diff --git a/.github/workflows/main-wasm.yml b/.github/workflows/main-wasm.yml
index 8cf2ea15..ca4ae216 100644
--- a/.github/workflows/main-wasm.yml
+++ b/.github/workflows/main-wasm.yml
@@ -1,13 +1,16 @@
 name: CI-wasm
 
-# Builds the Magic WebAssembly target on every push and pull request.
-# When the VERSION file changes on the default branch, the package is
-# additionally published to GitHub Packages (npm.pkg.github.com) as
-# @<owner>/magic-vlsi-wasm — no manual tag or token required.
-# Tim Edwards updates VERSION to trigger a new release; the scope resolves
-# automatically to the repo owner, so forks publish under their own namespace.
+# Builds the Magic WebAssembly target (both the non-TCL and TCL variants)
+# on every push and pull request as a CI check. **Publishing** only happens
+# when a release tag of the form v<x.y.z>... is pushed — that gate is the
+# manual release trigger:
 #
-# WASM is architecture-independent — built once on x86-64, usable everywhere.
+#   # bump magic/VERSION and/or npm/tcl.ref, commit, push to default branch
+#   git tag v8.3.638
+#   git push origin v8.3.638
+#
+# The tag name (minus the leading "v") becomes the published npm version.
+# Forks publish under their own namespace via the @<owner>/ scope.
 
 on:
   push:
@@ -70,32 +73,32 @@ jobs:
           echo "===== emcc -dM -E - ====="; echo | emcc -dM -E - | sort
           echo "===== em++ -dM -E - ====="; echo | em++ -dM -E - | sort
 
-      - name: Build WASM
+      # Clone intubun/tcl into a sibling directory at the pinned ref from
+      # npm/tcl.ref. npm/build.sh would do this on its own, but doing it as
+      # an explicit step makes the resolved SHA visible at the top of the
+      # job log and keeps the build step's output focused on the C build.
+      # The TCL source tree is treated as read-only — the actual WASM build
+      # runs inside magic (toolchains/emscripten/build-tcl-wasm.sh).
+      - name: Pin and clone intubun/tcl
+        run: |
+          . npm/tcl.ref
+          : "${TCL_REPO_URL:=https://github.com/intubun/tcl.git}"
+          : "${TCL_REF:=main}"
+          echo "Pinned TCL: $TCL_REF ($TCL_REPO_URL)"
+          # autocrlf=false: ubuntu-latest is already LF, but make it explicit.
+          git -c core.autocrlf=false clone "$TCL_REPO_URL" ../tcl
+          ( cd ../tcl && git checkout --detach "$TCL_REF" )
+
+      - name: Build WASM — both variants (tcl + notcl)
         run: |
           source ./emsdk/emsdk_env.sh
-          # --without/--disable flags: no WASM library available for these features
-          CFLAGS="--std=c17 -D_DEFAULT_SOURCE=1 -DEMSCRIPTEN=1" emconfigure ./configure \
-            --without-cairo --without-opengl --without-x --without-tk --without-tcl \
-            --disable-readline --disable-compression \
-            --host=asmjs-unknown-emscripten \
-            --target=asmjs-unknown-emscripten
-          # Append WASM linker flags and activate the WASM link target
-          cat toolchains/emscripten/defs.mak >> defs.mak
-          # Echo the merged defs.mak so CI logs show the exact build config
-          echo "===== defs.mak ====="; cat defs.mak; echo "===== defs.mak ====="
-          # Build in order: techs must exist before mains (--embed-file embeds them)
-          emmake make depend
-          emmake make -j$(nproc) modules libs
-          emmake make techs
-          emmake make mains
+          bash npm/build.sh --variant=both
 
-      - name: Copy WASM artifacts into npm/
-        run: |
-          cp magic/magic.js  npm/
-          cp magic/magic.wasm npm/
+      - name: Run example tests (non-TCL variant)
+        run: cd npm && npm test
 
-      - name: Run example tests
-        run: cd npm && npm run test
+      - name: Run smoke test (TCL variant)
+        run: cd npm && npm run test:tcl
 
       # Dump generated text outputs (.ext, .spice, .cif, …) into the CI log
       # so a regression in extraction / netlisting / cifoutput is visible
@@ -112,21 +115,40 @@ jobs:
             esac
           done
 
