ESP working: NPC detection + authoritative server-side health

- entitylist slot 6 (GetHighestEntityIndex); class name via
  GetClientNetworkable -> GetClientClass (replaces the unsafe slot-2 call)
- HL2 SP NPCs: class CAI_BaseNPC + m_lifeState, since NPC m_iHealth is not
  networked; model names from VModelInfoClient006 for labels/friend-foe
- real HP/HP-max from the listen-server entity (IVEngineServer021 ->
  PEntityOfEntIndex -> edict->m_pUnk -> GetBaseEntity) using offsets scanned
  from server.so's datamap; validated against the client model index
- world_to_screen via IVDebugOverlay003::ScreenPosition (fixes box drift)
- maxs sanity clamp, NPC-only debug logging, neutral colour for wildlife
- build.sh: restore -o libhl2hake.so and add server.cpp

7 files changed, 475 insertions, 59 deletions

diff --git a/src/cinput.cpp b/src/cinput.cpp
index 7c40b3b..f4ba322 100644
--- a/src/cinput.cpp
+++ b/src/cinput.cpp
@@ -1,5 +1,6 @@
 // cinput.cpp — CInput discovery, usercmd CRC, get/fix helpers
 #include "hl2h.h"
+uintptr_t g_input = 0;
 
 // ---------------------------------------------------------------------------
 // CRC-32 (standard IEEE reflected, matches Valve's implementation)
diff --git a/src/esp.cpp b/src/esp.cpp
index 87d0b80..d12c718 100644
--- a/src/esp.cpp
+++ b/src/esp.cpp
@@ -3,6 +3,7 @@
 #include <cmath>
 #include <cstring>
 #include <cstddef>
+#include <ctime>
 
 static constexpr float PI_F = 3.14159265358979323846f;
 
@@ -12,11 +13,15 @@ enum SurfSlot {
   SURF_GetScreenSize = 38,
 };
 
+enum { LIFE_ALIVE = 0 };
+
 struct EspTarget {
   float sx, sy;       // screen pos of feet
   float h;            // box height px
   float health, maxhealth;
-  int teamnum;
+  bool show_health;
+  bool friendly;
+  bool neutral;
   char name[48];
 };
 static EspTarget g_targets[128];
@@ -24,7 +29,27 @@ static int g_ntargets = 0;
 static int g_scr_w = 0, g_scr_h = 0;
 static bool g_esp_logged = false;
 
+static double esp_now() {
+  timespec ts;
+  clock_gettime(CLOCK_MONOTONIC, &ts);
+  return (double)ts.tv_sec + (double)ts.tv_nsec * 1e-9;
+}
+
 bool world_to_screen(const Vector &w, float &sx, float &sy) {
+  // Preferred: the engine's own transform. Uses the real view setup (FOV,
+  // aspect, roll), so boxes do not drift at the screen edges.
+  if (g_iface.debugoverlay) {
+    using Fn = int (*)(void *, const Vector *, Vector *);
+    Vector s;
+    int behind =
+        vfunc<Fn>(g_iface.debugoverlay, 9)(g_iface.debugoverlay, &w, &s);
+    if (behind)
+      return false;
+    sx = s.x;
+    sy = s.y;
+    return true;
+  }
+  // Fallback: local math with the default HL2 FOV.
   float pitch = g_cam_view.x * PI_F / 180.0f;
   float yaw = g_cam_view.y * PI_F / 180.0f;
   float sp = sinf(pitch), cp = cosf(pitch);
@@ -43,39 +68,195 @@ bool world_to_screen(const Vector &w, float &sx, float &sy) {
   return true;
 }
 
