Add memory configuration API to Go, Node, Python, .NET, and Java SDKs

Mirror the Rust session memory surface across the remaining SDK
languages: session create and resume accept an optional memory
configuration carrying a required `enabled` flag, omitted from the
wire when unset. Adds the type, the create/resume wiring, clone and
serialization coverage, and README docs per language.

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

Author: Morabbin

dotnet/README.md

@@ -410,6 +410,20 @@ When enabled, sessions emit compaction events:
 - `SessionCompactionStartEvent` - Background compaction started
 - `SessionCompactionCompleteEvent` - Compaction finished (includes token counts)
 
+## Memory
+
+Sessions can opt into persistent memory, allowing the agent to read and write memory across turns. Memory is configured per session and applies to both `CreateSessionAsync` and `ResumeSessionAsync`.
+
+```csharp
+var session = await client.CreateSessionAsync(new SessionConfig
+{
+    Model = "gpt-5",
+    Memory = new MemoryConfiguration { Enabled = true }
+});
+```
+
+When `Memory` is left unset, no memory configuration is sent and the runtime default applies.
+
 ## Advanced Usage
 
 ### Manual Server Control

dotnet/src/Client.cs

@@ -935,6 +935,7 @@ public async Task<CopilotSession> CreateSessionAsync(SessionConfig config, Cance
                 InstructionDirectories: config.InstructionDirectories,
                 PluginDirectories: config.PluginDirectories,
                 LargeOutput: config.LargeOutput,
+                Memory: config.Memory,
                 Canvases: config.Canvases,
                 RequestCanvasRenderer: config.RequestCanvasRenderer,
                 RequestExtensions: config.RequestExtensions,
@@ -1131,6 +1132,7 @@ public async Task<CopilotSession> ResumeSessionAsync(string sessionId, ResumeSes
                 InstructionDirectories: config.InstructionDirectories,
                 PluginDirectories: config.PluginDirectories,
                 LargeOutput: config.LargeOutput,
+                Memory: config.Memory,
                 Canvases: config.Canvases,
                 RequestCanvasRenderer: config.RequestCanvasRenderer,
                 RequestExtensions: config.RequestExtensions,
@@ -2322,6 +2324,7 @@ internal record CreateSessionRequest(
         IList<string>? InstructionDirectories = null,
         IList<string>? PluginDirectories = null,
         LargeToolOutputConfig? LargeOutput = null,
+        MemoryConfiguration? Memory = null,
 #pragma warning disable GHCP001
         IList<CanvasDeclaration>? Canvases = null,
         bool? RequestCanvasRenderer = null,
@@ -2409,6 +2412,7 @@ internal record ResumeSessionRequest(
         IList<string>? InstructionDirectories = null,
         IList<string>? PluginDirectories = null,
         LargeToolOutputConfig? LargeOutput = null,
+        MemoryConfiguration? Memory = null,
 #pragma warning disable GHCP001
         IList<CanvasDeclaration>? Canvases = null,
         bool? RequestCanvasRenderer = null,

dotnet/src/Types.cs

@@ -2364,6 +2364,18 @@ public sealed class LargeToolOutputConfig
     public string? OutputDirectory { get; set; }
 }
 
+/// <summary>
+/// Configuration for session memory.
+/// </summary>
+public sealed class MemoryConfiguration
+{
+    /// <summary>
+    /// Whether memory is enabled for the session.
+    /// </summary>
+    [JsonPropertyName("enabled")]
+    public bool Enabled { get; set; }
+}
+
 /// <summary>
 /// GitHub repository metadata to associate with a cloud session.
 /// </summary>
@@ -2458,6 +2470,7 @@ protected SessionConfigBase(SessionConfigBase? other)
         Hooks = other.Hooks;
         InfiniteSessions = other.InfiniteSessions;
         LargeOutput = other.LargeOutput;
+        Memory = other.Memory;
         McpServers = other.McpServers is not null
             ? (other.McpServers is Dictionary<string, McpServerConfig> dict
                 ? new Dictionary<string, McpServerConfig>(dict, dict.Comparer)
@@ -2805,6 +2818,12 @@ protected SessionConfigBase(SessionConfigBase? other)
     /// </summary>
     public LargeToolOutputConfig? LargeOutput { get; set; }
 
+    /// <summary>
+    /// Configuration for session memory. When set, controls whether the
+    /// session can read and write persistent memory.
+    /// </summary>
+    public MemoryConfiguration? Memory { 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/Unit/CloneTests.cs

