; then
+      printf 'Install type — [L]ocal machine (home/LAN) or [r]emote server (public IP)? [L/r] ' >&3 || true
+      IFS= read -r _ans <&3 || _ans=""
+      exec 3>&- 3<&- || true
+      case "$_ans" in
+        r | R | remote | Remote | REMOTE) MODE="remote" ;;
+      esac
+    fi
+    ;;
+esac
+
 # ---- obtain the binary ---------------------------------------------------
 if [ -n "$SCRIPT_DIR" ] && [ -f "$SCRIPT_DIR/go.mod" ] && command -v go >/dev/null 2>&1; then
   echo "==> Building omarchy-send from source..."
@@ -227,6 +256,323 @@ else
   echo "==> Headless system — installed as a plain TUI."
 fi
 
+# ---- agent context (AGENTS.md / CLAUDE.md) -------------------------------
+# Install a context file so any AI agent on this machine (Claude, etc.) knows
+# what omarchy-send is and — crucially — WHERE files land when other devices
+# send them here. The canonical copy lives in the config dir as AGENTS.md (the
+# cross-agent standard) with a CLAUDE.md symlink beside it; a short managed
+# section is also added to ~/.claude/CLAUDE.md so it's known in every session.
+CFG_DIR="$HOME/.config/omarchy-send"
+mkdir -p "$CFG_DIR"
+
+# Resolve the real receive directory: the config's receiveDir wins, else default.
+RECV_DIR="$HOME/Omarchy-Send"
+if [ -f "$CFG_DIR/config.json" ]; then
+  _rd="$(grep -oE '"receiveDir"[[:space:]]*:[[:space:]]*"[^"]*"' "$CFG_DIR/config.json" \
+    | sed -E 's/.*:[[:space:]]*"([^"]*)"/\1/' | head -n1 || true)"
+  [ -n "${_rd:-}" ] && RECV_DIR="$_rd"
+fi
+
+# AGENTS.md — quoted heredoc (so backticks stay literal); @@RECV_DIR@@ filled after.
+cat > "$CFG_DIR/AGENTS.md" <<'DOC'
+# Omarchy-Send — context for AI agents
+
+**What it is:** Omarchy-Send is a terminal (TUI) file-transfer tool installed on
+this machine. It speaks the LocalSend protocol, so phones, desktops, and other
+servers can send **files** and **plain-text messages** to this machine over the
+local network or a Tailscale tailnet. It can also send outbound.
+
+**Shorthand:** "OSF" means omarchy-send. When the user says e.g. "OSF
+report.pdf to gav" or "OSF that over to the laptop", run the headless CLI send
+described below — `omarchy-send -to "<alias>" <paths…>`.
+
+**Where received files live —** incoming files are saved under the *receive
+directory*:
+
+    @@RECV_DIR@@
+
+That is the current value; the authoritative source is the `receiveDir` key in
+`~/.config/omarchy-send/config.json` — read it if unsure. Details:
+
+- A file still transferring has a temporary `.part` suffix and is renamed to its
+  real name only when complete. Treat `*.part` files as incomplete — skip them.
+- Filename collisions are de-duplicated (e.g. `photo (1).jpg`).
+- A sent *folder* is recreated as a subdirectory tree under the receive dir.
+- Plain-text **messages** are not written to disk — they appear in the TUI's
+  Messages tab while the receiver is running.
+
+**How it runs:** files are received only while a receiver is running — it is a
+foreground TUI, not a background daemon. Start it with:
+
+    omarchy-send
+
+On a headless box, run it inside a TTY (tmux, or `ssh -t`). It listens on TCP
+port **53317**. Auto-accept and an optional PIN live in the config / Settings tab.
+
+**You can SEND messages AND files from the CLI** — no TUI, no TTY, works from
+scripts and agents. To message another device (e.g. to notify the user on
+their desktop), or to send files/folders to it:
+
+    omarchy-send -to "<device alias>" -message "<text>"
+    omarchy-send -to "<device alias>" <file-or-folder>…
+    omarchy-send -to "<device alias>" -message "<text>" <file>…
+
+Flags must come before the paths. A folder is sent whole (structure recreated
+on the receiver). Add `-send-pin <pin>` if the target requires a PIN, and
+`-wait 30s` to allow longer for discovery. Works over the LAN and Tailscale
+alike; exit code 0 means delivered. The receiving device must be running its
+receiver (this TUI, or LocalSend) and may prompt its user to accept. Paths
+*without* `-to` open the TUI instead, which needs a TTY.
+
+**Config:** `~/.config/omarchy-send/config.json`
+(keys: `alias`, `receiveDir`, `port`, `autoAccept`, `pin`, `knownPeers`, …).
+
+**If asked to "find / process what was just sent":** look in the receive
+directory above and skip any `*.part` files (still transferring).
+DOC
+sed -i "s|@@RECV_DIR@@|$RECV_DIR|g" "$CFG_DIR/AGENTS.md"
+ln -sf AGENTS.md "$CFG_DIR/CLAUDE.md"
+echo "==> Wrote agent context: $CFG_DIR/AGENTS.md (+ CLAUDE.md symlink)."
+
+# Managed, idempotent section in the user-global Claude memory.
+CLAUDE_MD="$HOME/.claude/CLAUDE.md"
+mkdir -p "$HOME/.claude"
+[ -f "$CLAUDE_MD" ] || : > "$CLAUDE_MD"
+BEGIN_MARK="<!-- BEGIN omarchy-send (managed by installer) -->"
+END_MARK="<!-- END omarchy-send (managed by installer) -->"
+
+# Build the fresh block (placeholder substituted) in a temp file.
+blk="$(mktemp)"
+cat > "$blk" <<'BLK'
+<!-- BEGIN omarchy-send (managed by installer) -->
+## Omarchy-Send (installed on this machine)
+
+Omarchy-Send is a LocalSend-compatible terminal file-transfer tool; other devices
+send files/messages to this box over LAN/Tailscale (TCP 53317). **Files sent here
+land in `@@RECV_DIR@@`** (authoritative: the `receiveDir` key in
+`~/.config/omarchy-send/config.json`). Files still transferring carry a `.part`
+suffix — skip them. Text messages appear in the TUI's Messages tab, not on disk.
+Receiving requires the TUI running (`omarchy-send`; use tmux or `ssh -t` when
+headless). **You can SEND messages and files to another device from the CLI**
+(no TUI/TTY, fine for scripts and agents):
+`omarchy-send -to "<alias>" -message "<text>"` and/or
+`omarchy-send -to "<alias>" <file-or-folder>…` (flags before paths; add
+`-send-pin <pin>` if the target requires one); exit 0 = delivered. Works
+over LAN and Tailscale. **"OSF" is user shorthand for omarchy-send** — "OSF
+<file> to <alias>" means run that CLI send. Full notes:
+`~/.config/omarchy-send/AGENTS.md`.
+<!-- END omarchy-send (managed by installer) -->
+BLK
+sed -i "s|@@RECV_DIR@@|$RECV_DIR|g" "$blk"
+
+# Strip any prior managed block, then append the fresh one (no duplicates on re-run).
+new_cm="$(mktemp)"
+awk -v b="$BEGIN_MARK" -v e="$END_MARK" '
+  $0==b {skip=1} skip && $0==e {skip=0; next} !skip' "$CLAUDE_MD" > "$new_cm"
+# Drop a trailing blank line then re-add exactly one before the block, for tidiness.
+{ cat "$new_cm"; printf '\n'; cat "$blk"; } > "$CLAUDE_MD"
+rm -f "$blk" "$new_cm"
+echo "    Added an Omarchy-Send section to $CLAUDE_MD."
+
+# ---- firewall posture ----------------------------------------------------
+# Shared by the remote-mode lockdown below and the local-mode public-IP warning.
+#
+# Tailscale interface: usually tailscale0, but absent when tailscaled runs in
+# userspace-networking mode (the default inside containers) — don't hardcode it.
+TS_IFACE="$(ip -o link show 2>/dev/null | grep -oE 'tailscale[0-9]+' | head -n1 || true)"
+
+# Container? Under Docker host-networking the port binds the *host's* stack, and
+# the firewall belongs on the host, not in this namespace.
+IN_CONTAINER=0
+if [ -f /.dockerenv ] || grep -qaE 'docker|containerd|kubepods' /proc/1/cgroup 2>/dev/null; then
+  IN_CONTAINER=1
+fi
+
+# A routable public IPv4 means $PORT is reachable from the internet unless
+# firewalled. Excludes loopback, link-local, RFC1918 and CGNAT/Tailscale
+# (100.64.0.0/10). Empty when the box is purely on private/tailnet addresses.
+PUBLIC_IP="$(ip -o -4 addr show scope global 2>/dev/null | awk '{print $4}' | cut -d/ -f1 \
+  | grep -vE '^(10\.|127\.|169\.254\.|192\.168\.|172\.(1[6-9]|2[0-9]|3[01])\.|100\.(6[4-9]|[7-9][0-9]|1[01][0-9]|12[0-7])\.)' \
+  | head -n1 || true)"
+
+# ---- remote server: restrict the port to the Tailscale network -----------
+# On a public-IP box, port 53317 would otherwise be reachable from the internet
+# (the receiver binds all interfaces). Lock it to the Tailscale interface so it
+# only answers over the tailnet. Multicast LAN discovery is link-local and never
+# routes off-LAN, so nothing else needs opening. Inside a container the firewall
+# can't be applied from here — userspace-networking has no tailscale0 and host-
+# networking puts the bind on the host's stack — so we detect that and say so.
+if [ "$MODE" = "remote" ]; then
+  echo "==> Remote server — restricting port $PORT to the Tailscale network."
+
+  if [ "$IN_CONTAINER" = "1" ] && [ -z "$TS_IFACE" ]; then
+    # Container + userspace-networking Tailscale: no tailscale0, and typically no
+    # CAP_NET_ADMIN to manage netfilter. A firewall can't be applied from in here.
+    echo "    Detected: inside a container with userspace-networking Tailscale"
+    echo "    (no tailscale0 interface). The receiver binds all interfaces — and under"
+    echo "    Docker host-networking that includes the host's PUBLIC interface."
+    echo
