diff --git a/Makefile b/Makefile
index 16bff45..b70d9ed 100644
--- a/Makefile
+++ b/Makefile
@@ -10,7 +10,8 @@ LDFLAGS = -Wl,--no-entry \
           -Wl,--import-memory \
           -Wl,--stack-first \
           -Wl,--export-all \
-          -Wl,--allow-undefined
+          -Wl,--undefined=Clay__MeasureText \
+          -Wl,--undefined=Clay__QueryScrollOffset
 
 all: $(TARGET)
 	@echo "Built $(TARGET) ($$(wc -c < $(TARGET)) bytes)"
diff --git a/src/buffer.c b/src/buffer.c
index 47f70d7..bc04cd6 100644
--- a/src/buffer.c
+++ b/src/buffer.c
@@ -5,10 +5,14 @@
 
 typedef __SIZE_TYPE__ size_t;
 
-static void *memcpy(void *dst, const void *src, size_t n) {
+void *memcpy(void *dst, const void *src, size_t n) {
   return __builtin_memcpy(dst, src, n);
 }
 
+void *memset(void *dst, int c, size_t n) {
+  return __builtin_memset(dst, c, n);
+}
+
 static size_t strlen(const char *s) {
   size_t n = 0;
   while (s[n])
diff --git a/src/clayterm.c b/src/clayterm.c
index 75f1273..600ad55 100644
--- a/src/clayterm.c
+++ b/src/clayterm.c
@@ -1,12 +1,36 @@
-/* clayterm.c — cell buffer, diff engine, escape gen, Clay render backend */
+/* clayterm.c — WASM terminal rendering engine for Clay UI
+ *
+ * Public API (exported to WASM):
+ *   clayterm_size  — compute arena size for given dimensions
+ *   init           — initialize a Clayterm instance in provided memory
+ *   reduce         — decode command buffer, run Clay layout, render to ANSI
+ *   output         — pointer to output byte buffer
+ *   length         — length of output byte buffer
+ *   measure        — Clay text measurement callback
+ */
 
+#include "../clay/clay.h"
 #include "clayterm.h"
 #include "buffer.h"
 #include "cell.h"
-#include "clay/clay.h"
 #include "utf8.h"
 #include "wcwidth.h"
 
+/* ── Command buffer protocol ──────────────────────────────────────── */
+
+#define OP_BEGIN_LAYOUT 0x01
+#define OP_OPEN_ELEMENT 0x02
+#define OP_TEXT 0x03
+#define OP_CLOSE_ELEMENT 0x04
+#define OP_END_LAYOUT 0x05
+
+#define PROP_LAYOUT 0x01
+#define PROP_BG_COLOR 0x02
+#define PROP_CORNER_RADIUS 0x04
+#define PROP_BORDER 0x08
+#define PROP_CLIP 0x10
+#define PROP_FLOATING 0x20
+
 /* ── Instance state ───────────────────────────────────────────────── */
 
 struct Clayterm {
@@ -255,39 +279,57 @@ static void render_border(struct Clayterm *ct, int x0, int y0, int x1, int y1,
       setcell(ct, x1 - 1, y, 0x2502, fg, bg);
 }
 
-static void walk(struct Clayterm *ct, Clay_RenderCommandArray cmds) {
-  for (int32_t i = 0; i < cmds.length; i++) {
-    Clay_RenderCommand *cmd = Clay_RenderCommandArray_Get(&cmds, i);
-    Clay_BoundingBox box = cmd->boundingBox;
-    int x0 = (int)box.x;
-    int y0 = (int)box.y;
-    int x1 = (int)(box.x + box.width);
-    int y1 = (int)(box.y + box.height);
+/* ── Command buffer helpers ───────────────────────────────────────── */
 
