feat: SDK v0.1.8 parity - infinite sessions and client utilities (#3)

Add InfiniteSessionConfig for automatic context window management with
configurable truncation strategy and summarization options.

Add client utility methods:
- get_status(): Returns CLI version and protocol info
- get_auth_status(): Returns authentication state
- list_models(): Returns available models with capabilities

Add skills configuration (skill_directories, disabled_skills) to
SessionConfig and ResumeSessionConfig.

Includes comprehensive E2E test coverage for all new features.
Tested with BYOK provider configuration.

Author: 0xeb

include/copilot/client.hpp

@@ -143,6 +143,19 @@ class Client
     /// @return Future that resolves to ping response
     std::future<PingResponse> ping(std::optional<std::string> message = std::nullopt);
 
+    /// Get CLI status including version and protocol information
+    /// @return Future that resolves to status response
+    std::future<GetStatusResponse> get_status();
+
+    /// Get current authentication status
+    /// @return Future that resolves to auth status response
+    std::future<GetAuthStatusResponse> get_auth_status();
+
+    /// List available models with their metadata
+    /// @return Future that resolves to list of model info
+    /// @throws Error if not authenticated
+    std::future<std::vector<ModelInfo>> list_models();
+
     // =========================================================================
     // Internal API (used by Session)
     // =========================================================================

include/copilot/session.hpp

@@ -106,7 +106,8 @@ class Session : public std::enable_shared_from_this<Session>
     using PermissionHandler = std::function<PermissionRequestResult(const PermissionRequest&)>;
 
     /// Create a session (called by Client)
-    Session(const std::string& session_id, Client* client);
+    Session(const std::string& session_id, Client* client,
+            const std::optional<std::string>& workspace_path = std::nullopt);
 
     ~Session();
 
@@ -124,6 +125,15 @@ class Session : public std::enable_shared_from_this<Session>
         return session_id_;
     }
 
+    /// Get the workspace path for infinite sessions.
+    ///
+    /// Contains checkpoints/, plan.md, and files/ subdirectories.
+    /// Returns nullopt if infinite sessions are disabled.
+    const std::optional<std::string>& workspace_path() const
+    {
+        return workspace_path_;
+    }
+
     // =========================================================================
     // Messaging
     // =========================================================================
@@ -191,6 +201,7 @@ class Session : public std::enable_shared_from_this<Session>
   private:
     std::string session_id_;
     Client* client_;
+    std::optional<std::string> workspace_path_;
 
     // Event handlers
     mutable std::mutex handlers_mutex_;

include/copilot/types.hpp

@@ -531,6 +531,51 @@ struct Tool
     ToolHandler handler;
 };
 
+// =============================================================================
+// Infinite Session Configuration
+// =============================================================================
+
+/// Configuration for infinite sessions with automatic context compaction.
+///
+/// When enabled, sessions automatically manage context window limits through
+/// background compaction and persist state to a workspace directory.
+struct InfiniteSessionConfig
+{
+    /// Whether infinite sessions are enabled (default: true when config is provided)
+    std::optional<bool> enabled;
+
+    /// Context utilization threshold (0.0-1.0) at which background compaction starts.
+    /// Compaction runs asynchronously, allowing the session to continue processing.
+    /// Default: 0.80
+    std::optional<double> background_compaction_threshold;
+
+    /// Context utilization threshold (0.0-1.0) at which the session blocks until
+    /// compaction completes. This prevents context overflow when compaction hasn't
+    /// finished in time. Default: 0.95
+    std::optional<double> buffer_exhaustion_threshold;
+};
+
+inline void to_json(json& j, const InfiniteSessionConfig& c)
+{
+    j = json::object();
+    if (c.enabled)
+        j["enabled"] = *c.enabled;
+    if (c.background_compaction_threshold)
+        j["backgroundCompactionThreshold"] = *c.background_compaction_threshold;
+    if (c.buffer_exhaustion_threshold)
+        j["bufferExhaustionThreshold"] = *c.buffer_exhaustion_threshold;
+}
+
+inline void from_json(const json& j, InfiniteSessionConfig& c)
+{
+    if (j.contains("enabled"))
+        c.enabled = j.at("enabled").get<bool>();
+    if (j.contains("backgroundCompactionThreshold"))
+        c.background_compaction_threshold = j.at("backgroundCompactionThreshold").get<double>();
+    if (j.contains("bufferExhaustionThreshold"))
+        c.buffer_exhaustion_threshold = j.at("bufferExhaustionThreshold").get<double>();
+}
+
 // =============================================================================
 // Session Configuration
 // =============================================================================
@@ -550,6 +595,16 @@ struct SessionConfig
     std::optional<std::map<std::string, json>> mcp_servers;
     std::optional<std::vector<CustomAgentConfig>> custom_agents;
 
