Config parity across SDKs: add largeOutput, pluginDirectories, spell out Directory (#1482)

* Config parity across SDKs: add largeOutput, pluginDirectories, spell out directory

Bring the six language SDKs (.NET, Node, Python, Go, Java, Rust) into closer
alignment on session-configuration surface area:

- Expose `largeOutput` / `LargeToolOutputConfig` on session create and
  resume in every SDK so callers can configure the CLI's large tool-output
  handling (enabled, maxSizeBytes, outputDirectory). Wire field stays
  `largeOutput.outputDir` for compatibility with the runtime.

- Expose `pluginDirectories` on session create and resume in every SDK,
  documented as an explicit opt-in that loads plugin agents and rules even
  when `enableConfigDiscovery` is false. Defaults to null/none, which is
  the safe choice for multi-tenant hosts.

- Spell out `Dir` -> `Directory` in public APIs for consistency with
  the rest of Types.cs (e.g. SkillDirectories, InstructionDirectories):
  `configDir` -> `configDirectory`, `outputDir` -> `outputDirectory`.
  The wire JSON names (`configDir`, `outputDir`) are preserved via
  language-specific serializer annotations, so this is a source-only rename.

- Node SDK also re-exports `ReasoningSummary` and adds `reasoningSummary`
  support on resume, matching what the other SDKs already had.

Notes for reviewers:

- `args`/`toolArgs`/`modifiedArgs` are intentionally left abbreviated,
  matching the wire field names and the shell/process/CLI argument idiom
  used elsewhere (RuntimeConnection, MCP stdio, hook inputs).

- New unit tests cover serialization (wire field stays `outputDir` /
  `configDir`), clone semantics for the new fields, and round-trips
  through CreateSessionRequest / ResumeSessionConfig in every SDK.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* Fix CI: formatters and linters across SDKs

- python: ruff isort fix (separate aliased import)

- nodejs: prettier format on test/client.test.ts

- go: gofmt alignment in client_test.go and session_e2e_test.go

- rust: clippy field_reassign_with_default fix in types.rs test

- java: spotless:apply across 10 files (line wrap, javadoc multi-line)

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* Go: type MaxSizeBytes as *int64 to match other SDKs

Reviewer flagged that `*int` is architecture-dependent and narrower than the u64/long/Long used in the other SDKs. Switch to `*int64` (matches Java `Long` and .NET `long?`) and update the test literal cast.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