+// ---------------------------------------------------------------------------
+// entity helpers (IClientEntityList / IClientNetworkable, header-documented)
+// ---------------------------------------------------------------------------
+
+using GetNetFn = void *(*)(void *, int);
+using GetCCFn = void *(*)(void *);
+using GetModelFn = const void *(*)(void *, int);
+using GetModelNameFn = const char *(*)(void *, const void *);
+
+// entitylist slot 0 = GetClientNetworkable(entnum). Safer than assuming the
+// IClientNetworkable subobject offset inside the entity (see projectz).
+static void *entity_networkable(int idx) {
+  return vfunc<GetNetFn>(g_iface.entitylist, 0)(g_iface.entitylist, idx);
+}
+
+// IClientNetworkable slot 2 = GetClientClass(); ClientClass::m_pNetworkName @ +8.
+static const char *entity_class_name(void *net, void **out_cc) {
+  if (!net) return nullptr;
+  void *cc = vfunc<GetCCFn>(net, 2)(net);
+  if (out_cc) *out_cc = cc;
+  return cc ? *(const char **)((uintptr_t)cc + 8) : nullptr;
+}
+
+// m_nModelIndex -> IVModelInfoClient(006)::GetModel/GetModelName.
+// Itanium ABI: two dtor slots, so GetModel=2, GetModelName=4.
+static const char *entity_model_name(void *ent) {
+  if (!g_iface.modelinfo || g_net.modelindex < 0) return nullptr;
+  int modelindex = *(int *)((uintptr_t)ent + g_net.modelindex);
+  if (modelindex <= 0) return nullptr;
+  const void *model =
+      vfunc<GetModelFn>(g_iface.modelinfo, 2)(g_iface.modelinfo, modelindex);
+  if (!model)
+    return nullptr;
+  return vfunc<GetModelNameFn>(g_iface.modelinfo, 4)(g_iface.modelinfo, model);
+}
+
+// HL2 SP: generic NPCs (combine, metrocop, zombie, citizen, antlion, ...) all
+// use the single client class "CAI_BaseNPC" — only special NPCs register their
+// own class names (CNPC_Manhack, CNPC_Strider, CNPC_CombineGunship, ...).
+static bool is_npc_class(const char *name) {
+  if (!name) return false;
+  return strstr(name, "NPC") != nullptr ||
+         strstr(name, "BaseHelicopter") != nullptr;
+}
+
+static bool model_is_friendly(const char *m) {
+  static const char *patterns[] = {
+      "citizen", "humans/",  "barney", "alyx",     "alex",   "scientist",
+      "kleiner", "eli",      "mossman", "vortigaunt", "dog", "grigori",
+      "monk",    "gman",     nullptr};
+  if (!m) return false;
+  for (int i = 0; patterns[i]; i++)
+    if (strstr(m, patterns[i]))
+      return true;
+  return false;
+}
+
+// harmless wildlife that also happens to be CAI_BaseNPC
+static bool model_is_neutral(const char *m) {
+  static const char *patterns[] = {"crow", "gull", "pigeon", "seagull",
+                                   "bird", nullptr};
+  if (!m) return false;
+  for (int i = 0; patterns[i]; i++)
+    if (strstr(m, patterns[i]))
+      return true;
+  return false;
+}
+
+static void short_name(const char *model, char *out, size_t outn) {
+  if (!model) { snprintf(out, outn, "NPC"); return; }
+  const char *base = strrchr(model, '/');
+  base = base ? base + 1 : model;
+  size_t n = strcspn(base, ".");
+  if (n >= outn) n = outn - 1;
+  memcpy(out, base, n);
+  out[n] = 0;
+}
+
 static void esp_collect(int local_idx) {
+  // outer_draw() runs once per PaintTraverseEx call (several per frame); cache
+  // the scan briefly so we do not walk the entity list dozens of times a frame.
+  static double last_scan = 0.0;
+  static double last_dbg = 0.0;
+  double now = esp_now();
+  if (now - last_scan < 0.01)
+    return;
+  last_scan = now;
+  bool dbg = (now - last_dbg) >= 2.0;
+  if (dbg) last_dbg = now;
+
   g_ntargets = 0;
   using Fn = int (*)(void *);
-  int maxent = vfunc<Fn>(g_iface.entitylist, 5)(g_iface.entitylist); // GetHighestEntityIndex
-  if (maxent < 0 || maxent > 512) maxent = 512;
-  for (int idx = 0; idx <= maxent && g_ntargets < 128; idx++) {
+  int hi = vfunc<Fn>(g_iface.entitylist, 6)(g_iface.entitylist); // GetHighestEntityIndex
+  if (hi < 0 || hi > 4096) hi = 4096;
+  int npc_alive = 0, dbg_lines = 0;
+  bool srv = resolve_server_netvars();
+  static bool srv_checked = false;
+  static bool srv_trusted = false;
+
+  for (int idx = 1; idx <= hi && g_ntargets < 128; idx++) {
     if (idx == local_idx) continue;
     void *ent = entitylist_get(idx);
     if (!ent) continue;
+    void *net = entity_networkable(idx);
