Fix release asset upload corrupted by echo of API response

The v1.1.0 release job created the release then died with a jq parse error
before uploading either package.

The runner executes run: steps with a shell whose echo expands backslash
escapes. Passing the API response through `echo "$BODY" | jq` turned the \n
escapes in the release body field into real newlines, producing invalid JSON.
This only surfaced now because the release body became multi-line; every
earlier release had a single-line body with no \n to expand.

Keep the response in a file and read it with jq directly, so no JSON passes
through echo. Also fall back to the existing release for the tag when creation
returns non-2xx, so a partially completed release can be re-run.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

.gitea/workflows/build.yaml

@@ -15,44 +15,48 @@ on:
 
 jobs:
   build:
-    runs-on: ubuntu-latest
+    runs-on: linux/amd64
+    container:
+      image: gitea.tourolle.paris/dtourolle/jellylms-builder:latest
 
     steps:
       - name: Checkout repository
         uses: actions/checkout@v4
+        with:
+          path: build-${{ github.run_id }}
 
-      - name: Verify .NET installation
+      - name: Cache NuGet packages
-        run: dotnet --version
+        uses: actions/cache@v3
+        with:
+          path: ~/.nuget/packages
+          key: nuget-${{ hashFiles('**/Jellyfin.Plugin.JellyLMS.csproj') }}
+          restore-keys: nuget-
 
       - name: Restore dependencies
+        working-directory: build-${{ github.run_id }}
         run: dotnet restore Jellyfin.Plugin.JellyLMS.sln
 
       - name: Build solution
-        run: dotnet build Jellyfin.Plugin.JellyLMS.sln --configuration Release --no-restore --no-self-contained
+        working-directory: build-${{ github.run_id }}
+        run: dotnet build Jellyfin.Plugin.JellyLMS.sln --configuration Release --no-restore --no-self-contained /m:1
 
-      - name: Install JPRM
+      - name: Build Jellyfin plugin packages
+        working-directory: build-${{ github.run_id }}
         run: |
-          python3 -m venv /tmp/jprm-venv
+          for VARIANT in jf11 jf12; do
-          /tmp/jprm-venv/bin/pip install jprm
+            ARTIFACT=$(./build-plugin.sh "${VARIANT}")
+            cp "${ARTIFACT}" "artifacts/jellylms_latest_${VARIANT}.zip"
+            echo "Built ${VARIANT}: ${ARTIFACT}"
+          done
 
-      - name: Build Jellyfin Plugin
+      - name: Upload build artifacts
-        id: jprm
-        run: |
-          # Create artifacts directory for JPRM output
-          mkdir -p artifacts
-
-          # Build plugin using JPRM
-          /tmp/jprm-venv/bin/jprm --verbosity=debug plugin build .
-
-          # Find the generated zip file
-          ARTIFACT=$(find . -name "*.zip" -type f -print -quit)
-          echo "artifact=${ARTIFACT}" >> $GITHUB_OUTPUT
-          echo "Found artifact: ${ARTIFACT}"
-
-      - name: Upload build artifact
         uses: actions/upload-artifact@v3
         with:
           name: jellylms-plugin
-          path: ${{ steps.jprm.outputs.artifact }}
+          path: build-${{ github.run_id }}/artifacts/jellylms_latest_*.zip
           retention-days: 30
           if-no-files-found: error
+
+      - name: Cleanup
+        if: always()
+        run: rm -rf build-${{ github.run_id }}

.gitea/workflows/release.yaml

@@ -13,14 +13,15 @@ on:
 
 jobs:
   build-and-release:
-    runs-on: ubuntu-latest
+    runs-on: linux/amd64
+    container:
+      image: gitea.tourolle.paris/dtourolle/jellylms-builder:latest
 
     steps:
       - name: Checkout repository
         uses: actions/checkout@v4
-
+        with:
-      - name: Verify .NET installation
+          path: release-${{ github.run_id }}
-        run: dotnet --version
 
       - name: Get version
         id: get_version
@@ -34,40 +35,36 @@ jobs:
           echo "version_number=${VERSION#v}" >> $GITHUB_OUTPUT
           echo "Building version: ${VERSION}"
 
-      - name: Update build.yaml with version
+      - name: Cache NuGet packages
-        run: |
+        uses: actions/cache@v3
-          VERSION="${{ steps.get_version.outputs.version_number }}"
+        with:
-          sed -i "s/^version:.*/version: \"${VERSION}\"/" build.yaml
+          path: ~/.nuget/packages
-          cat build.yaml
+          key: nuget-${{ hashFiles('**/Jellyfin.Plugin.JellyLMS.csproj') }}
+          restore-keys: nuget-
 
       - name: Restore dependencies
+        working-directory: release-${{ github.run_id }}
         run: dotnet restore Jellyfin.Plugin.JellyLMS.sln
 
       - name: Build solution
-        run: dotnet build Jellyfin.Plugin.JellyLMS.sln --configuration Release --no-restore --no-self-contained
+        working-directory: release-${{ github.run_id }}
+        run: dotnet build Jellyfin.Plugin.JellyLMS.sln --configuration Release --no-restore --no-self-contained /m:1
 
-      - name: Install JPRM
+      - name: Build Jellyfin plugin packages
-        run: |
-          python3 -m venv /tmp/jprm-venv
-          /tmp/jprm-venv/bin/pip install jprm
-
-      - name: Build Jellyfin Plugin
         id: jprm
+        working-directory: release-${{ github.run_id }}
         run: |
-          # Create artifacts directory for JPRM output
+          VERSION="${{ steps.get_version.outputs.version_number }}"
-          mkdir -p artifacts
+          for VARIANT in jf11 jf12; do
-
+            ARTIFACT=$(./build-plugin.sh "${VARIANT}" "${VERSION}")
-          # Build plugin using JPRM
+            echo "${VARIANT}_artifact=${ARTIFACT}" >> $GITHUB_OUTPUT
-          /tmp/jprm-venv/bin/jprm --verbosity=debug plugin build ./
+            echo "${VARIANT}_artifact_name=$(basename "${ARTIFACT}")" >> $GITHUB_OUTPUT
-
+            echo "${VARIANT}_checksum=$(md5sum "${ARTIFACT}" | awk '{print $1}')" >> $GITHUB_OUTPUT
-          # Find the generated zip file
+            echo "Built ${VARIANT}: ${ARTIFACT}"
-          ARTIFACT=$(find . -name "*.zip" -type f -print -quit)
+          done
-          ARTIFACT_NAME=$(basename "${ARTIFACT}")
-          echo "artifact=${ARTIFACT}" >> $GITHUB_OUTPUT
-          echo "artifact_name=${ARTIFACT_NAME}" >> $GITHUB_OUTPUT
-          echo "Found artifact: ${ARTIFACT}"
 
       - name: Create Release
+        working-directory: release-${{ github.run_id }}
         env:
           GITEA_TOKEN: ${{ secrets.GITHUB_TOKEN }}
         run: |
@@ -76,98 +73,109 @@ jobs:
           REPO_NAME="${{ github.event.repository.name }}"
           GITEA_URL="${{ github.server_url }}"
 
-          # Prepare release body
-          RELEASE_BODY="JellyLMS Jellyfin Plugin ${{ steps.get_version.outputs.version }}\n\nSee attached files for plugin installation."
-          RELEASE_BODY_JSON=$(echo -n "${RELEASE_BODY}" | jq -Rs .)
-
           # Create release using Gitea API
-          RESPONSE=$(curl -s -w "\n%{http_code}" -X POST \
+          VERSION="${{ steps.get_version.outputs.version }}"
+          RELEASE_BODY=$(printf '%s\n' \
+            "JellyLMS Jellyfin Plugin ${VERSION}." \
+            "" \
+            "Pick the package matching your server:" \
+            "" \
+            "- \`${{ steps.jprm.outputs.jf11_artifact_name }}\` - Jellyfin 10.11.x" \
+            "- \`${{ steps.jprm.outputs.jf12_artifact_name }}\` - Jellyfin 12.0.x")
+          API_URL="${GITEA_URL}/api/v1/repos/${REPO_OWNER}/${REPO_NAME}"
+
+          # Keep the API response in a file: it contains \n escapes, and `echo` in
+          # this shell expands those into real newlines, which corrupts the JSON.
+          HTTP_CODE=$(curl -s -o release-response.json -w "%{http_code}" -X POST \
             -H "Authorization: token ${GITEA_TOKEN}" \
             -H "Content-Type: application/json" \
-            "${GITEA_URL}/api/v1/repos/${REPO_OWNER}/${REPO_NAME}/releases" \
+            "${API_URL}/releases" \
-            -d "{
+            -d "$(jq -n --arg tag "$VERSION" --arg name "Release $VERSION" --arg body "$RELEASE_BODY" '{tag_name: $tag, name: $name, body: $body, draft: false, prerelease: false}')")
-              \"tag_name\": \"${{ steps.get_version.outputs.version }}\",
-              \"name\": \"Release ${{ steps.get_version.outputs.version }}\",
-              \"body\": ${RELEASE_BODY_JSON},
-              \"draft\": false,
-              \"prerelease\": false
-            }")
 
