diff --git a/.config/dotnet-tools.json b/.config/dotnet-tools.json
index c9d7f5d98b..1476155587 100644
--- a/.config/dotnet-tools.json
+++ b/.config/dotnet-tools.json
@@ -3,11 +3,11 @@
   "isRoot": true,
   "tools": {
     "nbgv": {
-      "version": "3.10.85",
+      "version": "3.10.91",
       "commands": [
         "nbgv"
       ],
       "rollForward": false
     }
   }
-}
+}
\ No newline at end of file
diff --git a/eng/skill-validator/src/Evaluate/AgentRunner.cs b/eng/skill-validator/src/Evaluate/AgentRunner.cs
index 4d17da2fce..e14a30d9eb 100644
--- a/eng/skill-validator/src/Evaluate/AgentRunner.cs
+++ b/eng/skill-validator/src/Evaluate/AgentRunner.cs
@@ -3,7 +3,7 @@
 using System.Text.Json;
 using System.Text.Json.Nodes;
 using SkillValidator.Shared;
-using GitHub.Copilot.SDK;
+using GitHub.Copilot;
 
 namespace SkillValidator.Evaluate;
 
@@ -68,14 +68,14 @@ public static async Task<CopilotClient> GetPluginClient(
 
             var options = new CopilotClientOptions
             {
-                LogLevel = verbose ? "info" : "none",
+                LogLevel = verbose ? CopilotLogLevel.Info : CopilotLogLevel.None,
                 SessionFs = new SessionFsConfig
                 {
-                    InitialCwd = Environment.CurrentDirectory,
+                    InitialWorkingDirectory = Environment.CurrentDirectory,
                     SessionStatePath = "session-state",
                     Conventions = OperatingSystem.IsWindows()
-                        ? GitHub.Copilot.SDK.Rpc.SessionFsSetProviderConventions.Windows
-                        : GitHub.Copilot.SDK.Rpc.SessionFsSetProviderConventions.Posix,
+                        ? GitHub.Copilot.Rpc.SessionFsSetProviderConventions.Windows
+                        : GitHub.Copilot.Rpc.SessionFsSetProviderConventions.Posix,
                 },
             };
 
@@ -443,22 +443,21 @@ internal static async Task<SessionConfig> BuildSessionConfig(
             Streaming = true,
             WorkingDirectory = workDir,
             SkillDirectories = [..skillDirs, ..noiseDirs],
-            ConfigDir = configDir,
+            ConfigDirectory = configDir,
             McpServers = sdkMcp,
             CustomAgents = customAgents,
             InfiniteSessions = new InfiniteSessionConfig { Enabled = false },
-            // SDK 0.3.0 requires a SessionFsProvider (abstract base class).
+            // The SDK requires a SessionFsProvider (abstract base class).
             // Without this, events.jsonl files are never written and
             // session replay data is lost.
-            CreateSessionFsHandler = _ => new LocalSessionFsHandler(configDir),
+            CreateSessionFsProvider = _ => new LocalSessionFsHandler(configDir),
             OnPermissionRequest = (request, _) =>
             {
-                // SDK 0.2.0: PermissionRequest only has Kind, no path data.
-                // Permission sandboxing is handled via Hooks.OnPreToolUse instead.
-                return Task.FromResult(new PermissionRequestResult
-                {
-                    Kind = PermissionRequestResultKind.Approved,
-                });
+                // PermissionRequest carries per-kind data (e.g. Read.Path,
+                // Write.FileName, Shell.FullCommandText/PossiblePaths), but we
+                // don't use it here: permission sandboxing is enforced via
+                // Hooks.OnPreToolUse instead, so this handler approves all.
+                return Task.FromResult(GitHub.Copilot.Rpc.PermissionDecision.ApproveOnce());
             },
             Hooks = new SessionHooks
             {
@@ -580,7 +579,7 @@ await BuildSessionConfig(options.Skill, options.PluginRoot, options.Model, workD
 
             // Register event handler BEFORE SelectAsync so SubagentSelectedEvent
             // from the agent selection is captured in the events list.
-            session.On(evt =>
+            session.On<SessionEvent>(evt =>
             {
                 var agentEvent = new AgentEvent(
                     evt.Type,
diff --git a/eng/skill-validator/src/Evaluate/Judge.cs b/eng/skill-validator/src/Evaluate/Judge.cs
index cfd17b3252..a2e3962ba3 100644
--- a/eng/skill-validator/src/Evaluate/Judge.cs
+++ b/eng/skill-validator/src/Evaluate/Judge.cs
@@ -1,7 +1,7 @@
 using System.Text.Json;
 using System.Text.Json.Nodes;
 using SkillValidator.Shared;
-using GitHub.Copilot.SDK;
+using GitHub.Copilot.Rpc;
 
 namespace SkillValidator.Evaluate;
 