+    /// Directories to load skills from.
+    std::optional<std::vector<std::string>> skill_directories;
+
+    /// List of skill names to disable.
+    std::optional<std::vector<std::string>> disabled_skills;
+
+    /// Infinite session configuration for persistent workspaces and automatic compaction.
+    /// When enabled (default), sessions automatically manage context limits and persist state.
+    std::optional<InfiniteSessionConfig> infinite_sessions;
+
     /// If true and provider/model not explicitly set, load from COPILOT_SDK_BYOK_* env vars.
     /// Default: false (explicit configuration preferred over environment variables)
     bool auto_byok_from_env = false;
@@ -565,6 +620,12 @@ struct ResumeSessionConfig
     std::optional<std::map<std::string, json>> mcp_servers;
     std::optional<std::vector<CustomAgentConfig>> custom_agents;
 
+    /// Directories to load skills from.
+    std::optional<std::vector<std::string>> skill_directories;
+
+    /// List of skill names to disable.
+    std::optional<std::vector<std::string>> disabled_skills;
+
     /// If true and provider not explicitly set, load from COPILOT_SDK_BYOK_* env vars.
     /// Default: false (explicit configuration preferred over environment variables)
     bool auto_byok_from_env = false;
@@ -784,4 +845,120 @@ inline void from_json(const json& j, PingResponse& r)
         r.protocol_version = j.at("protocolVersion").get<int>();
 }
 
+/// Response from status.get request
+struct GetStatusResponse
+{
+    std::string version;
+    int protocol_version;
+};
+
+inline void from_json(const json& j, GetStatusResponse& r)
+{
+    j.at("version").get_to(r.version);
+    j.at("protocolVersion").get_to(r.protocol_version);
+}
+
+/// Response from auth.getStatus request
+struct GetAuthStatusResponse
+{
+    bool is_authenticated;
+    std::optional<std::string> auth_type;
+    std::optional<std::string> host;
+    std::optional<std::string> login;
+    std::optional<std::string> status_message;
+};
+
+inline void from_json(const json& j, GetAuthStatusResponse& r)
+{
+    j.at("isAuthenticated").get_to(r.is_authenticated);
+    if (j.contains("authType") && !j["authType"].is_null())
+        r.auth_type = j["authType"].get<std::string>();
+    if (j.contains("host") && !j["host"].is_null())
+        r.host = j["host"].get<std::string>();
+    if (j.contains("login") && !j["login"].is_null())
+        r.login = j["login"].get<std::string>();
+    if (j.contains("statusMessage") && !j["statusMessage"].is_null())
+        r.status_message = j["statusMessage"].get<std::string>();
+}
+
+/// Model capabilities - what the model supports
+struct ModelCapabilities
+{
+    struct Supports
+    {
+        bool vision = false;
+    };
+    struct Limits
+    {
+        std::optional<int> max_prompt_tokens;
+        int max_context_window_tokens = 0;
+    };
+    Supports supports;
+    Limits limits;
+};
+
+inline void from_json(const json& j, ModelCapabilities& c)
+{
+    if (j.contains("supports"))
+    {
+        if (j["supports"].contains("vision"))
+            j["supports"]["vision"].get_to(c.supports.vision);
+    }
+    if (j.contains("limits"))
+    {
+        if (j["limits"].contains("max_prompt_tokens") && !j["limits"]["max_prompt_tokens"].is_null())
+            c.limits.max_prompt_tokens = j["limits"]["max_prompt_tokens"].get<int>();
+        if (j["limits"].contains("max_context_window_tokens"))
+            j["limits"]["max_context_window_tokens"].get_to(c.limits.max_context_window_tokens);
+    }
+}
+
+/// Model policy state
+struct ModelPolicy
+{
+    std::string state;
+    std::string terms;
+};
+
+inline void from_json(const json& j, ModelPolicy& p)
+{
+    j.at("state").get_to(p.state);
+    if (j.contains("terms"))
+        j.at("terms").get_to(p.terms);
+}
+
+/// Model billing information
+struct ModelBilling
+{
+    double multiplier = 1.0;
+};
+
+inline void from_json(const json& j, ModelBilling& b)
+{
+    if (j.contains("multiplier"))
+        j.at("multiplier").get_to(b.multiplier);
+}
+
+/// Information about an available model
+struct ModelInfo
+{
+    std::string id;
+    std::string name;
+    ModelCapabilities capabilities;
+    std::optional<ModelPolicy> policy;
+    std::optional<ModelBilling> billing;
+};
+
+inline void from_json(const json& j, ModelInfo& m)
+{
+    j.at("id").get_to(m.id);
+    j.at("name").get_to(m.name);
+    if (j.contains("capabilities"))
+        j.at("capabilities").get_to(m.capabilities);
+    if (j.contains("policy") && !j["policy"].is_null())
+        m.policy = j["policy"].get<ModelPolicy>();
+    if (j.contains("billing") && !j["billing"].is_null())
+        m.billing = j["billing"].get<ModelBilling>();
+}
+
 } // namespace copilot