---------

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: stephentoub

dotnet/src/Client.cs

@@ -852,6 +852,7 @@ public async Task<CopilotSession> CreateSessionAsync(SessionConfig config, Cance
                 localSessionId,
                 config.ClientName,
                 config.ReasoningEffort,
+                config.ReasoningSummary,
                 config.Tools?.Select(ToolDefinition.FromAIFunction).ToList(),
                 wireSystemMessage,
                 toolFilter.AvailableTools,
@@ -871,7 +872,7 @@ public async Task<CopilotSession> CreateSessionAsync(SessionConfig config, Cance
                 config.CustomAgents,
                 config.DefaultAgent,
                 config.Agent,
-                config.ConfigDir,
+                config.ConfigDirectory,
                 config.EnableConfigDiscovery,
                 config.SkillDirectories,
                 config.DisabledSkills,
@@ -886,6 +887,8 @@ public async Task<CopilotSession> CreateSessionAsync(SessionConfig config, Cance
                 RemoteSession: config.RemoteSession,
                 Cloud: config.Cloud,
                 InstructionDirectories: config.InstructionDirectories,
+                PluginDirectories: config.PluginDirectories,
+                LargeOutput: config.LargeOutput,
                 Canvases: config.Canvases,
                 RequestCanvasRenderer: config.RequestCanvasRenderer,
                 RequestExtensions: config.RequestExtensions,
@@ -1033,6 +1036,7 @@ public async Task<CopilotSession> ResumeSessionAsync(string sessionId, ResumeSes
                 config.ClientName,
                 config.Model,
                 config.ReasoningEffort,
+                config.ReasoningSummary,
                 config.Tools?.Select(ToolDefinition.FromAIFunction).ToList(),
                 wireSystemMessage,
                 toolFilter.AvailableTools,
@@ -1045,7 +1049,7 @@ public async Task<CopilotSession> ResumeSessionAsync(string sessionId, ResumeSes
                 config.OnAutoModeSwitchRequest != null ? true : null,
                 hasHooks ? true : null,
                 config.WorkingDirectory,
-                config.ConfigDir,
+                config.ConfigDirectory,
                 config.EnableConfigDiscovery,
                 config.SuppressResumeEvent is true ? true : null,
                 config.Streaming is true ? true : null,
@@ -1068,6 +1072,8 @@ public async Task<CopilotSession> ResumeSessionAsync(string sessionId, ResumeSes
                 RemoteSession: config.RemoteSession,
                 ContinuePendingWork: config.ContinuePendingWork,
                 InstructionDirectories: config.InstructionDirectories,
+                PluginDirectories: config.PluginDirectories,
+                LargeOutput: config.LargeOutput,
                 Canvases: config.Canvases,
                 RequestCanvasRenderer: config.RequestCanvasRenderer,
                 RequestExtensions: config.RequestExtensions,
@@ -2147,6 +2153,7 @@ internal record CreateSessionRequest(
         string? SessionId,
         string? ClientName,
         string? ReasoningEffort,
+        ReasoningSummary? ReasoningSummary,
         IList<ToolDefinition>? Tools,
         SystemMessageConfig? SystemMessage,
         IList<string>? AvailableTools,
@@ -2166,7 +2173,7 @@ internal record CreateSessionRequest(
         IList<CustomAgentConfig>? CustomAgents,
         DefaultAgentConfig? DefaultAgent,
         string? Agent,
-        string? ConfigDir,
+        [property: JsonPropertyName("configDir")] string? ConfigDirectory,
         bool? EnableConfigDiscovery,
         IList<string>? SkillDirectories,
         IList<string>? DisabledSkills,
@@ -2181,6 +2188,8 @@ internal record CreateSessionRequest(
         RemoteSessionMode? RemoteSession = null,
         CloudSessionOptions? Cloud = null,
         IList<string>? InstructionDirectories = null,
+        IList<string>? PluginDirectories = null,
+        LargeToolOutputConfig? LargeOutput = null,
 #pragma warning disable GHCP001
         IList<CanvasDeclaration>? Canvases = null,
         bool? RequestCanvasRenderer = null,
@@ -2219,6 +2228,7 @@ internal record ResumeSessionRequest(
         string? ClientName,
         string? Model,
         string? ReasoningEffort,
+        ReasoningSummary? ReasoningSummary,
         IList<ToolDefinition>? Tools,
         SystemMessageConfig? SystemMessage,
         IList<string>? AvailableTools,
@@ -2231,7 +2241,7 @@ internal record ResumeSessionRequest(
         bool? RequestAutoModeSwitch,
         bool? Hooks,
         string? WorkingDirectory,
-        string? ConfigDir,
+        [property: JsonPropertyName("configDir")] string? ConfigDirectory,
         bool? EnableConfigDiscovery,
         bool? SuppressResumeEvent,
         bool? Streaming,
@@ -2254,6 +2264,8 @@ internal record ResumeSessionRequest(
         RemoteSessionMode? RemoteSession = null,
         bool? ContinuePendingWork = null,
         IList<string>? InstructionDirectories = null,
+        IList<string>? PluginDirectories = null,
+        LargeToolOutputConfig? LargeOutput = null,
 #pragma warning disable GHCP001
         IList<CanvasDeclaration>? Canvases = null,
         bool? RequestCanvasRenderer = null,

dotnet/src/Types.cs

@@ -2303,6 +2303,37 @@ public sealed class InfiniteSessionConfig
     public double? BufferExhaustionThreshold { get; set; }
 }
 
