Unix Domain Socket auto discovery (#833)

This PR adds end-to-end Unix domain socket (UDS) support, allowing zen CLI to discover and connect to UDS-only servers automatically.

- **`unix://` URI scheme in zen CLI**: The `-u` / `--hosturl` option now accepts `unix:///path/to/socket` to connect to a zenserver via a Unix domain socket instead of TCP.
- **Per-instance shared memory for extended server info**: Each zenserver instance now publishes a small shared memory section (keyed by SessionId) containing per-instance data that doesn't fit in the fixed-size ZenServerEntry -- starting with the UDS socket path. This is a 4KB pagefile-backed section on Windows (`Global\ZenInstance_{sessionid}`) and a POSIX shared memory object on Linux/Mac (`/UnrealEngineZen_{sessionid}`).
- **Client-side auto-discovery of UDS servers**: `zen info`, `zen status`, etc. now automatically discover and prefer UDS connections when a server publishes a socket path. Servers running with `--no-network` (UDS-only) are no longer invisible to the CLI.
- **`kNoNetwork` flag in ZenServerEntry**: Servers started with `--no-network` advertise this in their shared state entry. Clients skip TCP fallback for these servers, and display commands (`ps`, `status`, `top`) show `-` instead of a port number to indicate TCP is not available.

28 files changed, 538 insertions, 105 deletions

diff --git a/src/zen/cmds/admin_cmd.cpp b/src/zen/cmds/admin_cmd.cpp
index 15e854796..034d430fd 100644
--- a/src/zen/cmds/admin_cmd.cpp
+++ b/src/zen/cmds/admin_cmd.cpp
@@ -17,7 +17,7 @@ namespace zen {
 ScrubCommand::ScrubCommand()
 {
 	m_Options.add_options()("h,help", "Print help");
-	m_Options.add_option("", "u", "hosturl", "Host URL", cxxopts::value(m_HostName)->default_value(""), "<hosturl>");
+	m_Options.add_option("", "u", "hosturl", kHostUrlHelp, cxxopts::value(m_HostName)->default_value(""), "<hosturl>");
 	m_Options.add_option("", "n", "dry", "Dry run (do not delete any data)", cxxopts::value(m_DryRun), "<bool>");
 	m_Options.add_option("", "", "no-gc", "Do not perform GC after scrub pass", cxxopts::value(m_NoGc), "<bool>");
 	m_Options.add_option("", "", "no-cas", "Do not scrub CAS stores", cxxopts::value(m_NoCas), "<bool>");
@@ -48,7 +48,7 @@ ScrubCommand::Run(const ZenCliOptions& GlobalOptions, int argc, char** argv)
 		throw OptionParseException("Unable to resolve server specification", m_Options.help());
 	}
 
-	HttpClient Http(m_HostName);
+	HttpClient Http = CreateHttpClient(m_HostName);
 
 	HttpClient::KeyValueMap Params{{"skipdelete", ToString(m_DryRun)},
 								   {"skipgc", ToString(m_NoGc)},
@@ -70,7 +70,7 @@ ScrubCommand::Run(const ZenCliOptions& GlobalOptions, int argc, char** argv)
 GcCommand::GcCommand()
 {
 	m_Options.add_options()("h,help", "Print help");
-	m_Options.add_option("", "u", "hosturl", "Host URL", cxxopts::value(m_HostName)->default_value(""), "<hosturl>");
+	m_Options.add_option("", "u", "hosturl", kHostUrlHelp, cxxopts::value(m_HostName)->default_value(""), "<hosturl>");
 	m_Options.add_option("",
 						 "s",
 						 "smallobjects",
@@ -258,7 +258,7 @@ GcCommand::Run(const ZenCliOptions& GlobalOptions, int argc, char** argv)
 	}
 	Params.Entries.insert({"enablevalidation", m_EnableValidation ? "true" : "false"});
 
-	HttpClient Http(m_HostName);
+	HttpClient Http = CreateHttpClient(m_HostName);
 	if (HttpClient::Response Response = Http.Post("/admin/gc"sv, HttpClient::Accept(HttpContentType::kJSON), Params))
 	{
 		ZEN_CONSOLE("OK: {}", Response.ToText());
@@ -272,7 +272,7 @@ GcCommand::Run(const ZenCliOptions& GlobalOptions, int argc, char** argv)
 GcStatusCommand::GcStatusCommand()
 {
 	m_Options.add_options()("h,help", "Print help");
-	m_Options.add_option("", "u", "hosturl", "Host URL", cxxopts::value(m_HostName)->default_value(""), "<hosturl>");
+	m_Options.add_option("", "u", "hosturl", kHostUrlHelp, cxxopts::value(m_HostName)->default_value(""), "<hosturl>");
 	m_Options.add_option("", "d", "details", "Show detailed GC report", cxxopts::value(m_Details)->default_value("false"), "<details>");
 }
 
@@ -297,7 +297,7 @@ GcStatusCommand::Run(const ZenCliOptions& GlobalOptions, int argc, char** argv)
 		throw OptionParseException("Unable to resolve server specification", m_Options.help());
 	}
 
-	HttpClient Http(m_HostName);
+	HttpClient Http = CreateHttpClient(m_HostName);
 	if (HttpClient::Response Response = Http.Get("/admin/gc"sv, HttpClient::Accept(HttpContentType::kJSON)))
 	{
 		ZEN_CONSOLE("OK: {}", Response.ToText());
@@ -311,7 +311,7 @@ GcStatusCommand::Run(const ZenCliOptions& GlobalOptions, int argc, char** argv)
 GcStopCommand::GcStopCommand()
 {
 	m_Options.add_options()("h,help", "Print help");
-	m_Options.add_option("", "u", "hosturl", "Host URL", cxxopts::value(m_HostName)->default_value(""), "<hosturl>");
+	m_Options.add_option("", "u", "hosturl", kHostUrlHelp, cxxopts::value(m_HostName)->default_value(""), "<hosturl>");
 }
 
 GcStopCommand::~GcStopCommand()
@@ -335,7 +335,7 @@ GcStopCommand::Run(const ZenCliOptions& GlobalOptions, int argc, char** argv)
 		throw OptionParseException("Unable to resolve server specification", m_Options.help());
 	}
 
-	HttpClient Http(m_HostName);
+	HttpClient Http = CreateHttpClient(m_HostName);
 	if (HttpClient::Response Response = Http.Post("/admin/gc-stop"sv, HttpClient::Accept(HttpContentType::kJSON)))
 	{
 		if (Response.StatusCode == HttpResponseCode::Accepted)
@@ -358,7 +358,7 @@ GcStopCommand::Run(const ZenCliOptions& GlobalOptions, int argc, char** argv)
 JobCommand::JobCommand()
 {
 	m_Options.add_options()("h,help", "Print help");
-	m_Options.add_option("", "u", "hosturl", "Host URL", cxxopts::value(m_HostName)->default_value(""), "<hosturl>");
+	m_Options.add_option("", "u", "hosturl", kHostUrlHelp, cxxopts::value(m_HostName)->default_value(""), "<hosturl>");
 	m_Options.add_option("", "j", "jobid", "Job id", cxxopts::value(m_JobId), "<jobid>");
 	m_Options.add_option("", "c", "cancel", "Cancel job id", cxxopts::value(m_Cancel), "<cancel>");
 }
@@ -384,7 +384,7 @@ JobCommand::Run(const ZenCliOptions& GlobalOptions, int argc, char** argv)
 		throw OptionParseException("Unable to resolve server specification", m_Options.help());
 	}
 
-	HttpClient Http(m_HostName);
+	HttpClient Http = CreateHttpClient(m_HostName);
 
 	if (m_Cancel)
 	{
@@ -421,7 +421,7 @@ JobCommand::Run(const ZenCliOptions& GlobalOptions, int argc, char** argv)
 LoggingCommand::LoggingCommand()
 {
 	m_Options.add_options()("h,help", "Print help");
-	m_Options.add_option("", "u", "hosturl", "Host URL", cxxopts::value(m_HostName)->default_value(""), "<hosturl>");
+	m_Options.add_option("", "u", "hosturl", kHostUrlHelp, cxxopts::value(m_HostName)->default_value(""), "<hosturl>");
 	m_Options.add_option("", "", "cache-write-log", "Enable cache write logging", cxxopts::value(m_CacheWriteLog), "<enable/disable>");
 	m_Options.add_option("", "", "cache-access-log", "Enable cache access logging", cxxopts::value(m_CacheAccessLog), "<enable/disable>");
 	m_Options
@@ -467,7 +467,7 @@ LoggingCommand::Run(const ZenCliOptions& GlobalOptions, int argc, char** argv)
 		throw OptionParseException("Unable to resolve server specification", m_Options.help());
 	}
 
-	HttpClient Http(m_HostName);
+	HttpClient Http = CreateHttpClient(m_HostName);
 
 	HttpClient::KeyValueMap Parameters;
 
@@ -564,7 +564,7 @@ LoggingCommand::Run(const ZenCliOptions& GlobalOptions, int argc, char** argv)
 FlushCommand::FlushCommand()
 {
 	m_Options.add_options()("h,help", "Print help");
-	m_Options.add_option("", "u", "hosturl", "Host URL", cxxopts::value(m_HostName)->default_value(""), "<hosturl>");
+	m_Options.add_option("", "u", "hosturl", kHostUrlHelp, cxxopts::value(m_HostName)->default_value(""), "<hosturl>");
 }
 
 FlushCommand::~FlushCommand() = default;
@@ -586,7 +586,7 @@ FlushCommand::Run(const ZenCliOptions& GlobalOptions, int argc, char** argv)
 		throw OptionParseException("Unable to resolve server specification", m_Options.help());
 	}
 
-	zen::HttpClient Http(m_HostName);
+	zen::HttpClient Http = CreateHttpClient(m_HostName);
 
 	if (zen::HttpClient::Response Response = Http.Post("/admin/flush"sv))
 	{
diff --git a/src/zen/cmds/cache_cmd.cpp b/src/zen/cmds/cache_cmd.cpp
index 2aa142973..a8c15f119 100644
--- a/src/zen/cmds/cache_cmd.cpp
+++ b/src/zen/cmds/cache_cmd.cpp
@@ -59,7 +59,7 @@ namespace {
 DropCommand::DropCommand()
 {
 	m_Options.add_options()("h,help", "Print help");
-	m_Options.add_option("", "u", "hosturl", "Host URL", cxxopts::value(m_HostName)->default_value(""), "<hosturl>");
+	m_Options.add_option("", "u", "hosturl", kHostUrlHelp, cxxopts::value(m_HostName)->default_value(""), "<hosturl>");
 	m_Options.add_option("", "n", "namespace", "Namespace name", cxxopts::value(m_NamespaceName), "<namespacename>");
 	m_Options.add_option("", "b", "bucket", "Bucket name", cxxopts::value(m_BucketName), "<bucketname>");
 	m_Options.parse_positional({"namespace", "bucket"});
@@ -105,7 +105,7 @@ DropCommand::Run(const ZenCliOptions& GlobalOptions, int argc, char** argv)
 
 	ZEN_CONSOLE("Dropping {}", DropDescription);
 