-      - name: Set package version and scope
+      # The release gate. We publish a new npm version only when a tag of the
+      # shape v<x.y.z>... is pushed. The tag name (minus the leading "v") is
+      # taken as the npm version verbatim — so `v8.3.638` → npm 8.3.638.
+      - name: Determine release version (tag-driven only)
+        id: release
+        run: |
+          if [ "${{ github.event_name }}" = "push" ] && \
+             echo "${{ github.ref }}" | grep -Eq '^refs/tags/v[0-9]+\.[0-9]+\.[0-9]+'; then
+            tag="${GITHUB_REF#refs/tags/}"
+            echo "publish=true"            >> "$GITHUB_OUTPUT"
+            echo "version=${tag#v}"        >> "$GITHUB_OUTPUT"
+            echo "Tag release: $tag → npm version ${tag#v}"
+          else
+            # For non-tag CI runs, use a dev-suffixed version so the packed
+            # tarball is still consumable for local inspection / artifact upload.
+            base=$(cat VERSION)
+            date=$(git show -s --format=%cs | tr -d '-')
+            hash=$(git show -s --format=%h)
+            echo "publish=false"                       >> "$GITHUB_OUTPUT"
+            echo "version=${base}-${date}.${hash}"     >> "$GITHUB_OUTPUT"
+            echo "Non-tag build: will not publish."
+          fi
+
+      - name: Set package version and scope
+        env:
+          VERSION: ${{ steps.release.outputs.version }}
         run: |
-          base=$(cat VERSION)                              # e.g. 8.3.637
-          date=$(git show -s --format=%cs | tr -d '-')    # e.g. 20260414
-          hash=$(git show -s --format=%h)                 # e.g. d157eea
-          VERSION="${base}-${date}.${hash}"
           # Scope the package to the repo owner so it lands in the right
           # GitHub Packages namespace regardless of who hosts the repo.
-          # e.g. @rtimothyedwards/magic-vlsi-wasm on Tim's repo,
-          #      @intubun/magic-vlsi-wasm on a fork.
           SCOPED_NAME="@${{ github.repository_owner }}/magic-vlsi-wasm"
           cd npm
           npm pkg set name="$SCOPED_NAME"
           npm pkg set publishConfig.registry="https://npm.pkg.github.com"
-          npm version "$VERSION" --no-git-tag-version
+          npm version "$VERSION" --no-git-tag-version --allow-same-version
 
       - name: Pack
         run: ./npm/pack.sh
@@ -137,24 +159,8 @@ jobs:
           name: magic-vlsi-wasm-npm
           path: npm/*.tgz
 
-      - name: Check if VERSION changed
-        id: version_changed
-        if: github.event_name == 'push'
-        run: |
-          if echo "${{ github.ref }}" | grep -q '^refs/tags/'; then
-            echo "changed=true" >> $GITHUB_OUTPUT
-          elif [ "${{ github.ref }}" = "refs/heads/${{ github.event.repository.default_branch }}" ]; then
-            if git diff --name-only HEAD~1 HEAD 2>/dev/null | grep -q '^VERSION$'; then
-              echo "changed=true" >> $GITHUB_OUTPUT
-            else
-              echo "changed=false" >> $GITHUB_OUTPUT
-            fi
-          else
-            echo "changed=false" >> $GITHUB_OUTPUT
-          fi
-
       - name: Publish to GitHub Packages
-        if: steps.version_changed.outputs.changed == 'true' && github.event.inputs.dry_run != 'true'
+        if: steps.release.outputs.publish == 'true' && github.event.inputs.dry_run != 'true'
         run: cd npm && npm publish
         env:
           NODE_AUTH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
diff --git a/.gitignore b/.gitignore
index c8beb02b..33650545 100644
--- a/.gitignore
+++ b/.gitignore
@@ -54,6 +54,7 @@ magic/magic.js
 magic/magic.js.symbols
 magic/magic.symbols
 magic/magic.wasm
+build-tcl-wasm/
 net2ir/net2ir
 net2ir/net2ir.js
 net2ir/net2ir.wasm
diff --git a/magic/Makefile b/magic/Makefile
index 87e23b1d..cefa8062 100644
--- a/magic/Makefile
+++ b/magic/Makefile
@@ -42,11 +42,25 @@ LIBS   += ${GR_LIBS} ${READLINE_LIBS} -lm ${LD_EXTRA_LIBS} \
 CLEANS += tclmagic${SHDLIB_EXT} libtclmagic${SHDLIB_EXT}.a proto.magicrc
 
