feat: add support for additional directories in session configuration

docs/troubleshooting/compatibility.md

@@ -84,6 +84,7 @@ The Copilot SDK communicates with the CLI via JSON-RPC protocol. Features must b
 | Config directory | `configDir` config | Override default config location |
 | Client name | `clientName` config | Identify app in User-Agent |
 | Working directory | `workingDirectory` config | Set session cwd |
+| Additional directories | `additionalDirectories` config | Grant session access beyond the working directory; re-supply on resume |
 | **Experimental** | | |
 | Agent management | `session.rpc.agent.*` | List, select, deselect, get current agent |
 | Fleet mode | `session.rpc.fleet.start()` | Parallel sub-agent execution; see [Fleet mode](../features/fleet-mode.md) |

dotnet/src/Client.cs

@@ -1196,7 +1196,8 @@ public async Task<CopilotSession> CreateSessionAsync(SessionConfig config, Cance
                 ToolFilterPrecedence: toolFilter.ToolFilterPrecedence,
                 ExpAssignments: config.ExpAssignments,
                 EnableManagedSettings: config.EnableManagedSettings,
-                EnableGitHubTelemetryForwarding: _options.OnGitHubTelemetry != null ? true : null);
+                EnableGitHubTelemetryForwarding: _options.OnGitHubTelemetry != null ? true : null,
+                AdditionalDirectories: config.AdditionalDirectories);
 
             var rpcTimestamp = Stopwatch.GetTimestamp();
 
@@ -1410,7 +1411,8 @@ public async Task<CopilotSession> ResumeSessionAsync(string sessionId, ResumeSes
                 ToolFilterPrecedence: toolFilter.ToolFilterPrecedence,
                 ExpAssignments: config.ExpAssignments,
                 EnableManagedSettings: config.EnableManagedSettings,
-                EnableGitHubTelemetryForwarding: _options.OnGitHubTelemetry != null ? true : null);
+                EnableGitHubTelemetryForwarding: _options.OnGitHubTelemetry != null ? true : null,
+                AdditionalDirectories: config.AdditionalDirectories);
 
             var rpcTimestamp = Stopwatch.GetTimestamp();
             var response = await InvokeRpcAsync<ResumeSessionResponse>(
@@ -2762,7 +2764,8 @@ internal record CreateSessionRequest(
         OptionsUpdateToolFilterPrecedence? ToolFilterPrecedence = null,
         [property: JsonPropertyName("expAssignments")] CopilotExpAssignmentResponse? ExpAssignments = null,
         [property: JsonPropertyName("enableManagedSettings")] bool? EnableManagedSettings = null,
-        bool? EnableGitHubTelemetryForwarding = null);
+        bool? EnableGitHubTelemetryForwarding = null,
+        IList<string>? AdditionalDirectories = null);
 #pragma warning restore GHCP001
 
     internal record ToolDefinition(
@@ -2868,7 +2871,8 @@ internal record ResumeSessionRequest(
         OptionsUpdateToolFilterPrecedence? ToolFilterPrecedence = null,
         [property: JsonPropertyName("expAssignments")] CopilotExpAssignmentResponse? ExpAssignments = null,
         [property: JsonPropertyName("enableManagedSettings")] bool? EnableManagedSettings = null,
-        bool? EnableGitHubTelemetryForwarding = null);
+        bool? EnableGitHubTelemetryForwarding = null,
+        IList<string>? AdditionalDirectories = null);
 #pragma warning restore GHCP001
 
     internal record ResumeSessionResponse(

dotnet/src/Types.cs

@@ -3051,6 +3051,7 @@ protected SessionConfigBase(SessionConfigBase? other)
         SystemMessage = other.SystemMessage;
         Tools = other.Tools is not null ? [.. other.Tools] : null;
         WorkingDirectory = other.WorkingDirectory;
+        AdditionalDirectories = other.AdditionalDirectories is not null ? [.. other.AdditionalDirectories] : null;
     }
 
     /// <summary>Client name to identify the application using the SDK.</summary>
@@ -3308,6 +3309,12 @@ protected SessionConfigBase(SessionConfigBase? other)
     /// <summary>Working directory for the session.</summary>
     public string? WorkingDirectory { get; set; }
 