+    echo "    A firewall CANNOT be applied from in here. Apply it on the HOST:"
+    echo "      • if the host already default-denies inbound (e.g. only 22/80/443 open),"
+    echo "        $PORT is already blocked from the internet yet still reachable over the"
+    echo "        tailnet (tailscaled delivers it via loopback) — nothing more to do."
+    echo "      • otherwise, on the host run:  ufw deny $PORT"
+    echo "    Strongly recommended in this setup: also set a PIN (--pin <code>)."
+  elif [ -n "$TS_IFACE" ] && command -v ufw >/dev/null 2>&1; then
+    SUDO=""
+    [ "$(id -u)" -ne 0 ] && SUDO="sudo"
+    echo "    Tailscale interface: $TS_IFACE"
+    echo "    Applying firewall rules (may prompt for sudo):"
+    echo "      ${SUDO:+$SUDO }ufw allow in on $TS_IFACE to any port $PORT"
+    echo "      ${SUDO:+$SUDO }ufw deny $PORT"
+    if $SUDO ufw allow in on "$TS_IFACE" to any port "$PORT" >/dev/null 2>&1 &&
+      $SUDO ufw deny "$PORT" >/dev/null 2>&1; then
+      echo "    Done — $PORT answers over Tailscale only."
+    else
+      echo "    Could not apply automatically (need root/sudo). Run the two commands above yourself."
+    fi
+  else
+    if [ -z "$TS_IFACE" ]; then
+      echo "    NOTE: no tailscale interface found. If tailscale isn't up yet, install it"
+      echo "          and run 'tailscale up', then re-run this installer. If it's running"
+      echo "          in userspace-networking mode, firewall the port on the host instead."
+      TS_IFACE="tailscale0"
+    fi
+    echo "    ufw not found. Apply the equivalent in your firewall:"
+    echo "      • allow inbound TCP $PORT only on the '$TS_IFACE' interface"
+    echo "      • deny inbound $PORT on all other interfaces"
+    echo "    nftables example (inet filter, input chain):"
+    echo "      iifname \"$TS_IFACE\" tcp dport $PORT accept"
+    echo "      tcp dport $PORT drop"
+  fi
+  echo "    Tip: a PIN adds a second layer — run with --pin <code> (or set it in Settings)."
+fi
+
+# ---- local mode on a public-IP box: inform, don't touch the firewall -----
+# We never change the firewall outside remote mode, but a public IP means the
+# port is internet-exposed while the TUI is open — so surface it with the exact
+# commands to lock it down. (Covers the silent `curl | bash` default-to-local
+# case, where the interactive remote prompt never ran.)
+if [ "$MODE" != "remote" ] && [ -n "$PUBLIC_IP" ]; then
+  iface="${TS_IFACE:-tailscale0}"
+  echo
+  echo "⚠  Heads up: this machine has a public IP ($PUBLIC_IP) and was installed in"
+  echo "   LOCAL mode, so port $PORT was NOT firewalled. The receiver binds all"
+  echo "   interfaces, so $PORT is reachable from the internet while the TUI is open."
+  echo "   The installer won't change your firewall without remote mode — lock it to"
+  echo "   your tailnet yourself (recommended):"
+  if [ "$IN_CONTAINER" = "1" ]; then
+    echo "     • You're in a container — apply on the HOST, not in here:  ufw deny $PORT"
+    echo "       (if the host already default-denies inbound, $PORT is already blocked"
+    echo "        from the internet yet still reachable over the tailnet via loopback)."
+  elif command -v ufw >/dev/null 2>&1; then
+    echo "     • ufw allow in on $iface to any port $PORT"
+    echo "     • ufw deny $PORT"
+  else
+    echo "     • nftables (inet filter, input chain):"
+    echo "         iifname \"$iface\" tcp dport $PORT accept"
+    echo "         tcp dport $PORT drop"
+  fi
+  echo "   Or re-run to firewall it automatically:  OMARCHY_SEND_MODE=remote bash install.sh"
+  echo "   And/or set a PIN:  omarchy-send --pin <code>"
+  echo "   Verify with an app-layer probe (raw TCP/nc lie behind some providers):"
+  echo "     curl -sk https://<public-ip>:$PORT/api/localsend/v2/info   # should time out"
+fi
+
+# ---- userspace-networking Tailscale: outbound proxy check -----------------
+# Under tailscaled --tun=userspace-networking (no TUN device — the default in
+# unprivileged containers), processes cannot dial OUT to tailnet addresses at
+# all; tailscaled's SOCKS5 proxy is the only outbound path. omarchy-send
+# auto-detects and uses it at localhost:1055 — so check it's there and say
+# exactly what to do when it isn't (receive works either way; send doesn't).
+if command -v tailscale >/dev/null 2>&1 && [ -z "$TS_IFACE" ] \
+  && tailscale status >/dev/null 2>&1; then
+  if (exec 3<>/dev/tcp/127.0.0.1/1055) 2>/dev/null; then
+    exec 3>&- || true
+    echo
+    echo "==> Userspace-networking Tailscale detected; SOCKS5 proxy found at"
+    echo "    localhost:1055 — sends to tailnet devices will route through it"
+    echo "    automatically. Nothing to do."
+  else
+    echo
+    echo "⚠  Tailscale is running in userspace-networking mode (no TUN interface)"
+    echo "   and no SOCKS5 proxy is listening on localhost:1055. This box can"
+    echo "   RECEIVE over the tailnet, but CANNOT SEND to tailnet devices until"
+    echo "   tailscaled runs with its proxy enabled."
+
+    # Offer to apply the fix: add --socks5-server=localhost:1055 to whatever
+    # launcher starts tailscaled (e.g. a container entrypoint) and restart it.
+    # Defaults to NO — non-interactive installs never restart someone else's
+    # daemon. OMARCHY_SEND_FIX_TAILSCALE=yes|no skips the prompt.
+    FIX_TS="${OMARCHY_SEND_FIX_TAILSCALE:-}"
+    case "$FIX_TS" in yes | no) : ;; *)
+      FIX_TS="no"
+      if { exec 3<>/dev/tty; } 2>/dev/null; then
+        printf '   Enable it now? The tailscaled launcher gets the flag added and\n   tailscaled is restarted — this briefly drops the tailnet, including\n   any tailscale SSH session. [y/N] ' >&3 || true
+        IFS= read -r _fx <&3 || _fx=""
+        exec 3>&- 3<&- || true
+        case "$_fx" in y | Y | yes | Yes | YES) FIX_TS="yes" ;; esac
+      fi
+      ;;
+    esac
+
+    if [ "$FIX_TS" = "yes" ]; then
+      # 1. Persist: patch every writable launcher script that starts tailscaled
+      #    in userspace mode (idempotent — skips ones already carrying the flag).
+      PATCHED=""
+      while IFS= read -r _f; do
+        [ -n "$_f" ] || continue
+        if grep -q "socks5-server" "$_f"; then PATCHED="$_f"; continue; fi
+        if [ -w "$_f" ] &&
+          sed -i "s|--tun=userspace-networking|--tun=userspace-networking --socks5-server=localhost:1055|" "$_f" 2>/dev/null; then
+          PATCHED="$_f"
+          echo "   Patched launcher: $_f"
+        fi
+      done < <(grep -rlse '--tun=userspace-networking' \
+        "$HOME/.local/bin" /usr/local/bin /usr/local/sbin 2>/dev/null || true)
+      [ -z "$PATCHED" ] &&
+        echo "   No writable tailscaled launcher found — the restart below won't survive a reboot."
+
+      # 2. Restart tailscaled now with its current flags + the proxy. Needs the
+      #    rights of whoever owns the daemon (root in most containers).
+      RESTARTED=0
+      _pid="$(pgrep -x tailscaled | head -n1 || true)"
+      if [ -n "$_pid" ] && mapfile -d '' _args <"/proc/$_pid/cmdline" 2>/dev/null &&
+        [ "${#_args[@]}" -gt 0 ]; then
+        case " ${_args[*]} " in *socks5-server*) : ;; *) _args+=("--socks5-server=localhost:1055") ;; esac
+        SUDO=""
+        [ "$(id -u)" -ne 0 ] && SUDO="sudo -n"
+        if [ -z "$SUDO" ] || sudo -n true 2>/dev/null; then
+          $SUDO pkill -x tailscaled 2>/dev/null || true
+          sleep 1
+          # shellcheck disable=SC2086 # $SUDO is deliberately word-split (empty or "sudo -n")
+          ($SUDO nohup "${_args[@]}" >"${TMPDIR:-/tmp}/tailscaled-restart.log" 2>&1 &)
+          sleep 3
+          if (exec 3<>/dev/tcp/127.0.0.1/1055) 2>/dev/null; then RESTARTED=1; fi
+        fi
+      fi
+
+      if [ "$RESTARTED" = "1" ]; then
+        echo "   Done — SOCKS5 proxy is up. Tailnet sends now work, no env vars needed"
+        [ -n "$PATCHED" ] && echo "   (and the patched launcher keeps it working across restarts)."
+      elif [ -n "$PATCHED" ]; then
+        echo "   Launcher patched, but tailscaled couldn't be restarted from here"
+        echo "   (needs root). Restart the container/box and the fix applies itself."
+      else
+        echo "   Couldn't patch or restart automatically. Add this flag wherever"
+        echo "   tailscaled is launched, keeping its existing flags:"
+        echo "       tailscaled --tun=userspace-networking --socks5-server=localhost:1055 …"
+      fi
+    else
+      echo "   Skipped. To fix manually, add this flag wherever tailscaled is"
+      echo "   launched (keeping its existing --state/--socket flags):"
+      echo "       tailscaled --tun=userspace-networking --socks5-server=localhost:1055 …"
+      echo "   omarchy-send then uses the proxy automatically — no env vars needed."
+      echo "   (Or re-run the installer with OMARCHY_SEND_FIX_TAILSCALE=yes.)"
+    fi
+  fi
+fi
+
 echo
 case ":$PATH:" in
   *":$BIN_DIR:"*) : ;;