@@ -97,6 +97,7 @@ public void SessionConfig_Clone_CopiesAllProperties()
             DisabledSkills = ["skill1"],
             PluginDirectories = ["/plugins"],
             LargeOutput = new LargeToolOutputConfig { Enabled = true, MaxSizeBytes = 2048, OutputDirectory = "/tmp/out" },
+            Memory = new MemoryConfiguration { Enabled = true },
             OnExitPlanModeRequest = static (_, _) => Task.FromResult(new ExitPlanModeResult()),
             OnAutoModeSwitchRequest = static (_, _) => Task.FromResult(AutoModeSwitchResponse.No),
         };
@@ -129,6 +130,7 @@ public void SessionConfig_Clone_CopiesAllProperties()
         Assert.Equal(original.DisabledSkills, clone.DisabledSkills);
         Assert.Equal(original.PluginDirectories, clone.PluginDirectories);
         Assert.Same(original.LargeOutput, clone.LargeOutput);
+        Assert.Same(original.Memory, clone.Memory);
         Assert.Same(original.OnExitPlanModeRequest, clone.OnExitPlanModeRequest);
         Assert.Same(original.OnAutoModeSwitchRequest, clone.OnAutoModeSwitchRequest);
     }
@@ -402,12 +404,14 @@ public void ResumeSessionConfig_Clone_CopiesPluginDirectoriesAndLargeOutput()
         {
             PluginDirectories = ["/resume/plugins"],
             LargeOutput = largeOutput,
+            Memory = new MemoryConfiguration { Enabled = true },
         };
 
         var clone = original.Clone();
 
         Assert.Equal(original.PluginDirectories, clone.PluginDirectories);
         Assert.Same(original.LargeOutput, clone.LargeOutput);
+        Assert.Same(original.Memory, clone.Memory);
     }
 
     [Fact]

dotnet/test/Unit/SerializationTests.cs

@@ -267,6 +267,58 @@ public void SessionRequests_CanSerializePluginDirectoriesAndLargeOutput_WithSdkO
         Assert.Equal("/tmp/large-output", resumeLargeOutput.GetProperty("outputDir").GetString());
     }
 
+    [Fact]
+    public void SessionRequests_CanSerializeMemory_WithSdkOptions()
+    {
+        var options = GetSerializerOptions();
+
+        var createRequestType = GetNestedType(typeof(CopilotClient), "CreateSessionRequest");
+        var createRequest = CreateInternalRequest(
+            createRequestType,
+            ("SessionId", "session-id"),
+            ("Memory", new MemoryConfiguration { Enabled = true }));
+
+        var createJson = JsonSerializer.Serialize(createRequest, createRequestType, options);
+        using var createDocument = JsonDocument.Parse(createJson);
+        var createRoot = createDocument.RootElement;
+        Assert.True(createRoot.GetProperty("memory").GetProperty("enabled").GetBoolean());
+
+        var resumeRequestType = GetNestedType(typeof(CopilotClient), "ResumeSessionRequest");
+        var resumeRequest = CreateInternalRequest(
+            resumeRequestType,
+            ("SessionId", "session-id"),
+            ("Memory", new MemoryConfiguration { Enabled = false }));
+
+        var resumeJson = JsonSerializer.Serialize(resumeRequest, resumeRequestType, options);
+        using var resumeDocument = JsonDocument.Parse(resumeJson);
+        var resumeRoot = resumeDocument.RootElement;
+        Assert.False(resumeRoot.GetProperty("memory").GetProperty("enabled").GetBoolean());
+    }
+
+    [Fact]
+    public void SessionRequests_OmitMemory_WhenUnset()
+    {
+        var options = GetSerializerOptions();
+
+        var createRequestType = GetNestedType(typeof(CopilotClient), "CreateSessionRequest");
+        var createRequest = CreateInternalRequest(
+            createRequestType,
+            ("SessionId", "session-id"));
+
+        var createJson = JsonSerializer.Serialize(createRequest, createRequestType, options);
+        using var createDocument = JsonDocument.Parse(createJson);
+        Assert.False(createDocument.RootElement.TryGetProperty("memory", out _));
+
+        var resumeRequestType = GetNestedType(typeof(CopilotClient), "ResumeSessionRequest");
+        var resumeRequest = CreateInternalRequest(
+            resumeRequestType,
+            ("SessionId", "session-id"));
+
+        var resumeJson = JsonSerializer.Serialize(resumeRequest, resumeRequestType, options);
+        using var resumeDocument = JsonDocument.Parse(resumeJson);
+        Assert.False(resumeDocument.RootElement.TryGetProperty("memory", out _));
+    }
+
     [Fact]
     public void CreateSessionRequest_CanSerializeEnableSessionTelemetry_WithSdkOptions()
     {

go/README.md

@@ -485,6 +485,30 @@ When enabled, sessions emit compaction events:
 - `session.compaction_start` - Background compaction started
 - `session.compaction_complete` - Compaction finished (includes token counts)
 