@@ -47,10 +47,7 @@ public static class Judge
             {
                 // Judge sessions: deny all tool permissions. Judging should be a
                 // pure LLM task — no file access or tool execution needed.
-                return Task.FromResult(new PermissionRequestResult
-                {
-                    Kind = PermissionRequestResultKind.UserNotAvailable,
-                });
+                return Task.FromResult(PermissionDecision.UserNotAvailable());
             },
             cancellationToken: cancellationToken);
 
diff --git a/eng/skill-validator/src/Evaluate/LlmSession.cs b/eng/skill-validator/src/Evaluate/LlmSession.cs
index c24a6cb5b1..0725c48539 100644
--- a/eng/skill-validator/src/Evaluate/LlmSession.cs
+++ b/eng/skill-validator/src/Evaluate/LlmSession.cs
@@ -1,4 +1,5 @@
-using GitHub.Copilot.SDK;
+using GitHub.Copilot;
+using GitHub.Copilot.Rpc;
 
 namespace SkillValidator.Evaluate;
 
@@ -30,7 +31,7 @@ internal static async Task<LlmResponse> SendAsync(
         int timeoutMs,
         bool verbose,
         string timeoutLabel = "LLM",
-        PermissionRequestHandler? onPermissionRequest = null,
+        Func<PermissionRequest, PermissionInvocation, Task<PermissionDecision>>? onPermissionRequest = null,
         CancellationToken cancellationToken = default)
     {
         var client = await AgentRunner.GetSharedClient(verbose);
@@ -52,11 +53,8 @@ internal static async Task<LlmResponse> SendAsync(
                 Content = systemPrompt,
             },
             InfiniteSessions = new InfiniteSessionConfig { Enabled = false },
-            CreateSessionFsHandler = _ => new LocalSessionFsHandler(tempConfigDir),
-            OnPermissionRequest = onPermissionRequest ?? ((_, _) => Task.FromResult(new PermissionRequestResult
-            {
-                Kind = PermissionRequestResultKind.UserNotAvailable,
-            })),
+            CreateSessionFsProvider = _ => new LocalSessionFsHandler(tempConfigDir),
+            OnPermissionRequest = onPermissionRequest ?? ((_, _) => Task.FromResult(PermissionDecision.UserNotAvailable())),
         });
 
         using var cts = CancellationTokenSource.CreateLinkedTokenSource(cancellationToken);
@@ -70,7 +68,7 @@ internal static async Task<LlmResponse> SendAsync(
         string responseContent = "";
         int inputTokens = 0, outputTokens = 0, cacheReadTokens = 0, cacheWriteTokens = 0;
 
-        session.On(evt =>
+        session.On<SessionEvent>(evt =>
         {
             switch (evt)
             {
diff --git a/eng/skill-validator/src/Evaluate/LocalSessionFsHandler.cs b/eng/skill-validator/src/Evaluate/LocalSessionFsHandler.cs
index 5fb5677e84..dddb134490 100644
--- a/eng/skill-validator/src/Evaluate/LocalSessionFsHandler.cs
+++ b/eng/skill-validator/src/Evaluate/LocalSessionFsHandler.cs
@@ -1,6 +1,6 @@
 using System.Collections.Concurrent;
-using GitHub.Copilot.SDK;
-using GitHub.Copilot.SDK.Rpc;
+using GitHub.Copilot;
+using GitHub.Copilot.Rpc;
 
 namespace SkillValidator.Evaluate;
 
@@ -117,14 +117,14 @@ protected override Task<SessionFsStatResult> StatAsync(string path, Cancellation
         throw new FileNotFoundException($"Not found: {path}");
     }
 
-    protected override Task MkdirAsync(string path, bool recursive, int? mode, CancellationToken cancellationToken)
+    protected override Task MakeDirectoryAsync(string path, bool recursive, int? mode, CancellationToken cancellationToken)
     {
         var resolved = ResolvePath(path);
         Directory.CreateDirectory(resolved);
         return Task.CompletedTask;
     }
 
-    protected override Task<IList<string>> ReaddirAsync(string path, CancellationToken cancellationToken)
+    protected override Task<IList<string>> ReadDirectoryAsync(string path, CancellationToken cancellationToken)
     {
         var resolved = ResolvePath(path);
         var entries = new List<string>();
@@ -136,7 +136,7 @@ protected override Task<IList<string>> ReaddirAsync(string path, CancellationTok
         return Task.FromResult<IList<string>>(entries);
     }
 