-	HttpClient Http(m_HostName);
+	HttpClient Http = CreateHttpClient(m_HostName);
 	if (HttpClient::Response Response = Http.Delete(Url))
 	{
 		ZEN_CONSOLE("{}", Response.ToText());
@@ -119,7 +119,7 @@ DropCommand::Run(const ZenCliOptions& GlobalOptions, int argc, char** argv)
 CacheInfoCommand::CacheInfoCommand()
 {
 	m_Options.add_options()("h,help", "Print help");
-	m_Options.add_option("", "u", "hosturl", "Host URL", cxxopts::value(m_HostName)->default_value(""), "<hosturl>");
+	m_Options.add_option("", "u", "hosturl", kHostUrlHelp, cxxopts::value(m_HostName)->default_value(""), "<hosturl>");
 	m_Options.add_option("", "n", "namespace", "Namespace name", cxxopts::value(m_NamespaceName), "<namespacename>");
 	m_Options.add_option("",
 						 "",
@@ -196,7 +196,7 @@ CacheInfoCommand::Run(const ZenCliOptions& GlobalOptions, int argc, char** argv)
 		Parameters.Entries.insert({"bucketsize", "true"});
 	}
 
-	HttpClient Http(m_HostName);
+	HttpClient Http = CreateHttpClient(m_HostName);
 	if (HttpClient::Response Response = Http.Get(Url, HttpClient::Accept(ZenContentType::kJSON), Parameters))
 	{
 		ZEN_CONSOLE("{}", Response.ToText());
@@ -210,7 +210,7 @@ CacheInfoCommand::Run(const ZenCliOptions& GlobalOptions, int argc, char** argv)
 CacheStatsCommand::CacheStatsCommand()
 {
 	m_Options.add_options()("h,help", "Print help");
-	m_Options.add_option("", "u", "hosturl", "Host URL", cxxopts::value(m_HostName)->default_value(""), "<hosturl>");
+	m_Options.add_option("", "u", "hosturl", kHostUrlHelp, cxxopts::value(m_HostName)->default_value(""), "<hosturl>");
 }
 
 CacheStatsCommand::~CacheStatsCommand() = default;
@@ -232,7 +232,7 @@ CacheStatsCommand::Run(const ZenCliOptions& GlobalOptions, int argc, char** argv
 		throw OptionParseException("Unable to resolve server specification", m_Options.help());
 	}
 
-	HttpClient Http(m_HostName);
+	HttpClient Http = CreateHttpClient(m_HostName);
 	if (HttpClient::Response Response = Http.Get("/stats/z$", HttpClient::Accept(ZenContentType::kJSON)))
 	{
 		ZEN_CONSOLE("{}", Response.ToText());
@@ -246,7 +246,7 @@ CacheStatsCommand::Run(const ZenCliOptions& GlobalOptions, int argc, char** argv
 CacheDetailsCommand::CacheDetailsCommand()
 {
 	m_Options.add_options()("h,help", "Print help");
-	m_Options.add_option("", "u", "hosturl", "Host URL", cxxopts::value(m_HostName)->default_value(""), "<hosturl>");
+	m_Options.add_option("", "u", "hosturl", kHostUrlHelp, cxxopts::value(m_HostName)->default_value(""), "<hosturl>");
 	m_Options.add_option("", "c", "csv", "Info on csv format", cxxopts::value(m_CSV), "<csv>");
 	m_Options.add_option("", "d", "details", "Get detailed information about records", cxxopts::value(m_Details), "<details>");
 	m_Options.add_option("",
@@ -329,7 +329,7 @@ CacheDetailsCommand::Run(const ZenCliOptions& GlobalOptions, int argc, char** ar
 		Url = "/z$/details$";
 	}
 
-	HttpClient Http(m_HostName);
+	HttpClient Http = CreateHttpClient(m_HostName);
 	if (HttpClient::Response Response = Http.Get(Url, Headers, Parameters))
 	{
 		ZEN_CONSOLE("{}", Response.ToText());
@@ -343,7 +343,7 @@ CacheDetailsCommand::Run(const ZenCliOptions& GlobalOptions, int argc, char** ar
 CacheGenerateCommand::CacheGenerateCommand()
 {
 	m_Options.add_options()("h,help", "Print help");
-	m_Options.add_option("", "u", "hosturl", "Host URL", cxxopts::value(m_HostName)->default_value(""), "<hosturl>");
+	m_Options.add_option("", "u", "hosturl", kHostUrlHelp, cxxopts::value(m_HostName)->default_value(""), "<hosturl>");
 	m_Options
 		.add_option("", "n", "namespace", "Namespace to generate cache values/records for", cxxopts::value(m_Namespace), "<namespace>");
 	m_Options.add_option("", "b", "bucket", "Bucket name to generate cache values/records for", cxxopts::value(m_Bucket), "<bucket>");
@@ -431,7 +431,7 @@ CacheGenerateCommand::Run(const ZenCliOptions& GlobalOptions, int argc, char** a
 
 	std::uniform_int_distribution<uint64_t> KeyDistribution;
 
-	HttpClient Http(m_HostName);
+	HttpClient Http = CreateHttpClient(m_HostName);
 
 	auto GeneratePutCacheValueRequest(
 		[this, &KeyDistribution, &Generator](std::span<std::uint64_t> BatchSizes, uint64_t RequestIndex) -> CbPackage {
@@ -586,7 +586,7 @@ CacheGenerateCommand::Run(const ZenCliOptions& GlobalOptions, int argc, char** a
 CacheGetCommand::CacheGetCommand()
 {
 	m_Options.add_options()("h,help", "Print help");
-	m_Options.add_option("", "u", "hosturl", "Host URL", cxxopts::value(m_HostName)->default_value(""), "<hosturl>");
+	m_Options.add_option("", "u", "hosturl", kHostUrlHelp, cxxopts::value(m_HostName)->default_value(""), "<hosturl>");
 	m_Options
 		.add_option("", "n", "namespace", "Namespace to generate cache values/records for", cxxopts::value(m_Namespace), "<namespace>");
 	m_Options.add_option("", "b", "bucket", "Bucket name to generate cache values/records for", cxxopts::value(m_Bucket), "<bucket>");
@@ -656,7 +656,7 @@ CacheGetCommand::Run(const ZenCliOptions& GlobalOptions, int argc, char** argv)
 		}
 	}
 
-	HttpClient Http(m_HostName);
+	HttpClient Http = CreateHttpClient(m_HostName);
 
 	if (!m_OutputPath.empty())
 	{
diff --git a/src/zen/cmds/exec_cmd.cpp b/src/zen/cmds/exec_cmd.cpp
index 42c7119e7..cbc153e07 100644
--- a/src/zen/cmds/exec_cmd.cpp
+++ b/src/zen/cmds/exec_cmd.cpp
@@ -44,7 +44,7 @@ namespace zen {
 ExecCommand::ExecCommand()
 {
 	m_Options.add_options()("h,help", "Print help");
-	m_Options.add_option("", "u", "hosturl", "Host URL", cxxopts::value(m_HostName), "<hosturl>");
+	m_Options.add_option("", "u", "hosturl", kHostUrlHelp, cxxopts::value(m_HostName), "<hosturl>");
 	m_Options.add_option("", "", "log", "Action log directory", cxxopts::value(m_RecordingLogPath), "<path>");
 	m_Options.add_option("", "p", "path", "Recording path (directory or .actionlog file)", cxxopts::value(m_RecordingPath), "<path>");
 	m_Options.add_option("", "", "offset", "Recording replay start offset", cxxopts::value(m_Offset), "<offset>");
diff --git a/src/zen/cmds/info_cmd.cpp b/src/zen/cmds/info_cmd.cpp
index 49ad022cf..9faad5691 100644
--- a/src/zen/cmds/info_cmd.cpp
+++ b/src/zen/cmds/info_cmd.cpp
@@ -14,7 +14,7 @@ namespace zen {
 InfoCommand::InfoCommand()
 {
 	m_Options.add_options()("h,help", "Print help");
-	m_Options.add_option("", "u", "hosturl", "Host URL", cxxopts::value(m_HostName)->default_value(""), "<hosturl>");
+	m_Options.add_option("", "u", "hosturl", kHostUrlHelp, cxxopts::value(m_HostName)->default_value(""), "<hosturl>");
 }
 
 InfoCommand::~InfoCommand()
@@ -38,7 +38,7 @@ InfoCommand::Run(const ZenCliOptions& GlobalOptions, int argc, char** argv)
 		throw OptionParseException("Unable to resolve server specification", m_Options.help());
 	}
 
-	HttpClient Http(m_HostName);
+	HttpClient Http = CreateHttpClient(m_HostName);
 
 	if (HttpClient::Response Result = Http.Get("/admin/info", HttpClient::Accept(ZenContentType::kJSON)))
 	{
diff --git a/src/zen/cmds/projectstore_cmd.cpp b/src/zen/cmds/projectstore_cmd.cpp
index c0780c7e8..d31c34fd0 100644
--- a/src/zen/cmds/projectstore_cmd.cpp
+++ b/src/zen/cmds/projectstore_cmd.cpp
@@ -507,7 +507,7 @@ namespace projectstore_impl {
 DropProjectCommand::DropProjectCommand()
 {
 	m_Options.add_options()("h,help", "Print help");
-	m_Options.add_option("", "u", "hosturl", "Host URL", cxxopts::value(m_HostName)->default_value(""), "<hosturl>");
+	m_Options.add_option("", "u", "hosturl", kHostUrlHelp, cxxopts::value(m_HostName)->default_value(""), "<hosturl>");
 	m_Options.add_option("", "p", "project", "Project name", cxxopts::value(m_ProjectName), "<projectid>");
 	m_Options.add_option("", "o", "oplog", "Oplog name", cxxopts::value(m_OplogName), "<oplogid>");
 	m_Options.add_option("", "", "dryrun", "Dry run - resolve arguments but do not drop", cxxopts::value(m_DryRun), "<dryrun>");
@@ -537,7 +537,7 @@ DropProjectCommand::Run(const ZenCliOptions& GlobalOptions, int argc, char** arg
 		throw OptionParseException("Unable to resolve server specification", m_Options.help());
 	}
 
-	HttpClient Http(m_HostName);
+	HttpClient Http = CreateHttpClient(m_HostName);
 
 	m_ProjectName = ResolveProject(Http, m_ProjectName);
 	if (m_ProjectName.empty())
@@ -598,7 +598,7 @@ DropProjectCommand::Run(const ZenCliOptions& GlobalOptions, int argc, char** arg
 ProjectInfoCommand::ProjectInfoCommand()
 {
 	m_Options.add_options()("h,help", "Print help");
-	m_Options.add_option("", "u", "hosturl", "Host URL", cxxopts::value(m_HostName)->default_value(""), "<hosturl>");
+	m_Options.add_option("", "u", "hosturl", kHostUrlHelp, cxxopts::value(m_HostName)->default_value(""), "<hosturl>");
 	m_Options.add_option("", "p", "project", "Project name", cxxopts::value(m_ProjectName), "<projectid>");
 	m_Options.add_option("", "o", "oplog", "Oplog name", cxxopts::value(m_OplogName), "<oplogid>");
 	m_Options.parse_positional({"project", "oplog"});
@@ -632,7 +632,7 @@ ProjectInfoCommand::Run(const ZenCliOptions& GlobalOptions, int argc, char** arg
 		throw OptionParseException("'--project' is required", m_Options.help());
 	}
 