-    switch (cmd->commandType) {
-    case CLAY_RENDER_COMMAND_TYPE_RECTANGLE:
-      render_rect(ct, x0, y0, x1, y1, &cmd->renderData.rectangle);
-      break;
-    case CLAY_RENDER_COMMAND_TYPE_TEXT:
-      render_text(ct, x0, y0, &cmd->renderData.text);
-      break;
-    case CLAY_RENDER_COMMAND_TYPE_BORDER:
-      render_border(ct, x0, y0, x1, y1, &cmd->renderData.border);
-      break;
-    case CLAY_RENDER_COMMAND_TYPE_SCISSOR_START:
-      ct->clipping = 1;
-      ct->clipx = x0;
-      ct->clipy = y0;
-      ct->clipw = x1 - x0;
-      ct->cliph = y1 - y0;
-      break;
-    case CLAY_RENDER_COMMAND_TYPE_SCISSOR_END:
-      ct->clipping = 0;
-      break;
-    default:
-      break;
-    }
+static uint32_t rd(uint32_t *buf, int len, int *i) {
+  if (*i < len)
+    return buf[(*i)++];
+  return 0;
+}
+
+static float rdf(uint32_t *buf, int len, int *i) {
+  uint32_t v = rd(buf, len, i);
+  float f;
+  __builtin_memcpy(&f, &v, 4);
+  return f;
+}
+
+static Clay_Color unpack_color(uint32_t c) {
+  return (Clay_Color){
+      .r = (float)((c >> 16) & 0xff),
+      .g = (float)((c >> 8) & 0xff),
+      .b = (float)(c & 0xff),
+      .a = (float)((c >> 24) & 0xff),
+  };
+}
+
+static Clay_SizingAxis decode_axis(uint32_t *buf, int len, int *i) {
+  uint32_t type = rd(buf, len, i);
+  float a = rdf(buf, len, i);
+  float b = rdf(buf, len, i);
+  Clay_SizingAxis axis = {0};
+  switch (type) {
+  case 0: /* FIT */
+    axis.type = CLAY__SIZING_TYPE_FIT;
+    axis.size.minMax.min = a;
+    axis.size.minMax.max = b;
+    break;
+  case 1: /* GROW */
+    axis.type = CLAY__SIZING_TYPE_GROW;
+    axis.size.minMax.min = a;
+    axis.size.minMax.max = b;
+    break;
+  case 2: /* PERCENT */
+    axis.type = CLAY__SIZING_TYPE_PERCENT;
+    axis.size.percent = a;
+    break;
+  case 3: /* FIXED */
+    axis.type = CLAY__SIZING_TYPE_FIXED;
+    axis.size.minMax.min = a;
+    axis.size.minMax.max = a;
+    break;
   }
+  return axis;
 }
 
 /* ── Public API ───────────────────────────────────────────────────── */
@@ -340,7 +382,132 @@ struct Clayterm *init(void *mem, int w, int h) {
   return ct;
 }
 