-          HTTP_CODE=$(echo "$RESPONSE" | tail -n1)
+          if [ "$HTTP_CODE" -lt 200 ] || [ "$HTTP_CODE" -ge 300 ]; then
-          BODY=$(echo "$RESPONSE" | sed '$d')
+            echo "Create release returned HTTP ${HTTP_CODE}:"
-
+            cat release-response.json
-          if [ "$HTTP_CODE" -ge 200 ] && [ "$HTTP_CODE" -lt 300 ]; then
+            echo "Falling back to an existing release for ${VERSION}..."
-            RELEASE_ID=$(echo "$BODY" | jq -r '.id')
+            curl -sf -o release-response.json \
-            echo "Created release with ID: ${RELEASE_ID}"
+              -H "Authorization: token ${GITEA_TOKEN}" \
-          else
+              "${API_URL}/releases/tags/${VERSION}"
-            echo "Failed to create release. HTTP ${HTTP_CODE}"
-            echo "$BODY"
-            exit 1
           fi
 
-          # Upload plugin artifact
+          RELEASE_ID=$(jq -r '.id // empty' release-response.json)
-          echo "Uploading plugin artifact..."
+          if [ -z "${RELEASE_ID}" ]; then
+            echo "Could not determine release ID from:"
+            cat release-response.json
+            exit 1
+          fi
+          echo "Using release ID: ${RELEASE_ID}"
+
+          # Upload plugin artifacts (one per supported Jellyfin generation)
+          for ASSET in \
+            "${{ steps.jprm.outputs.jf11_artifact }}" \
+            "${{ steps.jprm.outputs.jf12_artifact }}"; do
+            echo "Uploading $(basename "${ASSET}")..."
             curl -f -X POST \
               -H "Authorization: token ${GITEA_TOKEN}" \
               -H "Content-Type: application/zip" \
-            --data-binary "@${{ steps.jprm.outputs.artifact }}" \
+              --data-binary "@${ASSET}" \
-            "${GITEA_URL}/api/v1/repos/${REPO_OWNER}/${REPO_NAME}/releases/${RELEASE_ID}/assets?name=${{ steps.jprm.outputs.artifact_name }}"
+              "${API_URL}/releases/${RELEASE_ID}/assets?name=$(basename "${ASSET}")"
-
+          done
-          # Upload build.yaml
-          echo "Uploading build.yaml..."
-          curl -f -X POST \
-            -H "Authorization: token ${GITEA_TOKEN}" \
-            -H "Content-Type: application/x-yaml" \
-            --data-binary "@build.yaml" \
-            "${GITEA_URL}/api/v1/repos/${REPO_OWNER}/${REPO_NAME}/releases/${RELEASE_ID}/assets?name=build.yaml"
 
+          rm -f release-response.json
           echo "Release created successfully!"
           echo "View at: ${GITEA_URL}/${REPO_OWNER}/${REPO_NAME}/releases/tag/${{ steps.get_version.outputs.version }}"
 
-      - name: Calculate checksum
-        id: checksum
-        run: |
-          CHECKSUM=$(md5sum "${{ steps.jprm.outputs.artifact }}" | awk '{print $1}')
-          echo "checksum=${CHECKSUM}" >> $GITHUB_OUTPUT
-          echo "MD5 checksum: ${CHECKSUM}"
-
       - name: Update manifest.json
+        working-directory: release-${{ github.run_id }}
         run: |
+          git config user.name "Gitea Actions"
+          git config user.email "actions@gitea.tourolle.paris"
+          git fetch origin master
+          git checkout master
+
           VERSION="${{ steps.get_version.outputs.version_number }}"
-          CHECKSUM="${{ steps.checksum.outputs.checksum }}"
           TIMESTAMP=$(date -u +"%Y-%m-%dT%H:%M:%SZ")
-          ARTIFACT_NAME="${{ steps.jprm.outputs.artifact_name }}"
           REPO_OWNER="${{ github.repository_owner }}"
           REPO_NAME="${{ github.event.repository.name }}"
           GITEA_URL="${{ github.server_url }}"
-          DOWNLOAD_URL="${GITEA_URL}/${REPO_OWNER}/${REPO_NAME}/releases/download/${{ steps.get_version.outputs.version }}/${ARTIFACT_NAME}"
+          RELEASE_URL="${GITEA_URL}/${REPO_OWNER}/${REPO_NAME}/releases/download/${{ steps.get_version.outputs.version }}"
 
-          # Create the new version entry
+          # One manifest entry per Jellyfin generation. Jellyfin filters the list by
-          NEW_VERSION=$(cat <<EOF
+          # targetAbi, so both entries can share the same version number.
-          {
+          add_version() {
-            "version": "${VERSION}",
+            local abi="$1" artifact_name="$2" checksum="$3"
-            "changelog": "Release ${VERSION}",
+            jq \
-            "targetAbi": "10.10.0.0",
+              --arg version "${VERSION}" \
-            "sourceUrl": "${DOWNLOAD_URL}",
+              --arg abi "${abi}" \
-            "checksum": "${CHECKSUM}",
+              --arg url "${RELEASE_URL}/${artifact_name}" \
-            "timestamp": "${TIMESTAMP}"
+              --arg checksum "${checksum}" \
-          }
+              --arg timestamp "${TIMESTAMP}" \
-          EOF
+              '.[0].versions = [{
-          )
+                 version: $version,
-
+                 changelog: "Release \($version)",
-          # Prepend new version to the versions array in manifest.json
+                 targetAbi: $abi,
-          jq --argjson newver "${NEW_VERSION}" '.[0].versions = [$newver] + .[0].versions' manifest.json > manifest.tmp.json
+                 sourceUrl: $url,
+                 checksum: $checksum,
+                 timestamp: $timestamp
+               }] + .[0].versions' manifest.json > manifest.tmp.json
             mv manifest.tmp.json manifest.json
+          }
+
+          add_version "10.11.0.0" "${{ steps.jprm.outputs.jf11_artifact_name }}" "${{ steps.jprm.outputs.jf11_checksum }}"
+          add_version "12.0.0.0" "${{ steps.jprm.outputs.jf12_artifact_name }}" "${{ steps.jprm.outputs.jf12_checksum }}"
 
           echo "Updated manifest.json:"
           cat manifest.json
 
       - name: Commit and push manifest
+        working-directory: release-${{ github.run_id }}
         env:
           GITEA_TOKEN: ${{ secrets.GITHUB_TOKEN }}
         run: |
-          git config user.name "Gitea Actions"
-          git config user.email "actions@gitea.tourolle.paris"
           git add manifest.json
           git commit -m "Update manifest.json for ${{ steps.get_version.outputs.version }}"
-          git push origin HEAD:master
+          git push origin master
+
+      - name: Cleanup
+        if: always()
+        run: rm -rf release-${{ github.run_id }}

Dockerfile.builder

@@ -0,0 +1,19 @@
+# JellyLMS Builder Image
+# Pre-built image with .NET SDK and JPRM for building Jellyfin plugins
+# Build: docker build -f Dockerfile.builder -t gitea.tourolle.paris/dtourolle/jellylms-builder:latest .
+# Push:  docker push gitea.tourolle.paris/dtourolle/jellylms-builder:latest
+
+FROM mcr.microsoft.com/dotnet/sdk:10.0
+
+RUN apt-get update && apt-get install -y \
+    python3 \
+    python3-pip \
+    git \
+    jq \
+    nodejs \
+    npm \
+    && rm -rf /var/lib/apt/lists/*
+
+RUN pip install --break-system-packages jprm
+
+WORKDIR /src

Jellyfin.Plugin.JellyLMS/Api/JellyLmsController.cs

@@ -3,8 +3,10 @@ using System.Collections.Generic;
 using System.ComponentModel.DataAnnotations;
 using System.Linq;
 using System.Net.Mime;
+using System.Reflection;
 using System.Threading.Tasks;
 using Jellyfin.Data.Enums;
+using Jellyfin.Database.Implementations.Enums;
 using Jellyfin.Plugin.JellyLMS.Models;
 using Jellyfin.Plugin.JellyLMS.Services;
 using MediaBrowser.Controller.Entities;
@@ -29,6 +31,7 @@ public class JellyLmsController : ControllerBase
     private readonly ILmsApiClient _lmsClient;
     private readonly LmsPlayerManager _playerManager;
     private readonly ILibraryManager _libraryManager;
+    private readonly IUserManager _userManager;
 
     /// <summary>
     /// Initializes a new instance of the <see cref="JellyLmsController"/> class.
@@ -36,14 +39,54 @@ public class JellyLmsController : ControllerBase
     /// <param name="lmsClient">The LMS API client.</param>
     /// <param name="playerManager">The player manager.</param>
     /// <param name="libraryManager">The library manager.</param>
+    /// <param name="userManager">The user manager.</param>
     public JellyLmsController(
         ILmsApiClient lmsClient,
         LmsPlayerManager playerManager,
-        ILibraryManager libraryManager)
+        ILibraryManager libraryManager,
+        IUserManager userManager)
     {
         _lmsClient = lmsClient;
         _playerManager = playerManager;
         _libraryManager = libraryManager;
+        _userManager = userManager;
+    }
+
+    /// <summary>
+    /// Determines whether the current user is allowed to use the multi-room remote
+    /// control features (administrators, or users granted the
+    /// "Allow remote control of other users" permission).
+    /// </summary>
+    /// <returns><c>true</c> if the user may use remote control endpoints.</returns>
+    private bool HasRemoteControlAccess()
+    {
+        var username = User.Identity?.Name;
+        if (string.IsNullOrEmpty(username))
+        {
+            return false;
+        }
+
+        var user = _userManager.GetUserByName(username);
+        if (user is null)
+        {
+            return false;
+        }
+
+        return HasPermission(user, PermissionKind.IsAdministrator)
+            || HasPermission(user, PermissionKind.EnableRemoteControlOfOtherUsers);
+    }
+
+    private static bool HasPermission(Jellyfin.Database.Implementations.Entities.User user, PermissionKind kind)
+    {
+        foreach (var permission in user.Permissions)
+        {
+            if (permission.Kind == kind)
+            {
+                return permission.Value;
+            }
+        }
+
+        return false;
     }
 