-	HttpClient Http(m_HostName);
+	HttpClient Http = CreateHttpClient(m_HostName);
 
 	std::string Url;
 	if (m_ProjectName.empty())
@@ -684,7 +684,7 @@ ProjectInfoCommand::Run(const ZenCliOptions& GlobalOptions, int argc, char** arg
 CreateProjectCommand::CreateProjectCommand()
 {
 	m_Options.add_options()("h,help", "Print help");
-	m_Options.add_option("", "u", "hosturl", "Host URL", cxxopts::value(m_HostName)->default_value(""), "<hosturl>");
+	m_Options.add_option("", "u", "hosturl", kHostUrlHelp, cxxopts::value(m_HostName)->default_value(""), "<hosturl>");
 	m_Options.add_option("", "p", "project", "Project name", cxxopts::value(m_ProjectId), "<projectid>");
 	m_Options.add_option("", "", "rootdir", "Absolute path to root directory", cxxopts::value(m_RootDir), "<root>");
 	m_Options.add_option("", "", "enginedir", "Absolute path to engine root directory", cxxopts::value(m_EngineRootDir), "<engineroot>");
@@ -721,7 +721,7 @@ CreateProjectCommand::Run(const ZenCliOptions& GlobalOptions, int argc, char** a
 		throw OptionParseException("'--project' is required", m_Options.help());
 	}
 
-	HttpClient Http(m_HostName);
+	HttpClient Http = CreateHttpClient(m_HostName);
 
 	std::string Url = fmt::format("/prj/{}", m_ProjectId);
 
@@ -756,7 +756,7 @@ CreateProjectCommand::Run(const ZenCliOptions& GlobalOptions, int argc, char** a
 CreateOplogCommand::CreateOplogCommand()
 {
 	m_Options.add_options()("h,help", "Print help");
-	m_Options.add_option("", "u", "hosturl", "Host URL", cxxopts::value(m_HostName)->default_value(""), "<hosturl>");
+	m_Options.add_option("", "u", "hosturl", kHostUrlHelp, cxxopts::value(m_HostName)->default_value(""), "<hosturl>");
 	m_Options.add_option("", "p", "project", "Project name", cxxopts::value(m_ProjectId), "<projectid>");
 	m_Options.add_option("", "o", "oplog", "Oplog name", cxxopts::value(m_OplogId), "<oplogid>");
 	m_Options.add_option("", "", "gcpath", "Absolute path to oplog lifetime marker file", cxxopts::value(m_GcPath), "<path>");
@@ -791,8 +791,8 @@ CreateOplogCommand::Run(const ZenCliOptions& GlobalOptions, int argc, char** arg
 		throw OptionParseException("'--project' is required", m_Options.help());
 	}
 
-	HttpClient Http(m_HostName);
-	m_ProjectId = ResolveProject(Http, m_ProjectId);
+	HttpClient Http = CreateHttpClient(m_HostName);
+	m_ProjectId		= ResolveProject(Http, m_ProjectId);
 	if (m_ProjectId.empty())
 	{
 		throw std::runtime_error("Project can not be found");
@@ -835,7 +835,7 @@ CreateOplogCommand::Run(const ZenCliOptions& GlobalOptions, int argc, char** arg
 ExportOplogCommand::ExportOplogCommand()
 {
 	m_Options.add_options()("h,help", "Print help");
-	m_Options.add_option("", "u", "hosturl", "Host URL", cxxopts::value(m_HostName)->default_value(""), "<hosturl>");
+	m_Options.add_option("", "u", "hosturl", kHostUrlHelp, cxxopts::value(m_HostName)->default_value(""), "<hosturl>");
 	m_Options.add_option("", "p", "project", "Project name", cxxopts::value(m_ProjectName), "<projectid>");
 	m_Options.add_option("", "o", "oplog", "Oplog name", cxxopts::value(m_OplogName), "<oplogid>");
 	m_Options.add_option("", "", "maxblocksize", "Max size for bundled attachments", cxxopts::value(m_MaxBlockSize), "<blocksize>");
@@ -1022,8 +1022,8 @@ ExportOplogCommand::Run(const ZenCliOptions& GlobalOptions, int argc, char** arg
 		throw OptionParseException("'--project' is required", m_Options.help());
 	}
 
-	HttpClient Http(m_HostName);
-	m_ProjectName = ResolveProject(Http, m_ProjectName);
+	HttpClient Http = CreateHttpClient(m_HostName);
+	m_ProjectName	= ResolveProject(Http, m_ProjectName);
 	if (m_ProjectName.empty())
 	{
 		throw std::runtime_error("Project can not be found");
@@ -1368,7 +1368,7 @@ ExportOplogCommand::Run(const ZenCliOptions& GlobalOptions, int argc, char** arg
 ImportOplogCommand::ImportOplogCommand()
 {
 	m_Options.add_options()("h,help", "Print help");
-	m_Options.add_option("", "u", "hosturl", "Host URL", cxxopts::value(m_HostName)->default_value(""), "<hosturl>");
+	m_Options.add_option("", "u", "hosturl", kHostUrlHelp, cxxopts::value(m_HostName)->default_value(""), "<hosturl>");
 	m_Options.add_option("", "p", "project", "Project name", cxxopts::value(m_ProjectName), "<projectid>");
 	m_Options.add_option("", "o", "oplog", "Oplog name", cxxopts::value(m_OplogName), "<oplogid>");
 	m_Options.add_option("",
@@ -1541,8 +1541,8 @@ ImportOplogCommand::Run(const ZenCliOptions& GlobalOptions, int argc, char** arg
 								   m_Options.help());
 	}
 
-	HttpClient Http(m_HostName);
-	m_ProjectName = ResolveProject(Http, m_ProjectName);
+	HttpClient Http = CreateHttpClient(m_HostName);
+	m_ProjectName	= ResolveProject(Http, m_ProjectName);
 	if (m_ProjectName.empty())
 	{
 		throw std::runtime_error("Project can not be found");
@@ -1782,7 +1782,7 @@ ImportOplogCommand::Run(const ZenCliOptions& GlobalOptions, int argc, char** arg
 SnapshotOplogCommand::SnapshotOplogCommand()
 {
 	m_Options.add_options()("h,help", "Print help");
-	m_Options.add_option("", "u", "hosturl", "Host URL", cxxopts::value(m_HostName)->default_value(""), "<hosturl>");
+	m_Options.add_option("", "u", "hosturl", kHostUrlHelp, cxxopts::value(m_HostName)->default_value(""), "<hosturl>");
 	m_Options.add_option("", "p", "project", "Project name", cxxopts::value(m_ProjectName), "<projectid>");
 	m_Options.add_option("", "o", "oplog", "Oplog name", cxxopts::value(m_OplogName), "<oplogid>");
 
@@ -1813,7 +1813,7 @@ SnapshotOplogCommand::Run(const ZenCliOptions& GlobalOptions, int argc, char** a
 		throw OptionParseException("Unable to resolve server specification", m_Options.help());
 	}
 
-	HttpClient Http(m_HostName);
+	HttpClient Http = CreateHttpClient(m_HostName);
 
 	if (m_ProjectName.empty())
 	{
@@ -1851,7 +1851,7 @@ SnapshotOplogCommand::Run(const ZenCliOptions& GlobalOptions, int argc, char** a
 ProjectStatsCommand::ProjectStatsCommand()
 {
 	m_Options.add_options()("h,help", "Print help");
-	m_Options.add_option("", "u", "hosturl", "Host URL", cxxopts::value(m_HostName)->default_value(""), "<hosturl>");
+	m_Options.add_option("", "u", "hosturl", kHostUrlHelp, cxxopts::value(m_HostName)->default_value(""), "<hosturl>");
 }
 
 ProjectStatsCommand::~ProjectStatsCommand()
@@ -1876,7 +1876,7 @@ ProjectStatsCommand::Run(const ZenCliOptions& GlobalOptions, int argc, char** ar
 		throw OptionParseException("Unable to resolve server specification", m_Options.help());
 	}
 
-	HttpClient Http(m_HostName);
+	HttpClient Http = CreateHttpClient(m_HostName);
 	if (HttpClient::Response Result = Http.Get("/stats/prj", HttpClient::Accept(ZenContentType::kJSON)))
 	{
 		ZEN_CONSOLE("{}", Result.ToText());
@@ -1892,7 +1892,7 @@ ProjectStatsCommand::Run(const ZenCliOptions& GlobalOptions, int argc, char** ar
 ProjectOpDetailsCommand::ProjectOpDetailsCommand()
 {
 	m_Options.add_options()("h,help", "Print help");
-	m_Options.add_option("", "u", "hosturl", "Host URL", cxxopts::value(m_HostName)->default_value(""), "<hosturl>");
+	m_Options.add_option("", "u", "hosturl", kHostUrlHelp, cxxopts::value(m_HostName)->default_value(""), "<hosturl>");
 	m_Options.add_option("", "c", "csv", "Output in CSV format (default is JSon)", cxxopts::value(m_CSV), "<csv>");
 	m_Options.add_option("", "d", "details", "Detailed info on oplog", cxxopts::value(m_Details), "<details>");
 	m_Options.add_option("", "o", "opdetails", "Details info on oplog body", cxxopts::value(m_OpDetails), "<opdetails>");
@@ -1929,7 +1929,7 @@ ProjectOpDetailsCommand::Run(const ZenCliOptions& GlobalOptions, int argc, char*
 		throw OptionParseException("Unable to resolve server specification", m_Options.help());
 	}
 
-	HttpClient Http(m_HostName);
+	HttpClient Http = CreateHttpClient(m_HostName);
 
 	m_ProjectName = ResolveProject(Http, m_ProjectName);
 	if (m_ProjectName.empty())
@@ -1982,7 +1982,7 @@ ProjectOpDetailsCommand::Run(const ZenCliOptions& GlobalOptions, int argc, char*
 OplogMirrorCommand::OplogMirrorCommand()
 {
 	m_Options.add_options()("h,help", "Print help");
-	m_Options.add_option("", "u", "hosturl", "Host URL", cxxopts::value(m_HostName)->default_value(""), "<hosturl>");
+	m_Options.add_option("", "u", "hosturl", kHostUrlHelp, cxxopts::value(m_HostName)->default_value(""), "<hosturl>");
 	m_Options.add_option("", "p", "project", "Project name to get info from", cxxopts::value(m_ProjectName), "<projectid>");
 	m_Options.add_option("", "l", "oplog", "Oplog name to get info from", cxxopts::value(m_OplogName), "<oplogid>");
 	m_Options.add_option("", "t", "target", "Target directory for mirror", cxxopts::value(m_MirrorRootPath), "<path>");
@@ -2045,7 +2045,7 @@ OplogMirrorCommand::Run(const ZenCliOptions& GlobalOptions, int argc, char** arg
 		throw OptionParseException("Unable to resolve server specification", m_Options.help());
 	}
 