 ifeq (${MAKE_WASM},1)
-magic: magic.js
+# magicWasm.c bootstraps the embedded Tcl interp by calling Tcl_CreateInterp /
+# Tcl_Init before tclStubsPtr is initialised. With -DUSE_TCL_STUBS those calls
+# expand to (*tclStubsPtr->...)() and dereference a NULL stubs pointer; so
+# this one file must be compiled with DFLAGS_NOSTUB (= DFLAGS without
+# -DUSE_TCL_STUBS). All other files keep using stubs.
+magicWasm.o: magicWasm.c
+	@echo --- compiling magic/magicWasm.o '(no Tcl stubs)'
+	${RM} magicWasm.o
+	${CC} ${CFLAGS} ${CPPFLAGS} ${DFLAGS_NOSTUB} -c magicWasm.c
+
+# Pull in BOTH the main TCL archive (LIB_SPECS_NOSTUB → -ltcl9.x) and the
+# stub bootstrap archive (-L${TCL_LIB_DIR} -ltclstub). Magic's source uses
+# USE_TCL_STUBS macros, so tclStubsPtr (defined in libtclstub.a) and
+# Tcl_InitStubs must be present in the same binary as the actual TCL
+# implementation from libtcl9.x.a.
 magic.js: lib${MODULE}.o ${EXTRA_LIBS}
 	@echo --- building main magic WASM
 	${RM} magic.js magic.wasm
-	${CC} ${CFLAGS} ${CPPFLAGS} ${DFLAGS} lib${MODULE}.o ${EXTRA_LIBS} -o magic.js ${LIBS}
+	${CC} ${CFLAGS} ${CPPFLAGS} ${DFLAGS} lib${MODULE}.o ${EXTRA_LIBS} -o magic.js ${LIBS} ${LIB_SPECS_NOSTUB} -L${TCL_LIB_DIR} -ltclstub
 endif
 
 main: magic proto.magicrc
@@ -93,3 +107,14 @@ $(DESTDIR)${INSTALL_SYSDIR}/magicps.pro: magicps.pro
 	${CP} magicps.pro $(DESTDIR)${INSTALL_SYSDIR}/magicps.pro
 
 include ${MAGICDIR}/rules.mak
+
+ifeq (${MAKE_WASM},1)
+# rules.mak defines `${MODULE}` (= `magic`) with a recipe that links a native
+# executable without the TCL libraries. For the WASM build the real artifact
+# is `magic.js` (+ `magic.wasm`), so override the target to be a phony alias
+# that just rebuilds magic.js. Must come after the include so make uses this
+# recipe instead of rules.mak's.
+.PHONY: magic
+magic: magic.js
+	@:
+endif
diff --git a/magic/magicTop.c b/magic/magicTop.c
index 879b3eac..8573f98a 100644
--- a/magic/magicTop.c
+++ b/magic/magicTop.c
@@ -59,8 +59,14 @@ main(int argc, char *argv[])
  * here, nor its format.  It is updated by the Makefile in this directory.
  *
  * The version string originates at the top of scripts/config.
+ *
+ * Under MAGIC_WRAPPER (Tcl-embedded builds), tclmagic.c owns these globals;
+ * defining them here as well would produce duplicate-symbol errors when both
+ * objects end up in the same binary (as in the WASM build).
  */
 
+#ifndef MAGIC_WRAPPER
 char *MagicVersion = MAGIC_VERSION;
 char *MagicRevision = MAGIC_REVISION;
 char *MagicCompileTime = MAGIC_BUILDDATE;
+#endif
diff --git a/magic/magicWasm.c b/magic/magicWasm.c
index e8a116a9..ebb8e5ef 100644
--- a/magic/magicWasm.c
+++ b/magic/magicWasm.c
@@ -8,6 +8,10 @@
 #include <stdio.h>
 #include <stdlib.h>
 
