diff --git a/Containerfile.full b/Containerfile.full
index 7f7e02f..4db7ba0 100644
--- a/Containerfile.full
+++ b/Containerfile.full
@@ -60,6 +60,7 @@ RUN dpkg --add-architecture i386 \
       libqt5texttospeech5 libqt5websockets5 libqt5widgets5 libqt5xml5 \
       qml-module-qtquick2 \
       libvulkan1 libvulkan1:i386 vulkan-tools \
+      libglib2.0-bin \
  && rm -rf /var/lib/apt/lists/*
 
 # Stable's Mesa 25.0.7 is the prime suspect for mid-ride i915 GPU hangs (#5).
@@ -92,7 +93,9 @@ COPY --from=qzbuild /build/qdomyos-zwift /opt/qz/qdomyos-zwift
 RUN useradd -m -u 1000 -s /bin/bash tpv \
  && mkdir -p /opt/tpv && chown tpv:tpv /opt/tpv
 COPY scripts/ /opt/scripts/
-RUN chmod +x /opt/scripts/*.sh
+# Wine opens links via xdg-open; this one forwards them to the host browser.
+RUN chmod +x /opt/scripts/*.sh \
+ && ln -s /opt/scripts/xdg-open-host.sh /usr/local/bin/xdg-open
 
 USER tpv
 ENV WINEPREFIX=/opt/tpv/wine-template \
diff --git a/README.md b/README.md
index 00f5522..8ead1b2 100644
--- a/README.md
+++ b/README.md
@@ -169,6 +169,7 @@ it to the trainer. Set `QZ_HR_BELT` and pair `Wahoo HRM` in TPV explicitly.
 | `Containerfile.debian` | QZ only, built from source (bridge on a separate host) |
 | `patches/` | The QZ root-guard patch, published as GPL requires |
 | `scripts/entrypoint.sh` | Mode dispatch, prefix seeding, QZ + TPV startup |
+| `scripts/xdg-open-host.sh` | Opens links from TPV in the host browser |
 | `scripts/build-prefix.sh` | Builds the template Wine prefix at image build time |
 | `run-tpv.sh` | GPU, display and audio wiring for the combined image |
 | `run-qz-debian.sh` | Runs the QZ-only image |
@@ -184,6 +185,7 @@ it to the trainer. Set `QZ_HR_BELT` and pair `Wahoo HRM` in TPV explicitly.
 | writable `HOME` and workdir | QZ spins on failed debug-log writes and never gets past discovery. Looks like a hang |
 | D-Bus socket mount | No BlueZ at all: `Cannot find a running Bluez` |
 | Avahi socket mount | No mDNS advert, so TPV never discovers the bridge |
+| Session bus mount | Connect Garmin / Strava / TrainingPeaks buttons do nothing: Wine's `xdg-open` has no browser to reach. The image's `xdg-open` forwards links to the host browser through the OpenURI portal |
 | `BLUETOOTH_FORCE_DBUS_LE_VERSION` | Qt probes bluetoothd's version by executing its path *inside* the container, where it is absent; the `"4.0"` fallback selects a legacy raw-L2CAP backend that cannot connect |
 
 QZ needs **no root**. Its upstream `getuid()` guard predates QZ reaching BlueZ
@@ -192,7 +194,7 @@ check, which is why a patch rather than `--cap-add` is required.
 
 ## Scope
 
-This is packaging, not sandboxing. Host networking, host D-Bus and host Avahi mean
+This is packaging, not sandboxing. Host networking, host D-Bus (system and session) and host Avahi mean
 the container is tightly coupled to the host. What it removes is installing a Qt5
 build environment, compiling QZ, and assembling a working Wine prefix by hand.
 