-	HttpClient Http(m_HostName);
+	HttpClient Http = CreateHttpClient(m_HostName);
 
 	m_ProjectName = ResolveProject(Http, m_ProjectName);
 	if (m_ProjectName.empty())
@@ -2283,7 +2283,7 @@ OplogMirrorCommand::Run(const ZenCliOptions& GlobalOptions, int argc, char** arg
 OplogValidateCommand::OplogValidateCommand()
 {
 	m_Options.add_options()("h,help", "Print help");
-	m_Options.add_option("", "u", "hosturl", "Host URL", cxxopts::value(m_HostName)->default_value(""), "<hosturl>");
+	m_Options.add_option("", "u", "hosturl", kHostUrlHelp, cxxopts::value(m_HostName)->default_value(""), "<hosturl>");
 	m_Options.add_option("", "p", "project", "Project name to get info from", cxxopts::value(m_ProjectName), "<projectid>");
 	m_Options.add_option("", "l", "oplog", "Oplog name to get info from", cxxopts::value(m_OplogName), "<oplogid>");
 
@@ -2313,7 +2313,7 @@ OplogValidateCommand::Run(const ZenCliOptions& GlobalOptions, int argc, char** a
 		throw OptionParseException("Unable to resolve server specification", m_Options.help());
 	}
 
-	HttpClient Http(m_HostName);
+	HttpClient Http = CreateHttpClient(m_HostName);
 
 	m_ProjectName = ResolveProject(Http, m_ProjectName);
 	if (m_ProjectName.empty())
diff --git a/src/zen/cmds/rpcreplay_cmd.cpp b/src/zen/cmds/rpcreplay_cmd.cpp
index 70e9e5300..3bf81a9df 100644
--- a/src/zen/cmds/rpcreplay_cmd.cpp
+++ b/src/zen/cmds/rpcreplay_cmd.cpp
@@ -32,7 +32,7 @@ using namespace std::literals;
 RpcStartRecordingCommand::RpcStartRecordingCommand()
 {
 	m_Options.add_options()("h,help", "Print help");
-	m_Options.add_option("", "u", "hosturl", "Host URL", cxxopts::value(m_HostName)->default_value(""), "<hosturl>");
+	m_Options.add_option("", "u", "hosturl", kHostUrlHelp, cxxopts::value(m_HostName)->default_value(""), "<hosturl>");
 	m_Options.add_option("", "p", "path", "Recording file path", cxxopts::value(m_RecordingPath), "<path>");
 
 	m_Options.parse_positional("path");
@@ -61,7 +61,7 @@ RpcStartRecordingCommand::Run(const ZenCliOptions& GlobalOptions, int argc, char
 		throw OptionParseException("'--path' is required", m_Options.help());
 	}
 
-	HttpClient Http(m_HostName);
+	HttpClient Http = CreateHttpClient(m_HostName);
 	if (HttpClient::Response Response =
 			Http.Post("/z$/exec$/start-recording"sv, HttpClient::KeyValueMap{}, HttpClient::KeyValueMap({{"path", m_RecordingPath}})))
 	{
@@ -78,7 +78,7 @@ RpcStartRecordingCommand::Run(const ZenCliOptions& GlobalOptions, int argc, char
 RpcStopRecordingCommand::RpcStopRecordingCommand()
 {
 	m_Options.add_options()("h,help", "Print help");
-	m_Options.add_option("", "u", "hosturl", "Host URL", cxxopts::value(m_HostName)->default_value(""), "<hosturl>");
+	m_Options.add_option("", "u", "hosturl", kHostUrlHelp, cxxopts::value(m_HostName)->default_value(""), "<hosturl>");
 }
 
 RpcStopRecordingCommand::~RpcStopRecordingCommand() = default;
@@ -100,7 +100,7 @@ RpcStopRecordingCommand::Run(const ZenCliOptions& GlobalOptions, int argc, char*
 		throw OptionParseException("Unable to resolve server specification", m_Options.help());
 	}
 
-	HttpClient Http(m_HostName);
+	HttpClient Http = CreateHttpClient(m_HostName);
 	if (HttpClient::Response Response = Http.Post("/z$/exec$/stop-recording"sv))
 	{
 		ZEN_CONSOLE("{}", Response.ToText());
@@ -116,7 +116,7 @@ RpcStopRecordingCommand::Run(const ZenCliOptions& GlobalOptions, int argc, char*
 RpcReplayCommand::RpcReplayCommand()
 {
 	m_Options.add_options()("h,help", "Print help");
-	m_Options.add_option("", "u", "hosturl", "Host URL", cxxopts::value(m_HostName)->default_value(""), "<hosturl>");
+	m_Options.add_option("", "u", "hosturl", kHostUrlHelp, cxxopts::value(m_HostName)->default_value(""), "<hosturl>");
 	m_Options.add_option("", "p", "path", "Recording file path", cxxopts::value(m_RecordingPath), "<path>");
 	m_Options.add_option("", "", "dry", "Do a dry run", cxxopts::value(m_DryRun), "<enable>");
 	m_Options.add_option("",
@@ -223,7 +223,7 @@ RpcReplayCommand::Run(const ZenCliOptions& GlobalOptions, int argc, char** argv)
 
 	if (m_OnHost)
 	{
-		HttpClient Http(m_HostName);
+		HttpClient Http = CreateHttpClient(m_HostName);
 		if (HttpClient::Response Response =
 				Http.Post("/z$/exec$/replay-recording"sv,
 						  HttpClient::KeyValueMap{},
@@ -302,7 +302,7 @@ RpcReplayCommand::Run(const ZenCliOptions& GlobalOptions, int argc, char** argv)
 						}
 					});
 
-					HttpClient Http{m_HostName};
+					HttpClient Http = CreateHttpClient(m_HostName);
 
 					uint64_t EntryIndex = EntryOffset.fetch_add(m_Stride);
 					while (EntryIndex < EntryCount)
diff --git a/src/zen/cmds/serve_cmd.cpp b/src/zen/cmds/serve_cmd.cpp
index 49389bcdf..03007a86c 100644
--- a/src/zen/cmds/serve_cmd.cpp
+++ b/src/zen/cmds/serve_cmd.cpp
@@ -21,7 +21,7 @@ using namespace std::literals;
 ServeCommand::ServeCommand()
 {
 	m_Options.add_options()("h,help", "Print help");
-	m_Options.add_option("", "u", "hosturl", "Host URL", cxxopts::value(m_HostName)->default_value(""), "<hosturl>");
+	m_Options.add_option("", "u", "hosturl", kHostUrlHelp, cxxopts::value(m_HostName)->default_value(""), "<hosturl>");
 	m_Options.add_option("", "p", "project", "Project name", cxxopts::value(m_ProjectName), "<projectid>");
 	m_Options.add_option("", "o", "oplog", "Oplog name", cxxopts::value(m_OplogName), "<oplogid>");
 	m_Options.add_option("", "", "path", "Root path to directory", cxxopts::value(m_RootPath), "<rootpath>");
@@ -183,7 +183,7 @@ ServeCommand::Run(const ZenCliOptions& GlobalOptions, int argc, char** argv)
 	const std::string ProjectUri	  = fmt::format("/prj/{}", m_ProjectName);
 	const std::string ProjectOplogUri = fmt::format("/prj/{}/oplog/{}", m_ProjectName, m_OplogName);
 
-	HttpClient Client(m_HostName);
+	HttpClient Client = CreateHttpClient(m_HostName);
 
 	// Ensure project exists
 
diff --git a/src/zen/cmds/status_cmd.cpp b/src/zen/cmds/status_cmd.cpp
index c43f85052..6ed3c42e1 100644
--- a/src/zen/cmds/status_cmd.cpp
+++ b/src/zen/cmds/status_cmd.cpp
@@ -4,6 +4,7 @@
 
 #include <zencore/compactbinary.h>
 #include <zencore/compactbinaryutil.h>
+#include <zencore/filesystem.h>
 #include <zencore/fmtutils.h>
 #include <zencore/logging.h>
 #include <zencore/string.h>
@@ -64,7 +65,7 @@ StatusCommand::Run(const ZenCliOptions& GlobalOptions, int argc, char** argv)
 		return;
 	}
 
-	ZEN_CONSOLE("{:>5} {:>6} {:>24}", "port", "pid", "session");
+	ZEN_CONSOLE("{:>5} {:>6} {:>24}  {}", "port", "pid", "session", "socket");
 	State.Snapshot([&](const ZenServerState::ZenServerEntry& Entry) {
 		bool MatchesAnyPort		  = (m_Port == 0) && (EffectivePort == 0);
 		bool MatchesEffectivePort = (EffectivePort != 0) && (Entry.EffectiveListenPort.load() == EffectivePort);
@@ -73,7 +74,22 @@ StatusCommand::Run(const ZenCliOptions& GlobalOptions, int argc, char** argv)
 		{
 			StringBuilder<25> SessionStringBuilder;
 			Entry.GetSessionId().ToString(SessionStringBuilder);
-			ZEN_CONSOLE("{:>5} {:>6} {:>24}", Entry.EffectiveListenPort.load(), Entry.Pid.load(), SessionStringBuilder);
+
+			std::string SocketPath;
+			if (Entry.HasInstanceInfo())
+			{
+				ZenServerInstanceInfo Info;
+				if (Info.OpenReadOnly(Entry.GetSessionId()))
+				{
+					InstanceInfoData Data = Info.Read();
+					if (!Data.UnixSocketPath.empty())
+					{
+						SocketPath = PathToUtf8(Data.UnixSocketPath);
+					}
+				}
+			}
+			std::string PortStr = Entry.IsNoNetwork() ? std::string("-") : fmt::to_string(Entry.EffectiveListenPort.load());
+			ZEN_CONSOLE("{:>5} {:>6} {:>24}  {}", PortStr, Entry.Pid.load(), SessionStringBuilder, SocketPath);
 		}
 	});
 }
diff --git a/src/zen/cmds/top_cmd.cpp b/src/zen/cmds/top_cmd.cpp
index f674db6cd..cf2896f0f 100644
--- a/src/zen/cmds/top_cmd.cpp
+++ b/src/zen/cmds/top_cmd.cpp
@@ -2,6 +2,7 @@
 
 #include "top_cmd.h"
 
+#include <zencore/filesystem.h>
 #include <zencore/fmtutils.h>
 #include <zencore/logging.h>
 #include <zencore/system.h>
@@ -81,13 +82,29 @@ TopCommand::Run(const ZenCliOptions& GlobalOptions, int argc, char** argv)
 	{
 		if ((n++ % HeaderPeriod) == 0)
 		{
-			ZEN_CONSOLE("{:>5} {:>6} {:>24}", "port", "pid", "session");
+			ZEN_CONSOLE("{:>5} {:>6} {:>24}  {}", "port", "pid", "session", "socket");
 		}
 