+#ifdef MAGIC_WRAPPER
+#include "tcltk/tclmagic.h"
+#endif
+
 #include "utils/main.h"
 #include "utils/magic.h"
 #include "utils/paths.h"
@@ -38,6 +42,13 @@ magicWasmEnsureCadRoot(void)
     return 0;
 }
 
+#ifdef MAGIC_WRAPPER
+/* Forward decl — Tclmagic_Init installs all magic Tcl commands and calls
+ * Tcl_InitStubs(), which sets tclStubsPtr.  Without this, any Tcl_X macro
+ * dereferences a NULL stubs pointer at runtime (crashes the wasm). */
+extern int Tclmagic_Init(Tcl_Interp *interp);
+#endif
+
 EMSCRIPTEN_KEEPALIVE int
 magic_wasm_init(void)
 {
@@ -53,6 +64,40 @@ magic_wasm_init(void)
     if (magicWasmEnsureCadRoot() != 0)
 	return -1;
 
+#ifdef MAGIC_WRAPPER
+    /* In wrapper mode, magic's code (and our PaExpand path expansion) reaches
+     * for `magicinterp` to resolve $env vars via Tcl_GetVar.  In the normal
+     * Linux flow Tclmagic_Init() is called by tclsh after dlopen(); here we
+     * embed the interp directly, so we have to bootstrap it before
+     * magicMainInit() runs anything that might touch Tcl.
+     *
+     * Note: we deliberately avoid TxError here — in MAGIC_WRAPPER mode
+     * TxError flushes via Tcl_EvalEx through tclStubsPtr, which only becomes
+     * non-NULL after Tclmagic_Init -> Tcl_InitStubs.  So early errors go
+     * straight to stderr. */
+    if (magicinterp == NULL)
+    {
+	Tcl_Interp *interp = Tcl_CreateInterp();
+	if (interp == NULL)
+	{
+	    fprintf(stderr, "magic_wasm_init: Tcl_CreateInterp returned NULL\n");
+	    return -1;
+	}
+	/* Tcl_Init loads /init.tcl from the Tcl library directory; in our
+	 * embedded VFS that script isn't shipped, so failure here is expected
+	 * and non-fatal — the interpreter itself is still usable for embedded
+	 * evaluation, which is all we need. */
+	(void)Tcl_Init(interp);
+	consoleinterp = interp;
+	if (Tclmagic_Init(interp) != TCL_OK)
+	{
+	    fprintf(stderr, "magic_wasm_init: Tclmagic_Init failed: %s\n",
+		Tcl_GetStringResult(interp));
+	    return -1;
+	}
+    }
+#endif
+
     return magicMainInit(5, argv);
 }
 
@@ -75,7 +120,15 @@ magic_wasm_run_command(const char *command)
     TxSetPoint(GrScreenRect.r_xtop / 2, GrScreenRect.r_ytop / 2,
 	    WIND_UNKNOWN_WINDOW);
 
+#ifdef MAGIC_WRAPPER
+    /* In wrapper mode the command is Tcl. Evaluate it via the magic interp;
+     * the magic backend is reachable through ::magic:: ensemble commands. */
+    if (magicinterp == NULL)
+	return -1;
+    return Tcl_EvalEx(magicinterp, command, -1, 0);
+#else
     return TxDispatchString(command, FALSE);
+#endif
 }
 