     /// <summary>
@@ -65,8 +108,14 @@ public class JellyLmsController : ControllerBase
     /// <returns>List of players.</returns>
     [HttpGet("Players")]
     [ProducesResponseType(StatusCodes.Status200OK)]
+    [ProducesResponseType(StatusCodes.Status403Forbidden)]
     public async Task<ActionResult<List<LmsPlayer>>> GetPlayers([FromQuery] bool refresh = false)
     {
+        if (!HasRemoteControlAccess())
+        {
+            return Forbid();
+        }
+
         var players = await _playerManager.GetPlayersAsync(refresh).ConfigureAwait(false);
         return Ok(players);
     }
@@ -78,9 +127,15 @@ public class JellyLmsController : ControllerBase
     /// <returns>The player details.</returns>
     [HttpGet("Players/{mac}")]
     [ProducesResponseType(StatusCodes.Status200OK)]
+    [ProducesResponseType(StatusCodes.Status403Forbidden)]
     [ProducesResponseType(StatusCodes.Status404NotFound)]
     public async Task<ActionResult<LmsPlayer>> GetPlayer(string mac)
     {
+        if (!HasRemoteControlAccess())
+        {
+            return Forbid();
+        }
+
         var player = await _playerManager.GetPlayerAsync(mac).ConfigureAwait(false);
         if (player == null)
         {
@@ -98,8 +153,14 @@ public class JellyLmsController : ControllerBase
     [HttpPost("Players/{mac}/PowerOn")]
     [ProducesResponseType(StatusCodes.Status200OK)]
     [ProducesResponseType(StatusCodes.Status400BadRequest)]
+    [ProducesResponseType(StatusCodes.Status403Forbidden)]
     public async Task<ActionResult> PowerOn(string mac)
     {
+        if (!HasRemoteControlAccess())
+        {
+            return Forbid();
+        }
+
         var success = await _lmsClient.PowerOnAsync(mac).ConfigureAwait(false);
         return success ? Ok() : BadRequest("Failed to power on player");
     }
@@ -112,8 +173,14 @@ public class JellyLmsController : ControllerBase
     [HttpPost("Players/{mac}/PowerOff")]
     [ProducesResponseType(StatusCodes.Status200OK)]
     [ProducesResponseType(StatusCodes.Status400BadRequest)]
+    [ProducesResponseType(StatusCodes.Status403Forbidden)]
     public async Task<ActionResult> PowerOff(string mac)
     {
+        if (!HasRemoteControlAccess())
+        {
+            return Forbid();
+        }
+
         var success = await _lmsClient.PowerOffAsync(mac).ConfigureAwait(false);
         return success ? Ok() : BadRequest("Failed to power off player");
     }
@@ -127,8 +194,14 @@ public class JellyLmsController : ControllerBase
     [HttpPost("Players/{mac}/Volume")]
     [ProducesResponseType(StatusCodes.Status200OK)]
     [ProducesResponseType(StatusCodes.Status400BadRequest)]
+    [ProducesResponseType(StatusCodes.Status403Forbidden)]
     public async Task<ActionResult> SetVolume(string mac, [FromBody] VolumeRequest request)
     {
+        if (!HasRemoteControlAccess())
+        {
+            return Forbid();
+        }
+
         var success = await _lmsClient.SetVolumeAsync(mac, request.Volume).ConfigureAwait(false);
         return success ? Ok() : BadRequest("Failed to set volume");
     }
@@ -139,8 +212,14 @@ public class JellyLmsController : ControllerBase
     /// <returns>List of sync groups.</returns>
     [HttpGet("SyncGroups")]
     [ProducesResponseType(StatusCodes.Status200OK)]
+    [ProducesResponseType(StatusCodes.Status403Forbidden)]
     public async Task<ActionResult<List<SyncGroup>>> GetSyncGroups()
     {
+        if (!HasRemoteControlAccess())
+        {
+            return Forbid();
+        }
+
         var groups = await _playerManager.GetSyncGroupsAsync().ConfigureAwait(false);
         return Ok(groups);
     }
@@ -153,8 +232,14 @@ public class JellyLmsController : ControllerBase
     [HttpPost("SyncGroups")]
     [ProducesResponseType(StatusCodes.Status200OK)]
     [ProducesResponseType(StatusCodes.Status400BadRequest)]
+    [ProducesResponseType(StatusCodes.Status403Forbidden)]
     public async Task<ActionResult> CreateSyncGroup([FromBody] CreateSyncGroupRequest request)
     {
+        if (!HasRemoteControlAccess())
+        {
+            return Forbid();
+        }
+
         var success = await _playerManager.CreateSyncGroupAsync(request.MasterMac, request.SlaveMacs)
             .ConfigureAwait(false);
         return success ? Ok() : BadRequest("Failed to create sync group");
@@ -168,8 +253,14 @@ public class JellyLmsController : ControllerBase
     [HttpDelete("SyncGroups/Players/{mac}")]
     [ProducesResponseType(StatusCodes.Status200OK)]
     [ProducesResponseType(StatusCodes.Status400BadRequest)]
+    [ProducesResponseType(StatusCodes.Status403Forbidden)]
     public async Task<ActionResult> UnsyncPlayer(string mac)
     {
+        if (!HasRemoteControlAccess())
+        {
+            return Forbid();
+        }
+
         var success = await _playerManager.UnsyncPlayerAsync(mac).ConfigureAwait(false);
         return success ? Ok() : BadRequest("Failed to unsync player");
     }
@@ -182,12 +273,67 @@ public class JellyLmsController : ControllerBase
     [HttpDelete("SyncGroups/{masterMac}")]
     [ProducesResponseType(StatusCodes.Status200OK)]
     [ProducesResponseType(StatusCodes.Status400BadRequest)]
+    [ProducesResponseType(StatusCodes.Status403Forbidden)]
     public async Task<ActionResult> DissolveSyncGroup(string masterMac)
     {
+        if (!HasRemoteControlAccess())
+        {
+            return Forbid();
+        }
+
         var success = await _playerManager.DissolveSyncGroupAsync(masterMac).ConfigureAwait(false);
         return success ? Ok() : BadRequest("Failed to dissolve sync group");
     }
 
+    /// <summary>
+    /// Checks whether the current user is allowed to use the multi-room remote control.
+    /// Used by the remote control page and the injected web client button to decide
+    /// whether to show themselves.
+    /// </summary>
+    /// <returns>200 OK if allowed, otherwise 403 Forbidden.</returns>
+    [HttpGet("RemoteControl/Access")]
+    [ProducesResponseType(StatusCodes.Status200OK)]
+    [ProducesResponseType(StatusCodes.Status403Forbidden)]
+    public ActionResult CheckRemoteControlAccess()
+    {
+        return HasRemoteControlAccess() ? Ok() : Forbid();
+    }
+
+    /// <summary>
+    /// Serves the standalone multi-room remote control page. The page itself contains
+    /// no sensitive data; it authenticates API calls using the Jellyfin access token
+    /// stored by the web client, so it is reachable without a prior Jellyfin auth header.
+    /// </summary>
+    /// <returns>The remote control HTML page.</returns>
+    [HttpGet("RemoteControl")]
+    [AllowAnonymous]
+    [ProducesResponseType(StatusCodes.Status200OK)]
+    public ActionResult GetRemoteControlPage()
+    {
+        return ServeEmbeddedResource("Jellyfin.Plugin.JellyLMS.Web.RemoteControl.html", "text/html");
+    }
+
+    /// <summary>
+    /// Serves the client script that is injected into the Jellyfin web client to add a
+    /// floating button linking to the remote control page.
+    /// </summary>
+    /// <returns>The client script.</returns>
+    [HttpGet("RemoteControl/ClientScript")]
+    [AllowAnonymous]
+    [ProducesResponseType(StatusCodes.Status200OK)]
+    public ActionResult GetRemoteControlClientScript()
+    {
+        return ServeEmbeddedResource("Jellyfin.Plugin.JellyLMS.Web.remote-button.js", "application/javascript");
+    }
+
+    private FileStreamResult ServeEmbeddedResource(string resourceName, string contentType)
+    {
+        var stream = Assembly.GetExecutingAssembly().GetManifestResourceStream(resourceName)
+            ?? throw new InvalidOperationException($"Embedded resource '{resourceName}' not found.");
+
+        return File(stream, contentType);
+    }
+
     /// <summary>
     /// Discovers file paths used by Jellyfin's music libraries.
     /// Helps users configure path mappings for direct file access.