 		State.Snapshot([&](const ZenServerState::ZenServerEntry& Entry) {
 			StringBuilder<25> SessionStringBuilder;
 			Entry.GetSessionId().ToString(SessionStringBuilder);
-			ZEN_CONSOLE("{:>5} {:>6} {:>24}", Entry.EffectiveListenPort.load(), Entry.Pid.load(), SessionStringBuilder);
+
+			std::string SocketPath;
+			if (Entry.HasInstanceInfo())
+			{
+				ZenServerInstanceInfo Info;
+				if (Info.OpenReadOnly(Entry.GetSessionId()))
+				{
+					InstanceInfoData Data = Info.Read();
+					if (!Data.UnixSocketPath.empty())
+					{
+						SocketPath = PathToUtf8(Data.UnixSocketPath);
+					}
+				}
+			}
+
+			std::string PortStr = Entry.IsNoNetwork() ? std::string("-") : fmt::to_string(Entry.EffectiveListenPort.load());
+			ZEN_CONSOLE("{:>5} {:>6} {:>24}  {}", PortStr, Entry.Pid.load(), SessionStringBuilder, SocketPath);
 		});
 
 		zen::Sleep(1000);
@@ -121,7 +138,21 @@ PsCommand::Run(const ZenCliOptions& GlobalOptions, int argc, char** argv)
 	}
 
 	State.Snapshot([&](const ZenServerState::ZenServerEntry& Entry) {
-		ZEN_CONSOLE("Port {} : pid {}", Entry.EffectiveListenPort.load(), Entry.Pid.load());
+		std::string Extra;
+		if (Entry.HasInstanceInfo())
+		{
+			ZenServerInstanceInfo Info;
+			if (Info.OpenReadOnly(Entry.GetSessionId()))
+			{
+				InstanceInfoData Data = Info.Read();
+				if (!Data.UnixSocketPath.empty())
+				{
+					Extra = fmt::format(" (unix: {})", Data.UnixSocketPath);
+				}
+			}
+		}
+		std::string PortStr = Entry.IsNoNetwork() ? std::string("-") : fmt::to_string(Entry.EffectiveListenPort.load());
+		ZEN_CONSOLE("Port {} : pid {}{}", PortStr, Entry.Pid.load(), Extra);
 	});
 }
 
diff --git a/src/zen/cmds/trace_cmd.cpp b/src/zen/cmds/trace_cmd.cpp
index 41a30068c..54c0f080d 100644
--- a/src/zen/cmds/trace_cmd.cpp
+++ b/src/zen/cmds/trace_cmd.cpp
@@ -12,7 +12,7 @@ namespace zen {
 TraceCommand::TraceCommand()
 {
 	m_Options.add_options()("h,help", "Print help");
-	m_Options.add_option("", "u", "hosturl", "Host URL", cxxopts::value(m_HostName)->default_value(""), "<hosturl>");
+	m_Options.add_option("", "u", "hosturl", kHostUrlHelp, cxxopts::value(m_HostName)->default_value(""), "<hosturl>");
 	m_Options.add_option("", "s", "stop", "Stop tracing", cxxopts::value(m_Stop)->default_value("false"), "<stop>");
 	m_Options.add_option("", "", "host", "Start tracing to host", cxxopts::value(m_TraceHost), "<hostip>");
 	m_Options.add_option("", "", "file", "Start tracing to file", cxxopts::value(m_TraceFile), "<filepath>");
@@ -37,7 +37,7 @@ TraceCommand::Run(const ZenCliOptions& GlobalOptions, int argc, char** argv)
 		throw OptionParseException("Unable to resolve server specification", m_Options.help());
 	}
 
-	zen::HttpClient Http(m_HostName);
+	zen::HttpClient Http = CreateHttpClient(m_HostName);
 
 	if (m_Stop)
 	{
diff --git a/src/zen/cmds/ui_cmd.cpp b/src/zen/cmds/ui_cmd.cpp
index da06ce305..4846b4d18 100644
--- a/src/zen/cmds/ui_cmd.cpp
+++ b/src/zen/cmds/ui_cmd.cpp
@@ -50,7 +50,7 @@ UiCommand::UiCommand()
 {
 	m_Options.add_options()("h,help", "Print help");
 	m_Options.add_options()("a,all", "Open dashboard for all running instances", cxxopts::value(m_All)->default_value("false"));
-	m_Options.add_option("", "u", "hosturl", "Host URL", cxxopts::value(m_HostName)->default_value(""), "<hosturl>");
+	m_Options.add_option("", "u", "hosturl", kHostUrlHelp, cxxopts::value(m_HostName)->default_value(""), "<hosturl>");
 	m_Options.add_option("",
 						 "p",
 						 "path",
@@ -230,6 +230,11 @@ UiCommand::Run(const ZenCliOptions& GlobalOptions, int argc, char** argv)
 		throw OptionParseException("Unable to resolve server specification", m_Options.help());
 	}
 
+	if (IsUnixSocketSpec(m_HostName))
+	{
+		throw std::runtime_error("Cannot open browser for a Unix domain socket connection");
+	}
+
 	OpenBrowser(m_HostName);
 }
 
diff --git a/src/zen/cmds/version_cmd.cpp b/src/zen/cmds/version_cmd.cpp
index ed34d7011..0948de1bb 100644
--- a/src/zen/cmds/version_cmd.cpp
+++ b/src/zen/cmds/version_cmd.cpp
@@ -20,7 +20,7 @@ using namespace std::literals;
 VersionCommand::VersionCommand()
 {
 	m_Options.add_options()("h,help", "Print help");
-	m_Options.add_option("", "u", "hosturl", "Host URL", cxxopts::value(m_HostName), "[hosturl]");
+	m_Options.add_option("", "u", "hosturl", kHostUrlHelp, cxxopts::value(m_HostName), "[hosturl]");
 	m_Options.add_option("", "d", "detailed", "Detailed Version", cxxopts::value(m_DetailedVersion), "[detailedversion]");
 	m_Options.add_option("", "o", "output-path", "Path for output", cxxopts::value(m_OutputPath), "[outputpath]");
 	m_Options.parse_positional({"hosturl"});
@@ -57,7 +57,7 @@ VersionCommand::Run(const ZenCliOptions& GlobalOptions, int argc, char** argv)
 			ZEN_CONSOLE("Querying host {}", m_HostName);
 		}
 
-		HttpClient Client(m_HostName, HttpClientSettings{.Timeout = std::chrono::milliseconds(5000)});
+		HttpClient Client = CreateHttpClient(m_HostName, {.Timeout = std::chrono::milliseconds(5000)});
 
 		HttpClient::KeyValueMap Parameters;
 		if (m_DetailedVersion)
diff --git a/src/zen/cmds/vfs_cmd.cpp b/src/zen/cmds/vfs_cmd.cpp
index 79ec20ce2..29ad8dc7c 100644
--- a/src/zen/cmds/vfs_cmd.cpp
+++ b/src/zen/cmds/vfs_cmd.cpp
@@ -18,7 +18,7 @@ using namespace std::literals;
 VfsCommand::VfsCommand()
 {
 	m_Options.add_option("", "", "verb", "VFS management verb (mount, unmount, info)", cxxopts::value(m_Verb), "<verb>");
-	m_Options.add_option("", "u", "hosturl", "Host URL", cxxopts::value(m_HostName)->default_value(""), "<url>");
+	m_Options.add_option("", "u", "hosturl", kHostUrlHelp, cxxopts::value(m_HostName)->default_value(""), "<url>");
 	m_Options.add_option("", "", "vfs-path", "Specify VFS mount point path", cxxopts::value(m_MountPath), "<path>");
 
 	m_Options.parse_positional({"verb", "vfs-path"});
@@ -45,7 +45,7 @@ VfsCommand::Run(const ZenCliOptions& GlobalOptions, int argc, char** argv)
 	if (m_HostName.empty())
 		throw OptionParseException("Unable to resolve server specification", m_Options.help());
 
-	HttpClient Http(m_HostName);
+	HttpClient Http = CreateHttpClient(m_HostName);
 
 	if (m_Verb == "mount"sv)
 	{
diff --git a/src/zen/cmds/workspaces_cmd.cpp b/src/zen/cmds/workspaces_cmd.cpp
index af265d898..220ef6a9e 100644
--- a/src/zen/cmds/workspaces_cmd.cpp
+++ b/src/zen/cmds/workspaces_cmd.cpp
@@ -86,7 +86,7 @@ namespace {
 WorkspaceCommand::WorkspaceCommand()
 {
 	m_Options.add_options()("h,help", "Print help");
-	m_Options.add_option("", "u", "hosturl", "Host URL", cxxopts::value(m_HostName)->default_value(""), "<hosturl>");
+	m_Options.add_option("", "u", "hosturl", kHostUrlHelp, cxxopts::value(m_HostName)->default_value(""), "<hosturl>");
 	m_Options.add_options()("system-dir", "Specify system root", cxxopts::value(m_SystemRootDir));
 	m_Options.add_option("", "v", "verb", "Verb for workspace - create, remove, info", cxxopts::value(m_Verb), "<verb>");
 	m_Options.parse_positional({"verb"});
@@ -182,7 +182,7 @@ WorkspaceCommand::Run(const ZenCliOptions& GlobalOptions, int argc, char** argv)
 		{
 			if (!m_HostName.empty())
 			{
-				HttpClient Http(m_HostName);
+				HttpClient Http = CreateHttpClient(m_HostName);
 				if (HttpClient::Response Result = Http.Get("/ws/refresh"); !Result)
 				{
 					ZEN_CONSOLE_WARN("Failed to refresh workspaces for host {}. Reason: '{}'", m_HostName, Result.ErrorMessage(""sv));
@@ -254,7 +254,7 @@ WorkspaceCommand::Run(const ZenCliOptions& GlobalOptions, int argc, char** argv)
 		{
 			if (!m_HostName.empty())
 			{
-				HttpClient Http(m_HostName);
+				HttpClient Http = CreateHttpClient(m_HostName);
 				if (HttpClient::Response Result = Http.Get("/ws/refresh"); !Result)
 				{
 					ZEN_CONSOLE_WARN("Failed to refresh workspaces for host {}. Reason: '{}'", m_HostName, Result.ErrorMessage(""sv));
@@ -275,7 +275,7 @@ WorkspaceCommand::Run(const ZenCliOptions& GlobalOptions, int argc, char** argv)
 WorkspaceShareCommand::WorkspaceShareCommand()
 {
 	m_Options.add_options()("h,help", "Print help");
-	m_Options.add_option("", "u", "hosturl", "Host URL", cxxopts::value(m_HostName)->default_value(""), "<hosturl>");
+	m_Options.add_option("", "u", "hosturl", kHostUrlHelp, cxxopts::value(m_HostName)->default_value(""), "<hosturl>");
 	m_Options.add_options()("system-dir", "Specify system root", cxxopts::value(m_SystemRootDir));
 	m_Options.add_option("", "v", "verb", "Verb for workspace - create, remove, info", cxxopts::value(m_Verb), "<verb>");
 	m_Options.parse_positional({"verb"});
@@ -475,7 +475,7 @@ WorkspaceShareCommand::Run(const ZenCliOptions& GlobalOptions, int argc, char**
 		{
 			if (!m_HostName.empty())
 			{
-				HttpClient Http(m_HostName);
+				HttpClient Http = CreateHttpClient(m_HostName);
 				if (HttpClient::Response Result = Http.Get("/ws/refresh"); !Result)
 				{
 					ZEN_CONSOLE_WARN("Failed to refresh workspaces for host {}. Reason: '{}'", m_HostName, Result.ErrorMessage(""sv));
@@ -592,7 +592,7 @@ WorkspaceShareCommand::Run(const ZenCliOptions& GlobalOptions, int argc, char**
 		{
 			if (!m_HostName.empty())
 			{
-				HttpClient Http(m_HostName);
+				HttpClient Http = CreateHttpClient(m_HostName);
 				if (HttpClient::Response Result = Http.Get("/ws/refresh"); !Result)
 				{
 					ZEN_CONSOLE_WARN("Failed to refresh workspaces for host {}. Reason: '{}'", m_HostName, Result.ErrorMessage(""sv));
@@ -645,7 +645,7 @@ WorkspaceShareCommand::Run(const ZenCliOptions& GlobalOptions, int argc, char**
 			throw OptionParseException("Unable to resolve server specification", SubOption->help());
 		}
 