+    if (!net) continue;
+    const char *cls = entity_class_name(net, nullptr);
+    if (!cls) continue;
+
     uintptr_t e = (uintptr_t)ent;
-    float hpv = (float)*(int *)(e + g_net.health);  // m_iHealth is int
-    if (!(hpv > 0)) continue;
+    int cli_life = g_net.lifestate >= 0
+                       ? (int)*(unsigned char *)(e + g_net.lifestate)
+                       : -1;
+    int cli_hp = g_net.health >= 0 ? *(int *)(e + g_net.health) : 0;
+    bool npc = is_npc_class(cls);
+    const char *model = entity_model_name(ent);
+
+    // NPC health is not networked; read it from the listen-server entity.
+    int hp = cli_hp, maxhp = -1, life = cli_life;
+    if (npc && srv) {
+      int slife = -1, smax = -1;
+      void *sbase = nullptr;
+      int shp = server_entity_health(idx, &smax, &slife, &sbase);
+      if (!srv_checked && sbase) {
+        srv_checked = true;
+        int cli_mi =
+            g_net.modelindex >= 0 ? *(int *)(e + g_net.modelindex) : -1;
+        int srv_mi = server_model_index(sbase);
+        srv_trusted = (cli_mi == srv_mi);
+        logf("ESP server check: idx=%d base=%p cli_model=%d srv_model=%d "
+             "hp=%d maxhp=%d life=%d trusted=%d",
+             idx, sbase, cli_mi, srv_mi, shp, smax, slife, (int)srv_trusted);
+        if (!srv_trusted)
+          logf("ESP: server entity mismatch, ignoring server values");
+      }
+      if (srv_trusted) {
+        if (shp >= 0) hp = shp;
+        if (smax > 0) maxhp = smax;
+        if (slife >= 0) life = slife;
+      }
+    }
+
+    if (dbg && npc && dbg_lines < 40) {
+      dbg_lines++;
+      logf("ESP npc %d cls=%s life=%d(cli %d) hp=%d(cli %d) maxhp=%d model=%s",
+           idx, cls, life, cli_life, hp, cli_hp, maxhp,
+           model ? model : "?");
+    }
+
+    if (npc) {
+      if (life != LIFE_ALIVE) continue;
+      npc_alive++;
+    } else {
+      // players (HL2DM) are the only entities with a live networked m_iHealth
+      if (!strstr(cls, "Player") || !(hp > 0)) continue;
+    }
+
+    float minz = g_net.mins >= 0 ? *(float *)(e + g_net.mins + 8) : 0.0f;
+    float maxz = g_net.maxs >= 0 ? *(float *)(e + g_net.maxs + 8) : 72.0f;
+    if (!(maxz > minz + 4.0f && maxz - minz < 512.0f)) {
+      minz = 0.0f;
+      maxz = 72.0f;
+    }
     Vector origin{*(float *)(e + g_net.origin), *(float *)(e + g_net.origin + 4),
                   *(float *)(e + g_net.origin + 8)};
-    // ponytail: maxs netvar may be unresolved; fixed 72-unit torso fallback
-    float maxsz = g_net.maxs >= 0 ? *(float *)(e + g_net.maxs) : 72.0f;
-    Vector top{origin.x, origin.y, origin.z + maxsz};
+    Vector bottom{origin.x, origin.y, origin.z + minz};
+    Vector top{origin.x, origin.y, origin.z + maxz};
     float sx, sy, tx, ty;
-    if (!world_to_screen(origin, sx, sy) || !world_to_screen(top, tx, ty))
+    if (!world_to_screen(bottom, sx, sy) || !world_to_screen(top, tx, ty))
       continue;
     float h = sy - ty;
-    if (h < 4.0f || sy < 0 || ty > (float)g_scr_h) continue;  // behind / offscreen
+    if (h < 3.0f || sy < 0 || ty > (float)g_scr_h) continue; // behind / offscreen
+    if (sx < -(float)g_scr_w || sx > 2.0f * (float)g_scr_w) continue;
+
     EspTarget &t = g_targets[g_ntargets++];
     t.sx = sx; t.sy = sy; t.h = h;
-    t.health = hpv;
-    t.maxhealth = (float)*(int *)(e + g_net.maxhealth);
-    if (t.maxhealth <= 0) t.maxhealth = hpv;
-    // classname via IClientNetworkable::GetClientClass (slot 2) -> m_pNetworkName @ +8
-    using CCFn = void *(*)(void *);
-    void *cc = vfunc<CCFn>(ent, 2)(ent);
-    const char *nn = cc ? *(const char **)((uintptr_t)cc + 8) : nullptr;
-    strncpy(t.name, nn ? nn : "?", sizeof(t.name) - 1);
-    t.name[sizeof(t.name) - 1] = 0;
+    t.health = hp > 0 ? (float)hp : 0.0f;
+    t.maxhealth = maxhp > 0 ? (float)maxhp : 100.0f;
+    t.show_health = hp > 0;
+    t.friendly = model_is_friendly(model);
+    t.neutral = model_is_neutral(model);
+    short_name(model, t.name, sizeof(t.name));
+    if (npc && !model) snprintf(t.name, sizeof(t.name), "NPC");
+  }
+
+  if (dbg)
+    logf("ESP scan: hi=%d npc_alive=%d targets=%d", hi, npc_alive, g_ntargets);
+  if (g_ntargets && !g_esp_logged) {
+    g_esp_logged = true;
+    logf("ESP: first targets, %d", g_ntargets);
   }
 }
 