-void render(struct Clayterm *ct, Clay_RenderCommandArray cmds) {
+void reduce(struct Clayterm *ct, uint32_t *buf, int len) {
+  int i = 0;
+  uint32_t idx = 0;
+
+  Clay_BeginLayout();
+
+  while (i < len) {
+    uint32_t op = rd(buf, len, &i);
+
+    switch (op) {
+    case OP_OPEN_ELEMENT: {
+      /* read id string */
+      uint32_t id_len = rd(buf, len, &i);
+      int id_words = (id_len + 3) / 4;
+      char *id_chars = (char *)&buf[i];
+      i += id_words;
+
+      if (id_len > 0) {
+        Clay_String str = {.length = (int32_t)id_len, .chars = id_chars};
+        Clay_ElementId eid = Clay__HashString(str, idx++);
+        Clay__OpenElementWithId(eid);
+      } else {
+        Clay__OpenElement();
+      }
+
+      /* read property mask */
+      uint32_t mask = rd(buf, len, &i);
+      Clay_ElementDeclaration decl = {0};
+
+      if (mask & PROP_LAYOUT) {
+        decl.layout.sizing.width = decode_axis(buf, len, &i);
+        decl.layout.sizing.height = decode_axis(buf, len, &i);
+
+        uint32_t pad = rd(buf, len, &i);
+        decl.layout.padding.left = pad & 0xff;
+        decl.layout.padding.right = (pad >> 8) & 0xff;
+        decl.layout.padding.top = (pad >> 16) & 0xff;
+        decl.layout.padding.bottom = (pad >> 24) & 0xff;
+
+        uint32_t gd = rd(buf, len, &i);
+        decl.layout.childGap = gd & 0xffff;
+        decl.layout.layoutDirection = (gd >> 16) & 0xff;
+
+        uint32_t al = rd(buf, len, &i);
+        decl.layout.childAlignment.x = al & 0xff;
+        decl.layout.childAlignment.y = (al >> 8) & 0xff;
+      }
+
+      if (mask & PROP_BG_COLOR) {
+        decl.backgroundColor = unpack_color(rd(buf, len, &i));
+      }
+
+      if (mask & PROP_CORNER_RADIUS) {
+        uint32_t cr = rd(buf, len, &i);
+        decl.cornerRadius.topLeft = (float)(cr & 0xff);
+        decl.cornerRadius.topRight = (float)((cr >> 8) & 0xff);
+        decl.cornerRadius.bottomLeft = (float)((cr >> 16) & 0xff);
+        decl.cornerRadius.bottomRight = (float)((cr >> 24) & 0xff);
+      }
+
+      if (mask & PROP_BORDER) {
+        decl.border.color = unpack_color(rd(buf, len, &i));
+
+        uint32_t bw = rd(buf, len, &i);
+        decl.border.width.left = bw & 0xff;
+        decl.border.width.right = (bw >> 8) & 0xff;
+        decl.border.width.top = (bw >> 16) & 0xff;
+        decl.border.width.bottom = (bw >> 24) & 0xff;
+      }
+
+      if (mask & PROP_CLIP) {
+        uint32_t cl = rd(buf, len, &i);
+        decl.clip.horizontal = cl & 0xff;
+        decl.clip.vertical = (cl >> 8) & 0xff;
+      }
+
+      if (mask & PROP_FLOATING) {
+        decl.floating.offset.x = rdf(buf, len, &i);
+        decl.floating.offset.y = rdf(buf, len, &i);
+        decl.floating.parentId = rd(buf, len, &i);
+
+        uint32_t fc = rd(buf, len, &i);
+        decl.floating.attachTo = fc & 0xff;
+        decl.floating.attachPoints.element = (fc >> 8) & 0xff;
+        decl.floating.attachPoints.parent = (fc >> 16) & 0xff;
+        decl.floating.zIndex = (int16_t)((fc >> 24) & 0xff);
+      }
+
+      Clay__ConfigureOpenElement(decl);
+      break;
+    }
+
+    case OP_TEXT: {
+      uint32_t col = rd(buf, len, &i);
+      uint32_t cfg = rd(buf, len, &i);
+      uint32_t str_len = rd(buf, len, &i);
+      int str_words = (str_len + 3) / 4;
+      char *str_chars = (char *)&buf[i];
+      i += str_words;
+
+      Clay_String text = {.length = (int32_t)str_len, .chars = str_chars};
+
+      Clay_TextElementConfig config = {0};
+      config.textColor = unpack_color(col);
+      config.fontSize = cfg & 0xff;
+      config.fontId = (cfg >> 8) & 0xff;
+      config.wrapMode = (cfg >> 16) & 0xff;
+      /* attrs byte -> alpha channel for render_text to extract */
+      config.textColor.a = (float)((cfg >> 24) & 0xff);
+
+      Clay__OpenTextElement(text, Clay__StoreTextElementConfig(config));
+      break;
+    }
+
+    case OP_CLOSE_ELEMENT:
+      Clay__CloseElement();
+      break;
+
+    default:
+      break;
+    }
+  }
+
+  Clay_RenderCommandArray cmds = Clay_EndLayout();
+
+  /* reset output state */
   ct->out.length = 0;
   ct->lastfg = ct->lastbg = 0xffffffff;
   ct->lastx = ct->lasty = -1;
@@ -348,7 +515,38 @@ void render(struct Clayterm *ct, Clay_RenderCommandArray cmds) {
   cells_clear(ct->back, ct->w, ct->h);
 
