diff --git a/BililiveRecorder.Web.Schemas/RecorderMutation.cs b/BililiveRecorder.Web.Schemas/RecorderMutation.cs
index 1815cbf..243105e 100644
--- a/BililiveRecorder.Web.Schemas/RecorderMutation.cs
+++ b/BililiveRecorder.Web.Schemas/RecorderMutation.cs
@@ -30,6 +30,15 @@ namespace BililiveRecorder.Web.Schemas
                     var roomid = context.GetArgument<int>("roomId");
                     var enabled = context.GetArgument<bool>("autoRecord");
 
+                    if (roomid <= 0)
+                    {
+                        context.Errors.Add(new ExecutionError("Roomid out of range")
+                        {
+                            Code = "BREC_ROOMID_OUT_OF_RANGE"
+                        });
+                        return null;
+                    }
+
                     var room = this.recorder.Rooms.FirstOrDefault(x => x.RoomConfig.RoomId == roomid || x.ShortId == roomid);
 
                     if (room is not null)
diff --git a/BililiveRecorder.Web.Schemas/RecorderQuery.cs b/BililiveRecorder.Web.Schemas/RecorderQuery.cs
index 1e26d54..f0fb7c8 100644
--- a/BililiveRecorder.Web.Schemas/RecorderQuery.cs
+++ b/BililiveRecorder.Web.Schemas/RecorderQuery.cs
@@ -21,6 +21,8 @@ namespace BililiveRecorder.Web.Schemas
 
         private void SetupFields()
         {
+            this.Field<RecorderVersionType>("version", resolve: context => RecorderVersion.Instance);
+
             this.Field<GlobalConfigType>("config", resolve: context => this.recorder.Config.Global);
 
             this.Field<DefaultConfigType>("defaultConfig", resolve: context => DefaultConfig.Instance);
diff --git a/BililiveRecorder.Web.Schemas/Types/RecorderVersion.cs b/BililiveRecorder.Web.Schemas/Types/RecorderVersion.cs
new file mode 100644
index 0000000..db03a7c
--- /dev/null
+++ b/BililiveRecorder.Web.Schemas/Types/RecorderVersion.cs
@@ -0,0 +1,41 @@
+namespace BililiveRecorder.Web.Schemas.Types
+{
+    public class RecorderVersion
+    {
+        internal static readonly RecorderVersion Instance = new();
+
+        public string Major { get; } = GitVersionInformation.Major;
+        public string Minor { get; } = GitVersionInformation.Minor;
+        public string Patch { get; } = GitVersionInformation.Patch;
+        public string PreReleaseTag { get; } = GitVersionInformation.PreReleaseTag;
+        public string PreReleaseTagWithDash { get; } = GitVersionInformation.PreReleaseTagWithDash;
+        public string PreReleaseLabel { get; } = GitVersionInformation.PreReleaseLabel;
+        public string PreReleaseLabelWithDash { get; } = GitVersionInformation.PreReleaseLabelWithDash;
+        public string PreReleaseNumber { get; } = GitVersionInformation.PreReleaseNumber;
+        public string WeightedPreReleaseNumber { get; } = GitVersionInformation.WeightedPreReleaseNumber;
+        public string BuildMetaData { get; } = GitVersionInformation.BuildMetaData;
+        public string BuildMetaDataPadded { get; } = GitVersionInformation.BuildMetaDataPadded;
+        public string FullBuildMetaData { get; } = GitVersionInformation.FullBuildMetaData;
+        public string MajorMinorPatch { get; } = GitVersionInformation.MajorMinorPatch;
+        public string SemVer { get; } = GitVersionInformation.SemVer;
+        public string LegacySemVer { get; } = GitVersionInformation.LegacySemVer;
+        public string LegacySemVerPadded { get; } = GitVersionInformation.LegacySemVerPadded;
+        public string AssemblySemVer { get; } = GitVersionInformation.AssemblySemVer;
+        public string AssemblySemFileVer { get; } = GitVersionInformation.AssemblySemFileVer;
+        public string FullSemVer { get; } = GitVersionInformation.FullSemVer;