+    /// <summary>
+    /// Additional directories the agent may access beyond <see cref="WorkingDirectory"/>.
+    /// Relative paths resolve against the session working directory. Re-supply them when resuming.
+    /// </summary>
+    public IList<string>? AdditionalDirectories { get; set; }
+
     /// <summary>
     /// Enable streaming of assistant message and reasoning chunks.
     /// When true, assistant.message_delta and assistant.reasoning_delta events

dotnet/test/Unit/ClientSessionLifetimeTests.cs

@@ -255,6 +255,38 @@ public async Task CreateSessionAsync_Omits_CustomAgent_ReasoningEffort_When_Unse
         Assert.False(agent.TryGetProperty("reasoningEffort", out _));
     }
 
+    [Fact]
+    public async Task SessionRequests_Serialize_AdditionalDirectories()
+    {
+        await using var server = await FakeCopilotServer.StartAsync();
+        await using var client = new CopilotClient(new CopilotClientOptions { Connection = RuntimeConnection.ForUri(server.Url) });
+
+        await using var created = await client.CreateSessionAsync(new SessionConfig
+        {
+            AdditionalDirectories = ["/repo/shared", "/repo/generated"],
+            OnPermissionRequest = PermissionHandler.ApproveAll
+        });
+
+        var createRequest = Assert.Single(server.Requests, request => request.Method == "session.create");
+        Assert.Collection(
+            createRequest.Params.GetProperty("additionalDirectories").EnumerateArray(),
+            value => Assert.Equal("/repo/shared", value.GetString()),
+            value => Assert.Equal("/repo/generated", value.GetString()));
+
+        server.ClearRequests();
+
+        await using var resumed = await client.ResumeSessionAsync("resume-with-additional-directories", new ResumeSessionConfig
+        {
+            AdditionalDirectories = ["/repo/resumed"],
+            OnPermissionRequest = PermissionHandler.ApproveAll
+        });
+
+        var resumeRequest = Assert.Single(server.Requests, request => request.Method == "session.resume");
+        Assert.Collection(
+            resumeRequest.Params.GetProperty("additionalDirectories").EnumerateArray(),
+            value => Assert.Equal("/repo/resumed", value.GetString()));
+    }
+
     [Fact]
     public async Task CreateSessionAsync_Registers_McpAuth_Interest_Only_When_Handler_Configured()
     {