internal/client/client.go

@@ -27,6 +27,7 @@ import (
 	"omarchy-send/internal/discovery"
 	"omarchy-send/internal/protocol"
 	"omarchy-send/internal/transfer"
+	"omarchy-send/internal/tsproxy"
 )
 
 // errOpen wraps a failure to open a source file, so the send loop can skip just
@@ -60,6 +61,10 @@ func New(self protocol.DeviceInfo) *Sender {
 			// and waiting for response headers after the body is sent.
 			Timeout: 0,
 			Transport: &http.Transport{
+				// Proxy env vars + tailnet SOCKS5 auto-detection (see
+				// discovery) so transfers also work from userspace-networking
+				// Tailscale boxes.
+				Proxy:                 tsproxy.ProxyFunc,
 				TLSClientConfig:       &tls.Config{InsecureSkipVerify: true},
 				DialContext:           (&net.Dialer{Timeout: 10 * time.Second}).DialContext,
 				TLSHandshakeTimeout:   10 * time.Second,
@@ -132,6 +137,74 @@ func (s *Sender) SendMessageSync(peer discovery.Peer, text, pin string) error {
 	return err
 }
 
+// SendFilesSync uploads the given file/folder paths to peer and blocks until
+// the whole batch is done, returning the error directly — including
+// transfer.ErrPinRequired when the peer needs a PIN. Unlike Send it reports
+// nothing on Events(); it exists for the headless one-shot send path, where
+// there is no TUI to consume events (the progress events uploadFile emits are
+// harmlessly dropped). onDone, when non-nil, is called after each file lands,
+// so the CLI can print per-file progress lines.
+func (s *Sender) SendFilesSync(ctx context.Context, peer discovery.Peer, paths []string, pin string, onDone func(name string, size int64)) error {
+	// Explicitly named paths that don't exist are a hard error up front — in
+	// the TUI a stat failure is just an event on one staged entry, but a script
+	// passing a wrong path wants a non-zero exit, not a silent skip.
+	for _, p := range paths {
+		if _, err := os.Stat(p); err != nil {
+			return err
+		}
+	}
+	items := s.expand(paths)
+	if len(items) == 0 {
+		return errors.New("nothing to send: no readable files under the given paths")
+	}
+
+	files := make(map[string]protocol.FileMetadata, len(items))
+	pathByID := make(map[string]string, len(items))
+	for _, it := range items {
+		id := randID()
+		files[id] = protocol.FileMetadata{
+			ID:       id,
+			FileName: it.name,
+			Size:     it.size,
+			FileType: mimeType(it.path),
+		}
+		pathByID[id] = it.path
+	}
+
+	base := s.url(peer)
+	prepResp, err := s.prepareUpload(ctx, base, files, pin)
+	if err != nil {
+		return err
+	}
+
+	// An empty token map (204) means the peer accepted but wants nothing
+	// uploaded — e.g. it already has the files. That's success: the loop below
+	// simply finds no tokens to push.
+	var skipped []string
+	for id, token := range prepResp.Files {
+		meta := files[id]
+		key := prepResp.SessionID + ":" + id
+		if err := s.uploadFile(ctx, base, prepResp.SessionID, id, token, key, pathByID[id], meta); err != nil {
+			// A failure to open a local file is specific to that file (it
+			// vanished or lost permissions since staging) — skip it and keep
+			// the batch going, like the TUI path does. Anything else means the
+			// peer/session is gone and can't be resumed, so abort the batch.
+			if errors.Is(err, errOpen) {
+				skipped = append(skipped, meta.FileName)
+				continue
+			}
+			return fmt.Errorf("upload %q: %w", meta.FileName, err)
+		}
+		if onDone != nil {
+			onDone(meta.FileName, meta.Size)
+		}
+	}
+	if len(skipped) > 0 {
+		return fmt.Errorf("could not read: %s", strings.Join(skipped, ", "))
+	}
+	return nil
+}
+
 func (s *Sender) send(peer discovery.Peer, paths []string, pin string) {
 	// A new transfer to a peer supersedes any still-running one to the same
 	// peer: cancel it so a half-finished old batch can't carry on once the user