Jellyfin.Plugin.JellyLMS/Configuration/PluginConfiguration.cs

@@ -36,6 +36,7 @@ public class PluginConfiguration : BasePluginConfiguration
         ConnectionTimeoutSeconds = 10;
         EnableAutoSync = true;
         DefaultPlayerMac = string.Empty;
+        EnableHomeScreenButton = true;
     }
 
     /// <summary>
@@ -75,6 +76,12 @@ public class PluginConfiguration : BasePluginConfiguration
     /// </summary>
     public string DefaultPlayerMac { get; set; }
 
+    /// <summary>
+    /// Gets or sets a value indicating whether a floating "Remote" button linking to the
+    /// multi-room remote control page should be injected into the Jellyfin web client.
+    /// </summary>
+    public bool EnableHomeScreenButton { get; set; }
+
     /// <summary>
     /// Gets or sets the Jellyfin API key for authenticating stream requests from LMS.
     /// </summary>

Jellyfin.Plugin.JellyLMS/Configuration/configPage.html

@@ -182,6 +182,19 @@
                         </div>
                     </div>
 
+                    <div class="verticalSection">
+                        <h3>Multi-Room Remote</h3>
+                        <p class="fieldDescription">A standalone remote control page is available at <code>/JellyLms/RemoteControl</code> for any user granted the "Allow remote control of other users" permission (Dashboard &gt; Users).</p>
+
+                        <div class="checkboxContainer checkboxContainer-withDescription">
+                            <label class="emby-checkbox-label">
+                                <input id="EnableHomeScreenButton" name="EnableHomeScreenButton" type="checkbox" is="emby-checkbox" />
+                                <span>Show floating Remote button in web client</span>
+                            </label>
+                            <div class="fieldDescription checkboxFieldDescription">Adds a floating button to the Jellyfin web client that links to the remote control page (for authorized users only). Requires write access to the Jellyfin web root and a page reload to take effect.</div>
+                        </div>
+                    </div>
+
                     <div class="verticalSection">
                         <h3>Player Sync</h3>
                         <p class="fieldDescription">Select players to sync together for multi-room audio. Synced players play in perfect sync.</p>
@@ -567,6 +580,7 @@
                         document.querySelector('#EnableAutoSync').checked = config.EnableAutoSync !== false;
                         document.querySelector('#DefaultPlayerMac').value = config.DefaultPlayerMac || '';
                         document.querySelector('#UseDirectFilePath').checked = config.UseDirectFilePath || false;
+                        document.querySelector('#EnableHomeScreenButton').checked = config.EnableHomeScreenButton !== false;
 
                         // Load path mappings (new list format, with fallback to legacy single mapping)
                         JellyLmsConfig.pathMappings = config.PathMappings || [];
@@ -622,6 +636,7 @@
                         config.EnableAutoSync = document.querySelector('#EnableAutoSync').checked;
                         config.DefaultPlayerMac = document.querySelector('#DefaultPlayerMac').value;
                         config.UseDirectFilePath = document.querySelector('#UseDirectFilePath').checked;
+                        config.EnableHomeScreenButton = document.querySelector('#EnableHomeScreenButton').checked;
                         // Save path mappings (clear legacy single mapping when using list)
                         config.PathMappings = getPathMappingsFromUI();
                         config.JellyfinMediaPath = '';

Jellyfin.Plugin.JellyLMS/Jellyfin.Plugin.JellyLMS.csproj

@@ -1,7 +1,13 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
+  <!--
+    Multi-targeted against the two supported Jellyfin server generations:
+      net9.0  -> Jellyfin 10.11.x (targetAbi 10.11.0.0)
+      net10.0 -> Jellyfin 12.0.x  (targetAbi 12.0.0.0)
+    jprm builds one framework at a time (see build.yaml / build.jf12.yaml).
+  -->
   <PropertyGroup>
-    <TargetFramework>net9.0</TargetFramework>
+    <TargetFrameworks>net9.0;net10.0</TargetFrameworks>
     <RootNamespace>Jellyfin.Plugin.JellyLMS</RootNamespace>
     <GenerateDocumentationFile>true</GenerateDocumentationFile>
     <TreatWarningsAsErrors>true</TreatWarningsAsErrors>
@@ -10,7 +16,7 @@
     <CodeAnalysisRuleSet>../jellyfin.ruleset</CodeAnalysisRuleSet>
   </PropertyGroup>
 
-  <ItemGroup>
+  <ItemGroup Condition="'$(TargetFramework)' == 'net9.0'">
     <PackageReference Include="Jellyfin.Controller" Version="10.11.0">
       <ExcludeAssets>runtime</ExcludeAssets>
     </PackageReference>
@@ -19,6 +25,15 @@
     </PackageReference>
   </ItemGroup>
 
+  <ItemGroup Condition="'$(TargetFramework)' == 'net10.0'">
+    <PackageReference Include="Jellyfin.Controller" Version="12.0.0">
+      <ExcludeAssets>runtime</ExcludeAssets>
+    </PackageReference>
+    <PackageReference Include="Jellyfin.Model" Version="12.0.0">
+      <ExcludeAssets>runtime</ExcludeAssets>
+    </PackageReference>
+  </ItemGroup>
+
   <ItemGroup>
     <PackageReference Include="SerilogAnalyzer" Version="0.15.0" PrivateAssets="All" />
     <PackageReference Include="StyleCop.Analyzers" Version="1.2.0-beta.556" PrivateAssets="All" />
@@ -28,6 +43,10 @@
   <ItemGroup>
     <None Remove="Configuration\configPage.html" />
     <EmbeddedResource Include="Configuration\configPage.html" />
+    <None Remove="Web\RemoteControl.html" />
+    <EmbeddedResource Include="Web\RemoteControl.html" />
+    <None Remove="Web\remote-button.js" />
+    <EmbeddedResource Include="Web\remote-button.js" />
   </ItemGroup>
 
 </Project>

Jellyfin.Plugin.JellyLMS/Plugin.cs

@@ -2,10 +2,12 @@ using System;
 using System.Collections.Generic;
 using System.Globalization;
 using Jellyfin.Plugin.JellyLMS.Configuration;
+using Jellyfin.Plugin.JellyLMS.Services;
 using MediaBrowser.Common.Configuration;
 using MediaBrowser.Common.Plugins;
 using MediaBrowser.Model.Plugins;
 using MediaBrowser.Model.Serialization;
+using Microsoft.Extensions.Logging;
 
 namespace Jellyfin.Plugin.JellyLMS;
 
@@ -15,15 +17,22 @@ namespace Jellyfin.Plugin.JellyLMS;
 /// </summary>
 public class Plugin : BasePlugin<PluginConfiguration>, IHasWebPages
 {
+    private readonly ILogger<Plugin> _logger;
+
     /// <summary>
     /// Initializes a new instance of the <see cref="Plugin"/> class.
     /// </summary>
     /// <param name="applicationPaths">Instance of the <see cref="IApplicationPaths"/> interface.</param>
     /// <param name="xmlSerializer">Instance of the <see cref="IXmlSerializer"/> interface.</param>
-    public Plugin(IApplicationPaths applicationPaths, IXmlSerializer xmlSerializer)
+    /// <param name="logger">The logger.</param>
+    public Plugin(IApplicationPaths applicationPaths, IXmlSerializer xmlSerializer, ILogger<Plugin> logger)
         : base(applicationPaths, xmlSerializer)
     {
         Instance = this;
+        _logger = logger;
+
+        WebClientPatchService.Apply(ApplicationPaths, Configuration.EnableHomeScreenButton, _logger);
+        ConfigurationChanged += (_, _) => WebClientPatchService.Apply(ApplicationPaths, Configuration.EnableHomeScreenButton, _logger);
     }
 
     /// <inheritdoc />

Jellyfin.Plugin.JellyLMS/Services/LmsDeviceDiscoveryService.cs

@@ -211,7 +211,13 @@ public class LmsDeviceDiscoveryService : IHostedService, IDisposable
             SupportsPersistentIdentifier = true
         };
 
+#if NET10_0_OR_GREATER
+        // Jellyfin 12 added a controlling session parameter; an empty value skips the
+        // "can control" assertion, which is what we want for a server-side registration.
+        sessionManager.ReportCapabilities(string.Empty, session.Id, capabilities);
+#else
         sessionManager.ReportCapabilities(session.Id, capabilities);
+#endif
 
         // Track this device
         _registeredDeviceIds[player.MacAddress] = deviceId;

Jellyfin.Plugin.JellyLMS/Services/LmsSessionController.cs

@@ -59,6 +59,9 @@ public class LmsSessionController : ISessionController, IDisposable
         _libraryManager = libraryManager;
         _stateMachine = new PlaybackStateMachine(logger);
         _statusPoller = new LmsStatusPoller(lmsClient, logger);
+
+        // Start status polling immediately to keep volume in sync
+        StartProgressTimer();
     }
 
     private static PluginConfiguration Config => Plugin.Instance?.Configuration ?? new PluginConfiguration();
@@ -295,7 +298,7 @@ public class LmsSessionController : ISessionController, IDisposable
         // Stop any existing timer
         _progressTimer?.Dispose();
 