@@ -97,28 +278,29 @@ void esp_draw() {
     if (!g_scr_w) return;
   }
   esp_collect(engine_get_local_player());
-  if (g_ntargets && !g_esp_logged) {
-    g_esp_logged = true;
-    logf("ESP: first draw, %d targets", g_ntargets);
-  }
   for (int i = 0; i < g_ntargets; i++) {
     const EspTarget &t = g_targets[i];
-    // team color: 3 combine red, 2 rebels green, else white
-    if (t.teamnum == 3) surf_color(255, 60, 60, 255);
-    else if (t.teamnum == 2) surf_color(60, 255, 60, 255);
-    else surf_color(255, 255, 255, 255);
-    float w = t.h * 0.45f;  // ponytail: constant aspect, no OBB width — swap for m_vecMins/maxs span later
+    if (t.friendly) surf_color(60, 255, 60, 255);
+    else if (t.neutral) surf_color(220, 220, 220, 255);
+    else surf_color(255, 60, 60, 255);
+    float w = t.h * 0.45f;  // ponytail: constant aspect, no OBB width
     surf_rect(0, (int)(t.sx - w / 2), (int)(t.sy - t.h), (int)(t.sx + w / 2), (int)t.sy);
-    // health bar under box
-    float frac = t.health / t.maxhealth;
-    if (frac > 1) frac = 1;
-    surf_color(0, 0, 0, 200);
-    surf_rect(1, (int)(t.sx - w / 2), (int)t.sy + 1, (int)(t.sx + w / 2), (int)t.sy + 4);
-    if (frac > 0.5f) surf_color(40, 255, 40, 255);
-    else if (frac > 0.25f) surf_color(255, 255, 0, 255);
-    else surf_color(255, 40, 40, 255);
-    surf_rect(1, (int)(t.sx - w / 2), (int)t.sy + 2,
-              (int)(t.sx - w / 2 + w * frac), (int)t.sy + 3);
-    draw_text_col((int)(t.sx - w / 2), (int)(t.sy - t.h) - 14, t.name, 255, 255, 255);
+    if (t.show_health) {
+      float frac = t.health / (t.maxhealth > 1.0f ? t.maxhealth : 100.0f);
+      if (frac > 1) frac = 1;
+      surf_color(0, 0, 0, 200);
+      surf_rect(1, (int)(t.sx - w / 2), (int)t.sy + 1, (int)(t.sx + w / 2), (int)t.sy + 4);
+      if (frac > 0.5f) surf_color(40, 255, 40, 255);
+      else if (frac > 0.25f) surf_color(255, 255, 0, 255);
+      else surf_color(255, 40, 40, 255);
+      surf_rect(1, (int)(t.sx - w / 2), (int)t.sy + 2,
+                (int)(t.sx - w / 2 + w * frac), (int)t.sy + 3);
+    }
+    char label[64];
+    if (t.show_health)
+      snprintf(label, sizeof(label), "%s %d", t.name, (int)t.health);
+    else
+      snprintf(label, sizeof(label), "%s", t.name);
+    draw_text_col((int)(t.sx - w / 2), (int)(t.sy - t.h) - 14, label, 255, 255, 255);
   }
 }
diff --git a/src/hl2h.cpp b/src/hl2h.cpp
index 01fdb0f..a451a18 100644
--- a/src/hl2h.cpp
+++ b/src/hl2h.cpp
@@ -29,7 +29,7 @@ void logf(const char *fmt, ...) {
 // globals
 // ---------------------------------------------------------------------------
 