src/client.cpp

@@ -87,6 +87,12 @@ json build_session_create_request(const SessionConfig& config)
             agents.push_back(agent);
         request["customAgents"] = agents;
     }
+    if (config.skill_directories.has_value())
+        request["skillDirectories"] = *config.skill_directories;
+    if (config.disabled_skills.has_value())
+        request["disabledSkills"] = *config.disabled_skills;
+    if (config.infinite_sessions.has_value())
+        request["infiniteSessions"] = *config.infinite_sessions;
 
     return request;
 }
@@ -136,6 +142,10 @@ json build_session_resume_request(const std::string& session_id, const ResumeSes
             agents.push_back(agent);
         request["customAgents"] = agents;
     }
+    if (config.skill_directories.has_value())
+        request["skillDirectories"] = *config.skill_directories;
+    if (config.disabled_skills.has_value())
+        request["disabledSkills"] = *config.disabled_skills;
 
     return request;
 }
@@ -543,7 +553,12 @@ std::future<std::shared_ptr<Session>> Client::create_session(SessionConfig confi
             auto response = rpc_->invoke("session.create", request).get();
             std::string session_id = response["sessionId"].get<std::string>();
 
-            auto session = std::make_shared<Session>(session_id, this);
+            // Capture workspace path for infinite sessions
+            std::optional<std::string> workspace_path;
+            if (response.contains("workspacePath") && response["workspacePath"].is_string())
+                workspace_path = response["workspacePath"].get<std::string>();
+
+            auto session = std::make_shared<Session>(session_id, this, workspace_path);
 
             // Register tools locally for handling callbacks from the server
             for (const auto& tool : config.tools)
@@ -582,7 +597,12 @@ Client::resume_session(const std::string& session_id, ResumeSessionConfig config
             auto response = rpc_->invoke("session.resume", request).get();
             std::string returned_session_id = response["sessionId"].get<std::string>();
 
-            auto session = std::make_shared<Session>(returned_session_id, this);
+            // Capture workspace_path if present (for infinite sessions)
+            std::optional<std::string> workspace_path;
+            if (response.contains("workspacePath") && response["workspacePath"].is_string())
+                workspace_path = response["workspacePath"].get<std::string>();
+
+            auto session = std::make_shared<Session>(returned_session_id, this, workspace_path);
 
             // Register tools locally for handling callbacks from the server
             for (const auto& tool : config.tools)
@@ -714,6 +734,72 @@ std::future<PingResponse> Client::ping(std::optional<std::string> message)
     );
 }
 
+std::future<GetStatusResponse> Client::get_status()
+{
+    return std::async(
+        std::launch::async,
+        [this]()
+        {
+            if (state_ != ConnectionState::Connected)
+            {
+                if (options_.auto_start)
+                    start().get();
+                else
+                    throw std::runtime_error("Client not connected. Call start() first.");
+            }
+
+            auto response = rpc_->invoke("status.get", json::object()).get();
+            return response.get<GetStatusResponse>();
+        }
+    );
+}
+
+std::future<GetAuthStatusResponse> Client::get_auth_status()
+{
+    return std::async(
+        std::launch::async,
+        [this]()
+        {
+            if (state_ != ConnectionState::Connected)
+            {
+                if (options_.auto_start)
+                    start().get();
+                else
+                    throw std::runtime_error("Client not connected. Call start() first.");
+            }
+
+            auto response = rpc_->invoke("auth.getStatus", json::object()).get();
+            return response.get<GetAuthStatusResponse>();
+        }
+    );
+}
+
+std::future<std::vector<ModelInfo>> Client::list_models()
+{
+    return std::async(
+        std::launch::async,
+        [this]()
+        {
+            if (state_ != ConnectionState::Connected)
+            {
+                if (options_.auto_start)
+                    start().get();
+                else
+                    throw std::runtime_error("Client not connected. Call start() first.");
+            }
+
+            auto response = rpc_->invoke("models.list", json::object()).get();
+            std::vector<ModelInfo> models;
+            if (response.contains("models") && response["models"].is_array())
+            {
+                for (const auto& m : response["models"])
+                    models.push_back(m.get<ModelInfo>());
+            }
+            return models;
+        }
+    );
+}
+
 std::shared_ptr<Session> Client::get_session(const std::string& session_id)
 {
     std::lock_guard<std::mutex> lock(mutex_);

src/session.cpp

@@ -11,8 +11,9 @@ namespace copilot
 // Constructor / Destructor
 // =============================================================================
 
-Session::Session(const std::string& session_id, Client* client)
-    : session_id_(session_id), client_(client)
+Session::Session(const std::string& session_id, Client* client,
+                 const std::optional<std::string>& workspace_path)
+    : session_id_(session_id), client_(client), workspace_path_(workspace_path)
 {
 }