+/// <summary>
+/// Configuration for handling large tool outputs.
+/// </summary>
+/// <remarks>
+/// When a tool produces output exceeding the configured size, the output is
+/// written to a temp file and a reference is returned to the model instead of
+/// returning to it the full payload.
+/// </remarks>
+public sealed class LargeToolOutputConfig
+{
+    /// <summary>
+    /// Whether large output handling is enabled.
+    /// </summary>
+    /// <remarks>The default value is <see langword="true"/>.</remarks>
+    [JsonPropertyName("enabled")]
+    public bool? Enabled { get; set; }
+
+    /// <summary>
+    /// Maximum size in bytes before output is written to a temp file.
+    /// </summary>
+    [JsonPropertyName("maxSizeBytes")]
+    public long? MaxSizeBytes { get; set; }
+
+    /// <summary>
+    /// Directory to write temp files to.
+    /// </summary>
+    /// <remarks>The default value is the OS temp directory.</remarks>
+    [JsonPropertyName("outputDir")]
+    public string? OutputDirectory { get; set; }
+}
+
 /// <summary>
 /// GitHub repository metadata to associate with a cloud session.
 /// </summary>
@@ -2350,7 +2381,7 @@ protected SessionConfigBase(SessionConfigBase? other)
         AvailableTools = other.AvailableTools is not null ? [.. other.AvailableTools] : null;
         ClientName = other.ClientName;
         Commands = other.Commands is not null ? [.. other.Commands] : null;
-        ConfigDir = other.ConfigDir;
+        ConfigDirectory = other.ConfigDirectory;
         CustomAgents = other.CustomAgents is not null ? [.. other.CustomAgents] : null;
         DefaultAgent = other.DefaultAgent;
         Agent = other.Agent;
@@ -2360,6 +2391,7 @@ protected SessionConfigBase(SessionConfigBase? other)
         ExcludedTools = other.ExcludedTools is not null ? [.. other.ExcludedTools] : null;
         Hooks = other.Hooks;
         InfiniteSessions = other.InfiniteSessions;
+        LargeOutput = other.LargeOutput;
         McpServers = other.McpServers is not null
             ? (other.McpServers is Dictionary<string, McpServerConfig> dict
                 ? new Dictionary<string, McpServerConfig>(dict, dict.Comparer)
@@ -2380,6 +2412,7 @@ protected SessionConfigBase(SessionConfigBase? other)
         CoauthorEnabled = other.CoauthorEnabled;
         ManageScheduleEnabled = other.ManageScheduleEnabled;
         ReasoningEffort = other.ReasoningEffort;
+        ReasoningSummary = other.ReasoningSummary;
         CreateSessionFsProvider = other.CreateSessionFsProvider;
         GitHubToken = other.GitHubToken;
         RemoteSession = other.RemoteSession;
@@ -2391,6 +2424,7 @@ protected SessionConfigBase(SessionConfigBase? other)
         CanvasHandler = other.CanvasHandler;
 #pragma warning restore GHCP001
         SkillDirectories = other.SkillDirectories is not null ? [.. other.SkillDirectories] : null;
+        PluginDirectories = other.PluginDirectories is not null ? [.. other.PluginDirectories] : null;
         InstructionDirectories = other.InstructionDirectories is not null ? [.. other.InstructionDirectories] : null;
         Streaming = other.Streaming;
         IncludeSubAgentStreamingEvents = other.IncludeSubAgentStreamingEvents;
@@ -2412,14 +2446,22 @@ protected SessionConfigBase(SessionConfigBase? other)
     /// </summary>
     public string? ReasoningEffort { get; set; }
 