-		HttpClient Http(m_HostName);
+		HttpClient Http = CreateHttpClient(m_HostName);
 		if (HttpClient::Response Result = Http.Get(fmt::format("/ws/{}/files", GetShareIdentityUrl(m_FilesOptions)), {}, Params))
 		{
 			ZEN_CONSOLE("{}: {}", Result, Result.ToText());
@@ -678,7 +678,7 @@ WorkspaceShareCommand::Run(const ZenCliOptions& GlobalOptions, int argc, char**
 			throw OptionParseException("Unable to resolve server specification", SubOption->help());
 		}
 
-		HttpClient Http(m_HostName);
+		HttpClient Http = CreateHttpClient(m_HostName);
 		if (HttpClient::Response Result = Http.Get(fmt::format("/ws/{}/entries", GetShareIdentityUrl(m_EntriesOptions)), {}, Params))
 		{
 			ZEN_CONSOLE("{}: {}", Result, Result.ToText());
@@ -753,8 +753,8 @@ WorkspaceShareCommand::Run(const ZenCliOptions& GlobalOptions, int argc, char**
 			throw OptionParseException("'--chunk' is required", SubOption->help());
 		}
 
-		HttpClient Http(m_HostName);
-		m_ChunkId = ChunksToOidStrings(Http, m_WorkspaceId, m_ShareId, std::vector<std::string>{m_ChunkId})[0];
+		HttpClient Http = CreateHttpClient(m_HostName);
+		m_ChunkId		= ChunksToOidStrings(Http, m_WorkspaceId, m_ShareId, std::vector<std::string>{m_ChunkId})[0];
 
 		HttpClient::KeyValueMap Params;
 		if (m_Offset != 0)
@@ -794,8 +794,8 @@ WorkspaceShareCommand::Run(const ZenCliOptions& GlobalOptions, int argc, char**
 			throw OptionParseException("'--chunks' is required", SubOption->help());
 		}
 
-		HttpClient Http(m_HostName);
-		m_ChunkIds = ChunksToOidStrings(Http, m_WorkspaceId, m_ShareId, m_ChunkIds);
+		HttpClient Http = CreateHttpClient(m_HostName);
+		m_ChunkIds		= ChunksToOidStrings(Http, m_WorkspaceId, m_ShareId, m_ChunkIds);
 
 		std::vector<RequestChunkEntry> ChunkRequests;
 		ChunkRequests.resize(m_ChunkIds.size());
diff --git a/src/zen/zen.cpp b/src/zen/zen.cpp
index 10e3a85fe..86154c291 100644
--- a/src/zen/zen.cpp
+++ b/src/zen/zen.cpp
@@ -369,9 +369,31 @@ GetReturnCodeFromHttpResult(const HttpClientError& Ex)
 	}
 }
 
+bool
+ZenCmdBase::IsUnixSocketSpec(std::string_view Spec)
+{
+	return Spec.starts_with("unix://");
+}
+
+HttpClient
+ZenCmdBase::CreateHttpClient(const std::string& HostSpec, HttpClientSettings Settings)
+{
+	if (IsUnixSocketSpec(HostSpec))
+	{
+		Settings.UnixSocketPath = HostSpec.substr(7);  // strip "unix://"
+		return HttpClient("http://localhost", Settings);
+	}
+	return HttpClient(HostSpec, Settings);
+}
+
 std::string
 ZenCmdBase::ResolveTargetHostSpec(const std::string& InHostSpec, uint16_t& OutEffectivePort)
 {
+	if (IsUnixSocketSpec(InHostSpec))
+	{
+		return InHostSpec;	// pass through as-is; parsed later in CreateHttpClient
+	}
+
 	if (InHostSpec.empty())
 	{
 		// If no host is specified then look to see if we have an instance
@@ -386,8 +408,30 @@ ZenCmdBase::ResolveTargetHostSpec(const std::string& InHostSpec, uint16_t& OutEf
 			Servers.Snapshot([&](const zen::ZenServerState::ZenServerEntry& Entry) {
 				if (ResolvedSpec.empty())
 				{
-					ResolvedSpec	 = fmt::format("http://localhost:{}", Entry.EffectiveListenPort.load());
 					OutEffectivePort = Entry.EffectiveListenPort;
+
+					// Check for per-instance info (e.g. UDS path)
+					if (Entry.HasInstanceInfo())
+					{
+						ZenServerInstanceInfo Info;
+						if (Info.OpenReadOnly(Entry.GetSessionId()))
+						{
+							InstanceInfoData Data = Info.Read();
+							if (!Data.UnixSocketPath.empty())
+							{
+								ResolvedSpec = "unix://" + PathToUtf8(Data.UnixSocketPath);
+								return;
+							}
+						}
+					}
+
+					// Skip servers with --no-network since TCP is not reachable
+					if (Entry.IsNoNetwork())
+					{
+						return;
+					}
+
+					ResolvedSpec = fmt::format("http://localhost:{}", Entry.EffectiveListenPort.load());
 				}
 			});
 
diff --git a/src/zen/zen.h b/src/zen/zen.h
index 3cc06eea6..05ce32d0a 100644
--- a/src/zen/zen.h
+++ b/src/zen/zen.h
@@ -5,6 +5,7 @@
 #include <zencore/except.h>
 #include <zencore/timer.h>
 #include <zencore/zencore.h>
+#include <zenhttp/httpclient.h>
 #include <zenutil/config/commandlineoptions.h>
 #include <zenutil/config/loggingconfig.h>
 
@@ -68,6 +69,11 @@ public:
 	static std::string ResolveTargetHostSpec(const std::string& InHostSpec);
 	static std::string ResolveTargetHostSpec(const std::string& InHostSpec, uint16_t& OutEffectivePort);
 
+	static bool		  IsUnixSocketSpec(std::string_view Spec);
+	static HttpClient CreateHttpClient(const std::string& HostSpec, HttpClientSettings Settings = {});
+
+	static constexpr const char* kHostUrlHelp = "Host URL or unix:///path/to/socket";
+
 	static void LogExecutableVersionAndPid();
 };
 
diff --git a/src/zenhttp/clients/httpclientcpr.cpp b/src/zenhttp/clients/httpclientcpr.cpp
index a0f5cc38f..a52b8f74b 100644
--- a/src/zenhttp/clients/httpclientcpr.cpp
+++ b/src/zenhttp/clients/httpclientcpr.cpp
@@ -7,6 +7,7 @@
 #include <zencore/compactbinarypackage.h>
 #include <zencore/compactbinaryutil.h>
 #include <zencore/compress.h>
+#include <zencore/filesystem.h>
 #include <zencore/iobuffer.h>
 #include <zencore/iohash.h>
 #include <zencore/session.h>
@@ -513,7 +514,7 @@ CprHttpClient::AllocSession(const std::string_view				 BaseUrl,
 
 	if (!ConnectionSettings.UnixSocketPath.empty())
 	{
-		CprSession->SetUnixSocket(cpr::UnixSocket(ConnectionSettings.UnixSocketPath));
+		CprSession->SetUnixSocket(cpr::UnixSocket(PathToUtf8(ConnectionSettings.UnixSocketPath)));
 	}
 
 	if (ConnectionSettings.InsecureSsl || !ConnectionSettings.CaBundlePath.empty())
diff --git a/src/zenhttp/clients/httpclientcurl.cpp b/src/zenhttp/clients/httpclientcurl.cpp
index 0dbd5b975..ec9b7bac6 100644
--- a/src/zenhttp/clients/httpclientcurl.cpp
+++ b/src/zenhttp/clients/httpclientcurl.cpp
@@ -8,6 +8,7 @@
 #include <zencore/compactbinaryutil.h>
 #include <zencore/compress.h>
 #include <zencore/except.h>
+#include <zencore/filesystem.h>
 #include <zencore/iobuffer.h>
 #include <zencore/iohash.h>
 #include <zencore/session.h>
@@ -808,7 +809,8 @@ CurlHttpClient::AllocSession(std::string_view ResourcePath, const KeyValueMap& P
 	// Unix domain socket
 	if (!m_ConnectionSettings.UnixSocketPath.empty())
 	{
-		curl_easy_setopt(Handle, CURLOPT_UNIX_SOCKET_PATH, m_ConnectionSettings.UnixSocketPath.c_str());
+		std::string SocketPathUtf8 = PathToUtf8(m_ConnectionSettings.UnixSocketPath);
+		curl_easy_setopt(Handle, CURLOPT_UNIX_SOCKET_PATH, SocketPathUtf8.c_str());
 	}
 
 	// Build URL with parameters
diff --git a/src/zenhttp/clients/httpwsclient.cpp b/src/zenhttp/clients/httpwsclient.cpp
index 2d566ae86..fbae9f5fe 100644
--- a/src/zenhttp/clients/httpwsclient.cpp
+++ b/src/zenhttp/clients/httpwsclient.cpp
@@ -5,6 +5,8 @@
 #include "../servers/wsframecodec.h"
 
 #include <zencore/base64.h>
+#include <zencore/filesystem.h>
+#include <zencore/fmtutils.h>
 #include <zencore/logging.h>
 #include <zencore/string.h>
 
@@ -155,7 +157,7 @@ struct HttpWsClient::Impl
 			}
 		});
 
-		asio::local::stream_protocol::endpoint Endpoint(m_Settings.UnixSocketPath);
+		asio::local::stream_protocol::endpoint Endpoint(PathToUtf8(m_Settings.UnixSocketPath));
 		m_UnixSocket->async_connect(Endpoint, [this](const asio::error_code& Ec) {
 			if (Ec)
 			{
diff --git a/src/zenhttp/httpserver.cpp b/src/zenhttp/httpserver.cpp
index 6ba0ca563..672467f56 100644
--- a/src/zenhttp/httpserver.cpp
+++ b/src/zenhttp/httpserver.cpp
@@ -2,6 +2,8 @@
 
