5 files changed, 78 insertions, 9 deletions

diff --git a/src/Makefile b/src/Makefile
index c0b6e1d..9846d8e 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -71,5 +71,35 @@ bitflash: $(IMGUI_OBJS) $(NODE_OBJS) $(GUI_OBJS)
         $(CXX) $(CXXFLAGS) -o $@ $^ $(LIBS)
         @echo "Built: bitflash"
 
+# ---- headless node ---------------------------------------------------------
+#
+# Same node, built without ImGui, GLFW or OpenGL. Linking the GUI made the
+# binary require libGL at load time even when started with -nogui, because the
+# dynamic loader resolves everything before main() runs -- so on a clean server,
+# which is where a node most naturally lives, it failed to start with an error
+# about shared libraries and no hint that it would otherwise work.
+#
+# Objects go to obj-node/ because main_gui.cpp is compiled twice, with and
+# without -DBITFLASH_NO_GUI, and the two must not overwrite each other.
+
+NODE_LIBS = -L$(SECP_LIB) -lsecp256k1 \
+            -L$(RANDOMX_DIR)/build -lrandomx \
+            -lsodium -lssl -lcrypto -ldb_cxx -lpthread
+
+NODE_ONLY_OBJS = $(patsubst obj/%,obj-node/%,$(NODE_OBJS)) \
+                 obj-node/main_gui.o obj-node/headless.o
+
+obj-node/%.o: %.cpp $(HEADERS)
+        @mkdir -p obj-node
+        $(CXX) -c $(CXXFLAGS) -DBITFLASH_NO_GUI -o $@ $<
+
+obj-node/sha.o: sha.cpp sha.h
+        @mkdir -p obj-node
+        $(CXX) -c $(CXXFLAGS) -DBITFLASH_NO_GUI -O3 -o $@ $<
+
+bitflash-node: $(NODE_ONLY_OBJS)
+        $(CXX) $(CXXFLAGS) -o $@ $^ $(NODE_LIBS)
+        @echo "Built: bitflash-node (headless, no libGL needed)"
+
 clean:
-        rm -rf obj bitflash
+        rm -rf obj obj-node bitflash bitflash-node
diff --git a/src/gui.cpp b/src/gui.cpp
index a1a0698..fc6f1e1 100644
--- a/src/gui.cpp
+++ b/src/gui.cpp
@@ -171,14 +171,8 @@ static void RefreshWallet()
 
 void MainFrameRepaint() { g_needRefresh = true; }
 
-string DateTimeStr(int64 nTime)
-{
-    time_t t = (time_t)nTime;
-    struct tm* p = localtime(&t);
-    if (!p) return "";
-    char buf[32]; strftime(buf, sizeof(buf), "%m/%d/%y %H:%M", p);
-    return buf;
-}
+// DateTimeStr moved to util.cpp: main.cpp logs block times with it, so it is
+// needed by builds that have no GUI at all.
 
 // ---------------------------------------------------------------------------
 // Status bar -- separate fullscreen-width overlay pinned to bottom edge.
diff --git a/src/headless.cpp b/src/headless.cpp
new file mode 100644
index 0000000..3372936
--- /dev/null
+++ b/src/headless.cpp
@@ -0,0 +1,20 @@
+// Copyright (c) 2026 Bitflash developers
+// Distributed under the MIT/X11 software license.
+//
+// Stand-ins for the handful of symbols the node core expects the GUI to
+// provide, so a headless binary can be linked without ImGui, GLFW or OpenGL.
+//
+// This exists because linking the GUI made the node need libGL at load time
+// even when started with -nogui: the dynamic loader resolves everything before
+// main() runs, so the flag came far too late. On a clean server -- which is
+// where a node most naturally lives -- that is a hard failure with an error
+// message about shared libraries and no hint that the program would otherwise
+// have worked fine.
+
+#include "headers_core.h"
+
+// The GUI uses this to mark itself dirty. With no window to repaint there is
+// nothing to do, and the call sites in main.cpp and net.cpp stay unchanged.
+void MainFrameRepaint()
+{
+}
diff --git a/src/main_gui.cpp b/src/main_gui.cpp
index 9f7e34e..99e63d4 100644
--- a/src/main_gui.cpp
+++ b/src/main_gui.cpp
@@ -5,7 +5,11 @@
 #include <csignal>
 #endif
 
+// BITFLASH_NO_GUI builds the same entry point without ImGui, GLFW or OpenGL,
+// so the binary does not need libGL present just to start. See headless.cpp.
+#ifndef BITFLASH_NO_GUI
 int RunGUI(int argc, char* argv[]);
+#endif
 
 // Global definitions (were in ui.cpp, now here)
 map<string,string> mapAddressBook;
@@ -186,8 +190,13 @@ int main(int argc, char* argv[])
         if (_beginthread(ThreadBitcoinMiner, 0, NULL) == (uintptr_t)-1)
             printf("Error: _beginthread(ThreadBitcoinMiner) failed\n");
 
+#ifdef BITFLASH_NO_GUI
+    // Nothing else this binary can do; /nogui is accepted and redundant.
+    bool fHeadless = true;
+#else
     bool fHeadless = arg(argc,argv,"/nogui") || arg(argc,argv,"-nogui") ||
                      arg(argc,argv,"/daemon") || arg(argc,argv,"-daemon");
+#endif
 
     if (fHeadless) {
 #ifndef _WIN32
@@ -200,8 +209,12 @@ int main(int argc, char* argv[])
         return 0;
     }
 
+#ifdef BITFLASH_NO_GUI
+    return 0;   // unreachable: fHeadless is always true in this build
+#else
     int ret = RunGUI(argc, argv);
     fShutdown = true;
     StopNode();
     return ret;
+#endif
 }
diff --git a/src/util.cpp b/src/util.cpp
index 68bd18e..e4e314f 100644
--- a/src/util.cpp
+++ b/src/util.cpp
@@ -490,3 +490,15 @@ void AddTimeData(unsigned int ip, int64 nTime)
         printf("|  nTimeOffset = %+lld  (%+lld minutes)\n", nTimeOffset, nTimeOffset/60);
     }
 }
+
+// Formats a block or transaction timestamp for logs and for the wallet view.
+// It lived in gui.cpp, but main.cpp logs block times with it, so a headless
+// build needed it too -- and nothing about formatting a date is GUI work.
+string DateTimeStr(int64 nTime)
+{
+    time_t t = (time_t)nTime;
+    struct tm* p = localtime(&t);
+    if (!p) return "";
+    char buf[32]; strftime(buf, sizeof(buf), "%m/%d/%y %H:%M", p);
+    return buf;
+}