-        // Report progress every 2 seconds
+        // Poll status every 2 seconds (for progress reporting when playing and volume sync always)
         _progressTimer = new Timer(
             async _ => await ReportPlaybackProgressAsync().ConfigureAwait(false),
             null,
@@ -305,13 +308,26 @@ public class LmsSessionController : ISessionController, IDisposable
 
     private void StopProgressTimer()
     {
-        _progressTimer?.Dispose();
+        // Don't actually stop the timer - keep polling for volume updates
-        _progressTimer = null;
+        // This ensures Jellyfin stays in sync with the device volume
+        // even when not playing media
     }
 
     private async Task ReportPlaybackProgressAsync()
     {
-        // Don't report during Loading, Seeking, or Error states
+        try
+        {
+            // Always poll status to keep volume in sync, even when not playing
+            var status = await _lmsClient.GetPlayerStatusAsync(_player.MacAddress).ConfigureAwait(false);
+            if (status == null)
+            {
+                return;
+            }
+
+            // Update cached volume so Jellyfin stays in sync with device
+            _player.Volume = status.Volume;
+
+            // Don't report playback progress during Loading, Seeking, Error, Stopped, or Idle states
             var currentState = _stateMachine.CurrentState;
             if (currentState == PlaybackState.Loading
                 || currentState == PlaybackState.Seeking
@@ -323,14 +339,6 @@ public class LmsSessionController : ISessionController, IDisposable
                 return;
             }
 
-        try
-        {
-            var status = await _lmsClient.GetPlayerStatusAsync(_player.MacAddress).ConfigureAwait(false);
-            if (status == null)
-            {
-                return;
-            }
-
             // LMS reports time relative to the current stream, but after seeking
             // we're playing a transcoded stream that starts at the seek position.
             // Add the seek offset to get the actual track position.
@@ -812,7 +820,9 @@ public class LmsSessionController : ISessionController, IDisposable
             _cancellationTokenSource.Cancel();
             _cancellationTokenSource.Dispose();
 
-            StopProgressTimer();
+            // Actually stop the timer when disposing
+            _progressTimer?.Dispose();
+            _progressTimer = null;
 
             // Reset state machine
             _stateMachine.Reset();

Jellyfin.Plugin.JellyLMS/Services/WebClientPatchService.cs

@@ -0,0 +1,72 @@
+using System;
+using System.IO;
+using MediaBrowser.Common.Configuration;
+using Microsoft.Extensions.Logging;
+
+namespace Jellyfin.Plugin.JellyLMS.Services;
+
+/// <summary>
+/// Injects (or removes) a script tag in the web client's <c>index.html</c>
+/// that adds a floating button linking to the JellyLMS remote control page.
+/// This follows the pattern used by other Jellyfin plugins (e.g. Intro Skipper)
+/// since there is no official plugin hook for adding buttons to the web client.
+/// </summary>
+public static class WebClientPatchService
+{
+    private const string Marker = "<!-- jellylms-remote-button -->";
+    private const string ScriptTag = "<script defer src=\"/JellyLms/RemoteControl/ClientScript\"></script>";
+    private const string Injected = ScriptTag + Marker + "\n</body>";
+
+    /// <summary>
+    /// Ensures the web client's index.html either has or does not have the
+    /// JellyLMS remote button script injected, matching <paramref name="enableButton"/>.
+    /// </summary>
+    /// <param name="applicationPaths">The Jellyfin application paths.</param>
+    /// <param name="enableButton">Whether the remote button script should be present.</param>
+    /// <param name="logger">The logger.</param>
+    public static void Apply(IApplicationPaths applicationPaths, bool enableButton, ILogger logger)
+    {
+        var indexPath = Path.Combine(applicationPaths.WebPath, "index.html");
+
+        try
+        {
+            if (!File.Exists(indexPath))
+            {
+                logger.LogDebug("JellyLMS: web client index.html not found at {Path}", indexPath);
+                return;
+            }
+
+            var html = File.ReadAllText(indexPath);
+            var hasMarker = html.Contains(Marker, StringComparison.Ordinal);
+
+            if (enableButton && !hasMarker)
+            {
+                var patched = ReplaceLast(html, "</body>", Injected);
+                File.WriteAllText(indexPath, patched);
+                logger.LogInformation("JellyLMS: injected remote control button into {Path}", indexPath);
+            }
+            else if (!enableButton && hasMarker)
+            {
+                var patched = html.Replace(ScriptTag + Marker + "\n", string.Empty, StringComparison.Ordinal)
+                    .Replace(ScriptTag + Marker, string.Empty, StringComparison.Ordinal);
+                File.WriteAllText(indexPath, patched);
+                logger.LogInformation("JellyLMS: removed remote control button from {Path}", indexPath);
+            }
+        }
+        catch (Exception ex) when (ex is IOException or UnauthorizedAccessException)
+        {
+            logger.LogWarning(ex, "JellyLMS: failed to patch web client index.html at {Path}", indexPath);
+        }
+    }
+
+    private static string ReplaceLast(string source, string find, string replace)
+    {
+        var index = source.LastIndexOf(find, StringComparison.Ordinal);
+        if (index < 0)
+        {
+            return source;
+        }
+
+        return source[..index] + replace + source[(index + find.Length)..];
+    }
+}