internal/client/files_sync_test.go

@@ -0,0 +1,128 @@
+package client
+
+import (
+	"bytes"
+	"context"
+	"errors"
+	"os"
+	"path/filepath"
+	"testing"
+	"time"
+
+	"omarchy-send/internal/discovery"
+	"omarchy-send/internal/protocol"
+	"omarchy-send/internal/server"
+	"omarchy-send/internal/transfer"
+)
+
+// SendFilesSync delivers a file and a folder over loopback HTTP and returns
+// nil, with the contents arriving intact — the synchronous path used by
+// headless `-to <alias> <paths…>` sends.
+func TestSendFilesSyncSuccess(t *testing.T) {
+	recvDir := t.TempDir()
+	recvInfo := protocol.DeviceInfo{
+		Alias: "recv", Version: protocol.ProtocolVersion, Port: 53993, Protocol: "http",
+	}
+	srv := server.New(server.Options{Info: recvInfo, ReceiveDir: recvDir, AutoAccept: true})
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+	if err := srv.Start(ctx); err != nil {
+		t.Fatalf("server start: %v", err)
+	}
+	go func() {
+		for range srv.Transfers() {
+		}
+	}()
+	time.Sleep(50 * time.Millisecond)
+
+	// One loose file plus a folder, so the relative-name path is covered too.
+	srcDir := t.TempDir()
+	loose := filepath.Join(srcDir, "report.pdf")
+	content := bytes.Repeat([]byte("headless-payload-"), 5000) // ~85KB
+	if err := os.WriteFile(loose, content, 0o644); err != nil {
+		t.Fatalf("write src: %v", err)
+	}
+	folder := filepath.Join(srcDir, "Trip")
+	if err := os.MkdirAll(filepath.Join(folder, "day1"), 0o755); err != nil {
+		t.Fatalf("mkdir: %v", err)
+	}
+	nested := filepath.Join(folder, "day1", "img.jpg")
+	if err := os.WriteFile(nested, []byte("nested"), 0o644); err != nil {
+		t.Fatalf("write nested: %v", err)
+	}
+
+	sender := New(protocol.DeviceInfo{Alias: "cli", Fingerprint: "cli1", Version: "2.1", Protocol: "http"})
+	peer := discovery.Peer{Info: recvInfo, IP: "127.0.0.1"}
+
+	var done []string
+	err := sender.SendFilesSync(ctx, peer, []string{loose, folder}, "", func(name string, size int64) {
+		done = append(done, name)
+	})
+	if err != nil {
+		t.Fatalf("SendFilesSync: %v", err)
+	}
+	if len(done) != 2 {
+		t.Fatalf("onDone called %d times, want 2 (%v)", len(done), done)
+	}
+
+	got, err := os.ReadFile(filepath.Join(recvDir, "report.pdf"))
+	if err != nil {
+		t.Fatalf("read received: %v", err)
+	}
+	if !bytes.Equal(got, content) {
+		t.Fatalf("content mismatch: %d vs %d bytes", len(got), len(content))
+	}
+	if _, err := os.Stat(filepath.Join(recvDir, "Trip", "day1", "img.jpg")); err != nil {
+		t.Fatalf("folder structure not recreated: %v", err)
+	}
+}
+
+// A missing path is a hard error before any network work — a script passing a
+// wrong path wants a non-zero exit, not a silent skip.
+func TestSendFilesSyncMissingPath(t *testing.T) {
+	sender := New(protocol.DeviceInfo{Alias: "cli", Fingerprint: "cli1", Version: "2.1", Protocol: "http"})
+	peer := discovery.Peer{Info: protocol.DeviceInfo{Protocol: "http", Port: 1}, IP: "127.0.0.1"}
+	err := sender.SendFilesSync(context.Background(), peer, []string{"/no/such/file"}, "", nil)
+	if err == nil || !os.IsNotExist(errors.Unwrap(err)) && !os.IsNotExist(err) {
+		t.Fatalf("err = %v, want not-exist", err)
+	}
+}
+
+// A peer that requires a PIN rejects a PIN-less file send with ErrPinRequired,
+// so the CLI can tell the user to pass -send-pin; with the PIN it goes through.
+func TestSendFilesSyncPinRequired(t *testing.T) {
+	recvDir := t.TempDir()
+	recvInfo := protocol.DeviceInfo{
+		Alias: "recv", Version: protocol.ProtocolVersion, Port: 53994, Protocol: "http",
+	}
+	srv := server.New(server.Options{Info: recvInfo, ReceiveDir: recvDir, AutoAccept: true, PIN: "2468"})
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+	if err := srv.Start(ctx); err != nil {
+		t.Fatalf("server start: %v", err)
+	}
+	go func() {
+		for range srv.Transfers() {
+		}
+	}()
+	time.Sleep(50 * time.Millisecond)
+
+	src := filepath.Join(t.TempDir(), "note.txt")
+	if err := os.WriteFile(src, []byte("pinned"), 0o644); err != nil {
+		t.Fatalf("write src: %v", err)
+	}
+
+	sender := New(protocol.DeviceInfo{Alias: "cli", Fingerprint: "cli1", Version: "2.1", Protocol: "http"})
+	peer := discovery.Peer{Info: recvInfo, IP: "127.0.0.1"}
+
+	err := sender.SendFilesSync(ctx, peer, []string{src}, "", nil)
+	if !errors.Is(err, transfer.ErrPinRequired) {
+		t.Fatalf("err = %v, want ErrPinRequired", err)
+	}
+	if err := sender.SendFilesSync(ctx, peer, []string{src}, "2468", nil); err != nil {
+		t.Fatalf("SendFilesSync with PIN: %v", err)
+	}
+	if _, err := os.Stat(filepath.Join(recvDir, "note.txt")); err != nil {
+		t.Fatalf("file not received: %v", err)
+	}
+}

internal/config/config.go

@@ -6,11 +6,31 @@ import (
 	"encoding/json"
 	"os"
 	"path/filepath"
+	"strings"
 
 	"omarchy-send/internal/protocol"
 	"omarchy-send/internal/security"
 )
 
+// ExpandHome resolves a leading "~" or "~/" to the user's home directory, so a
+// receiveDir stored as "~/Omarchy-Send" (hand-edited, or typed into the
+// Settings tab) means what the user means — and is not treated as a relative
+// path that silently creates a literal "~" directory under the process cwd.
+func ExpandHome(p string) string {
+	if p == "~" {
+		if home, err := os.UserHomeDir(); err == nil {
+			return home
+		}
+		return p
+	}
+	if strings.HasPrefix(p, "~/") {
+		if home, err := os.UserHomeDir(); err == nil {
+			return filepath.Join(home, p[2:])
+		}
+	}
+	return p
+}
+
 // Config is the persisted user configuration.
 type Config struct {
 	Alias       string `json:"alias"`
@@ -25,6 +45,11 @@ type Config struct {
 	NoIcons     bool   `json:"noIcons"`  // hide Nerd Font device icons (non-NF terminals)
 	NoNotify    bool   `json:"noNotify"` // don't raise desktop notifications on incoming messages/files
 
+	// KnownPeers are hosts (name, IP, or host:port) probed directly over unicast
+	// so peers off the local subnet — e.g. reached over Tailscale — show up even
+	// though multicast discovery can't find them.
+	KnownPeers []string `json:"knownPeers,omitempty"`
+
 	// TLS identity for encrypted (HTTPS) mode, generated once and persisted.
 	CertPEM string `json:"certPem"`
 	KeyPEM  string `json:"keyPem"`
@@ -101,6 +126,9 @@ func Load() (Config, error) {
 	if cfg.ReceiveDir == "" {
 		cfg.ReceiveDir = d.ReceiveDir
 	}
+	// Normalise a ~-form receive dir to absolute; Load persists below, so the
+	// stored value is unambiguous from then on.
+	cfg.ReceiveDir = ExpandHome(cfg.ReceiveDir)
 	if cfg.DeviceType == "" {
 		cfg.DeviceType = d.DeviceType
 	}

internal/config/config_test.go

@@ -0,0 +1,76 @@
+package config
+
+import (
+	"encoding/json"
+	"os"
+	"path/filepath"
+	"testing"
+)
+
+// ExpandHome resolves the ~-forms a user may type or hand-edit, and leaves
+// everything else untouched.
+func TestExpandHome(t *testing.T) {
+	home, err := os.UserHomeDir()
+	if err != nil {
+		t.Skipf("no home dir: %v", err)
+	}
+	cases := map[string]string{
+		"~":                 home,
+		"~/Omarchy-Send":    filepath.Join(home, "Omarchy-Send"),
+		"~/a/b":             filepath.Join(home, "a", "b"),
+		"/abs/path":         "/abs/path",
+		"relative/path":     "relative/path",
+		"~user/not-ours":    "~user/not-ours", // ~user expansion is not supported
+		"mid/~/not-leading": "mid/~/not-leading",
+		"":                  "",
+	}
+	for in, want := range cases {
+		if got := ExpandHome(in); got != want {
+			t.Errorf("ExpandHome(%q) = %q, want %q", in, got, want)
+		}
+	}
+}
+
+// A config file whose receiveDir was stored as "~/…" is normalised to an
+// absolute path by Load — the regression that sent files into a literal "~"
+// directory under the process cwd.
+func TestLoadExpandsTildeReceiveDir(t *testing.T) {
+	home, err := os.UserHomeDir()
+	if err != nil {
+		t.Skipf("no home dir: %v", err)
+	}
+	cfgHome := t.TempDir()
+	t.Setenv("XDG_CONFIG_HOME", cfgHome)
+
+	dir := filepath.Join(cfgHome, "omarchy-send")
+	if err := os.MkdirAll(dir, 0o755); err != nil {
+		t.Fatalf("mkdir: %v", err)
+	}
+	seed := map[string]any{"alias": "t", "receiveDir": "~/Omarchy-Send"}
+	data, _ := json.Marshal(seed)
+	if err := os.WriteFile(filepath.Join(dir, "config.json"), data, 0o600); err != nil {
+		t.Fatalf("seed config: %v", err)
+	}
+
+	cfg, err := Load()
+	if err != nil {
+		t.Fatalf("Load: %v", err)
+	}
+	want := filepath.Join(home, "Omarchy-Send")
+	if cfg.ReceiveDir != want {
+		t.Fatalf("ReceiveDir = %q, want %q", cfg.ReceiveDir, want)
+	}
+
+	// And the normalised value is what got persisted back.
+	raw, err := os.ReadFile(filepath.Join(dir, "config.json"))
+	if err != nil {
+		t.Fatalf("read back: %v", err)
+	}
+	var onDisk map[string]any
+	if err := json.Unmarshal(raw, &onDisk); err != nil {
+		t.Fatalf("unmarshal: %v", err)
+	}
+	if onDisk["receiveDir"] != want {
+		t.Fatalf("persisted receiveDir = %q, want %q", onDisk["receiveDir"], want)
+	}
+}