   /* walk Clay render commands into back buffer */
-  walk(ct, cmds);
+  for (int32_t j = 0; j < cmds.length; j++) {
+    Clay_RenderCommand *cmd = Clay_RenderCommandArray_Get(&cmds, j);
+    Clay_BoundingBox box = cmd->boundingBox;
+    int x0 = (int)box.x;
+    int y0 = (int)box.y;
+    int x1 = (int)(box.x + box.width);
+    int y1 = (int)(box.y + box.height);
+
+    switch (cmd->commandType) {
+    case CLAY_RENDER_COMMAND_TYPE_RECTANGLE:
+      render_rect(ct, x0, y0, x1, y1, &cmd->renderData.rectangle);
+      break;
+    case CLAY_RENDER_COMMAND_TYPE_TEXT:
+      render_text(ct, x0, y0, &cmd->renderData.text);
+      break;
+    case CLAY_RENDER_COMMAND_TYPE_BORDER:
+      render_border(ct, x0, y0, x1, y1, &cmd->renderData.border);
+      break;
+    case CLAY_RENDER_COMMAND_TYPE_SCISSOR_START:
+      ct->clipping = 1;
+      ct->clipx = x0;
+      ct->clipy = y0;
+      ct->clipw = x1 - x0;
+      ct->cliph = y1 - y0;
+      break;
+    case CLAY_RENDER_COMMAND_TYPE_SCISSOR_END:
+      ct->clipping = 0;
+      break;
+    default:
+      break;
+    }
+  }
 
   /* diff front vs back, emit escape sequences */
   present(ct);
diff --git a/src/clayterm.h b/src/clayterm.h
index fa7aa24..703497b 100644
--- a/src/clayterm.h
+++ b/src/clayterm.h
@@ -3,6 +3,8 @@
 #ifndef CLAYTERM_H
 #define CLAYTERM_H
 
+#include <stdint.h>
+
 #include "cell.h"
 
 struct Clayterm;
@@ -10,7 +12,7 @@ struct Clayterm;
 /* WASM exports */
 int clayterm_size(int w, int h);
 struct Clayterm *init(void *mem, int w, int h);
-void render(struct Clayterm *ct, Clay_RenderCommandArray cmds);
+void reduce(struct Clayterm *ct, uint32_t *buf, int len);
 char *output(struct Clayterm *ct);
 int length(struct Clayterm *ct);
 void measure(int ret, int txt);
diff --git a/src/module.c b/src/module.c
index 1f5ad1c..3e4c0bc 100644
--- a/src/module.c
+++ b/src/module.c
@@ -1,10 +1,9 @@
 /* module.c — single compilation unit for clayterm WASM module */
 
-#include "clay/clay.h"
+#include "../clay/clay.h"
 