Jellyfin.Plugin.JellyLMS/Web/RemoteControl.html

@@ -0,0 +1,393 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="utf-8">
+    <meta name="viewport" content="width=device-width, initial-scale=1, maximum-scale=1, user-scalable=no">
+    <title>JellyLMS Remote</title>
+    <style>
+        :root {
+            color-scheme: dark;
+        }
+        * { box-sizing: border-box; }
+        body {
+            margin: 0;
+            font-family: -apple-system, "Helvetica Neue", Helvetica, Arial, sans-serif;
+            background: #101010;
+            color: #fff;
+            padding: 16px;
+            padding-bottom: 60px;
+        }
+        h1 {
+            font-size: 1.4em;
+            font-weight: 500;
+            margin: 8px 0 16px;
+        }
+        h2 {
+            font-size: 1.05em;
+            font-weight: 500;
+            color: #ccc;
+            margin: 24px 0 8px;
+            text-transform: uppercase;
+            letter-spacing: 0.05em;
+        }
+        .card {
+            background: #1c1c1c;
+            border-radius: 10px;
+            padding: 14px;
+            margin-bottom: 10px;
+        }
+        .player-row {
+            display: flex;
+            align-items: center;
+            gap: 12px;
+        }
+        .player-info {
+            flex: 1;
+            min-width: 0;
+        }
+        .player-name {
+            font-weight: 500;
+            font-size: 1.05em;
+            white-space: nowrap;
+            overflow: hidden;
+            text-overflow: ellipsis;
+        }
+        .player-status {
+            display: flex;
+            align-items: center;
+            gap: 6px;
+            color: #888;
+            font-size: 0.85em;
+            margin-top: 2px;
+        }
+        .status-dot {
+            width: 8px;
+            height: 8px;
+            border-radius: 50%;
+            display: inline-block;
+        }
+        .status-dot.on { background: #52b54b; }
+        .status-dot.standby { background: #f9a825; }
+        .status-dot.off { background: #f44336; }
+        .power-btn {
+            border: none;
+            border-radius: 50%;
+            width: 44px;
+            height: 44px;
+            font-size: 1.2em;
+            background: #2a2a2a;
+            color: #aaa;
+            cursor: pointer;
+            flex-shrink: 0;
+        }
+        .power-btn.on {
+            background: #00a4dc;
+            color: #fff;
+        }
+        .volume-row {
+            display: flex;
+            align-items: center;
+            gap: 10px;
+            margin-top: 10px;
+        }
+        .volume-row input[type="range"] {
+            flex: 1;
+        }
+        .volume-value {
+            width: 2.5em;
+            text-align: right;
+            color: #ccc;
+            font-size: 0.9em;
+        }
+        .sync-group-players {
+            color: #ccc;
+            flex: 1;
+        }
+        .sync-checkbox-row {
+            display: flex;
+            align-items: center;
+            gap: 10px;
+            padding: 6px 0;
+        }
+        button.action {
+            background: #00a4dc;
+            color: #fff;
+            border: none;
+            border-radius: 6px;
+            padding: 8px 14px;
+            font-size: 0.95em;
+            cursor: pointer;
+        }
+        button.action:disabled {
+            background: #333;
+            color: #777;
+            cursor: default;
+        }
+        button.action.alt {
+            background: #333;
+            color: #ccc;
+        }
+        .empty, .message {
+            color: #888;
+            padding: 8px 0;
+        }
+        .message.error { color: #f44336; }
+        .message a { color: #00a4dc; }
+        #refreshBtn {
+            position: fixed;
+            bottom: 16px;
+            right: 16px;
+        }
+    </style>
+</head>
+<body>
+    <h1>🔊 JellyLMS Remote</h1>
+    <div id="app">
+        <p class="message">Loading…</p>
+    </div>
+
+    <script>
+        var API_BASE = '/JellyLms';
+        var state = { players: [], syncGroups: [] };
+
+        function getAuthToken() {
+            try {
+                var creds = JSON.parse(localStorage.getItem('jellyfin_credentials'));
+                var server = creds && creds.Servers && creds.Servers[0];
+                return (server && server.AccessToken) || null;
+            } catch (e) {
+                return null;
+            }
+        }
+
+        function api(path, options) {
+            options = options || {};
+            var headers = options.headers || {};
+            var token = getAuthToken();
+            if (token) {
+                headers['X-Emby-Token'] = token;
+            }
+
+            if (options.body) {
+                headers['Content-Type'] = 'application/json';
+            }
+
+            return fetch(API_BASE + path, {
+                method: options.method || 'GET',
+                headers: headers,
+                body: options.body
+            }).then(function (resp) {
+                if (!resp.ok) {
+                    var err = new Error('Request failed: ' + resp.status);
+                    err.status = resp.status;
+                    throw err;
+                }
+
+                if (resp.status === 204) {
+                    return null;
+                }
+
+                var contentType = resp.headers.get('content-type') || '';
+                return contentType.indexOf('application/json') !== -1 ? resp.json() : null;
+            });
+        }
+
+        function renderMessage(text, isError) {
+            document.getElementById('app').innerHTML =
+                '<p class="message' + (isError ? ' error' : '') + '">' + text + '</p>';
+        }
+
+        function getStatusClass(player) {
+            if (!player.IsConnected) return 'off';
+            return player.IsPoweredOn ? 'on' : 'standby';
+        }
+
+        function getStatusText(player) {
+            if (!player.IsConnected) return 'Disconnected';
+            return player.IsPoweredOn ? 'Playing' : 'Standby';
+        }
+
+        function syncedMacs() {
+            var macs = new Set();
+            state.syncGroups.forEach(function (group) {
+                macs.add(group.MasterMac);
+                group.SlaveMacs.forEach(function (mac) { macs.add(mac); });
+            });
+            return macs;
+        }
+
+        function findPlayer(mac) {
+            return state.players.find(function (p) { return p.MacAddress === mac; });
+        }
+
+        function render() {
+            var app = document.getElementById('app');
+            var html = '';
+
+            html += '<h2>Players</h2>';
+            if (state.players.length === 0) {
+                html += '<p class="empty">No players found.</p>';
+            } else {
+                state.players.forEach(function (player) {
+                    var mac = player.MacAddress;
+                    html += '<div class="card">';
+                    html += '<div class="player-row">';
+                    html += '<div class="player-info">';
+                    html += '<div class="player-name">' + player.Name + '</div>';
+                    html += '<div class="player-status"><span class="status-dot ' + getStatusClass(player) + '"></span>' +
+                        '<span>' + getStatusText(player) + '</span></div>';
+                    html += '</div>';
+                    html += '<button class="power-btn' + (player.IsPoweredOn ? ' on' : '') + '" data-action="power" data-mac="' + mac + '" data-on="' + player.IsPoweredOn + '" title="Power">⏻</button>';
+                    html += '</div>';
+                    html += '<div class="volume-row">';
+                    html += '<span>🔈</span>';
+                    html += '<input type="range" min="0" max="100" value="' + player.Volume + '" data-action="volume" data-mac="' + mac + '">';
+                    html += '<span class="volume-value">' + player.Volume + '</span>';
+                    html += '</div>';
+                    html += '</div>';
+                });
+            }
+
+            html += '<h2>Multi-Room Sync</h2>';
+            if (state.syncGroups.length > 0) {
+                state.syncGroups.forEach(function (group) {
+                    var names = [];
+                    var master = findPlayer(group.MasterMac);
+                    if (master) names.push(master.Name);
+                    group.SlaveMacs.forEach(function (mac) {
+                        var p = findPlayer(mac);
+                        if (p) names.push(p.Name);
+                    });
+
+                    html += '<div class="card">';
+                    html += '<div class="player-row">';
+                    html += '<span class="sync-group-players">' + names.join(' + ') + '</span>';
+                    html += '<button class="action alt" data-action="unsync" data-master="' + group.MasterMac + '">Unsync</button>';
+                    html += '</div>';
+                    html += '</div>';
+                });
+            }
+
+            var unsynced = state.players.filter(function (p) { return !syncedMacs().has(p.MacAddress); });
+            if (unsynced.length > 1) {
+                html += '<div class="card">';
+                html += '<p class="empty" style="margin-top:0;">Select players to sync together:</p>';
+                unsynced.forEach(function (player) {
+                    html += '<label class="sync-checkbox-row">';
+                    html += '<input type="checkbox" data-action="sync-select" data-mac="' + player.MacAddress + '">';
+                    html += '<span>' + player.Name + '</span>';
+                    html += '</label>';
+                });
+                html += '<div style="margin-top:10px;">';
+                html += '<button class="action" id="syncSelectedBtn" disabled>Sync Selected</button>';
+                html += '</div>';
+                html += '</div>';
+            } else if (state.syncGroups.length === 0) {
+                html += '<p class="empty">No players synced yet.</p>';
+            }
+
+            app.innerHTML = html;
+            attachHandlers();
+        }
+
+        function attachHandlers() {
+            document.querySelectorAll('[data-action="power"]').forEach(function (btn) {
+                btn.addEventListener('click', function () {
+                    var mac = btn.getAttribute('data-mac');
+                    var isOn = btn.getAttribute('data-on') === 'true';
+                    var endpoint = isOn ? '/Players/' + encodeURIComponent(mac) + '/PowerOff' : '/Players/' + encodeURIComponent(mac) + '/PowerOn';
+                    btn.disabled = true;
+                    api(endpoint, { method: 'POST' }).then(loadPlayers).catch(function () {
+                        btn.disabled = false;
+                    });
+                });
+            });
+
+            document.querySelectorAll('[data-action="volume"]').forEach(function (input) {
+                input.addEventListener('change', function () {
+                    var mac = input.getAttribute('data-mac');
+                    var volume = parseInt(input.value, 10);
+                    input.nextElementSibling.textContent = volume;
+                    api('/Players/' + encodeURIComponent(mac) + '/Volume', {
+                        method: 'POST',
+                        body: JSON.stringify({ Volume: volume })
+                    }).catch(function () {});
+                });
+                input.addEventListener('input', function () {
+                    input.nextElementSibling.textContent = input.value;
+                });
+            });
+
+            document.querySelectorAll('[data-action="unsync"]').forEach(function (btn) {
+                btn.addEventListener('click', function () {
+                    var masterMac = btn.getAttribute('data-master');
+                    btn.disabled = true;
+                    api('/SyncGroups/' + encodeURIComponent(masterMac), { method: 'DELETE' })
+                        .then(loadAll)
+                        .catch(function () { btn.disabled = false; });
+                });
+            });
+
+            var syncBtn = document.getElementById('syncSelectedBtn');
+            if (syncBtn) {
+                var checkboxes = document.querySelectorAll('[data-action="sync-select"]');
+                var updateSyncBtn = function () {
+                    var checked = Array.from(checkboxes).filter(function (cb) { return cb.checked; });
+                    syncBtn.disabled = checked.length < 2;
+                };
+                checkboxes.forEach(function (cb) { cb.addEventListener('change', updateSyncBtn); });
+
+                syncBtn.addEventListener('click', function () {
+                    var macs = Array.from(checkboxes).filter(function (cb) { return cb.checked; })
+                        .map(function (cb) { return cb.getAttribute('data-mac'); });
+                    if (macs.length < 2) return;
+
+                    syncBtn.disabled = true;
+                    api('/SyncGroups', {
+                        method: 'POST',
+                        body: JSON.stringify({ MasterMac: macs[0], SlaveMacs: macs.slice(1) })
+                    }).then(loadAll).catch(function () { syncBtn.disabled = false; });
+                });
+            }
+        }
+
+        function loadPlayers() {
+            return api('/Players?refresh=true').then(function (players) {
+                state.players = players || [];
+                render();
+            });
+        }
+
+        function loadSyncGroups() {
+            return api('/SyncGroups').then(function (groups) {
+                state.syncGroups = groups || [];
+            });
+        }
+
+        function loadAll() {
+            return Promise.all([loadPlayers(), loadSyncGroups()]).then(render);
+        }
+
+        function init() {
+            if (!getAuthToken()) {
+                renderMessage('Please <a href="/web/">log in to Jellyfin</a> first, then reload this page.', true);
+                return;
+            }
+
+            api('/RemoteControl/Access').then(function () {
+                loadAll().catch(function () {
+                    renderMessage('Failed to load players. Check the JellyLMS plugin configuration.', true);
+                });
+            }).catch(function (err) {
+                if (err.status === 403) {
+                    renderMessage('Your account does not have permission to use the multi-room remote. Ask an admin to grant "Allow remote control of other users".', true);
+                } else {
+                    renderMessage('Could not reach JellyLMS. <a href="/web/">Return to Jellyfin</a>.', true);
+                }
+            });
+        }
+
+        init();
+    </script>
+</body>
+</html>