 #include <zenhttp/httpserver.h>
 
+#include <zencore/filesystem.h>
+
 #include "servers/httpasio.h"
 #include "servers/httpmulti.h"
 #include "servers/httpnull.h"
@@ -1157,7 +1159,7 @@ CreateHttpServerClass(const std::string_view ServerClass, const HttpServerConfig
 		ZEN_INFO("using asio HTTP server implementation")
 		return CreateHttpAsioServer(AsioConfig {
 			.ThreadCount = Config.ThreadCount, .ForceLoopback = Config.ForceLoopback, .IsDedicatedServer = Config.IsDedicatedServer,
-			.NoNetwork = Config.NoNetwork, .UnixSocketPath = Config.UnixSocketPath,
+			.NoNetwork = Config.NoNetwork, .UnixSocketPath = PathToUtf8(Config.UnixSocketPath),
 #if ZEN_USE_OPENSSL
 			.HttpsPort = Config.HttpsPort, .CertFile = Config.CertFile, .KeyFile = Config.KeyFile,
 #endif
diff --git a/src/zenhttp/include/zenhttp/httpclient.h b/src/zenhttp/include/zenhttp/httpclient.h
index 03c98af7e..e95d78772 100644
--- a/src/zenhttp/include/zenhttp/httpclient.h
+++ b/src/zenhttp/include/zenhttp/httpclient.h
@@ -10,6 +10,7 @@
 #include <zencore/uid.h>
 #include <zenhttp/httpcommon.h>
 
+#include <filesystem>
 #include <functional>
 #include <optional>
 #include <unordered_map>
@@ -91,7 +92,7 @@ struct HttpClientSettings
 
 	/// Unix domain socket path. When non-empty, the client connects via this
 	/// socket instead of TCP. BaseUri is still used for the Host header and URL.
-	std::string UnixSocketPath;
+	std::filesystem::path UnixSocketPath;
 
 	/// Disable HTTP keep-alive by closing the connection after each request.
 	/// Useful for testing per-connection overhead.
@@ -174,11 +175,14 @@ class HttpClientBase;
 class HttpClient
 {
 public:
-	HttpClient(std::string_view			 BaseUri,
-			   const HttpClientSettings& Connectionsettings	  = {},
-			   std::function<bool()>&&	 CheckIfAbortFunction = {});
+	explicit HttpClient(std::string_view		  BaseUri,
+						const HttpClientSettings& Connectionsettings   = {},
+						std::function<bool()>&&	  CheckIfAbortFunction = {});
 	~HttpClient();
 
+	HttpClient(const HttpClient&) = delete;
+	HttpClient& operator=(const HttpClient&) = delete;
+
 	struct ErrorContext
 	{
 		HttpClientErrorCode ErrorCode;
diff --git a/src/zenhttp/include/zenhttp/httpserver.h b/src/zenhttp/include/zenhttp/httpserver.h
index 627e7921f..77feb6568 100644
--- a/src/zenhttp/include/zenhttp/httpserver.h
+++ b/src/zenhttp/include/zenhttp/httpserver.h
@@ -15,6 +15,7 @@
 
 #include <zentelemetry/stats.h>
 
+#include <filesystem>
 #include <functional>
 #include <gsl/gsl-lite.hpp>
 #include <list>
@@ -329,7 +330,7 @@ struct HttpServerConfig
 	std::vector<HttpServerPluginConfig> PluginConfigs;
 	bool								ForceLoopback = false;
 	unsigned int						ThreadCount	  = 0;
-	std::string							UnixSocketPath;		// Unix domain socket path (empty = disabled, non-Windows only)
+	std::filesystem::path				UnixSocketPath;		// Unix domain socket path (empty = disabled)
 	bool								NoNetwork = false;	// Disable TCP/HTTPS listeners; only accept connections via UnixSocketPath
 	int									HttpsPort = 0;		// HTTPS listen port (0 = disabled, ASIO backend)
 	std::string							CertFile;			// PEM certificate chain file path
diff --git a/src/zenhttp/include/zenhttp/httpwsclient.h b/src/zenhttp/include/zenhttp/httpwsclient.h
index 34d338b1d..2ca9b7ab1 100644
--- a/src/zenhttp/include/zenhttp/httpwsclient.h
+++ b/src/zenhttp/include/zenhttp/httpwsclient.h
@@ -46,7 +46,7 @@ struct HttpWsClientSettings
 
 	/// Unix domain socket path. When non-empty, connects via this socket
 	/// instead of TCP. The URL host is still used for the Host header.
-	std::string UnixSocketPath;
+	std::filesystem::path UnixSocketPath;
 };
 
 /**
diff --git a/src/zenserver/config/config.cpp b/src/zenserver/config/config.cpp
index 8118cb424..60ae93853 100644
--- a/src/zenserver/config/config.cpp
+++ b/src/zenserver/config/config.cpp
@@ -201,6 +201,7 @@ struct ZenServerCmdLineOptions
 	std::string DataDir;
 	std::string BaseSnapshotDir;
 	std::string SecurityConfigPath;
+	std::string UnixSocketPath;
 	std::string PortStr;
 
 	ZenLoggingCmdLineOptions LoggingOptions;
@@ -320,7 +321,7 @@ ZenServerCmdLineOptions::AddCliOptions(cxxopts::Options& options, ZenServerConfi
 					   "",
 					   "unix-socket",
 					   "Unix domain socket path to listen on (in addition to TCP)",
-					   cxxopts::value<std::string>(ServerOptions.HttpConfig.UnixSocketPath),
+					   cxxopts::value<std::string>(UnixSocketPath),
 					   "<path>");
 
 	options.add_option("network",
@@ -480,6 +481,11 @@ ZenServerCmdLineOptions::ApplyOptions(cxxopts::Options& options, ZenServerConfig
 	ServerOptions.BaseSnapshotDir	 = MakeSafeAbsolutePath(BaseSnapshotDir);
 	ServerOptions.SecurityConfigPath = MakeSafeAbsolutePath(SecurityConfigPath);
 
+	if (!UnixSocketPath.empty())
+	{
+		ServerOptions.HttpConfig.UnixSocketPath = MakeSafeAbsolutePath(UnixSocketPath);
+	}
+
 	if (PortStr != "auto")
 	{
 		int Port	   = 0;
diff --git a/src/zenserver/zenserver.cpp b/src/zenserver/zenserver.cpp
index 8283f0cbe..519176ffe 100644
--- a/src/zenserver/zenserver.cpp
+++ b/src/zenserver/zenserver.cpp
@@ -726,6 +726,20 @@ ZenServerMain::Run()
 
 		Entry = ServerState.Register(m_ServerOptions.BasePort);
 
+		// Publish per-instance extended info (e.g. UDS path) via a small shared memory
+		// section keyed by SessionId so clients can discover it during Snapshot() enumeration.
+		{
+			InstanceInfoData InstanceData;
+			InstanceData.UnixSocketPath = m_ServerOptions.HttpConfig.UnixSocketPath;
+			m_InstanceInfo.Create(GetSessionId(), InstanceData);
+			Entry->SignalHasInstanceInfo();
+		}
+
+		if (m_ServerOptions.HttpConfig.NoNetwork)
+		{
+			Entry->SignalNoNetwork();
+		}
+
 		if (m_ServerOptions.OwnerPid)
 		{
 			// We are adding a sponsor process to our own entry, can't wait for pick since the code is not run until later
@@ -786,7 +800,8 @@ ZenServerMain::MakeLockData(bool IsReady)
 								.EffectiveListenPort = gsl::narrow<uint16_t>(m_ServerOptions.BasePort),
 								.Ready				 = IsReady,
 								.DataDir			 = m_ServerOptions.DataDir,
-								.ExecutablePath		 = GetRunningExecutablePath()});
+								.ExecutablePath		 = GetRunningExecutablePath(),
+								.UnixSocketPath		 = m_ServerOptions.HttpConfig.UnixSocketPath});
 };
 
 }  // namespace zen
diff --git a/src/zenserver/zenserver.h b/src/zenserver/zenserver.h
index 374184aa9..830f36e54 100644
--- a/src/zenserver/zenserver.h
+++ b/src/zenserver/zenserver.h
@@ -148,8 +148,9 @@ public:
 	ZenServerMain& operator=(const ZenServerMain&) = delete;
 
 protected:
-	ZenServerConfig& m_ServerOptions;
-	LockFile		 m_LockFile;
+	ZenServerConfig&	  m_ServerOptions;
+	LockFile			  m_LockFile;
+	ZenServerInstanceInfo m_InstanceInfo;
 
 	virtual void InitializeLogging();
 	virtual void DoRun(ZenServerState::ZenServerEntry* Entry) = 0;
diff --git a/src/zenutil/include/zenutil/zenserverprocess.h b/src/zenutil/include/zenutil/zenserverprocess.h
index 1b8750628..2f76f0d6c 100644
--- a/src/zenutil/include/zenutil/zenserverprocess.h
+++ b/src/zenutil/include/zenutil/zenserverprocess.h
@@ -224,8 +224,10 @@ public:
 
 		enum class FlagsEnum : uint16_t
 		{
-			kShutdownPlease = 1 << 0,
-			kIsReady		= 1 << 1,
+			kShutdownPlease	 = 1 << 0,
+			kIsReady		 = 1 << 1,
+			kHasInstanceInfo = 1 << 2,
+			kNoNetwork		 = 1 << 3,
 		};
 
 		FRIEND_ENUM_CLASS_FLAGS(FlagsEnum);
@@ -236,6 +238,10 @@ public:
 		bool IsShutdownRequested() const;
 		void SignalReady();
 		bool IsReady() const;
+		void SignalHasInstanceInfo();
+		bool HasInstanceInfo() const;
+		void SignalNoNetwork();
+		bool IsNoNetwork() const;
 		bool AddSponsorProcess(uint32_t Pid, uint64_t Timeout = 0);
 	};
 
@@ -258,6 +264,51 @@ private:
 	bool			m_IsReadOnly	= true;
 };
 
+/** Per-instance extended data published via a small shared memory section keyed by SessionId.
+
+	Servers create a writable section; clients open it read-only during Snapshot()
+	enumeration to discover fields that don't fit in the fixed-size ZenServerEntry
+	(e.g. Unix domain socket path).
+
+	SessionId is preferred over PID for naming because it is unique per server
+	instance lifetime, avoiding issues with PID reuse on crash/restart.
+ */
+
+struct InstanceInfoData
+{
+	std::filesystem::path UnixSocketPath;
+	// Extensible: add more per-instance fields here in the future
+};
+
+class ZenServerInstanceInfo
+{
+public:
+	ZenServerInstanceInfo();
+	~ZenServerInstanceInfo();
+
+	ZenServerInstanceInfo(const ZenServerInstanceInfo&) = delete;
+	ZenServerInstanceInfo& operator=(const ZenServerInstanceInfo&) = delete;
+
+	/// Server-side: create read-write, populate with data
+	void Create(const Oid& SessionId, const InstanceInfoData& Data);
+
+	/// Client-side: open read-only by SessionId, returns false if not found
+	[[nodiscard]] bool OpenReadOnly(const Oid& SessionId);
+
+	/// Read the data (valid after Create or successful OpenReadOnly)
+	[[nodiscard]] InstanceInfoData Read() const;
+
+	bool IsValid() const { return m_Data != nullptr; }
+
+private:
+	static std::string MakeName(const Oid& SessionId);
+
+	void*	 m_hMapFile = nullptr;
+	uint8_t* m_Data		= nullptr;
+	bool	 m_IsOwner	= false;
+	Oid		 m_SessionId;  // for POSIX cleanup (shm_unlink)
+};
+
 struct LockFileInfo
 {
 	int32_t				  Pid;
@@ -266,6 +317,7 @@ struct LockFileInfo
 	bool				  Ready;
 	std::filesystem::path DataDir;
 	std::filesystem::path ExecutablePath;
+	std::filesystem::path UnixSocketPath;
 };
 