internal/discovery/discovery.go

@@ -18,6 +18,7 @@ import (
 
 	"omarchy-send/internal/dbg"
 	"omarchy-send/internal/protocol"
+	"omarchy-send/internal/tsproxy"
 )
 
 // EventKind distinguishes peer lifecycle events.
@@ -73,6 +74,11 @@ func New(self protocol.DeviceInfo) *Discoverer {
 		client: &http.Client{
 			Timeout: 3 * time.Second,
 			Transport: &http.Transport{
+				// Proxy env vars are honoured like the default transport, and
+				// tailnet destinations are auto-routed through the local
+				// tailscaled SOCKS5 proxy on userspace-networking boxes (no
+				// TUN), where direct outbound tailnet dials cannot work.
+				Proxy:           tsproxy.ProxyFunc,
 				TLSClientConfig: &tls.Config{InsecureSkipVerify: true},
 			},
 		},
@@ -295,6 +301,67 @@ func (d *Discoverer) reply(ip string, port int, proto string) {
 	_ = resp.Body.Close()
 }
 
+// Probe contacts host directly over unicast — bypassing multicast — and records
+// it as a peer on success. It POSTs our info to the peer's /register (so the
+// peer also learns us) and reads the peer's info from the reply. host may carry
+// a port; otherwise the default LocalSend port is used. https is tried first,
+// then http. Used for known/remote peers (e.g. reached over Tailscale) that
+// multicast can't find. Re-probing a live peer refreshes its LastSeen so it is
+// not reaped; a peer that stops answering ages out normally.
+func (d *Discoverer) Probe(ctx context.Context, host string) error {
+	h, port := hostPort(host)
+	body, err := json.Marshal(d.selfCopy().WithAnnounce(false))
+	if err != nil {
+		return err
+	}
+	var lastErr error
+	for _, scheme := range []string{"https", "http"} {
+		url := fmt.Sprintf("%s://%s/api/localsend/v2/register", scheme, net.JoinHostPort(h, strconv.Itoa(port)))
+		req, err := http.NewRequestWithContext(ctx, http.MethodPost, url, bytes.NewReader(body))
+		if err != nil {
+			return err
+		}
+		req.Header.Set("Content-Type", "application/json")
+		resp, err := d.client.Do(req)
+		if err != nil {
+			lastErr = err
+			continue
+		}
+		var info protocol.DeviceInfo
+		derr := json.NewDecoder(resp.Body).Decode(&info)
+		_ = resp.Body.Close()
+		if derr != nil || info.Fingerprint == "" {
+			lastErr = fmt.Errorf("probe %s: no usable device info", url)
+			continue
+		}
+		dbg.Logf("probe %s -> alias=%q fp=%s", url, info.Alias, info.Fingerprint)
+		d.NotePeer(info, h) // reach it back at the host we dialed
+		return nil
+	}
+	if lastErr == nil {
+		lastErr = fmt.Errorf("could not reach %s", host)
+	}
+	return lastErr
+}
+
+// isLoopback reports whether ip parses as a loopback address (e.g. 127.0.0.1).
+func isLoopback(ip string) bool {
+	p := net.ParseIP(ip)
+	return p != nil && p.IsLoopback()
+}
+
+// hostPort splits an optional :port off host, defaulting to the LocalSend port.
+// It handles bare IPv6 by requiring the [::]:port form for a custom port.
+func hostPort(host string) (string, int) {
+	if h, p, err := net.SplitHostPort(host); err == nil {
+		if n, err := strconv.Atoi(p); err == nil {
+			return h, n
+		}
+		return h, protocol.DefaultPort
+	}
+	return host, protocol.DefaultPort
+}
+
 // NotePeer records a peer (from multicast or from an inbound /register) and
 // emits PeerFound on first sight or when its address changes. Safe for
 // concurrent use; ignores our own fingerprint.
@@ -306,7 +373,13 @@ func (d *Discoverer) NotePeer(info protocol.DeviceInfo, ip string) {
 
 	d.mu.Lock()
 	prev, existed := d.peers[info.Fingerprint]
-	changed := !existed || prev.IP != ip || prev.Info.Alias != info.Alias
+	// Never downgrade a routable address to loopback: behind a
+	// userspace-networking tailscaled, inbound registers all appear to come
+	// from 127.0.0.1 — recording that would make us "reply" to ourselves.
+	if existed && isLoopback(ip) && !isLoopback(prev.IP) {
+		peer.IP = prev.IP
+	}
+	changed := !existed || prev.IP != peer.IP || prev.Info.Alias != info.Alias
 	d.peers[info.Fingerprint] = peer
 	d.mu.Unlock()
 