Jellyfin.Plugin.JellyLMS/Web/remote-button.js

@@ -0,0 +1,309 @@
+(function () {
+    var hasAccess = false;
+    var panel = null;
+
+    function getAuthToken() {
+        try {
+            var creds = JSON.parse(localStorage.getItem('jellyfin_credentials'));
+            var server = creds && creds.Servers && creds.Servers[0];
+            return (server && server.AccessToken) || null;
+        } catch (e) {
+            return null;
+        }
+    }
+
+    function api(path, options) {
+        var token = getAuthToken();
+        var opts = Object.assign({ headers: {} }, options);
+        if (token) {
+            opts.headers['X-Emby-Token'] = token;
+        }
+
+        if (opts.body && typeof opts.body === 'object') {
+            opts.body = JSON.stringify(opts.body);
+            opts.headers['Content-Type'] = 'application/json';
+        }
+
+        return fetch('/JellyLms' + path, opts);
+    }
+
+    function checkAccess() {
+        return api('/RemoteControl/Access')
+            .then(function (r) { return r.ok; })
+            .catch(function () { return false; });
+    }
+
+    // ---------- panel ----------
+
+    function createPanel(anchorBtn) {
+        var rect = anchorBtn.getBoundingClientRect();
+        var p = document.createElement('div');
+        p.id = 'jellylms-panel';
+        p.style.cssText = [
+            'position:fixed',
+            'top:' + (rect.bottom + 4) + 'px',
+            'right:' + (window.innerWidth - rect.right) + 'px',
+            'width:300px',
+            'max-height:70vh',
+            'overflow-y:auto',
+            'background:#1c1c1c',
+            'border:1px solid #333',
+            'border-radius:4px',
+            'box-shadow:0 4px 24px rgba(0,0,0,.7)',
+            'z-index:999999',
+            'font-family:inherit',
+            'font-size:14px',
+            'color:#ddd',
+            'padding:12px',
+        ].join(';');
+        return p;
+    }
+
+    function el(tag, css, html) {
+        var e = document.createElement(tag);
+        if (css) { e.style.cssText = css; }
+        if (html != null) { e.innerHTML = html; }
+        return e;
+    }
+
+    function renderError(p, msg) {
+        p.innerHTML = '<div style="color:#f44;padding:8px">' + msg + '</div>';
+    }
+
+    function renderPlayers(p, players) {
+        p.innerHTML = '';
+
+        // ---- Players ----
+        p.appendChild(el('div',
+            'font-size:11px;text-transform:uppercase;letter-spacing:.08em;color:#888;margin-bottom:8px',
+            'Players'));
+
+        players.forEach(function (player) {
+            // name row: status dot + name + power button
+            var row = el('div', 'display:flex;align-items:center;gap:8px;margin-bottom:6px');
+
+            row.appendChild(el('span',
+                'width:8px;height:8px;border-radius:50%;flex-shrink:0;background:' +
+                (player.isConnected ? '#4caf50' : '#555')));
+
+            var label = player.name || player.macAddress;
+            row.appendChild(el('span',
+                'flex:1;overflow:hidden;text-overflow:ellipsis;white-space:nowrap',
+                label));
+
+            var pwrBtn = el('button',
+                'background:none;border:1px solid #555;border-radius:3px;color:#ddd;' +
+                'padding:2px 7px;cursor:pointer;font-size:12px;flex-shrink:0',
+                player.isPoweredOn ? 'Off' : 'On');
+            pwrBtn.title = player.isPoweredOn ? 'Power off' : 'Power on';
+            pwrBtn.addEventListener('click', function () {
+                var endpoint = player.isPoweredOn
+                    ? '/Players/' + player.macAddress + '/PowerOff'
+                    : '/Players/' + player.macAddress + '/PowerOn';
+                api(endpoint, { method: 'POST' }).then(function () { refresh(p); });
+            });
+            row.appendChild(pwrBtn);
+            p.appendChild(row);
+
+            // volume row — show when powered on
+            if (player.isPoweredOn) {
+                var volRow = el('div',
+                    'display:flex;align-items:center;gap:8px;margin-bottom:8px;padding-left:16px');
+
+                volRow.appendChild(el('span',
+                    'color:#888;font-size:16px;font-family:"Material Icons";line-height:1',
+                    'volume_up'));
+
+                var slider = document.createElement('input');
+                slider.type = 'range';
+                slider.min = 0;
+                slider.max = 100;
+                slider.value = player.volume;
+                slider.style.cssText = 'flex:1;accent-color:#00a4dc';
+                slider.addEventListener('change', function () {
+                    api('/Players/' + player.macAddress + '/Volume', {
+                        method: 'POST',
+                        body: { volume: parseInt(slider.value, 10) }
+                    });
+                });
+                volRow.appendChild(slider);
+
+                var volVal = el('span', 'color:#888;font-size:12px;width:28px;text-align:right',
+                    player.volume + '%');
+                slider.addEventListener('input', function () { volVal.textContent = slider.value + '%'; });
+                volRow.appendChild(volVal);
+
+                p.appendChild(volRow);
+            }
+        });
+
+        // ---- Sync Groups ----
+        var synced = {};
+        players.forEach(function (pl) {
+            if (pl.syncMaster) { synced[pl.macAddress] = true; }
+            if (pl.syncSlaves && pl.syncSlaves.length) {
+                synced[pl.macAddress] = true;
+                pl.syncSlaves.forEach(function (m) { synced[m] = true; });
+            }
+        });
+
+        var masters = players.filter(function (pl) {
+            return pl.syncSlaves && pl.syncSlaves.length > 0;
+        });
+
+        if (masters.length > 0) {
+            p.appendChild(el('div', 'border-top:1px solid #333;margin:8px 0'));
+            p.appendChild(el('div',
+                'font-size:11px;text-transform:uppercase;letter-spacing:.08em;color:#888;margin-bottom:8px',
+                'Sync Groups'));
+
+            masters.forEach(function (master) {
+                var slaveNames = master.syncSlaves.map(function (mac) {
+                    var found = players.find(function (pl) { return pl.macAddress === mac; });
+                    return found ? (found.name || mac) : mac;
+                });
+                var label = (master.name || master.macAddress) + ' + ' + slaveNames.join(', ');
+
+                var grow = el('div', 'display:flex;align-items:center;gap:8px;margin-bottom:8px');
+                grow.appendChild(el('span',
+                    'flex:1;overflow:hidden;text-overflow:ellipsis;white-space:nowrap;font-size:13px',
+                    label));
+
+                var dissolveBtn = el('button',
+                    'background:none;border:1px solid #555;border-radius:3px;color:#f88;' +
+                    'padding:2px 7px;cursor:pointer;font-size:12px;flex-shrink:0',
+                    'Unsync');
+                dissolveBtn.addEventListener('click', function () {
+                    api('/SyncGroups/' + master.macAddress, { method: 'DELETE' })
+                        .then(function () { refresh(p); });
+                });
+                grow.appendChild(dissolveBtn);
+                p.appendChild(grow);
+            });
+        }
+
+        // ---- Create Sync Group ----
+        var unsynced = players.filter(function (pl) { return !synced[pl.macAddress]; });
+
+        if (unsynced.length >= 2) {
+            p.appendChild(el('div', 'border-top:1px solid #333;margin:8px 0'));
+            p.appendChild(el('div',
+                'font-size:11px;text-transform:uppercase;letter-spacing:.08em;color:#888;margin-bottom:8px',
+                'Create Sync Group'));
+
+            var checkboxes = [];
+            unsynced.forEach(function (pl) {
+                var crow = el('div', 'display:flex;align-items:center;gap:8px;margin-bottom:6px');
+                var cb = document.createElement('input');
+                cb.type = 'checkbox';
+                cb.style.accentColor = '#00a4dc';
+                cb.dataset.mac = pl.macAddress;
+                checkboxes.push(cb);
+                crow.appendChild(cb);
+                crow.appendChild(el('span', 'flex:1', pl.name || pl.macAddress));
+                p.appendChild(crow);
+            });
+
+            var syncBtn = el('button',
+                'margin-top:6px;width:100%;background:#00a4dc;border:none;border-radius:3px;' +
+                'color:#fff;padding:5px 0;cursor:pointer;font-size:13px',
+                'Sync Selected');
+            syncBtn.addEventListener('click', function () {
+                var selected = checkboxes.filter(function (cb) { return cb.checked; });
+                if (selected.length < 2) { return; }
+                var macs = selected.map(function (cb) { return cb.dataset.mac; });
+                api('/SyncGroups', {
+                    method: 'POST',
+                    body: { masterMac: macs[0], slaveMacs: macs.slice(1) }
+                }).then(function () { refresh(p); });
+            });
+            p.appendChild(syncBtn);
+        }
+    }
+
+    function refresh(p) {
+        p.innerHTML = '<div style="color:#888;padding:8px">Loading…</div>';
+        api('/Players')
+            .then(function (r) { return r.json(); })
+            .then(function (players) { renderPlayers(p, players); })
+            .catch(function () { renderError(p, 'Failed to load players.'); });
+    }
+
+    function togglePanel(btn) {
+        if (panel) {
+            panel.remove();
+            panel = null;
+            return;
+        }
+
+        panel = createPanel(btn);
+        document.body.appendChild(panel);
+        refresh(panel);
+    }
+
+    function closePanel() {
+        if (panel) {
+            panel.remove();
+            panel = null;
+        }
+    }
+
+    // ---------- header button ----------
+
+    function addButton(headerRight) {
+        if (headerRight.querySelector('.headerLmsRemoteButton')) {
+            return;
+        }
+
+        var btn = document.createElement('button');
+        btn.setAttribute('is', 'paper-icon-button-light');
+        btn.setAttribute('type', 'button');
+        btn.className = 'headerLmsRemoteButton headerButton headerButtonRight paper-icon-button-light';
+        btn.title = 'Multi-room Remote';
+        btn.innerHTML = '<span class="material-icons speaker_group" aria-hidden="true"></span>';
+        btn.addEventListener('click', function (e) {
+            e.stopPropagation();
+            togglePanel(btn);
+        });
+
+        var castButton = headerRight.querySelector('.headerCastButton');
+        if (castButton) {
+            headerRight.insertBefore(btn, castButton);
+        } else {
+            headerRight.appendChild(btn);
+        }
+    }
+
+    function tryInject() {
+        if (!hasAccess) { return; }
+        var headerRight = document.querySelector('.headerRight');
+        if (headerRight) { addButton(headerRight); }
+    }
+
+    // ---------- bootstrap ----------
+
+    function init() {
+        checkAccess().then(function (ok) {
+            hasAccess = ok;
+            if (!ok) { return; }
+
+            tryInject();
+
+            var observer = new MutationObserver(function () {
+                if (panel && !document.body.contains(panel)) { panel = null; }
+                tryInject();
+            });
+            observer.observe(document.body, { childList: true, subtree: true });
+
+            document.addEventListener('click', function (e) {
+                if (panel && !panel.contains(e.target)) { closePanel(); }
+            });
+        });
+    }
+
+    if (document.readyState === 'loading') {
+        document.addEventListener('DOMContentLoaded', init);
+    } else {
+        init();
+    }
+})();