 #include "buffer.c"
 #include "cell.c"
-#include "clayterm.c"
-#include "ops.c"
 #include "utf8.c"
 #include "wcwidth.c"
+#include "clayterm.c"
diff --git a/src/ops.c b/src/ops.c
deleted file mode 100644
index 35bd8c7..0000000
--- a/src/ops.c
+++ /dev/null
@@ -1,187 +0,0 @@
-/* ops.c — command buffer reducer for Clay layout commands */
-
-#include "ops.h"
-#include "clay/clay.h"
-#include "clayterm.h"
-
-/* ── Command buffer helpers ────────────────────────────────────────── */
-
-static uint32_t rd(uint32_t *buf, int len, int *i) {
-  if (*i < len)
-    return buf[(*i)++];
-  return 0;
-}
-
-static float rdf(uint32_t *buf, int len, int *i) {
-  uint32_t v = rd(buf, len, i);
-  float f;
-  __builtin_memcpy(&f, &v, 4);
-  return f;
-}
-
-static Clay_Color unpack_color(uint32_t c) {
-  return (Clay_Color){
-      .r = (float)((c >> 16) & 0xff),
-      .g = (float)((c >> 8) & 0xff),
-      .b = (float)(c & 0xff),
-      .a = (float)((c >> 24) & 0xff),
-  };
-}
-
-static Clay_SizingAxis decode_axis(uint32_t *buf, int len, int *i) {
-  uint32_t type = rd(buf, len, i);
-  float a = rdf(buf, len, i);
-  float b = rdf(buf, len, i);
-  Clay_SizingAxis axis = {0};
-  switch (type) {
-  case 0: /* FIT */
-    axis.type = CLAY__SIZING_TYPE_FIT;
-    axis.size.minMax.min = a;
-    axis.size.minMax.max = b;
-    break;
-  case 1: /* GROW */
-    axis.type = CLAY__SIZING_TYPE_GROW;
-    axis.size.minMax.min = a;
-    axis.size.minMax.max = b;
-    break;
-  case 2: /* PERCENT */
-    axis.type = CLAY__SIZING_TYPE_PERCENT;
-    axis.size.percent = a;
-    break;
-  case 3: /* FIXED */
-    axis.type = CLAY__SIZING_TYPE_FIXED;
-    axis.size.minMax.min = a;
-    axis.size.minMax.max = a;
-    break;
-  }
-  return axis;
-}
-
-/* ── Command buffer reducer ───────────────────────────────────────── */
-
-void reduce(struct Clayterm *ct, uint32_t *buf, int len) {
-  int i = 0;
-  uint32_t idx = 0;
-
-  Clay_BeginLayout();
-
-  while (i < len) {
-    uint32_t op = rd(buf, len, &i);
-
-    switch (op) {
-    case OP_OPEN_ELEMENT: {
-      /* read id string */
-      uint32_t id_len = rd(buf, len, &i);
-      int id_words = (id_len + 3) / 4;
-      char *id_chars = (char *)&buf[i];
-      i += id_words;
-
-      if (id_len > 0) {
-        Clay_String str = {.length = (int32_t)id_len, .chars = id_chars};
-        Clay_ElementId eid = Clay__HashString(str, idx++);
-        Clay__OpenElementWithId(eid);
-      } else {
-        Clay__OpenElement();
-      }
-
-      /* read property mask */
-      uint32_t mask = rd(buf, len, &i);
-      Clay_ElementDeclaration decl = {0};
-
-      if (mask & PROP_LAYOUT) {
-        decl.layout.sizing.width = decode_axis(buf, len, &i);
-        decl.layout.sizing.height = decode_axis(buf, len, &i);
-
-        uint32_t pad = rd(buf, len, &i);
-        decl.layout.padding.left = pad & 0xff;
-        decl.layout.padding.right = (pad >> 8) & 0xff;
-        decl.layout.padding.top = (pad >> 16) & 0xff;
-        decl.layout.padding.bottom = (pad >> 24) & 0xff;
-
-        uint32_t gd = rd(buf, len, &i);
-        decl.layout.childGap = gd & 0xffff;
-        decl.layout.layoutDirection = (gd >> 16) & 0xff;
-
-        uint32_t al = rd(buf, len, &i);
-        decl.layout.childAlignment.x = al & 0xff;