+    /// <summary>
+    /// Reasoning summary mode for models that support configurable reasoning summaries.
+    /// </summary>
+    /// <remarks>
+    /// Use <see cref="ReasoningSummary.None"/> to suppress summary output regardless of whether reasoning is enabled.
+    /// </remarks>
+    public ReasoningSummary? ReasoningSummary { get; set; }
+
     /// <summary>Per-property overrides for model capabilities, deep-merged over runtime defaults.</summary>
     public ModelCapabilitiesOverride? ModelCapabilities { get; set; }
 
     /// <summary>
     /// Override the default configuration directory location.
     /// When specified, the session will use this directory for storing config and state.
     /// </summary>
-    public string? ConfigDir { get; set; }
+    public string? ConfigDirectory { get; set; }
 
     /// <summary>
     /// When <see langword="true"/>, automatically discovers MCP server configurations
@@ -2593,6 +2635,17 @@ protected SessionConfigBase(SessionConfigBase? other)
     /// <summary>Directories to load skills from.</summary>
     public IList<string>? SkillDirectories { get; set; }
 
+    /// <summary>
+    /// Local filesystem paths to Open Plugins-format directories
+    /// (https://open-plugins.com/) to load for this session.
+    /// </summary>
+    /// <remarks>
+    /// Relative paths resolve against <see cref="WorkingDirectory"/> (or the
+    /// runtime cwd if unset). Treated as an explicit opt-in: plugin agents
+    /// and rules load even when <see cref="EnableConfigDiscovery"/> is false.
+    /// </remarks>
+    public IList<string>? PluginDirectories { get; set; }
+
     /// <summary>Additional directories to search for custom instruction files.</summary>
     public IList<string>? InstructionDirectories { get; set; }
 
@@ -2605,6 +2658,14 @@ protected SessionConfigBase(SessionConfigBase? other)
     /// </summary>
     public InfiniteSessionConfig? InfiniteSessions { get; set; }
 
+    /// <summary>
+    /// Configuration for handling large tool outputs. When a tool produces
+    /// output exceeding the configured size, the output is written to a temp
+    /// file and a reference is returned to the model instead of the full
+    /// payload.
+    /// </summary>
+    public LargeToolOutputConfig? LargeOutput { get; set; }
+
     /// <summary>
     /// Optional event handler registered on the session before the session.create / session.resume
     /// RPC is issued, ensuring early events are delivered.

dotnet/test/E2E/ClientE2ETests.cs

@@ -1,4 +1,4 @@
-/*---------------------------------------------------------------------------------------------
+/*---------------------------------------------------------------------------------------------
  *  Copyright (c) Microsoft Corporation. All rights reserved.
  *--------------------------------------------------------------------------------------------*/
 

dotnet/test/E2E/ClientOptionsE2ETests.cs

@@ -1,4 +1,4 @@
-/*---------------------------------------------------------------------------------------------
+/*---------------------------------------------------------------------------------------------
  *  Copyright (c) Microsoft Corporation. All rights reserved.
  *--------------------------------------------------------------------------------------------*/
 

dotnet/test/E2E/SessionE2ETests.cs

@@ -550,7 +550,7 @@ public async Task SendAndWait_Throws_OperationCanceledException_When_Token_Cance
     public async Task Should_Create_Session_With_Custom_Config_Dir()
     {
         var customConfigDir = Path.Join(Ctx.HomeDir, "custom-config");
-        var session = await CreateSessionAsync(new SessionConfig { ConfigDir = customConfigDir });
+        var session = await CreateSessionAsync(new SessionConfig { ConfigDirectory = customConfigDir });
 
         Assert.Matches(@"^[a-f0-9-]+$", session.SessionId);
 

dotnet/test/Unit/CloneTests.cs

@@ -1,4 +1,4 @@
-/*---------------------------------------------------------------------------------------------
+/*---------------------------------------------------------------------------------------------
  *  Copyright (c) Microsoft Corporation. All rights reserved.
  *--------------------------------------------------------------------------------------------*/
 