dotnet/test/Unit/CloneTests.cs

@@ -75,6 +75,7 @@ public void SessionConfig_Clone_CopiesAllProperties()
             ExcludedTools = ["tool3"],
             ExcludedBuiltInAgents = ["explore", "task"],
             WorkingDirectory = "/workspace",
+            AdditionalDirectories = ["/shared", "/generated"],
             Streaming = true,
             EnableCitations = true,
             EnableSessionTelemetry = false,
@@ -119,6 +120,7 @@ public void SessionConfig_Clone_CopiesAllProperties()
         Assert.Equal(original.ExcludedTools, clone.ExcludedTools);
         Assert.Equal(original.ExcludedBuiltInAgents, clone.ExcludedBuiltInAgents);
         Assert.Equal(original.WorkingDirectory, clone.WorkingDirectory);
+        Assert.Equal(original.AdditionalDirectories, clone.AdditionalDirectories);
         Assert.Equal(original.Streaming, clone.Streaming);
         Assert.Equal(original.EnableCitations, clone.EnableCitations);
         Assert.Equal(original.EnableSessionTelemetry, clone.EnableSessionTelemetry);
@@ -154,6 +156,7 @@ public void SessionConfig_Clone_CollectionsAreIndependent()
             ExcludedBuiltInAgents = ["explore"],
             McpServers = new Dictionary<string, McpServerConfig> { ["s1"] = new McpStdioServerConfig { Command = "echo" } },
             CustomAgents = [new CustomAgentConfig { Name = "a1" }],
+            AdditionalDirectories = ["/shared"],
             SkillDirectories = ["/skills"],
             InstructionDirectories = ["/instructions"],
             DisabledSkills = ["skill1"],
@@ -167,6 +170,7 @@ public void SessionConfig_Clone_CollectionsAreIndependent()
         clone.ExcludedBuiltInAgents!.Add("task");
         clone.McpServers!["s2"] = new McpStdioServerConfig { Command = "echo" };
         clone.CustomAgents!.Add(new CustomAgentConfig { Name = "a2" });
+        clone.AdditionalDirectories!.Add("/generated");
         clone.SkillDirectories!.Add("/more");
         clone.InstructionDirectories!.Add("/more-instructions");
         clone.DisabledSkills!.Add("skill99");
@@ -177,6 +181,7 @@ public void SessionConfig_Clone_CollectionsAreIndependent()
         Assert.Single(original.ExcludedBuiltInAgents!);
         Assert.Single(original.McpServers!);
         Assert.Single(original.CustomAgents!);
+        Assert.Single(original.AdditionalDirectories!);
         Assert.Single(original.SkillDirectories!);
         Assert.Single(original.InstructionDirectories!);
         Assert.Single(original.DisabledSkills!);
@@ -203,6 +208,7 @@ public void ResumeSessionConfig_Clone_CollectionsAreIndependent()
             ExcludedBuiltInAgents = ["explore"],
             McpServers = new Dictionary<string, McpServerConfig> { ["s1"] = new McpStdioServerConfig { Command = "echo" } },
             CustomAgents = [new CustomAgentConfig { Name = "a1" }],
+            AdditionalDirectories = ["/shared"],
             SkillDirectories = ["/skills"],
             InstructionDirectories = ["/instructions"],
             DisabledSkills = ["skill1"],
@@ -216,6 +222,7 @@ public void ResumeSessionConfig_Clone_CollectionsAreIndependent()
         clone.ExcludedBuiltInAgents!.Add("task");
         clone.McpServers!["s2"] = new McpStdioServerConfig { Command = "echo" };
         clone.CustomAgents!.Add(new CustomAgentConfig { Name = "a2" });
+        clone.AdditionalDirectories!.Add("/generated");
         clone.SkillDirectories!.Add("/more");
         clone.InstructionDirectories!.Add("/more-instructions");
         clone.DisabledSkills!.Add("skill99");
@@ -226,6 +233,7 @@ public void ResumeSessionConfig_Clone_CollectionsAreIndependent()
         Assert.Single(original.ExcludedBuiltInAgents!);
         Assert.Single(original.McpServers!);
         Assert.Single(original.CustomAgents!);
+        Assert.Single(original.AdditionalDirectories!);
         Assert.Single(original.SkillDirectories!);
         Assert.Single(original.InstructionDirectories!);
         Assert.Single(original.DisabledSkills!);

go/client.go

@@ -802,6 +802,7 @@ func (c *Client) CreateSession(ctx context.Context, config *SessionConfig) (*Ses
 	req.ManageScheduleEnabled = config.ManageScheduleEnabled
 	req.ModelCapabilities = config.ModelCapabilities
 	req.WorkingDirectory = config.WorkingDirectory
+	req.AdditionalDirectories = config.AdditionalDirectories
 	req.MCPServers = config.MCPServers
 	req.MCPOAuthTokenStorage = config.MCPOAuthTokenStorage
 	req.EnvValueMode = "direct"
@@ -1157,6 +1158,7 @@ func (c *Client) ResumeSessionWithOptions(ctx context.Context, sessionID string,
 		req.Hooks = Bool(true)
 	}
 	req.WorkingDirectory = config.WorkingDirectory
+	req.AdditionalDirectories = config.AdditionalDirectories
 	req.ConfigDir = config.ConfigDirectory
 	req.EnableConfigDiscovery = config.EnableConfigDiscovery
 	req.SkipEmbeddingRetrieval = config.SkipEmbeddingRetrieval

go/client_test.go

@@ -251,6 +251,60 @@ func TestClient_ForwardsCapiOptionsToSessionRequests(t *testing.T) {
 	assertCapiEnableWebSocketResponses(t, <-resumeParams)
 }
 