-Module g_client, g_engine;
+Module g_client, g_engine, g_server;
 GameInterfaces g_iface;
 NetVars g_net;
 Vector g_cam_eye{0, 0, 0};
@@ -335,6 +335,13 @@ static void *setup_thread(void *) {
        "VEngineClient014=%p",
        g_iface.client, g_iface.entitylist, g_iface.engine);
 
+  g_iface.modelinfo = ef("VModelInfoClient006", nullptr);
+  g_iface.engineserver = ef("VEngineServer021", nullptr);
+  g_iface.debugoverlay = ef("VDebugOverlay003", nullptr);
+  logf("modelinfo: %p (VModelInfoClient006)", g_iface.modelinfo);
+  logf("engineserver: %p (VEngineServer021), debugoverlay: %p",
+       g_iface.engineserver, g_iface.debugoverlay);
+
   resolve_netvars();
   if (!find_input_global())
     return nullptr;
diff --git a/src/hl2h.h b/src/hl2h.h
index d6a005e..b693617 100644
--- a/src/hl2h.h
+++ b/src/hl2h.h
@@ -36,7 +36,7 @@ struct Module {
     return false;
   }
 };
-extern Module g_client, g_engine;
+extern Module g_client, g_engine, g_server;
 
 // ---------------------------------------------------------------------------
 // game interfaces
@@ -48,6 +48,9 @@ struct GameInterfaces {
   void *client = nullptr;
   void *entitylist = nullptr;
   void *engine = nullptr;
+  void *modelinfo = nullptr;    // IVModelInfoClient006 (model index -> model name)
+  void *engineserver = nullptr; // IVEngineServer021 (edict access, incl. server entities)
+  void *debugoverlay = nullptr; // IVDebugOverlay003 (engine-accurate world->screen)
 };
 extern GameInterfaces g_iface;
 
@@ -70,9 +73,13 @@ struct NetVars {
   int viewoffset = -1;
   int mins = -1;
   int maxs = -1;
+  int lifestate = -1;
+  int modelindex = -1;
   // ponytail: mins/maxs may be absent from some HL2 netvar tables; esp.cpp falls back to h=72
   bool ok() const { return flags >= 0 && velocity >= 0 && movetype >= 0; }
-  bool esp_ok() const { return ok() && health >= 0 && maxhealth >= 0 && teamnum >= 0 && origin >= 0 && viewoffset >= 0; }
+  // ponytail: m_iMaxHealth isn't a netvar in HL2 SP; esp.cpp falls back to 100.
+  // m_iHealth only ever updates for players — NPCs are detected via m_lifeState.
+  bool esp_ok() const { return ok() && health >= 0 && teamnum >= 0 && origin >= 0 && viewoffset >= 0; }
 };
 extern NetVars g_net;
 
@@ -139,6 +146,10 @@ void fix_verified_crc(int seq, uint32_t crc);
 uint32_t usercmd_checksum(const CUserCmd *c);
 bool find_input_global();
 void resolve_netvars();
+int class_health_off(const char *name);
+bool resolve_server_netvars();
+int server_entity_health(int idx, int *maxhealth, int *lifestate, void **base_out);
+int server_model_index(void *base);
 void find_modules();
 void init_conmsg();
 bool feature_active(int feature);
diff --git a/src/modules.cpp b/src/modules.cpp
index d20fe04..70e2dff 100644
--- a/src/modules.cpp
+++ b/src/modules.cpp
@@ -11,6 +11,7 @@ static bool basename_is(const char *path, const char *base) {
 void find_modules() {
   g_client = Module();
   g_engine = Module();
+  g_server = Module();
   FILE *f = fopen("/proc/self/maps", "r");
   if (!f)
     return;
@@ -41,6 +42,8 @@ void find_modules() {
         m = &g_client;
       else if (basename_is(clean, "engine.so"))
         m = &g_engine;
+      else if (basename_is(clean, "server.so"))
+        m = &g_server;
     } else {
       // anon: absorb only as .bss tail after a file-backed range
       if (g_client.valid() && g_client.ranges.back().file &&
diff --git a/src/netvars.cpp b/src/netvars.cpp
index 5c8c296..f702c41 100644
--- a/src/netvars.cpp
+++ b/src/netvars.cpp
@@ -27,7 +27,24 @@ static bool module_string(uintptr_t p, char *out, size_t outn) {
 
 static int g_dumped_tables = 0;
 