+        public string InformationalVersion { get; } = GitVersionInformation.InformationalVersion;
+        public string BranchName { get; } = GitVersionInformation.BranchName;
+        public string EscapedBranchName { get; } = GitVersionInformation.EscapedBranchName;
+        public string Sha { get; } = GitVersionInformation.Sha;
+        public string ShortSha { get; } = GitVersionInformation.ShortSha;
+        public string NuGetVersionV2 { get; } = GitVersionInformation.NuGetVersionV2;
+        public string NuGetVersion { get; } = GitVersionInformation.NuGetVersion;
+        public string NuGetPreReleaseTagV2 { get; } = GitVersionInformation.NuGetPreReleaseTagV2;
+        public string NuGetPreReleaseTag { get; } = GitVersionInformation.NuGetPreReleaseTag;
+        public string VersionSourceSha { get; } = GitVersionInformation.VersionSourceSha;
+        public string CommitsSinceVersionSource { get; } = GitVersionInformation.CommitsSinceVersionSource;
+        public string CommitsSinceVersionSourcePadded { get; } = GitVersionInformation.CommitsSinceVersionSourcePadded;
+        public string UncommittedChanges { get; } = GitVersionInformation.UncommittedChanges;
+        public string CommitDate { get; } = GitVersionInformation.CommitDate;
+    }
+}
diff --git a/BililiveRecorder.Web.Schemas/Types/RecorderVersionType.cs b/BililiveRecorder.Web.Schemas/Types/RecorderVersionType.cs
new file mode 100644
index 0000000..65cfc14
--- /dev/null
+++ b/BililiveRecorder.Web.Schemas/Types/RecorderVersionType.cs
@@ -0,0 +1,44 @@
+using GraphQL.Types;
+
+namespace BililiveRecorder.Web.Schemas.Types
+{
+    public class RecorderVersionType : ObjectGraphType<RecorderVersion>
+    {
+        public RecorderVersionType()
+        {
+            this.Field(x => x.Major);
+            this.Field(x => x.Minor);
+            this.Field(x => x.Patch);
+            this.Field(x => x.PreReleaseTag);
+            this.Field(x => x.PreReleaseTagWithDash);
+            this.Field(x => x.PreReleaseLabel);
+            this.Field(x => x.PreReleaseLabelWithDash);
+            this.Field(x => x.PreReleaseNumber);
+            this.Field(x => x.WeightedPreReleaseNumber);
+            this.Field(x => x.BuildMetaData);
+            this.Field(x => x.BuildMetaDataPadded);
+            this.Field(x => x.FullBuildMetaData);
+            this.Field(x => x.MajorMinorPatch);
+            this.Field(x => x.SemVer);
+            this.Field(x => x.LegacySemVer);
+            this.Field(x => x.LegacySemVerPadded);
+            this.Field(x => x.AssemblySemVer);
+            this.Field(x => x.AssemblySemFileVer);
+            this.Field(x => x.FullSemVer);
+            this.Field(x => x.InformationalVersion);
+            this.Field(x => x.BranchName);
+            this.Field(x => x.EscapedBranchName);
+            this.Field(x => x.Sha);
+            this.Field(x => x.ShortSha);
+            this.Field(x => x.NuGetVersionV2);
+            this.Field(x => x.NuGetVersion);
+            this.Field(x => x.NuGetPreReleaseTagV2);
+            this.Field(x => x.NuGetPreReleaseTag);
+            this.Field(x => x.VersionSourceSha);
+            this.Field(x => x.CommitsSinceVersionSource);
+            this.Field(x => x.CommitsSinceVersionSourcePadded);
+            this.Field(x => x.UncommittedChanges);
+            this.Field(x => x.CommitDate);
+        }
+    }
+}
diff --git a/BililiveRecorder.Web/ConstStrings.cs b/BililiveRecorder.Web/ConstStrings.cs
new file mode 100644
index 0000000..07972a2
--- /dev/null
+++ b/BililiveRecorder.Web/ConstStrings.cs
@@ -0,0 +1,120 @@
+namespace BililiveRecorder.Web
+{
+    internal static class ConstStrings
+    {