+func TestClient_ForwardsAdditionalDirectoriesToSessionRequests(t *testing.T) {
+	rpcClient, server, _ := newRuntimeShutdownRpcPair(t)
+	t.Cleanup(server.Stop)
+	client := &Client{
+		client:   rpcClient,
+		RPC:      rpc.NewServerRPC(rpcClient),
+		sessions: make(map[string]*Session),
+	}
+
+	createParams := make(chan json.RawMessage, 1)
+	server.SetRequestHandler("session.create", func(params json.RawMessage) (json.RawMessage, *jsonrpc2.Error) {
+		createParams <- append(json.RawMessage(nil), params...)
+		sessionID := sessionIDFromParams(t, params)
+		return []byte(`{"sessionId":"` + sessionID + `","workspacePath":"/workspace"}`), nil
+	})
+
+	_, err := client.CreateSession(t.Context(), &SessionConfig{
+		AdditionalDirectories: []string{"/repo/shared", "/repo/generated"},
+	})
+	if err != nil {
+		t.Fatalf("CreateSession failed: %v", err)
+	}
+	assertAdditionalDirectories(t, <-createParams, []string{"/repo/shared", "/repo/generated"})
+
+	resumeParams := make(chan json.RawMessage, 1)
+	server.SetRequestHandler("session.resume", func(params json.RawMessage) (json.RawMessage, *jsonrpc2.Error) {
+		resumeParams <- append(json.RawMessage(nil), params...)
+		return []byte(`{"sessionId":"resumed-additional-directories","workspacePath":"/workspace"}`), nil
+	})
+
+	_, err = client.ResumeSessionWithOptions(
+		t.Context(),
+		"resumed-additional-directories",
+		&ResumeSessionConfig{AdditionalDirectories: []string{"/repo/resumed"}},
+	)
+	if err != nil {
+		t.Fatalf("ResumeSessionWithOptions failed: %v", err)
+	}
+	assertAdditionalDirectories(t, <-resumeParams, []string{"/repo/resumed"})
+}
+
+func assertAdditionalDirectories(t *testing.T, params json.RawMessage, want []string) {
+	t.Helper()
+	var payload struct {
+		AdditionalDirectories []string `json:"additionalDirectories"`
+	}
+	if err := json.Unmarshal(params, &payload); err != nil {
+		t.Fatalf("failed to decode request params: %v", err)
+	}
+	if !reflect.DeepEqual(payload.AdditionalDirectories, want) {
+		t.Fatalf("additionalDirectories = %v, want %v", payload.AdditionalDirectories, want)
+	}
+}
+
 func TestClient_ForwardsCanvasProviderToSessionRequests(t *testing.T) {
 	rpcClient, server, _ := newRuntimeShutdownRpcPair(t)
 	t.Cleanup(server.Stop)

go/types.go

@@ -1229,6 +1229,9 @@ type SessionConfig struct {
 	// WorkingDirectory is the working directory for the session.
 	// Tool operations will be relative to this directory.
 	WorkingDirectory string
+	// AdditionalDirectories are directories the agent may access beyond WorkingDirectory.
+	// Relative paths are resolved against WorkingDirectory. Re-supply them when resuming.
+	AdditionalDirectories []string
 	// Streaming enables streaming of assistant message and reasoning chunks.
 	// When non-nil and true, assistant.message_delta and assistant.reasoning_delta
 	// events with deltaContent are sent as the response is generated.
@@ -1715,6 +1718,9 @@ type ResumeSessionConfig struct {
 	// WorkingDirectory is the working directory for the session.
 	// Tool operations will be relative to this directory.
 	WorkingDirectory string
+	// AdditionalDirectories are directories the agent may access beyond WorkingDirectory.
+	// Relative paths are resolved against WorkingDirectory. Re-supply them when resuming.
+	AdditionalDirectories []string
 	// ConfigDirectory overrides the default configuration directory location.
 	ConfigDirectory string
 	// EnableConfigDiscovery enables runtime discovery of supported configuration.
@@ -2289,6 +2295,7 @@ type createSessionRequest struct {
 	RequestAutoModeSwitch              *bool                                  `json:"requestAutoModeSwitch,omitempty"`
 	Hooks                              *bool                                  `json:"hooks,omitempty"`
 	WorkingDirectory                   string                                 `json:"workingDirectory,omitempty"`
+	AdditionalDirectories              []string                               `json:"additionalDirectories,omitempty"`
 	Streaming                          *bool                                  `json:"streaming,omitempty"`
 	IncludeSubAgentStreamingEvents     *bool                                  `json:"includeSubAgentStreamingEvents,omitempty"`
 	EnableGitHubTelemetryForwarding    *bool                                  `json:"enableGitHubTelemetryForwarding,omitempty"`
@@ -2379,6 +2386,7 @@ type resumeSessionRequest struct {
 	RequestAutoModeSwitch              *bool                                  `json:"requestAutoModeSwitch,omitempty"`
 	Hooks                              *bool                                  `json:"hooks,omitempty"`
 	WorkingDirectory                   string                                 `json:"workingDirectory,omitempty"`
+	AdditionalDirectories              []string                               `json:"additionalDirectories,omitempty"`
 	ConfigDir                          string                                 `json:"configDir,omitempty"`
 	EnableConfigDiscovery              *bool                                  `json:"enableConfigDiscovery,omitempty"`
 	SkipEmbeddingRetrieval             *bool                                  `json:"skipEmbeddingRetrieval,omitempty"`