-    protected override Task<IList<SessionFsReaddirWithTypesEntry>> ReaddirWithTypesAsync(string path, CancellationToken cancellationToken)
+    protected override Task<IList<SessionFsReaddirWithTypesEntry>> ReadDirectoryWithTypesAsync(string path, CancellationToken cancellationToken)
     {
         var resolved = ResolvePath(path);
         var entries = new List<SessionFsReaddirWithTypesEntry>();
@@ -154,7 +154,7 @@ protected override Task<IList<SessionFsReaddirWithTypesEntry>> ReaddirWithTypesA
         return Task.FromResult<IList<SessionFsReaddirWithTypesEntry>>(entries);
     }
 
-    protected override Task RmAsync(string path, bool recursive, bool force, CancellationToken cancellationToken)
+    protected override Task RemoveAsync(string path, bool recursive, bool force, CancellationToken cancellationToken)
     {
         var resolved = ResolvePath(path);
         if (File.Exists(resolved))
diff --git a/eng/skill-validator/src/Evaluate/PairwiseJudge.cs b/eng/skill-validator/src/Evaluate/PairwiseJudge.cs
index e3f9829744..cfd5b7728e 100644
--- a/eng/skill-validator/src/Evaluate/PairwiseJudge.cs
+++ b/eng/skill-validator/src/Evaluate/PairwiseJudge.cs
@@ -1,7 +1,7 @@
 using System.Text.Json;
 using System.Text.Json.Nodes;
 using SkillValidator.Shared;
-using GitHub.Copilot.SDK;
+using GitHub.Copilot.Rpc;
 
 namespace SkillValidator.Evaluate;
 
@@ -87,10 +87,7 @@ public static class PairwiseJudge
             {
                 // Pairwise judge sessions: deny all tool permissions. The judge
                 // should operate purely on the provided text — no tool execution.
-                return Task.FromResult(new PermissionRequestResult
-                {
-                    Kind = PermissionRequestResultKind.UserNotAvailable,
-                });
+                return Task.FromResult(PermissionDecision.UserNotAvailable());
             },
             cancellationToken: cancellationToken);
 
diff --git a/eng/skill-validator/src/SkillValidator.csproj b/eng/skill-validator/src/SkillValidator.csproj
index 7c40e0f10f..0e095416ee 100644
--- a/eng/skill-validator/src/SkillValidator.csproj
+++ b/eng/skill-validator/src/SkillValidator.csproj
@@ -9,6 +9,12 @@
     <!-- YamlDotNet 17.x is not fully trim/AOT-compatible; suppress the
          assembly-level trim analysis warning so native publish succeeds. -->
     <NoWarn>$(NoWarn);IL2104</NoWarn>
+    <!-- GitHub.Copilot.SDK 1.x marks its permission-decision and session-fs
+         RPC types ([Experimental] "GHCP001"). These types appear directly in
+         the SessionFsProvider base-class signatures and the OnPermissionRequest
+         delegate, so consuming them is unavoidable. Suppress the experimental
+         diagnostic until the SDK promotes them to stable. -->
+    <NoWarn>$(NoWarn);GHCP001</NoWarn>
 
     <!-- Packaging -->
     <PackageId>Microsoft.DotNet.SkillValidator</PackageId>
@@ -42,34 +48,19 @@
     <PackageReference Include="Microsoft.ML.Tokenizers.Data.Cl100kBase" Version="2.0.0" />
     <PackageReference Include="System.CommandLine" Version="2.0.10" />
     <!-- external -->
-    <PackageReference Include="GitHub.Copilot.SDK" Version="0.3.0" />
-    <PackageReference Include="YamlDotNet" Version="18.0.0" />
-    <PackageReference Include="Vecc.YamlDotNet.Analyzers.StaticGenerator" Version="18.0.0" />
+    <PackageReference Include="GitHub.Copilot.SDK" Version="1.0.7" />
+    <PackageReference Include="YamlDotNet" Version="18.1.0" />
+    <PackageReference Include="Vecc.YamlDotNet.Analyzers.StaticGenerator" Version="18.1.0" />
 