+        internal const string HOME_PAGE_HTML = @"<meta charset=utf-8><meta content=""width=device-width,initial-scale=1""name=viewport><title>录播姬</title><style>a{margin:5px}textarea{width:300px;height:200px}</style><h1>录播姬，以后再写管理界面</h1><p><span style=color:red;font-weight:700>API 界面</span>： <a href=/ui/graphiql>GraphiQL</a> <a href=/ui/playground>Playground</a> <a href=/ui/altair>Altair</a> <a href=/ui/voyager>Voyager</a><p>说明：录播姬 API 里的 objectId 在重启后会重新生成，是不保存到配置文件里的<div><h2>API 用法示例</h2><p>graphql 的<b>语法</b>请查看官方文档 <a href=https://graphql.org/learn/ >https://graphql.org/learn/</a> ，或中文翻译镜像 <a href=https://graphql.cn/learn/ >https://graphql.cn/learn/</a><div><h3>列出所有直播间和基本信息</h3><textarea>
+query {
+  rooms {
+    objectId
+    roomConfig {
+      roomId
+      autoRecord
+    }
+    shortId
+    name
+    streaming
+    title
+    areaNameParent
+    areaNameChild
+  }
+}</textarea></div><div><h3>列出所有直播间的所有信息（截至编写此页面时，具体最新属性见API界面的文档）</h3><textarea>
+query {
+  rooms {
+    objectId
+    shortId
+    recording
+    roomConfig {
+      roomId
+      autoRecord
+      optionalRecordingQuality {
+        value
+        hasValue
+      }
+      optionalRecordMode {
+        value
+        hasValue
+      }
+      optionalRecordDanmakuSuperChat {
+        value
+        hasValue
+      }
+      optionalRecordDanmakuRaw {
+        value
+        hasValue
+      }
+      optionalRecordDanmakuGuard {
+        value
+        hasValue
+      }
+      optionalRecordDanmakuGift {
+        value
+        hasValue
+      }
+      optionalRecordDanmaku {
+        value
+        hasValue
+      }
+      optionalCuttingNumber {
+        value
+        hasValue
+      }
+      optionalCuttingMode {
+        value
+        hasValue
+      }
+    }
+    stats {
+      durationRatio
+      fileMaxTimestamp
+      networkMbps
+      sessionDuration
+      totalInputBytes
+      sessionMaxTimestamp
+      totalOutputBytes
+    }
+    streaming
+    title
+    name
+    danmakuConnected
+    autoRecordForThisSession
+    areaNameParent
+    areaNameChild
+  }
+}  
+</textarea></div><div><h3>添加一个房间</h3><textarea>
+mutation {
+  addRoom(roomId: 3, autoRecord: false) {
+    objectId
+    shortId
+    roomConfig {
+      roomId
+      autoRecord
+    }
+  }
+}
+</textarea></div><div><h3>添加一个房间，用变量传参版</h3><textarea>
+mutation AddRoom($roomid: Int, $autoRecord: Boolean) {
+  addRoom(roomId: $roomid, autoRecord: $autoRecord) {
+    objectId
+    shortId
+    roomConfig {
+      roomId
+      autoRecord
+    }
+  }
+}
+</textarea> <textarea>{'roomid': 4, 'autoRecord': false}</textarea></div><div><h3>启用自动录制</h3><textarea>
+mutation {
+  setRoomConfig(roomId: 3, config: { autoRecord: true }) {
+    objectId
+    shortId
+    recording
+    roomConfig {
+      roomId
+      autoRecord
+    }
+  }
+}
+</textarea></div><div>开始录制、结束录制、手动切分，都是 mutation，在 graphql 文档页面里可以看到</div></div>";
+    }
+}
diff --git a/BililiveRecorder.Web/Startup.cs b/BililiveRecorder.Web/Startup.cs
index 9132ea5..c075738 100644
--- a/BililiveRecorder.Web/Startup.cs
+++ b/BililiveRecorder.Web/Startup.cs
@@ -70,7 +70,8 @@ namespace BililiveRecorder.Web
             {
                 if (context.Request.Path == "/")
                 {
-                    await context.Response.WriteAsync(@"<h1>to be done</h1><style>a{margin:5px}</style><a href=""/ui/playground"">Playground</a><a href=""/ui/graphiql"">GraphiQL</a><a href=""/ui/altair"">Altair</a><a href=""/ui/voyager"">Voyager</a>").ConfigureAwait(false);
+                    context.Response.ContentType = "text/html";
+                    await context.Response.WriteAsync(ConstStrings.HOME_PAGE_HTML, encoding: System.Text.Encoding.UTF8).ConfigureAwait(false);
                 }
                 else
                 {