README.md

@@ -76,10 +76,19 @@ Create and manage synchronized playback groups for multi-room audio:
 
 ## Requirements
 
-- Jellyfin Server 10.10.0 or later
+- Jellyfin Server 10.11.x or 12.0.x
-- .NET 9.0 Runtime
 - Logitech Media Server (LMS) with JSON-RPC API enabled (default on port 9000)
 
+Each release ships two packages, one per Jellyfin generation:
+
+| Package | Jellyfin | targetAbi | Runtime |
+| --- | --- | --- | --- |
+| `jellylms_<version>_jf11.zip` | 10.11.x | `10.11.0.0` | .NET 9.0 |
+| `jellylms_<version>_jf12.zip` | 12.0.x | `12.0.0.0` | .NET 10.0 |
+
+If you install through the plugin repository, Jellyfin picks the matching
+package automatically. For manual installs, download the one for your server.
+
 ## Playback Architecture
 
 JellyLMS uses Jellyfin's native "Play On" (cast) interface to control LMS players. When you select an LMS player from Jellyfin's cast menu, playback is managed through a robust state machine that ensures reliable operation.
@@ -151,13 +160,20 @@ The state machine includes automatic retry with exponential backoff:
 git clone https://gitea.tourolle.paris/dtourolle/jellyLMS.git
 cd jellyLMS
 
-# Build
+# Build both target frameworks
 dotnet build Jellyfin.Plugin.JellyLMS.sln -c Release
 
-# The DLL will be in:
+# The DLLs will be in:
-# Jellyfin.Plugin.JellyLMS/bin/Release/net9.0/
+# Jellyfin.Plugin.JellyLMS/bin/Release/net9.0/   (Jellyfin 10.11.x)
+# Jellyfin.Plugin.JellyLMS/bin/Release/net10.0/  (Jellyfin 12.0.x)
+
+# Or produce installable plugin packages (requires jprm)
+./build-plugin.sh jf11
+./build-plugin.sh jf12
 ```
 
+Building requires the .NET 10 SDK, which can target both `net9.0` and `net10.0`.
+
 ## Configuration
 
 1. Navigate to Jellyfin Dashboard → Plugins → JellyLMS
@@ -293,8 +309,8 @@ Jellyfin.Plugin.JellyLMS/
 ### Building for Development
 
 ```bash
-# Build in debug mode
+# Build in debug mode (use -f net10.0 for a Jellyfin 12 server)
-dotnet build Jellyfin.Plugin.JellyLMS.sln
+dotnet build Jellyfin.Plugin.JellyLMS.sln -f net9.0
 
 # Copy to Jellyfin plugins directory
 cp Jellyfin.Plugin.JellyLMS/bin/Debug/net9.0/Jellyfin.Plugin.JellyLMS.dll \

build-plugin.sh

@@ -0,0 +1,53 @@
+#!/usr/bin/env bash
+#
+# Package the JellyLMS plugin for one Jellyfin server generation.
+#
+#   ./build-plugin.sh jf11 [version]   -> Jellyfin 10.11.x, net9.0
+#   ./build-plugin.sh jf12 [version]   -> Jellyfin 12.0.x,  net10.0
+#
+# jprm always reads ./build.yaml, so this temporarily rewrites the targetAbi and
+# framework fields for the requested variant and restores the file afterwards.
+# The resulting zip is written to artifacts/ with a variant suffix, and its path
+# is printed on stdout.
+set -euo pipefail
+
+VARIANT="${1:-}"
+VERSION="${2:-}"
+
+case "${VARIANT}" in
+    jf11) TARGET_ABI="10.11.0.0"; FRAMEWORK="net9.0" ;;
+    jf12) TARGET_ABI="12.0.0.0";  FRAMEWORK="net10.0" ;;
+    *) echo "usage: $0 <jf11|jf12> [version]" >&2; exit 1 ;;
+esac
+
+cd "$(dirname "$0")"
+
+if [ -z "${VERSION}" ]; then
+    VERSION=$(sed -n 's/^version:[[:space:]]*"\{0,1\}\([^"]*\)"\{0,1\}[[:space:]]*$/\1/p' build.yaml)
+fi
+
+# jprm normalises the version to four components for the artifact name.
+FULL_VERSION="${VERSION}"
+while [ "$(printf '%s' "${FULL_VERSION}" | tr -cd '.' | wc -c)" -lt 3 ]; do
+    FULL_VERSION="${FULL_VERSION}.0"
+done
+
+BACKUP=$(mktemp)
+cp build.yaml "${BACKUP}"
+trap 'cp "${BACKUP}" build.yaml; rm -f "${BACKUP}"' EXIT
+
+sed -i "s/^version:.*/version: \"${VERSION}\"/" build.yaml
+sed -i "s/^targetAbi:.*/targetAbi: \"${TARGET_ABI}\"/" build.yaml
+sed -i "s/^framework:.*/framework: \"${FRAMEWORK}\"/" build.yaml
+
+echo "Building ${VARIANT}: targetAbi=${TARGET_ABI} framework=${FRAMEWORK} version=${VERSION}" >&2
+
+mkdir -p "artifacts/${VARIANT}"
+jprm --verbosity=debug plugin build ./ --output "artifacts/${VARIANT}" >&2
+
+SRC="artifacts/${VARIANT}/jellylms_${FULL_VERSION}.zip"
+DEST="artifacts/jellylms_${FULL_VERSION}_${VARIANT}.zip"
+mv "${SRC}" "${DEST}"
+rm -rf "artifacts/${VARIANT}"
+
+echo "${DEST}"

jellyfin.ruleset

@@ -100,6 +100,8 @@
         <Rule Id="CA1308" Action="None" />
         <!-- disable warning CA1848: Use the LoggerMessage delegates -->
         <Rule Id="CA1848" Action="None" />
+        <!-- disable warning CA1873: Evaluation of logging argument may be expensive (same rationale as CA1848) -->
+        <Rule Id="CA1873" Action="None" />
         <!-- disable warning CA2101: Specify marshaling for P/Invoke string arguments -->
         <Rule Id="CA2101" Action="None" />
         <!-- disable warning CA2234: Pass System.Uri objects instead of strings -->

manifest.json

@@ -7,6 +7,54 @@
     "owner": "dtourolle",
     "category": "Music",
     "versions": [
+      {
+        "version": "1.0.6",
+        "changelog": "Release 1.0.6",
+        "targetAbi": "10.10.0.0",
+        "sourceUrl": "https://gitea.tourolle.paris/dtourolle/jellyLMS/releases/download/v1.0.6/jellylms_1.0.6.0.zip",
+        "checksum": "026fae22c793a5e71fb322811d964dfd",
+        "timestamp": "2026-06-17T20:24:41Z"
+      },
+      {
+        "version": "1.0.5",
+        "changelog": "Release 1.0.5",
+        "targetAbi": "10.10.0.0",
+        "sourceUrl": "https://gitea.tourolle.paris/dtourolle/jellyLMS/releases/download/v1.0.5/jellylms_1.0.5.0.zip",
+        "checksum": "13ecfe05b1a0f4f137211d9b6660f66e",
+        "timestamp": "2026-06-17T19:20:00Z"
+      },
+      {
+        "version": "1.0.4",
+        "changelog": "Release 1.0.4",
+        "targetAbi": "10.10.0.0",
+        "sourceUrl": "https://gitea.tourolle.paris/dtourolle/jellyLMS/releases/download/v1.0.4/jellylms_1.0.4.0.zip",
+        "checksum": "6db64bf2ad625c735aff5178e0b53894",
+        "timestamp": "2026-06-17T18:44:44Z"
+      },
+      {
+        "version": "1.0.3",
+        "changelog": "Release 1.0.3",
+        "targetAbi": "10.10.0.0",
+        "sourceUrl": "https://gitea.tourolle.paris/dtourolle/jellyLMS/releases/download/v1.0.3/jellylms_1.0.3.0.zip",
+        "checksum": "c6fa1b9f303babb9664e35cca1180985",
+        "timestamp": "2026-06-14T15:48:18Z"
+      },
+      {
+        "version": "1.0.2",
+        "changelog": "Release 1.0.2",
+        "targetAbi": "10.10.0.0",
+        "sourceUrl": "https://gitea.tourolle.paris/dtourolle/jellyLMS/releases/download/v1.0.2/jellylms_1.0.2.0.zip",
+        "checksum": "43e4fcd6dc67be82a1e9d8816cdf00df",
+        "timestamp": "2026-01-25T18:35:06Z"
+      },
+      {
+        "version": "1.0.1",
+        "changelog": "Release 1.0.1",
+        "targetAbi": "10.10.0.0",
+        "sourceUrl": "https://gitea.tourolle.paris/dtourolle/jellyLMS/releases/download/v1.0.1/jellylms_1.0.1.0.zip",
+        "checksum": "093a1821b86a220cdfad49c3d93345a7",
+        "timestamp": "2025-12-30T13:43:10Z"
+      },
       {
         "version": "1.0.0",
         "changelog": "Release 1.0.0",