internal/discovery/probe_test.go

@@ -0,0 +1,129 @@
+package discovery
+
+import (
+	"context"
+	"encoding/json"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"testing"
+	"time"
+
+	"omarchy-send/internal/protocol"
+)
+
+// TestProbeRegistersPeer drives Probe against a stub /register that behaves like
+// a real peer: it records the caller and returns its own DeviceInfo. The https
+// attempt fails against the plain-http test server and Probe falls back to http.
+func TestProbeRegistersPeer(t *testing.T) {
+	peerInfo := protocol.DeviceInfo{Alias: "Remote", Fingerprint: "remote-fp", Port: 53317, Protocol: "http"}
+	var sawOurInfo bool
+
+	mux := http.NewServeMux()
+	mux.HandleFunc("/api/localsend/v2/register", func(w http.ResponseWriter, r *http.Request) {
+		var in protocol.DeviceInfo
+		if err := json.NewDecoder(r.Body).Decode(&in); err == nil && in.Fingerprint == "self-fp" {
+			sawOurInfo = true
+		}
+		_ = json.NewEncoder(w).Encode(peerInfo)
+	})
+	srv := httptest.NewServer(mux)
+	defer srv.Close()
+	host := strings.TrimPrefix(srv.URL, "http://") // host:port
+
+	d := New(protocol.DeviceInfo{Fingerprint: "self-fp", Alias: "Self"})
+	if err := d.Probe(context.Background(), host); err != nil {
+		t.Fatalf("Probe failed: %v", err)
+	}
+	if !sawOurInfo {
+		t.Error("peer did not receive our device info in the register body")
+	}
+	peers := d.Snapshot()
+	if len(peers) != 1 || peers[0].Info.Fingerprint != "remote-fp" {
+		t.Fatalf("peer not recorded as expected: %+v", peers)
+	}
+	if wantIP := strings.Split(host, ":")[0]; peers[0].IP != wantIP {
+		t.Errorf("peer IP = %q, want %q (the host we dialed)", peers[0].IP, wantIP)
+	}
+}
+
+// TestFindPeerViaProbe covers the headless-send path for remote peers: a peer
+// that multicast can't see (here: only reachable by unicast Probe) must still
+// satisfy a FindPeer that is already waiting — Probe → NotePeer → PeerFound.
+func TestFindPeerViaProbe(t *testing.T) {
+	peerInfo := protocol.DeviceInfo{Alias: "titan-box", Fingerprint: "titan-fp", Port: 53317, Protocol: "http"}
+	mux := http.NewServeMux()
+	mux.HandleFunc("/api/localsend/v2/register", func(w http.ResponseWriter, r *http.Request) {
+		_ = json.NewEncoder(w).Encode(peerInfo)
+	})
+	srv := httptest.NewServer(mux)
+	defer srv.Close()
+	host := strings.TrimPrefix(srv.URL, "http://")
+
+	d := New(protocol.DeviceInfo{Fingerprint: "self-fp", Alias: "Self"})
+
+	// Probe concurrently, like watchRemotes does while FindPeer waits.
+	go func() {
+		if err := d.Probe(context.Background(), host); err != nil {
+			t.Errorf("Probe failed: %v", err)
+		}
+	}()
+
+	ctx, cancel := context.WithTimeout(context.Background(), 2*time.Second)
+	defer cancel()
+	got, err := d.FindPeer(ctx, func(p Peer) bool {
+		return strings.EqualFold(strings.TrimSpace(p.Info.Alias), "titan-box")
+	})
+	if err != nil {
+		t.Fatalf("FindPeer did not see the probed peer: %v", err)
+	}
+	if got.Info.Fingerprint != "titan-fp" {
+		t.Errorf("fingerprint = %q, want titan-fp", got.Info.Fingerprint)
+	}
+	if wantIP := strings.Split(host, ":")[0]; got.IP != wantIP {
+		t.Errorf("peer IP = %q, want %q (the host probed)", got.IP, wantIP)
+	}
+}
+
+func TestProbeUnreachableErrors(t *testing.T) {
+	d := New(protocol.DeviceInfo{Fingerprint: "self-fp"})
+	// 127.0.0.1:1 — nothing listening; both https and http should fail fast.
+	if err := d.Probe(context.Background(), "127.0.0.1:1"); err == nil {
+		t.Fatal("expected an error probing an unreachable host")
+	}
+}
+
+// A register arriving via a userspace-networking tailscaled proxy appears to
+// come from 127.0.0.1; that must not overwrite a peer's known routable address
+// (sending to it would loop back to our own receiver).
+func TestNotePeerKeepsRoutableOverLoopback(t *testing.T) {
+	d := New(protocol.DeviceInfo{Fingerprint: "self-fp"})
+	info := protocol.DeviceInfo{Alias: "gav", Fingerprint: "gav-fp", Port: 53317}
+
+	d.NotePeer(info, "100.91.41.111")
+	d.NotePeer(info, "127.0.0.1") // inbound register through the local proxy
+	if got := d.Snapshot()[0].IP; got != "100.91.41.111" {
+		t.Errorf("IP downgraded to %q, want 100.91.41.111 kept", got)
+	}
+
+	// A first sight at loopback is still recorded (nothing better known)…
+	d2 := New(protocol.DeviceInfo{Fingerprint: "self-fp"})
+	d2.NotePeer(info, "127.0.0.1")
+	if got := d2.Snapshot()[0].IP; got != "127.0.0.1" {
+		t.Errorf("first-sight IP = %q, want 127.0.0.1", got)
+	}
+	// …and upgrades to the routable address as soon as one is learned.
+	d2.NotePeer(info, "100.91.41.111")
+	if got := d2.Snapshot()[0].IP; got != "100.91.41.111" {
+		t.Errorf("IP = %q, want upgrade to 100.91.41.111", got)
+	}
+}
+
+func TestHostPortDefaults(t *testing.T) {
+	if h, p := hostPort("colossus"); h != "colossus" || p != protocol.DefaultPort {
+		t.Errorf("hostPort(bare) = %q,%d; want colossus,%d", h, p, protocol.DefaultPort)
+	}
+	if h, p := hostPort("100.64.0.2:9999"); h != "100.64.0.2" || p != 9999 {
+		t.Errorf("hostPort(host:port) = %q,%d; want 100.64.0.2,9999", h, p)
+	}
+}

internal/tailscale/tailscale.go

@@ -0,0 +1,77 @@
+// Package tailscale discovers peer addresses from a local Tailscale daemon, so
+// omarchy-send can reach devices that share a tailnet but not a LAN subnet (and
+// therefore can't be found by multicast). It shells out to the `tailscale` CLI
+// and is a no-op when that isn't present.
+package tailscale
+
+import (
+	"context"
+	"encoding/json"
+	"os/exec"
+)
+
+// status is the subset of `tailscale status --json` we care about.
+type status struct {
+	Peer map[string]struct {
+		TailscaleIPs []string `json:"TailscaleIPs"`
+		Online       bool     `json:"Online"`
+	} `json:"Peer"`
+}
+
+// Available reports whether the tailscale CLI is on PATH.
+func Available() bool {
+	_, err := exec.LookPath("tailscale")
+	return err == nil
+}
+
+// Peers returns the IPv4 Tailscale address of each online peer in the tailnet.
+// It returns nil (no error) when tailscale isn't installed, isn't running, or
+// the output can't be parsed — callers treat Tailscale discovery as best-effort.
+func Peers(ctx context.Context) []string {
+	if !Available() {
+		return nil
+	}
+	out, err := exec.CommandContext(ctx, "tailscale", "status", "--json").Output()
+	if err != nil {
+		return nil
+	}
+	return parsePeers(out)
+}
+
+// parsePeers extracts each online peer's first IPv4 address from the JSON of
+// `tailscale status --json`. Split out so it can be tested without the CLI.
+func parsePeers(data []byte) []string {
+	var st status
+	if err := json.Unmarshal(data, &st); err != nil {
+		return nil
+	}
+	var hosts []string
+	for _, p := range st.Peer {
+		if !p.Online {
+			continue
+		}
+		for _, ip := range p.TailscaleIPs {
+			if isIPv4(ip) {
+				hosts = append(hosts, ip)
+				break // one address per peer is enough to probe
+			}
+		}
+	}
+	return hosts
+}
+
+// isIPv4 reports whether s looks like a dotted-quad (cheap check — avoids
+// pulling in net just to skip the IPv6 entries Tailscale also reports).
+func isIPv4(s string) bool {
+	dots := 0
+	for _, c := range s {
+		switch {
+		case c == '.':
+			dots++
+		case c >= '0' && c <= '9':
+		default:
+			return false
+		}
+	}
+	return dots == 3
+}

internal/tailscale/tailscale_test.go

@@ -0,0 +1,46 @@
+package tailscale
+
+import (
+	"reflect"
+	"sort"
+	"testing"
+)
+
+func TestParsePeersOnlineIPv4Only(t *testing.T) {
+	data := []byte(`{
+		"Peer": {
+			"key1": {"TailscaleIPs": ["100.64.0.1", "fd7a:115c::1"], "Online": true},
+			"key2": {"TailscaleIPs": ["100.64.0.2"], "Online": false},
+			"key3": {"TailscaleIPs": ["fd7a:115c::3"], "Online": true},
+			"key4": {"TailscaleIPs": ["100.64.0.4"], "Online": true}
+		}
+	}`)
+	got := parsePeers(data)
+	sort.Strings(got)
+	want := []string{"100.64.0.1", "100.64.0.4"} // online + has IPv4; offline and v6-only excluded
+	if !reflect.DeepEqual(got, want) {
+		t.Errorf("parsePeers = %v, want %v", got, want)
+	}
+}
+
+func TestParsePeersBadJSON(t *testing.T) {
+	if got := parsePeers([]byte("not json")); got != nil {
+		t.Errorf("bad JSON should yield nil, got %v", got)
+	}
+}
+
+func TestIsIPv4(t *testing.T) {
+	cases := map[string]bool{
+		"100.64.0.1":   true,
+		"1.2.3.4":      true,
+		"fd7a:115c::1": false,
+		"1.2.3":        false,
+		"":             false,
+		"abc":          false,
+	}
+	for in, want := range cases {
+		if got := isIPv4(in); got != want {
+			t.Errorf("isIPv4(%q) = %v, want %v", in, got, want)
+		}
+	}
+}