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

@@ -131,6 +131,7 @@ static CreateSessionRequest buildCreateRequest(SessionConfig config, String sess
             request.setHooks(true);
         }
         request.setWorkingDirectory(config.getWorkingDirectory());
+        request.setAdditionalDirectories(config.getAdditionalDirectories());
         if (config.isStreaming()) {
             request.setStreaming(true);
         }
@@ -252,6 +253,7 @@ static ResumeSessionRequest buildResumeRequest(String sessionId, ResumeSessionCo
             request.setHooks(true);
         }
         request.setWorkingDirectory(config.getWorkingDirectory());
+        request.setAdditionalDirectories(config.getAdditionalDirectories());
         request.setConfigDirectory(config.getConfigDirectory());
         config.getEnableConfigDiscovery().ifPresent(request::setEnableConfigDiscovery);
         config.getSkipEmbeddingRetrieval().ifPresent(request::setSkipEmbeddingRetrieval);

java/src/main/java/com/github/copilot/rpc/CreateSessionRequest.java

@@ -95,6 +95,9 @@ public final class CreateSessionRequest {
     @JsonProperty("workingDirectory")
     private String workingDirectory;
 
+    @JsonProperty("additionalDirectories")
+    private List<String> additionalDirectories;
+
     @JsonProperty("streaming")
     private Boolean streaming;
 
@@ -492,6 +495,21 @@ public void setWorkingDirectory(String workingDirectory) {
         this.workingDirectory = workingDirectory;
     }
 
+    /** Gets additional directories. @return the additional directories */
+    public List<String> getAdditionalDirectories() {
+        return additionalDirectories;
+    }
+
+    /**
+     * Sets additional directories.
+     *
+     * @param additionalDirectories
+     *            the additional directories
+     */
+    public void setAdditionalDirectories(List<String> additionalDirectories) {
+        this.additionalDirectories = additionalDirectories;
+    }
+
     /** Gets streaming flag. @return the flag */
     public Boolean getStreaming() {
         return streaming;

java/src/main/java/com/github/copilot/rpc/ResumeSessionConfig.java

@@ -67,6 +67,7 @@ public class ResumeSessionConfig {
     private UserInputHandler onUserInputRequest;
     private SessionHooks hooks;
     private String workingDirectory;
+    private List<String> additionalDirectories;
     private String configDirectory;
     private Boolean enableConfigDiscovery;
     private Boolean skipEmbeddingRetrieval;
@@ -811,6 +812,27 @@ public ResumeSessionConfig setWorkingDirectory(String workingDirectory) {
         return this;
     }
 
+    /**
+     * Gets the directories the agent may access beyond the working directory.
+     *
+     * @return the additional directory paths
+     */
+    public List<String> getAdditionalDirectories() {
+        return additionalDirectories;
+    }
+
+    /**
+     * Sets directories the agent may access beyond the working directory.
+     *
+     * @param additionalDirectories
+     *            the additional directory paths
+     * @return this config for method chaining
+     */
+    public ResumeSessionConfig setAdditionalDirectories(List<String> additionalDirectories) {
+        this.additionalDirectories = additionalDirectories;
+        return this;
+    }
+
     /**
      * Gets the configuration directory path.
      *
@@ -1832,6 +1854,9 @@ public ResumeSessionConfig clone() {
         copy.onUserInputRequest = this.onUserInputRequest;
         copy.hooks = this.hooks;
         copy.workingDirectory = this.workingDirectory;
+        copy.additionalDirectories = this.additionalDirectories != null
+                ? new ArrayList<>(this.additionalDirectories)
+                : null;
         copy.configDirectory = this.configDirectory;
         copy.enableConfigDiscovery = this.enableConfigDiscovery;
         copy.skipEmbeddingRetrieval = this.skipEmbeddingRetrieval;