-        decl.layout.childAlignment.y = (al >> 8) & 0xff;
-      }
-
-      if (mask & PROP_BG_COLOR) {
-        decl.backgroundColor = unpack_color(rd(buf, len, &i));
-      }
-
-      if (mask & PROP_CORNER_RADIUS) {
-        uint32_t cr = rd(buf, len, &i);
-        decl.cornerRadius.topLeft = (float)(cr & 0xff);
-        decl.cornerRadius.topRight = (float)((cr >> 8) & 0xff);
-        decl.cornerRadius.bottomLeft = (float)((cr >> 16) & 0xff);
-        decl.cornerRadius.bottomRight = (float)((cr >> 24) & 0xff);
-      }
-
-      if (mask & PROP_BORDER) {
-        decl.border.color = unpack_color(rd(buf, len, &i));
-
-        uint32_t bw = rd(buf, len, &i);
-        decl.border.width.left = bw & 0xff;
-        decl.border.width.right = (bw >> 8) & 0xff;
-        decl.border.width.top = (bw >> 16) & 0xff;
-        decl.border.width.bottom = (bw >> 24) & 0xff;
-      }
-
-      if (mask & PROP_CLIP) {
-        uint32_t cl = rd(buf, len, &i);
-        decl.clip.horizontal = cl & 0xff;
-        decl.clip.vertical = (cl >> 8) & 0xff;
-      }
-
-      if (mask & PROP_FLOATING) {
-        decl.floating.offset.x = rdf(buf, len, &i);
-        decl.floating.offset.y = rdf(buf, len, &i);
-        decl.floating.parentId = rd(buf, len, &i);
-
-        uint32_t fc = rd(buf, len, &i);
-        decl.floating.attachTo = fc & 0xff;
-        decl.floating.attachPoints.element = (fc >> 8) & 0xff;
-        decl.floating.attachPoints.parent = (fc >> 16) & 0xff;
-        decl.floating.zIndex = (int16_t)((fc >> 24) & 0xff);
-      }
-
-      Clay__ConfigureOpenElement(decl);
-      break;
-    }
-
-    case OP_TEXT: {
-      uint32_t col = rd(buf, len, &i);
-      uint32_t cfg = rd(buf, len, &i);
-      uint32_t str_len = rd(buf, len, &i);
-      int str_words = (str_len + 3) / 4;
-      char *str_chars = (char *)&buf[i];
-      i += str_words;
-
-      Clay_String text = {.length = (int32_t)str_len, .chars = str_chars};
-
-      Clay_TextElementConfig config = {0};
-      config.textColor = unpack_color(col);
-      config.fontSize = cfg & 0xff;
-      config.fontId = (cfg >> 8) & 0xff;
-      config.wrapMode = (cfg >> 16) & 0xff;
-      /* attrs byte → alpha channel for render_text to extract */
-      config.textColor.a = (float)((cfg >> 24) & 0xff);
-
-      Clay__OpenTextElement(text, Clay__StoreTextElementConfig(config));
-      break;
-    }
-
-    case OP_CLOSE_ELEMENT:
-      Clay__CloseElement();
-      break;
-
-    default:
-      break;
-    }
-  }
-
-  Clay_RenderCommandArray cmds = Clay_EndLayout();
-  render(ct, cmds);
-}
diff --git a/src/ops.h b/src/ops.h
deleted file mode 100644
index a1f9bf3..0000000
--- a/src/ops.h
+++ /dev/null
@@ -1,27 +0,0 @@
-/* ops.h — command buffer protocol for Clay layout commands */
-
-#ifndef OPS_H
-#define OPS_H
-
-#include <stdint.h>
-
-struct Clayterm;
-
-/* Command buffer opcodes */
-#define OP_BEGIN_LAYOUT 0x01
-#define OP_OPEN_ELEMENT 0x02
-#define OP_TEXT 0x03
-#define OP_CLOSE_ELEMENT 0x04
-#define OP_END_LAYOUT 0x05
-
-/* Property group masks for OPEN_ELEMENT */
-#define PROP_LAYOUT 0x01
-#define PROP_BG_COLOR 0x02
-#define PROP_CORNER_RADIUS 0x04
-#define PROP_BORDER 0x08
-#define PROP_CLIP 0x10
-#define PROP_FLOATING 0x20
-
-void reduce(struct Clayterm *ct, uint32_t *buf, int len);
-
-#endif