     <!--
-      Transitive pin: GitHub.Copilot.SDK still drags in Nerdbank.MessagePack
-      1.0.2 which has a known high-severity vulnerability (GHSA-2cwq-pwfr-wcw3).
-      Fixed in 1.1.62.  Drop this once the upstream chain bumps past 1.1.62.
-    -->
-    <PackageReference Include="Nerdbank.MessagePack" Version="1.2.4" />
-
-    <!--
-      Transitive pin: GitHub.Copilot.SDK -> StreamJsonRpc 2.24.84 drags in
-      MessagePack 2.5.198 which has a known high-severity vulnerability
-      (GHSA-hv8m-jj95-wg3x, out-of-bounds read in LZ4 decompression). Patched in
-      the v2 line as of 2.5.301.  Drop this once the upstream chain bumps past it.
-    -->
-    <PackageReference Include="MessagePack" Version="2.5.301" />
-
-    <!--
-      Transitive pin: Microsoft.Data.Sqlite 10.0.7 -> SQLitePCLRaw.bundle_e_sqlite3
+      Transitive pin: Microsoft.Data.Sqlite 10.0.10 -> SQLitePCLRaw.bundle_e_sqlite3
       drags in the native SQLitePCLRaw.lib.e_sqlite3 2.1.11, which bundles a
       SQLite older than 3.50.2 and carries a known high-severity vulnerability
       (GHSA-2m69-gcr7-jv3q / CVE-2025-6965). 3.50.3 ships the patched SQLite
       native library and is API-compatible with the 2.1.x managed provider.
       Drop this once Microsoft.Data.Sqlite bumps past it.
     -->
-    <PackageReference Include="SQLitePCLRaw.lib.e_sqlite3" Version="3.50.3" />
+    <PackageReference Include="SQLitePCLRaw.lib.e_sqlite3" Version="3.53.3" />
   </ItemGroup>
 
 </Project>
diff --git a/eng/skill-validator/tests/Evaluate/RunnerTests.cs b/eng/skill-validator/tests/Evaluate/RunnerTests.cs
index 610fdbee52..4d91ece2e8 100644
--- a/eng/skill-validator/tests/Evaluate/RunnerTests.cs
+++ b/eng/skill-validator/tests/Evaluate/RunnerTests.cs
@@ -1,6 +1,6 @@
 using System.Diagnostics;
 using System.Text.Json;
-using GitHub.Copilot.SDK;
+using GitHub.Copilot;
 using SkillValidator.Evaluate;
 using SkillValidator.Shared;
 
@@ -213,17 +213,17 @@ public async Task SetsWorkingDirectoryToWorkDir()
     public async Task SetsConfigDirToUniqueTempDirForSkillIsolation()
     {
         var config = await AgentRunner.BuildSessionConfig(MockSkill, null, "gpt-4.1", "C:\\tmp\\work");
-        Assert.NotEqual("C:\\tmp\\work", config.ConfigDir);
-        Assert.StartsWith(Path.GetTempPath(), config.ConfigDir);
-        Assert.True(Directory.Exists(config.ConfigDir));
+        Assert.NotEqual("C:\\tmp\\work", config.ConfigDirectory);
+        Assert.StartsWith(Path.GetTempPath(), config.ConfigDirectory);
+        Assert.True(Directory.Exists(config.ConfigDirectory));
     }
 
     [Fact]
     public async Task SetsConfigDirToUniqueTempDirEvenWithoutSkill()
     {
         var config = await AgentRunner.BuildSessionConfig(null, null, "gpt-4.1", "C:\\tmp\\work");
-        Assert.NotEqual("C:\\tmp\\work", config.ConfigDir);
-        Assert.StartsWith(Path.GetTempPath(), config.ConfigDir);
+        Assert.NotEqual("C:\\tmp\\work", config.ConfigDirectory);
+        Assert.StartsWith(Path.GetTempPath(), config.ConfigDirectory);
     }
 
     [Fact]
@@ -231,7 +231,7 @@ public async Task EachCallGetsUniqueConfigDir()
     {
         var config1 = await AgentRunner.BuildSessionConfig(null, null, "gpt-4.1", "C:\\tmp\\work");
         var config2 = await AgentRunner.BuildSessionConfig(null, null, "gpt-4.1", "C:\\tmp\\work");
-        Assert.NotEqual(config1.ConfigDir, config2.ConfigDir);
+        Assert.NotEqual(config1.ConfigDirectory, config2.ConfigDirectory);
     }
 
     [Fact]
@@ -356,7 +356,7 @@ public async Task DropsMcpCwd()
         var config = await AgentRunner.BuildSessionConfig(MockSkill, null, "gpt-4.1", "C:\\tmp\\work", mcpServers);
         Assert.NotNull(config.McpServers);
         var entry = (McpStdioServerConfig)config.McpServers["ok"];
-        Assert.Null(entry.Cwd);
+        Assert.Null(entry.WorkingDirectory);
     }
 
     [Fact]
@@ -451,7 +451,7 @@ public async Task PluginRootNullPreservesSkillDirectories()
 
 public class ExtractPathFromToolArgsTests
 {
-    private static PreToolUseHookInput MakeInput(object? toolArgs) =>
+    private static PreToolUseHookInput MakeInput(JsonElement? toolArgs) =>
         new() { ToolArgs = toolArgs };
 
     [Fact]