internal/tsproxy/tsproxy.go

@@ -0,0 +1,111 @@
+// Package tsproxy routes tailnet-bound HTTP connections through the local
+// tailscaled SOCKS5 proxy when — and only when — the box needs it. On a box
+// whose tailscaled runs with --tun=userspace-networking (e.g. an unprivileged
+// container), there is no TUN interface, so ordinary outbound dials to
+// 100.64.0.0/10 addresses cannot route; tailscaled's --socks5-server is the
+// only outbound path. On a normal box the tailnet address is a local interface
+// address and no proxy is involved.
+package tsproxy
+
+import (
+	"net"
+	"net/http"
+	"net/url"
+	"sync"
+	"time"
+
+	"omarchy-send/internal/dbg"
+)
+
+// conventionalAddr is where tailscaled's SOCKS5 proxy conventionally listens
+// (--socks5-server=localhost:1055, the address used throughout Tailscale's
+// userspace-networking docs). An explicit HTTPS_PROXY/HTTP_PROXY overrides it.
+const conventionalAddr = "127.0.0.1:1055"
+
+// detectTTL bounds how long a detection result is trusted, so a tailscaled
+// (re)started after us is picked up without restarting omarchy-send.
+const detectTTL = 30 * time.Second
+
+// tailnetCIDR is Tailscale's CGNAT range; every tailnet IPv4 falls in it.
+var tailnetCIDR = func() *net.IPNet {
+	_, n, _ := net.ParseCIDR("100.64.0.0/10")
+	return n
+}()
+
+// envProxy resolves the proxy environment variables; a seam for tests (the
+// stdlib caches the env process-wide on first use).
+var envProxy = http.ProxyFromEnvironment
+
+// ProxyFunc is an http.Transport.Proxy implementation. Explicit proxy
+// environment variables (HTTPS_PROXY/HTTP_PROXY/NO_PROXY) always win, like the
+// default transport; otherwise requests to tailnet addresses are routed via
+// the local tailscaled SOCKS5 proxy when the box can't dial them directly.
+func ProxyFunc(req *http.Request) (*url.URL, error) {
+	if u, err := envProxy(req); err != nil || u != nil {
+		return u, err
+	}
+	if isTailnetHost(req.URL.Hostname()) {
+		return detect(), nil
+	}
+	return nil, nil
+}
+
+// isTailnetHost reports whether host is an IP in the Tailscale CGNAT range.
+func isTailnetHost(host string) bool {
+	ip := net.ParseIP(host)
+	return ip != nil && tailnetCIDR.Contains(ip)
+}
+
+var (
+	mu      sync.Mutex
+	checked time.Time
+	cached  *url.URL // non-nil when tailnet dials must go through the proxy
+)
+
+// detect decides (with a short cache) whether tailnet destinations need the
+// local SOCKS5 proxy: only when no local interface carries a tailnet address
+// (i.e. userspace networking — a TUN box can dial directly) AND something is
+// listening at the conventional proxy address.
+func detect() *url.URL {
+	mu.Lock()
+	defer mu.Unlock()
+	if time.Since(checked) < detectTTL {
+		return cached
+	}
+	checked = time.Now()
+	prev := cached
+	cached = nil
+	if !hasLocalTailnetAddr() && listening(conventionalAddr) {
+		cached = &url.URL{Scheme: "socks5", Host: conventionalAddr}
+	}
+	if (cached == nil) != (prev == nil) {
+		dbg.Logf("tsproxy: tailnet SOCKS5 proxy at %s: %v", conventionalAddr, cached != nil)
+	}
+	return cached
+}
+
+// hasLocalTailnetAddr reports whether any local interface has a tailnet
+// address — true on kernel-TUN tailscale boxes, false under userspace
+// networking (the box's own tailnet IP is not a local address there).
+func hasLocalTailnetAddr() bool {
+	addrs, err := net.InterfaceAddrs()
+	if err != nil {
+		return false
+	}
+	for _, a := range addrs {
+		if ipn, ok := a.(*net.IPNet); ok && tailnetCIDR.Contains(ipn.IP) {
+			return true
+		}
+	}
+	return false
+}
+
+// listening reports whether a TCP listener answers at addr.
+func listening(addr string) bool {
+	c, err := net.DialTimeout("tcp", addr, 300*time.Millisecond)
+	if err != nil {
+		return false
+	}
+	_ = c.Close()
+	return true
+}

internal/tsproxy/tsproxy_test.go

@@ -0,0 +1,96 @@
+package tsproxy
+
+import (
+	"net/http"
+	"net/url"
+	"testing"
+	"time"
+)
+
+func TestIsTailnetHost(t *testing.T) {
+	cases := []struct {
+		host string
+		want bool
+	}{
+		{"100.90.62.102", true},                                           // tailnet (CGNAT range)
+		{"100.64.0.1", true},                                              // range start
+		{"100.127.255.254", true} /* range end */, {"100.128.0.1", false}, // just past the /10
+		{"192.168.1.46", false}, // LAN
+		{"127.0.0.1", false},    // loopback
+		{"colossus", false},     // hostname, not an IP
+		{"", false},
+	}
+	for _, c := range cases {
+		if got := isTailnetHost(c.host); got != c.want {
+			t.Errorf("isTailnetHost(%q) = %v, want %v", c.host, got, c.want)
+		}
+	}
+}
+
+// stubEnvProxy replaces the env-var proxy lookup for a test. The stdlib's
+// ProxyFromEnvironment caches the environment process-wide on first use, so
+// t.Setenv can't drive these tests reliably.
+func stubEnvProxy(t *testing.T, u *url.URL) {
+	t.Helper()
+	orig := envProxy
+	envProxy = func(*http.Request) (*url.URL, error) { return u, nil }
+	t.Cleanup(func() { envProxy = orig })
+}
+
+// Explicit proxy env vars must win over auto-detection, like the default
+// transport.
+func TestProxyFuncEnvOverride(t *testing.T) {
+	stubEnvProxy(t, &url.URL{Scheme: "socks5", Host: "127.0.0.1:9999"})
+	prime(&url.URL{Scheme: "socks5", Host: conventionalAddr}) // detection would say 1055
+	req, _ := http.NewRequest(http.MethodGet, "https://100.90.62.102:53317/info", nil)
+	u, err := ProxyFunc(req)
+	if err != nil {
+		t.Fatalf("ProxyFunc: %v", err)
+	}
+	if u == nil || u.Host != "127.0.0.1:9999" {
+		t.Errorf("proxy = %v, want explicit socks5://127.0.0.1:9999", u)
+	}
+}
+
+// Non-tailnet destinations never get the auto-detected proxy.
+func TestProxyFuncNonTailnetDirect(t *testing.T) {
+	stubEnvProxy(t, nil)
+	prime(&url.URL{Scheme: "socks5", Host: conventionalAddr})
+	req, _ := http.NewRequest(http.MethodGet, "https://192.168.1.46:53317/info", nil)
+	u, err := ProxyFunc(req)
+	if err != nil {
+		t.Fatalf("ProxyFunc: %v", err)
+	}
+	if u != nil {
+		t.Errorf("proxy = %v, want nil (direct) for a LAN destination", u)
+	}
+}
+
+// A tailnet destination uses the cached detection result; with the cache
+// primed to "proxy present" the URL comes back, and direct otherwise.
+func TestProxyFuncTailnetUsesDetection(t *testing.T) {
+	stubEnvProxy(t, nil)
+	req, _ := http.NewRequest(http.MethodGet, "https://100.90.62.102:53317/info", nil)
+
+	prime(&url.URL{Scheme: "socks5", Host: conventionalAddr})
+	u, err := ProxyFunc(req)
+	if err != nil {
+		t.Fatalf("ProxyFunc: %v", err)
+	}
+	if u == nil || u.Scheme != "socks5" || u.Host != conventionalAddr {
+		t.Errorf("proxy = %v, want socks5://%s", u, conventionalAddr)
+	}
+
+	prime(nil)
+	if u, _ := ProxyFunc(req); u != nil {
+		t.Errorf("proxy = %v, want nil when no proxy detected", u)
+	}
+}
+
+// prime seeds the detection cache for tests.
+func prime(u *url.URL) {
+	mu.Lock()
+	defer mu.Unlock()
+	checked = time.Now()
+	cached = u
+}

internal/tui/manage_test.go

@@ -64,15 +64,15 @@ func TestManageDeleteSingleViaConfirm(t *testing.T) {
 	m, dir := manageModel(t, "keep.txt", "drop.txt")
 	// Cursor starts on the newest (drop.txt was written last). Marking it and
 	// confirming should remove exactly that file.
-	m = key(m, " ")     // mark file under cursor
+	m = key(m, " ") // mark file under cursor
 	if len(m.marked) != 1 {
 		t.Fatalf("expected 1 marked, got %d", len(m.marked))
 	}
-	m = key(m, "d")     // request delete -> confirm card
+	m = key(m, "d") // request delete -> confirm card
 	if !m.confirmDel {
 		t.Fatal("expected confirm card to be showing")
 	}
-	m = key(m, "y")     // confirm
+	m = key(m, "y") // confirm
 	if m.confirmDel {
 		t.Error("confirm card should be dismissed after delete")
 	}

internal/tui/model.go

@@ -38,6 +38,7 @@ type Controller interface {
 	SetReceiveDir(string)
 	SetPIN(string)
 	SetNotify(bool)
+	AddKnownPeer(host string) // probe a remote host directly (off-LAN / Tailscale)
 }
 
 type screen int
@@ -123,6 +124,10 @@ type Model struct {
 	sendPaths  []string
 	pendingMsg string
 