+## Memory
+
+Sessions can opt in to the memory feature, which lets the agent persist and recall
+information across turns. Provide a `MemoryConfiguration` on session create or resume;
+when omitted, the runtime default applies.
+
+```go
+// Enable memory for a session
+session, _ := client.CreateSession(context.Background(), &copilot.SessionConfig{
+    Model: "gpt-5",
+    Memory: &copilot.MemoryConfiguration{
+        Enabled: true,
+    },
+})
+
+// Disable memory for a session
+session, _ := client.CreateSession(context.Background(), &copilot.SessionConfig{
+    Model: "gpt-5",
+    Memory: &copilot.MemoryConfiguration{
+        Enabled: false,
+    },
+})
+```
+
 ## Custom Providers
 
 The SDK supports custom OpenAI-compatible API providers (BYOK - Bring Your Own Key), including local providers like Ollama. When using a custom provider, you must specify the `Model` explicitly.

go/client.go

@@ -647,6 +647,7 @@ func (c *Client) CreateSession(ctx context.Context, config *SessionConfig) (*Ses
 	req.DisabledSkills = config.DisabledSkills
 	req.InfiniteSessions = config.InfiniteSessions
 	req.LargeOutput = config.LargeOutput
+	req.Memory = config.Memory
 	req.GitHubToken = config.GitHubToken
 	req.RemoteSession = config.RemoteSession
 	req.Cloud = config.Cloud
@@ -983,6 +984,7 @@ func (c *Client) ResumeSessionWithOptions(ctx context.Context, sessionID string,
 	req.DisabledSkills = config.DisabledSkills
 	req.InfiniteSessions = config.InfiniteSessions
 	req.LargeOutput = config.LargeOutput
+	req.Memory = config.Memory
 	req.GitHubToken = config.GitHubToken
 	req.RemoteSession = config.RemoteSession
 	req.Canvases = config.Canvases

go/client_test.go

@@ -605,6 +605,70 @@ func TestSessionRequests_PluginDirectoriesAndLargeOutput(t *testing.T) {
 	})
 }
 
+func TestSessionRequests_Memory(t *testing.T) {
+	t.Run("create includes memory in JSON when enabled", func(t *testing.T) {
+		req := createSessionRequest{Memory: &MemoryConfiguration{Enabled: true}}
+		data, err := json.Marshal(req)
+		if err != nil {
+			t.Fatalf("Failed to marshal: %v", err)
+		}
+		var m map[string]any
+		if err := json.Unmarshal(data, &m); err != nil {
+			t.Fatalf("Failed to unmarshal: %v", err)
+		}
+		expected := map[string]any{"enabled": true}
+		if !reflect.DeepEqual(m["memory"], expected) {
+			t.Errorf("Expected memory %v, got %v", expected, m["memory"])
+		}
+	})
+
+	t.Run("resume includes memory in JSON when disabled", func(t *testing.T) {
+		req := resumeSessionRequest{SessionID: "s1", Memory: &MemoryConfiguration{Enabled: false}}
+		data, err := json.Marshal(req)
+		if err != nil {
+			t.Fatalf("Failed to marshal: %v", err)
+		}
+		var m map[string]any
+		if err := json.Unmarshal(data, &m); err != nil {
+			t.Fatalf("Failed to unmarshal: %v", err)
+		}
+		expected := map[string]any{"enabled": false}
+		if !reflect.DeepEqual(m["memory"], expected) {
+			t.Errorf("Expected memory %v, got %v", expected, m["memory"])
+		}
+	})
+
+	t.Run("create omits memory when nil", func(t *testing.T) {
+		req := createSessionRequest{}
+		data, err := json.Marshal(req)
+		if err != nil {
+			t.Fatalf("Failed to marshal: %v", err)
+		}
+		var m map[string]any
+		if err := json.Unmarshal(data, &m); err != nil {
+			t.Fatalf("Failed to unmarshal: %v", err)
+		}
+		if _, ok := m["memory"]; ok {
+			t.Errorf("Expected memory to be omitted")
+		}
+	})
+
+	t.Run("resume omits memory when nil", func(t *testing.T) {
+		req := resumeSessionRequest{SessionID: "s1"}
+		data, err := json.Marshal(req)
+		if err != nil {
+			t.Fatalf("Failed to marshal: %v", err)
+		}
+		var m map[string]any
+		if err := json.Unmarshal(data, &m); err != nil {
+			t.Fatalf("Failed to unmarshal: %v", err)
+		}
+		if _, ok := m["memory"]; ok {
+			t.Errorf("Expected memory to be omitted")
+		}
+	})
+}
+
 func TestCreateSessionRequest_Agent(t *testing.T) {
 	t.Run("includes agent in JSON when set", func(t *testing.T) {
 		req := createSessionRequest{Agent: "test-agent"}