-static void collect_netvars(uintptr_t table, uintptr_t base_off, int depth) {
+// per-client-class health offset (m_iHealth lives at different offsets per
+// class chain: CBasePlayer via DT_BasePlayer=128, NPCs via DT_BaseCombatCharacter)
+static struct {
+  char name[32];
+  int off;
+} g_class_health[256];
+static int g_class_health_n = 0;
+
+int class_health_off(const char *name) {
+  for (int i = 0; i < g_class_health_n; i++)
+    if (strcmp(name, g_class_health[i].name) == 0)
+      return g_class_health[i].off;
+  return -1;
+}
+
+static void collect_netvars(uintptr_t table, uintptr_t base_off, int depth,
+                            int *out_health)
+{
   if (depth > 8)
     return;
   uintptr_t props = *(uintptr_t *)(table + 0x00);
@@ -67,13 +84,19 @@ static void collect_netvars(uintptr_t table, uintptr_t base_off, int depth) {
     if (dump)
       logf("  [%s] %s type=%d off=%d(0x%x) table=%s array=%s", tname, pname2,
            ptype, poff, poff, ptable ? "yes" : "no", parray ? "yes" : "no");
-
     if (ptable) {
-      collect_netvars(ptable, base_off + (uint32_t)poff, depth + 1);
+      collect_netvars(ptable, base_off + (uint32_t)poff, depth + 1,
+                      out_health);
       continue;
     }
 
-    if (strcmp(pname2, "m_fFlags") == 0 && g_net.flags < 0) {
+    if (out_health && *out_health < 0 && strcmp(pname2, "m_iHealth") == 0)
+      *out_health = (int)(base_off + (uint32_t)poff);
+    if (strcmp(pname2, "m_lifeState") == 0 && g_net.lifestate < 0) {
+      g_net.lifestate = (int)(base_off + (uint32_t)poff);
+    } else if (strcmp(pname2, "m_nModelIndex") == 0 && g_net.modelindex < 0) {
+      g_net.modelindex = (int)(base_off + (uint32_t)poff);
+    } else if (strcmp(pname2, "m_fFlags") == 0 && g_net.flags < 0) {
       g_net.flags = (int)(base_off + (uint32_t)poff);
     } else if (strcmp(pname2, "m_vecVelocity") == 0 && g_net.velocity < 0) {
       if (parray && g_client.contains(parray)) {
@@ -95,7 +118,8 @@ static void collect_netvars(uintptr_t table, uintptr_t base_off, int depth) {
       } else {
         g_net.origin = (int)(base_off + (uint32_t)poff);
       }
-    } else if (strcmp(pname2, "m_vecViewOffset") == 0 && g_net.viewoffset < 0) {
+    } else if (strncmp(pname2, "m_vecViewOffset", 15) == 0 &&
+               g_net.viewoffset < 0) {
       if (parray && g_client.contains(parray)) {
         int32_t eoff = *(int32_t *)(parray + 0x2C);
         g_net.viewoffset = (int)(base_off + (uint32_t)(eoff ? eoff : poff));
@@ -117,9 +141,7 @@ static void collect_netvars(uintptr_t table, uintptr_t base_off, int depth) {
         g_net.maxs = (int)(base_off + (uint32_t)poff);
       }
     }
-    if (g_net.esp_ok())
-      return;
-}
+  }
 }
 
 // prediction datamap scan for m_MoveType (FIELD_CHARACTER, fieldOffset in range)
@@ -195,21 +217,34 @@ void resolve_netvars() {
   for (uintptr_t cc = head; cc && g_client.contains(cc) && classes < 1024;
        cc = *(uintptr_t *)(cc + 0x10)) {
     classes++;
-    collect_netvars(*(uintptr_t *)(cc + 0x0C), 0, 0);
-    if (g_net.esp_ok() || (g_net.flags >= 0 && g_net.velocity >= 0 &&
-                           g_net.health < 0))
-      break;
+    char cname[32];
+    int hoff = -1;
+    // per-class health offset — NPCs send m_iHealth via their own table chain,
+    // not DT_BasePlayer's; g_net.health keeps the player's for aimbot use
+    if (module_string(*(uintptr_t *)(cc + 0x08), cname, sizeof(cname))) {
+      collect_netvars(*(uintptr_t *)(cc + 0x0C), 0, 0, &hoff);
+      if (hoff >= 0 && g_class_health_n < 256) {
+        char *dst = g_class_health[g_class_health_n].name;
+        const char *src = cname;
+        size_t n = sizeof(g_class_health[g_class_health_n].name) - 1;
+        for (size_t i = 0; i < n && src[i]; i++) dst[i] = src[i];
+        dst[n] = 0;
+        g_class_health[g_class_health_n].off = hoff;
+        g_class_health_n++;
+      }
+    }
   }
-  logf("client classes walked: %d", classes);
+  logf("client classes walked: %d, health-offset classes: %d", classes,
+       g_class_health_n);
 