@@ -68,7 +68,8 @@ public void SessionConfig_Clone_CopiesAllProperties()
             ClientName = "my-app",
             Model = "gpt-4",
             ReasoningEffort = "high",
-            ConfigDir = "/config",
+            ReasoningSummary = ReasoningSummary.Detailed,
+            ConfigDirectory = "/config",
             AvailableTools = ["tool1", "tool2"],
             ExcludedTools = ["tool3"],
             WorkingDirectory = "/workspace",
@@ -91,6 +92,8 @@ public void SessionConfig_Clone_CopiesAllProperties()
             SkillDirectories = ["/skills"],
             InstructionDirectories = ["/instructions"],
             DisabledSkills = ["skill1"],
+            PluginDirectories = ["/plugins"],
+            LargeOutput = new LargeToolOutputConfig { Enabled = true, MaxSizeBytes = 2048, OutputDirectory = "/tmp/out" },
             OnExitPlanModeRequest = static (_, _) => Task.FromResult(new ExitPlanModeResult()),
             OnAutoModeSwitchRequest = static (_, _) => Task.FromResult(AutoModeSwitchResponse.No),
         };
@@ -101,7 +104,8 @@ public void SessionConfig_Clone_CopiesAllProperties()
         Assert.Equal(original.ClientName, clone.ClientName);
         Assert.Equal(original.Model, clone.Model);
         Assert.Equal(original.ReasoningEffort, clone.ReasoningEffort);
-        Assert.Equal(original.ConfigDir, clone.ConfigDir);
+        Assert.Equal(original.ReasoningSummary, clone.ReasoningSummary);
+        Assert.Equal(original.ConfigDirectory, clone.ConfigDirectory);
         Assert.Equal(original.AvailableTools, clone.AvailableTools);
         Assert.Equal(original.ExcludedTools, clone.ExcludedTools);
         Assert.Equal(original.WorkingDirectory, clone.WorkingDirectory);
@@ -117,6 +121,8 @@ public void SessionConfig_Clone_CopiesAllProperties()
         Assert.Equal(original.SkillDirectories, clone.SkillDirectories);
         Assert.Equal(original.InstructionDirectories, clone.InstructionDirectories);
         Assert.Equal(original.DisabledSkills, clone.DisabledSkills);
+        Assert.Equal(original.PluginDirectories, clone.PluginDirectories);
+        Assert.Same(original.LargeOutput, clone.LargeOutput);
         Assert.Same(original.OnExitPlanModeRequest, clone.OnExitPlanModeRequest);
         Assert.Same(original.OnAutoModeSwitchRequest, clone.OnAutoModeSwitchRequest);
     }
@@ -356,6 +362,35 @@ public void ResumeSessionConfig_Clone_CopiesContinuePendingWork()
         Assert.True(clone.ContinuePendingWork);
     }
 
+    [Fact]
+    public void ResumeSessionConfig_Clone_CopiesReasoningSummary()
+    {
+        var original = new ResumeSessionConfig
+        {
+            ReasoningSummary = ReasoningSummary.None,
+        };
+
+        var clone = original.Clone();
+
+        Assert.Equal(original.ReasoningSummary, clone.ReasoningSummary);
+    }
+
+    [Fact]
+    public void ResumeSessionConfig_Clone_CopiesPluginDirectoriesAndLargeOutput()
+    {
+        var largeOutput = new LargeToolOutputConfig { Enabled = false, MaxSizeBytes = 4096, OutputDirectory = "/tmp/resume" };
+        var original = new ResumeSessionConfig
+        {
+            PluginDirectories = ["/resume/plugins"],
+            LargeOutput = largeOutput,
+        };
+
+        var clone = original.Clone();
+
+        Assert.Equal(original.PluginDirectories, clone.PluginDirectories);
+        Assert.Same(original.LargeOutput, clone.LargeOutput);
+    }
+
     [Fact]
     public void ResumeSessionConfig_Clone_PreservesContinuePendingWorkDefault()
     {