 CbObject	 MakeLockFilePayload(const LockFileInfo& Info);
diff --git a/src/zenutil/zenserverprocess.cpp b/src/zenutil/zenserverprocess.cpp
index b9c50be4f..ac614f779 100644
--- a/src/zenutil/zenserverprocess.cpp
+++ b/src/zenutil/zenserverprocess.cpp
@@ -449,6 +449,30 @@ ZenServerState::ZenServerEntry::IsReady() const
 	return (Flags.load() & static_cast<uint16_t>(FlagsEnum::kIsReady)) != 0;
 }
 
+void
+ZenServerState::ZenServerEntry::SignalHasInstanceInfo()
+{
+	Flags |= uint16_t(FlagsEnum::kHasInstanceInfo);
+}
+
+bool
+ZenServerState::ZenServerEntry::HasInstanceInfo() const
+{
+	return (Flags.load() & static_cast<uint16_t>(FlagsEnum::kHasInstanceInfo)) != 0;
+}
+
+void
+ZenServerState::ZenServerEntry::SignalNoNetwork()
+{
+	Flags |= uint16_t(FlagsEnum::kNoNetwork);
+}
+
+bool
+ZenServerState::ZenServerEntry::IsNoNetwork() const
+{
+	return (Flags.load() & static_cast<uint16_t>(FlagsEnum::kNoNetwork)) != 0;
+}
+
 bool
 ZenServerState::ZenServerEntry::AddSponsorProcess(uint32_t PidToAdd, uint64_t Timeout)
 {
@@ -492,6 +516,222 @@ ZenServerState::ZenServerEntry::AddSponsorProcess(uint32_t PidToAdd, uint64_t Ti
 }
 
 //////////////////////////////////////////////////////////////////////////
+// ZenServerInstanceInfo
+//////////////////////////////////////////////////////////////////////////
+
+static constexpr size_t kInstanceInfoSize = 4096;
+
+ZenServerInstanceInfo::ZenServerInstanceInfo() = default;
+
+ZenServerInstanceInfo::~ZenServerInstanceInfo()
+{
+#if ZEN_PLATFORM_WINDOWS
+	if (m_Data)
+	{
+		UnmapViewOfFile(m_Data);
+	}
+	if (m_hMapFile)
+	{
+		CloseHandle(m_hMapFile);
+	}
+#else
+	if (m_Data != nullptr)
+	{
+		munmap(m_Data, kInstanceInfoSize);
+	}
+	if (m_hMapFile != nullptr)
+	{
+		int Fd = int(intptr_t(m_hMapFile));
+		close(Fd);
+	}
+	if (m_IsOwner)
+	{
+		std::string Name = MakeName(m_SessionId);
+		shm_unlink(Name.c_str());
+	}
+#endif
+	m_Data = nullptr;
+}
+
+std::string
+ZenServerInstanceInfo::MakeName(const Oid& SessionId)
+{
+#if ZEN_PLATFORM_WINDOWS
+	return fmt::format("Global\\ZenInstance_{}", SessionId);
+#else
+	// macOS limits shm_open names to ~31 chars (PSHMNAMLEN), so keep this short.
+	// "/ZenI_" (6) + 24 hex = 30 chars, within the limit.
+	return fmt::format("/ZenI_{}", SessionId);
+#endif
+}
+
+void
+ZenServerInstanceInfo::Create(const Oid& SessionId, const InstanceInfoData& Data)
+{
+	m_SessionId = SessionId;
+	m_IsOwner	= true;
+
+	// Serialize the data to compact binary
+	CbObjectWriter Cbo;
+	if (!Data.UnixSocketPath.empty())
+	{
+		Cbo << "unix_socket" << PathToUtf8(Data.UnixSocketPath);
+	}
+	CbObject Payload = Cbo.Save();
+
+	MemoryView PayloadView = Payload.GetView();
+	uint32_t   PayloadSize = gsl::narrow<uint32_t>(PayloadView.GetSize());
+
+	std::string Name = MakeName(SessionId);
+
+#if ZEN_PLATFORM_WINDOWS
+	zenutil::AnyUserSecurityAttributes Attrs;
+
+	std::wstring WideName(Name.begin(), Name.end());
+
+	HANDLE hMap =
+		CreateFileMappingW(INVALID_HANDLE_VALUE, Attrs.Attributes(), PAGE_READWRITE, 0, DWORD(kInstanceInfoSize), WideName.c_str());
+
+	if (hMap == NULL)
+	{
+		// Fall back to Local namespace
+		std::string	 LocalName = fmt::format("Local\\ZenInstance_{}", SessionId);
+		std::wstring WideLocalName(LocalName.begin(), LocalName.end());
+		hMap = CreateFileMappingW(INVALID_HANDLE_VALUE,
+								  Attrs.Attributes(),
+								  PAGE_READWRITE,
+								  0,
+								  DWORD(kInstanceInfoSize),
+								  WideLocalName.c_str());
+	}
+
+	if (hMap == NULL)
+	{
+		ThrowLastError("Could not create instance info shared memory");
+	}
+
+	void* pBuf = MapViewOfFile(hMap, FILE_MAP_ALL_ACCESS, 0, 0, DWORD(kInstanceInfoSize));
+	if (pBuf == NULL)
+	{
+		CloseHandle(hMap);
+		ThrowLastError("Could not map instance info shared memory");
+	}
+#else
+	int Fd = shm_open(Name.c_str(), O_RDWR | O_CREAT | O_TRUNC | O_CLOEXEC, 0666);
+	if (Fd < 0)
+	{
+		ThrowLastError("Could not create instance info shared memory");
+	}
+	fchmod(Fd, 0666);
+
+	if (ftruncate(Fd, kInstanceInfoSize) < 0)
+	{
+		close(Fd);
+		shm_unlink(Name.c_str());
+		ThrowLastError("Could not resize instance info shared memory");
+	}
+
+	void* pBuf = mmap(nullptr, kInstanceInfoSize, PROT_READ | PROT_WRITE, MAP_SHARED, Fd, 0);
+	if (pBuf == MAP_FAILED)
+	{
+		close(Fd);
+		shm_unlink(Name.c_str());
+		ThrowLastError("Could not map instance info shared memory");
+	}
+
+	void* hMap = reinterpret_cast<void*>(intptr_t(Fd));
+#endif
+
+	m_hMapFile = hMap;
+	m_Data	   = reinterpret_cast<uint8_t*>(pBuf);
+
+	// Write payload: [uint32_t size][compact binary bytes]
+	memcpy(m_Data, &PayloadSize, sizeof PayloadSize);
+	if (PayloadSize > 0)
+	{
+		memcpy(m_Data + sizeof(uint32_t), PayloadView.GetData(), PayloadSize);
+	}
+}
+
+bool
+ZenServerInstanceInfo::OpenReadOnly(const Oid& SessionId)
+{
+	m_SessionId = SessionId;
+
+	std::string Name = MakeName(SessionId);
+
+#if ZEN_PLATFORM_WINDOWS
+	std::wstring WideName(Name.begin(), Name.end());
+
+	HANDLE hMap = OpenFileMappingW(FILE_MAP_READ, FALSE, WideName.c_str());
+	if (hMap == NULL)
+	{
+		// Fall back to Local namespace
+		std::string	 LocalName = fmt::format("Local\\ZenInstance_{}", SessionId);
+		std::wstring WideLocalName(LocalName.begin(), LocalName.end());
+		hMap = OpenFileMappingW(FILE_MAP_READ, FALSE, WideLocalName.c_str());
+	}
+
+	if (hMap == NULL)
+	{
+		return false;
+	}
+
+	void* pBuf = MapViewOfFile(hMap, FILE_MAP_READ, 0, 0, DWORD(kInstanceInfoSize));
+	if (pBuf == NULL)
+	{
+		CloseHandle(hMap);
+		return false;
+	}
+#else
+	int	  Fd   = shm_open(Name.c_str(), O_RDONLY | O_CLOEXEC, 0666);
+	if (Fd < 0)
+	{
+		return false;
+	}
+
+	void* pBuf = mmap(nullptr, kInstanceInfoSize, PROT_READ, MAP_SHARED, Fd, 0);
+	if (pBuf == MAP_FAILED)
+	{
+		close(Fd);
+		return false;
+	}
+
+	void* hMap = reinterpret_cast<void*>(intptr_t(Fd));
+#endif
+
+	m_hMapFile = hMap;
+	m_Data	   = reinterpret_cast<uint8_t*>(pBuf);
+	m_IsOwner  = false;
+
+	return true;
+}
+
+InstanceInfoData
+ZenServerInstanceInfo::Read() const
+{
+	InstanceInfoData Result;
+
+	if (m_Data == nullptr)
+	{
+		return Result;
+	}
+
+	uint32_t PayloadSize = 0;
+	memcpy(&PayloadSize, m_Data, sizeof PayloadSize);
+
+	if (PayloadSize == 0 || PayloadSize > kInstanceInfoSize - sizeof(uint32_t))
+	{
+		return Result;
+	}
+
+	CbObject Payload	  = CbObject::Clone(m_Data + sizeof(uint32_t));
+	Result.UnixSocketPath = Payload["unix_socket"].AsU8String();
+
+	return Result;
+}
+
+//////////////////////////////////////////////////////////////////////////
 
 std::atomic<int> ZenServerTestCounter{0};
 
@@ -1234,6 +1474,10 @@ MakeLockFilePayload(const LockFileInfo& Info)
 	CbObjectWriter Cbo;
 	Cbo << "pid" << Info.Pid << "data" << PathToUtf8(Info.DataDir) << "port" << Info.EffectiveListenPort << "session_id" << Info.SessionId
 		<< "ready" << Info.Ready << "executable" << PathToUtf8(Info.ExecutablePath);
+	if (!Info.UnixSocketPath.empty())
+	{
+		Cbo << "unix_socket" << PathToUtf8(Info.UnixSocketPath);
+	}
 	return Cbo.Save();
 }
 LockFileInfo
@@ -1246,6 +1490,7 @@ ReadLockFilePayload(const CbObject& Payload)
 	Info.Ready				 = Payload["ready"].AsBool();
 	Info.DataDir			 = Payload["data"].AsU8String();
 	Info.ExecutablePath		 = Payload["executable"].AsU8String();
+	Info.UnixSocketPath		 = Payload["unix_socket"].AsU8String();
 	return Info;
 }
 
@@ -1275,7 +1520,7 @@ ValidateLockFileInfo(const LockFileInfo& Info, std::string& OutReason)
 		OutReason = fmt::format("session id ({}) is not valid", Info.SessionId);
 		return false;
 	}
-	if (Info.EffectiveListenPort == 0)
+	if (Info.EffectiveListenPort == 0 && Info.UnixSocketPath.empty())
 	{
 		OutReason = fmt::format("listen port ({}) is not valid", Info.EffectiveListenPort);
 		return false;