   if (g_net.movetype < 0 && !resolve_movetype()) {
     // movetype unresolved — bhop still works, just no noclip/ladder guard
     logf("movetype guard disabled");
   }
-
   logf("netvars: flags=%d velocity=%d movetype=%d health=%d maxhealth=%d "
-       "teamnum=%d origin=%d viewoffset=%d mins=%d maxs=%d",
+       "teamnum=%d origin=%d viewoffset=%d mins=%d maxs=%d lifeste=%d "
+       "modelindex=%d",
        g_net.flags, g_net.velocity, g_net.movetype, g_net.health,
        g_net.maxhealth, g_net.teamnum, g_net.origin, g_net.viewoffset,
-       g_net.mins, g_net.maxs);
+       g_net.mins, g_net.maxs, g_net.lifestate, g_net.modelindex);
 }
diff --git a/src/server.cpp b/src/server.cpp
new file mode 100644
index 0000000..6feb55b
--- /dev/null
+++ b/src/server.cpp
@@ -0,0 +1,177 @@
+// server.cpp — authoritative listen-server entity access.
+//
+// HL2 single-player runs the server (server.so) in the same process as the
+// client. The client only receives fields the server actually networks (NPC
+// health is *not* networked), but the server's CBaseEntity still holds the real
+// m_iHealth. We reach it through IVEngineServer021:
+//   PEntityOfEntIndex(engine, idx) -> edict_t*
+//   edict->m_pUnk (offset 0xC) -> IServerUnknown*
+//   IServerUnknown::GetBaseEntity (vtable slot 6) -> CBaseEntity*
+// then read the field offsets from the server datamap, which we resolve by
+// scanning server.so for the typedescription_t entries referencing the field
+// names (same idea as the client RecvTable walk).
+
+#include "hl2h.h"
+#include <cstdlib>
+
+// IVEngineServer (VEngineServer021, no virtual destructor):
+//   slot 17 = GetEntityCount, slot 19 = PEntityOfEntIndex(int)
+enum { SRV_GetEntityCount = 17, SRV_PEntityOfEntIndex = 19 };
+// IServerUnknown derives IHandleEntity (virtual dtor = 2 slots, 2 methods),
+// then adds GetCollideable(4), GetNetworkable(5), GetBaseEntity(6).
+enum { SRV_GetBaseEntity = 6 };
+// CBaseEdict layout: m_fStateFlags@0, serial/index@4, m_pNetworkable@8, m_pUnk@0xC
+enum { EDICT_UNKNOWN_OFF = 0x0C };
+
+// typedescription_t (32-bit): fieldType@0, fieldName@4, fieldOffset[0]@8,
+// fieldOffset[1]@0xC, fieldSize@0x10, flags@0x12, externalName@0x14
+enum { FIELD_INTEGER = 5, FIELD_CHARACTER = 8 };
+
+int g_srv_health = -1;
+int g_srv_maxhealth = -1;
+int g_srv_lifestate = -1;
+int g_srv_modelindex = -1;
+static bool g_srv_ready = false;
+static bool g_srv_checked = false;
+
+static uintptr_t find_string(const char *s) {
+  size_t n = strlen(s) + 1;
+  for (auto &r : g_server.ranges) {
+    const uint8_t *base = (const uint8_t *)r.lo;
+    size_t span = r.hi - r.lo;
+    for (size_t i = 0; i + n <= span; i++)
+      if (memcmp(base + i, s, n) == 0)
+        return r.lo + i;
+  }
+  return 0;
+}
+
+// Find the typedescription_t whose fieldName points at `name` and read its
+// fieldOffset. type filters false positives (m_iHealth is FIELD_INTEGER).
+static int datamap_offset(const char *name, int want_type) {
+  uintptr_t str = find_string(name);
+  if (!str)
+    return -1;
+  for (auto &r : g_server.ranges) {
+    const uint8_t *base = (const uint8_t *)r.lo;
+    size_t span = r.hi - r.lo;
+    for (size_t off = 4; off + 0x18 <= span; off += 4) {
+      if (*(const uint32_t *)(base + off) != (uint32_t)str)
+        continue;
+      const uint8_t *e = base + off - 4; // entry->fieldName
+      int ftype = *(const int32_t *)(e + 0x00);
+      int foff = *(const int32_t *)(e + 0x08);
+      int fsize = *(const uint16_t *)(e + 0x10);
+      uintptr_t ext = *(const uintptr_t *)(e + 0x14);
+      if (ftype != want_type)
+        continue;
+      if (foff < 0x40 || foff > 0x2000)