+	// Add-remote-peer modal (Devices tab): host/IP/Tailscale-name entry.
+	addingPeer bool
+	peerInput  textinput.Model
+
 	// Messages tab + compose modal.
 	msgList      list.Model
 	messages     []server.ReceivedMessage
@@ -199,6 +204,11 @@ func New(cfg config.Config, ctrl Controller, opts ...Option) Model {
 	compose.CharLimit = 2000
 	compose.Width = 48
 
+	peerInput := textinput.New()
+	peerInput.Placeholder = "host, IP, or Tailscale name"
+	peerInput.CharLimit = 256
+	peerInput.Width = 48
+
 	mkInput := func(placeholder string, limit int) textinput.Model {
 		ti := textinput.New()
 		ti.Placeholder = placeholder
@@ -229,6 +239,7 @@ func New(cfg config.Config, ctrl Controller, opts ...Option) Model {
 		editInputs:   editInputs,
 		msgList:      ml,
 		composeInput: compose,
+		peerInput:    peerInput,
 	}
 	for _, o := range opts {
 		o(&m)
@@ -321,6 +332,9 @@ func (m Model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 		if m.composing {
 			return m.updateCompose(msg)
 		}
+		if m.addingPeer {
+			return m.updateAddPeer(msg)
+		}
 		if m.readingMsg != nil {
 			switch msg.String() {
 			case "esc", "q", "enter":
@@ -387,6 +401,15 @@ func (m Model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 				m.refreshManage()
 			}
 			return m, nil
+		case "+":
+			// Add a remote device by host/IP/Tailscale-name (off-LAN peer).
+			if m.screen == screenPeers {
+				m.addingPeer = true
+				m.peerInput.SetValue("")
+				m.peerInput.Focus()
+				return m, textinput.Blink
+			}
+			return m, nil
 		case "r":
 			if m.screen == screenPeers && m.ctrl != nil {
 				m.ctrl.Announce()
@@ -547,6 +570,11 @@ func (m Model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 		}
 	}
 
+	if m.addingPeer {
+		var cmd tea.Cmd
+		m.peerInput, cmd = m.peerInput.Update(msg)
+		return m, cmd
+	}
 	if m.pending == nil && m.screen == screenPicker {
 		var cmd tea.Cmd
 		m.fzfQuery, cmd = m.fzfQuery.Update(msg)
@@ -597,6 +625,33 @@ func (m Model) updateCompose(msg tea.KeyMsg) (tea.Model, tea.Cmd) {
 	return m, cmd
 }
 
+// updateAddPeer handles the add-remote-device modal. On enter it persists the
+// host to config's known-peers and asks the controller to probe it now.
+func (m Model) updateAddPeer(msg tea.KeyMsg) (tea.Model, tea.Cmd) {
+	switch msg.String() {
+	case "esc":
+		m.addingPeer = false
+		return m, nil
+	case "enter":
+		host := strings.TrimSpace(m.peerInput.Value())
+		if host != "" {
+			if !contains(m.cfg.KnownPeers, host) {
+				m.cfg.KnownPeers = append(m.cfg.KnownPeers, host)
+				_ = m.cfg.Save()
+			}
+			if m.ctrl != nil {
+				m.ctrl.AddKnownPeer(host)
+			}
+			m.notice = "added remote " + host + " — probing…"
+		}
+		m.addingPeer = false
+		return m, nil
+	}
+	var cmd tea.Cmd
+	m.peerInput, cmd = m.peerInput.Update(msg)
+	return m, cmd
+}
+
 // deleteSelectedMessage drops the highlighted message from the list.
 func (m *Model) deleteSelectedMessage() {
 	it, ok := m.msgList.SelectedItem().(msgItem)
@@ -679,7 +734,9 @@ func (m Model) saveEdit() (tea.Model, tea.Cmd) {
 		m.cfg.DeviceModel = alias
 	}
 	if dir != "" {
-		m.cfg.ReceiveDir = dir
+		// Expand a typed ~-form immediately so the live server and the saved
+		// config both carry the absolute path.
+		m.cfg.ReceiveDir = config.ExpandHome(dir)
 	}
 	m.cfg.PIN = pin
 	_ = m.cfg.Save()
@@ -848,6 +905,9 @@ func (m Model) View() string {
 	if m.composing {
 		return lipgloss.Place(w, h, lipgloss.Center, lipgloss.Center, cardStyle.Render(m.composeView()))
 	}
+	if m.addingPeer {
+		return lipgloss.Place(w, h, lipgloss.Center, lipgloss.Center, cardStyle.Render(m.addPeerView()))
+	}
 	if m.readingMsg != nil {
 		return lipgloss.Place(w, h, lipgloss.Center, lipgloss.Center, cardStyle.Render(m.readMessageView()))
 	}
@@ -984,6 +1044,18 @@ func (m Model) pinView() string {
 	return b.String()
 }
 
+func (m Model) addPeerView() string {
+	var b strings.Builder
+	b.WriteString(titleStyle.Render("Add remote device"))
+	b.WriteString("\n\n")
+	b.WriteString(headerStyle.Render("A device off your LAN — e.g. a Tailscale name or IP.\nIt's probed directly (no multicast) and saved."))
+	b.WriteString("\n\n")
+	b.WriteString(m.peerInput.View())
+	b.WriteString("\n\n")
+	b.WriteString(footerStyle.Render("enter add · esc cancel"))
+	return b.String()
+}
+
 func (m Model) acceptView() string {
 	var b strings.Builder
 	b.WriteString(titleStyle.Render("Incoming files"))
@@ -1233,6 +1305,8 @@ func (m Model) footerText() string {
 		return m.notice
 	case m.composing:
 		return "enter send · esc cancel"
+	case m.addingPeer:
+		return "enter add remote · esc cancel"
 	case m.readingMsg != nil:
 		return "y copy · esc/enter close"
 	case m.confirmDel:
@@ -1244,7 +1318,7 @@ func (m Model) footerText() string {
 	case m.screen == screenPeers && m.quickSend:
 		return fmt.Sprintf("enter send %d item(s) to selected device · r refresh · q cancel", len(m.staged))
 	case m.screen == screenPeers:
-		return "enter send-to · m message · v send-clipboard · r refresh · / filter · 1-5 · q quit"
+		return "enter send-to · m message · v clipboard · + add remote · r refresh · / filter · q quit"
 	case m.screen == screenTransfers:
 		return "c clear finished · 1-5 switch · q quit"
 	case m.screen == screenManage:
@@ -1282,21 +1356,10 @@ func collapseHome(p string) string {
 }
 
 // expandHome resolves a leading ~ (or ~/) to the user's home directory. It is
-// the inverse of collapseHome and tolerates the ~-form a user may type into the
-// receive-dir setting.
+// the inverse of collapseHome; the canonical implementation lives in config so
+// every consumer of ReceiveDir expands the same way.
 func expandHome(p string) string {
-	if p == "~" {
-		if home, err := os.UserHomeDir(); err == nil {
-			return home
-		}
-		return p
-	}
-	if strings.HasPrefix(p, "~/") {
-		if home, err := os.UserHomeDir(); err == nil {
-			return filepath.Join(home, p[2:])
-		}
-	}
-	return p
+	return config.ExpandHome(p)
 }
 
 func truncate(s string, n int) string {

internal/tui/send_test.go

@@ -33,6 +33,7 @@ func (f *fakeCtrl) SetAlias(string)                                {}
 func (f *fakeCtrl) SetReceiveDir(string)                           {}
 func (f *fakeCtrl) SetPIN(string)                                  {}
 func (f *fakeCtrl) SetNotify(bool)                                 {}
+func (f *fakeCtrl) AddKnownPeer(string)                            {}
 
 // writeTree lays out a small fixture tree under a temp dir for walkIndex tests.
 func writeTree(t *testing.T) string {

internal/tui/view_manage.go

@@ -24,7 +24,7 @@ type fileItem struct {
 }
 
 func (i fileItem) Title() string       { return i.name }
-func (i fileItem) Description() string  { return "" }
+func (i fileItem) Description() string { return "" }
 func (i fileItem) FilterValue() string { return i.name }
 
 // receivedFiles lists the top-level entries in dir, newest first. In-progress