diff --git a/docs/adr/0004-open-links-in-the-host-browser-via-the-openuri-portal.md b/docs/adr/0004-open-links-in-the-host-browser-via-the-openuri-portal.md
new file mode 100644
index 0000000..7e828ff
--- /dev/null
+++ b/docs/adr/0004-open-links-in-the-host-browser-via-the-openuri-portal.md
@@ -0,0 +1,66 @@
+# 0004. Open TPV's account-linking links in the host browser via the OpenURI portal
+
+- **Status:** Accepted
+- **Date:** 2026-09-17
+- **Deciders:** Ben Atkinson
+- **Feature / area:** host-browser-links
+- **Builds on:** none — first ADR for host-browser-links
+- **Supersedes / Superseded by:** none
+
+## What problem were we trying to solve?
+
+Clicking **Connect Garmin** when TPV loads did nothing: no browser and no error
+(#6). The same applies to Strava, TrainingPeaks, intervals.icu and the other
+account-linking buttons. TPV calls `OpenURL` with an OAuth page. Under Wine
+that goes to `xdg-open`, and the container has no browser, so the request was
+silently dropped.
+
+A key finding shaped the fix: the OAuth redirect goes to
+`api.indievelo.com`, **not** a localhost callback or a custom URI scheme. The
+login only has to happen in *a* browser; nothing needs to reach back into the
+container or Wine.
+
+## What did we try?
+
+### Option 1: install a browser in the image ❌ considered, rejected
+
+It would add hundreds of MB to an already ~6.6 GB image, give a second browser
+profile without the user's saved logins or password manager, and need more
+display and sandbox plumbing inside the container.
+
+### Option 2: only print the URL for the user to open by hand ❌ considered, kept as the fallback
+
+It always works, but it's poor UX for a button users expect to just open a
+page, and the URL only appears in container output.
+
+### Option 3: forward links to the host desktop over D-Bus ✅ chosen
+
+`org.freedesktop.portal.OpenURI` is the standard way sandboxed apps (Flatpak)
+ask the desktop to open a link, and every mainstream Linux desktop provides it.
+The container only needs the host session bus mounted.
+
+## What did we land on, and why?
+
+- **`scripts/xdg-open-host.sh`**, symlinked as `/usr/local/bin/xdg-open` in the
+  image. It accepts only `http(s)` and `mailto` links and calls
+  `OpenURI.OpenURI` with `gdbus` (new package `libglib2.0-bin`). If there's no
+  session bus or the portal refuses, it prints the link to open by hand.
+- **`run-tpv.sh`** mounts `$XDG_RUNTIME_DIR/bus` as `/run/host-session-bus`
+  and sets `DBUS_SESSION_BUS_ADDRESS`. Without a session bus it warns that the
+  account-linking buttons can't open a browser.
+
+This won because the link opens in the user's own browser, with their existing
+logins, at the cost of one small package and one mount. Because the OAuth
+redirect lands on TPV's servers, no callback handling is needed.
+
+## What does this cost us?
+
+- **More host coupling:** the container now has the host **session** bus as
+  well as the system bus. Anything in the container can talk to session
+  services, so this is packaging, not sandboxing (see README Scope).
+- **Only link types are filtered:** anything other than http(s)/mailto is
+  refused, but any http(s) URL TPV asks for will open without confirmation.
+- **Headless sessions** (no session bus or portal) fall back to printing the
+  link.
+- **Not yet verified here:** that Garmin linking completes end to end and
+  persists across container restarts.
diff --git a/run-tpv.sh b/run-tpv.sh
index 9e9af13..6a9d874 100755
--- a/run-tpv.sh
+++ b/run-tpv.sh
@@ -68,6 +68,15 @@ HOST_TZ="${TZ:-$(timedatectl show -p Timezone --value 2>/dev/null || true)}"
 [ -e /etc/localtime ] && TIMEZONE+=(-v /etc/localtime:/etc/localtime:ro)
 echo "==> timezone: ${HOST_TZ:-host /etc/localtime}"
 
+HOST_LINKS=()
+SESSION_BUS="${XDG_RUNTIME_DIR:-/run/user/$(id -u)}/bus"
+if [ -S "$SESSION_BUS" ]; then
+  HOST_LINKS=(-v "$SESSION_BUS:/run/host-session-bus"
+              -e DBUS_SESSION_BUS_ADDRESS=unix:path=/run/host-session-bus)
+else
+  echo "==> WARNING: no session bus; account-linking buttons cannot open a browser" >&2
+fi
+
 INHIBIT=()
 if [ "$MODE" != qz ] && command -v gnome-session-inhibit >/dev/null; then
   INHIBIT=(gnome-session-inhibit --inhibit idle:suspend
@@ -83,6 +92,7 @@ exec "${INHIBIT[@]}" podman run --rm --name tpv \
   "${GPU[@]}" "${AUDIO[@]}" \
   "${DISPLAY_ARGS[@]}" \
   "${TIMEZONE[@]}" \
+  "${HOST_LINKS[@]}" \
   -e "QZ_TRAINER=${TRAINER}" \
   -e "QZ_HR_BELT=${HR_BELT}" \
   -e "TPV_DIRECT=${TPV_DIRECT:-0}" \
diff --git a/scripts/xdg-open-host.sh b/scripts/xdg-open-host.sh
new file mode 100755
index 0000000..4ad0b74
--- /dev/null
+++ b/scripts/xdg-open-host.sh
@@ -0,0 +1,30 @@
+#!/usr/bin/env bash
+# xdg-open for the container: hands links to the host desktop's browser through
+# the OpenURI portal on the host session bus (mounted by run-tpv.sh).
+set -uo pipefail
+
+URL="${1:-}"
+if [ -z "$URL" ]; then
+  echo "usage: xdg-open <url>" >&2
+  exit 1
+fi
+
+case "$URL" in
+  http://*|https://*|mailto:*) ;;
+  *) echo "==> xdg-open: not forwarding unsupported link: $URL" >&2; exit 1 ;;
+esac
+
+if [ -z "${DBUS_SESSION_BUS_ADDRESS:-}" ]; then
+  echo "!! xdg-open: no host session bus; open this link manually: $URL" >&2
+  exit 1
+fi
+
+if ! ERR=$(gdbus call --session \
+      --dest org.freedesktop.portal.Desktop \
+      --object-path /org/freedesktop/portal/desktop \
+      --method org.freedesktop.portal.OpenURI.OpenURI \
+      "" "$URL" "{}" 2>&1 >/dev/null); then
+  echo "!! xdg-open: host portal refused ($ERR); open this link manually: $URL" >&2
+  exit 1
+fi
+echo "==> opened in host browser: ${URL%%\?*}" >&2