+        continue;
+      if (fsize < 1 || fsize > 64)
+        continue;
+      // DEFINE_KEYFIELD entries have an external name ("health"); plain
+      // DEFINE_FIELD entries have none. Either way it must be in server.so.
+      if (ext && !g_server.contains(ext))
+        continue;
+      return foff;
+    }
+  }
+  return -1;
+}
+
+bool resolve_server_netvars() {
+  if (g_srv_ready)
+    return true;
+  static const bool disabled = getenv("HL2H_NO_SERVER") != nullptr;
+  if (disabled) // escape hatch if server-side access misbehaves
+    return false;
+  // esp_collect runs at ~100 Hz; retry the (cheap-ish) module refresh and
+  // datamap scan about once a second until server.so is up and scan succeeds.
+  static unsigned retry = 0;
+  static bool fail_logged = false;
+  if ((retry++ % 100) != 0)
+    return false;
+  // server.so is only mapped once a map is running; refresh the module list.
+  if (!g_server.valid())
+    find_modules();
+  if (!g_server.valid()) {
+    if (!fail_logged) {
+      fail_logged = true;
+      logf("server datamap: server.so not mapped yet");
+    }
+    return false;
+  }
+  g_srv_health = datamap_offset("m_iHealth", FIELD_INTEGER);
+  g_srv_maxhealth = datamap_offset("m_iMaxHealth", FIELD_INTEGER);
+  g_srv_lifestate = datamap_offset("m_lifeState", FIELD_CHARACTER);
+  g_srv_modelindex = datamap_offset("m_nModelIndex", 7); // FIELD_SHORT
+  g_srv_ready = g_srv_health > 0;
+  if (g_srv_ready) {
+    logf("server datamap (%s): health=%d maxhealth=%d lifeste=%d "
+         "modelindex=%d",
+         g_server.path.c_str(), g_srv_health, g_srv_maxhealth, g_srv_lifestate,
+         g_srv_modelindex);
+    fail_logged = false;
+  } else if (!fail_logged) {
+    fail_logged = true;
+    logf("server datamap: scan failed (server.so at %s)",
+         g_server.path.c_str());
+  }
+  return g_srv_ready;
+}
+
+// Returns the authoritative health of the server entity at this index, or -1.
+int server_entity_health(int idx, int *maxhealth, int *lifestate,
+                         void **base_out) {
+  if (base_out)
+    *base_out = nullptr;
+  if (!g_srv_ready || !g_iface.engineserver || g_srv_health < 0)
+    return -1;
+
+  using PEntityFn = void *(*)(void *, int);
+  void *edict = vfunc<PEntityFn>(g_iface.engineserver, SRV_PEntityOfEntIndex)(
+      g_iface.engineserver, idx);
+  if (!edict)
+    return -1;
+  void *unk = *(void **)((uintptr_t)edict + EDICT_UNKNOWN_OFF);
+  if (!unk)
+    return -1;
+
+  using GetBaseFn = void *(*)(void *);
+  void *base = vfunc<GetBaseFn>(unk, SRV_GetBaseEntity)(unk);
+  if (!base)
+    return -1;
+
+  uintptr_t b = (uintptr_t)base;
+  int hp = g_srv_health > 0 ? *(int *)(b + g_srv_health) : -1;
+  int mx = g_srv_maxhealth > 0 ? *(int *)(b + g_srv_maxhealth) : -1;
+  int ls = g_srv_lifestate > 0
+               ? (int)*(unsigned char *)(b + g_srv_lifestate)
+               : -1;
+  if (base_out)
+    *base_out = base;
+  if (maxhealth)
+    *maxhealth = mx;
+  if (lifestate)
+    *lifestate = ls;
+
+  if (!g_srv_checked) {
+    g_srv_checked = true;
+    using CountFn = int (*)(void *);
+    int count = vfunc<CountFn>(g_iface.engineserver, SRV_GetEntityCount)(
+        g_iface.engineserver);
+    logf("server access: entity_count=%d first_idx=%d base=%p hp=%d maxhp=%d "
+         "life=%d srv_model=%d",
+         count, idx, base, hp, mx, ls,
+         g_srv_modelindex > 0
+             ? (int)*(short *)(b + g_srv_modelindex)
+             : -1);
+  }
+  return hp;
+}
+
+int server_model_index(void *base) {
+  if (!base || g_srv_modelindex <= 0)
+    return -1;
+  return (int)*(short *)((uintptr_t)base + g_srv_modelindex);
+}