go/types.go

@@ -841,6 +841,12 @@ type InfiniteSessionConfig struct {
 	BufferExhaustionThreshold *float64 `json:"bufferExhaustionThreshold,omitempty"`
 }
 
+// MemoryConfiguration configures the memory feature for a session.
+type MemoryConfiguration struct {
+	// Enabled controls whether the memory feature is enabled for this session.
+	Enabled bool `json:"enabled"`
+}
+
 // LargeToolOutputConfig configures handling of 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
@@ -1028,6 +1034,9 @@ type SessionConfig struct {
 	// 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.
 	LargeOutput *LargeToolOutputConfig
+	// Memory configures the memory feature for the session. When omitted, the
+	// runtime default applies.
+	Memory *MemoryConfiguration
 	// OnEvent is an optional event handler that is registered on the session before
 	// the session.create RPC is issued. This guarantees that early events emitted
 	// by the CLI during session creation (e.g. session.start) are delivered to the
@@ -1409,6 +1418,9 @@ type ResumeSessionConfig struct {
 	// 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.
 	LargeOutput *LargeToolOutputConfig
+	// Memory configures the memory feature for the session. When omitted, the
+	// runtime default applies.
+	Memory *MemoryConfiguration
 	// GitHubToken is an optional per-session GitHub token used for authentication.
 	// When provided, the session authenticates as the token's owner instead of
 	// using the global client-level auth.
@@ -1725,6 +1737,7 @@ type createSessionRequest struct {
 	DisabledSkills                     []string                               `json:"disabledSkills,omitempty"`
 	InfiniteSessions                   *InfiniteSessionConfig                 `json:"infiniteSessions,omitempty"`
 	LargeOutput                        *LargeToolOutputConfig                 `json:"largeOutput,omitempty"`
+	Memory                             *MemoryConfiguration                   `json:"memory,omitempty"`
 	Commands                           []wireCommand                          `json:"commands,omitempty"`
 	RequestElicitation                 *bool                                  `json:"requestElicitation,omitempty"`
 	RequestMCPApps                     *bool                                  `json:"requestMcpApps,omitempty"`
@@ -1805,6 +1818,7 @@ type resumeSessionRequest struct {
 	DisabledSkills                     []string                               `json:"disabledSkills,omitempty"`
 	InfiniteSessions                   *InfiniteSessionConfig                 `json:"infiniteSessions,omitempty"`
 	LargeOutput                        *LargeToolOutputConfig                 `json:"largeOutput,omitempty"`
+	Memory                             *MemoryConfiguration                   `json:"memory,omitempty"`
 	Commands                           []wireCommand                          `json:"commands,omitempty"`
 	RequestElicitation                 *bool                                  `json:"requestElicitation,omitempty"`
 	RequestMCPApps                     *bool                                  `json:"requestMcpApps,omitempty"`

java/src/main/java/com/github/copilot/SessionRequestBuilder.java

@@ -135,6 +135,7 @@ static CreateSessionRequest buildCreateRequest(SessionConfig config, String sess
         request.setInstructionDirectories(config.getInstructionDirectories());
         request.setPluginDirectories(config.getPluginDirectories());
         request.setLargeOutput(config.getLargeOutput());
+        request.setMemory(config.getMemory());
         request.setDisabledSkills(config.getDisabledSkills());
         request.setConfigDirectory(config.getConfigDirectory());
         config.getEnableConfigDiscovery().ifPresent(request::setEnableConfigDiscovery);
@@ -262,6 +263,7 @@ static ResumeSessionRequest buildResumeRequest(String sessionId, ResumeSessionCo
         request.setInstructionDirectories(config.getInstructionDirectories());
         request.setPluginDirectories(config.getPluginDirectories());
         request.setLargeOutput(config.getLargeOutput());
+        request.setMemory(config.getMemory());
         request.setDisabledSkills(config.getDisabledSkills());
         request.setInfiniteSessions(config.getInfiniteSessions());
         request.setModelCapabilities(config.getModelCapabilities());