 EMSCRIPTEN_KEEPALIVE int
diff --git a/npm/.gitignore b/npm/.gitignore
index 228c6d22..2baee00c 100644
--- a/npm/.gitignore
+++ b/npm/.gitignore
@@ -1,5 +1,13 @@
+# Variant build outputs (regenerable via npm/build.sh).
+tcl/magic.js
+tcl/magic.wasm
+notcl/magic.js
+notcl/magic.wasm
+
+# Pre-restructure artifacts (just in case anyone still has them locally).
 magic.js
 magic.wasm
+
 *.tgz
 node_modules/
 package-lock.json
diff --git a/npm/build.sh b/npm/build.sh
index 4c4928c9..946a667e 100755
--- a/npm/build.sh
+++ b/npm/build.sh
@@ -2,9 +2,13 @@
 # Build Magic WASM and copy artifacts into this npm/ directory.
 #
 # Usage:
-#   npm/build.sh [--release] [--test] [--pack]
+#   npm/build.sh [--variant=<tcl|notcl|both>] [--release] [--test] [--pack]
 #
-#   --release   Omit debug symbols (-g).
+#   --variant=tcl    Build only the TCL-embedded variant       → npm/tcl/
+#   --variant=notcl  Build only the plain (no Tcl/Tk) variant  → npm/notcl/
+#   --variant=both   Build both (default)
+#
+#   --release   Omit debug symbols (-g) and build with -O2.
 #   --test      Run `npm run test` after copying artifacts.
 #   --pack      Run `npm pack` after copying artifacts (and tests, if given).
 #
@@ -17,20 +21,33 @@
 #   EMSDK_DIR   Path to an activated emsdk checkout.
 #               If set, emsdk_env.sh is sourced from there.
 #               If unset, emcc must already be on PATH (e.g. sourced externally).
+#   TCL_REPO    Override the path to the intubun/tcl checkout (default:
+#               ../tcl relative to this magic checkout). Used by the TCL
+#               variant only.
 
 set -euo pipefail
 
 SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
 REPO_ROOT="$(dirname "$SCRIPT_DIR")"
+# The TCL variant builds against a sibling clone of intubun/tcl (pristine —
+# magic never modifies it). The build itself happens inside magic under
+# build-tcl-wasm/, so the TCL source tree stays clean.
+TCL_REPO="${TCL_REPO:-$(dirname "$REPO_ROOT")/tcl}"
+TCL_BUILD_DIR="${TCL_BUILD_DIR:-$REPO_ROOT/build-tcl-wasm}"
+TCL_WASM_PREFIX="$TCL_BUILD_DIR/install"
 
 OPT_RELEASE=0
 OPT_TEST=0
 OPT_PACK=0
+OPT_VARIANT=both
 for arg in "$@"; do
   case "$arg" in
-    --release) OPT_RELEASE=1 ;;
-    --test)    OPT_TEST=1    ;;
-    --pack)    OPT_PACK=1    ;;
+    --release)        OPT_RELEASE=1 ;;
+    --test)           OPT_TEST=1    ;;
+    --pack)           OPT_PACK=1    ;;
+    --variant=tcl)    OPT_VARIANT=tcl   ;;
+    --variant=notcl)  OPT_VARIANT=notcl ;;
+    --variant=both)   OPT_VARIANT=both  ;;
     *) echo "Unknown option: $arg" >&2; exit 1 ;;
   esac
 done
@@ -76,50 +93,120 @@ sed_strip_cr() {
   sed 's/\r//' "$file" > "$tmp" && cat "$tmp" > "$file" && rm "$tmp"
 }
 
-# --- clean -------------------------------------------------------------------
-cd "$REPO_ROOT"
-
-# Only distclean if there's something to clean. A stale `|| true` here would
-# hide real failures (e.g. broken toolchain) on a fresh checkout.
-if [ -f defs.mak ]; then
-  emmake make distclean || true
-fi
-rm -f defs.mak database/database.h
-
-# --- configure ---------------------------------------------------------------
-
-# Strip Windows CRLF line endings (no-op on Linux-native files).
-sed_strip_cr configure
-find scripts/ -type f -print0 | while IFS= read -r -d '' f; do sed_strip_cr "$f"; done
-
 if [ $OPT_RELEASE -eq 1 ]; then
   EXTRA_CFLAGS=" -O2"
 else
   EXTRA_CFLAGS=" -g"
 fi
 
-CFLAGS="--std=c17 -D_DEFAULT_SOURCE=1 -DEMSCRIPTEN=1${EXTRA_CFLAGS}" \
-  emconfigure ./configure \
-    --without-cairo --without-opengl --without-x --without-tk --without-tcl \
-    --disable-readline --disable-compression \
-    --host=asmjs-unknown-emscripten \
-    --target=asmjs-unknown-emscripten
+# --- TCL fork: locate, pin, prebuild (TCL variant only) ---------------------
+# Reads npm/tcl.ref to get the upstream URL + commit SHA. If the TCL source
+# tree does not exist yet, clone it (with autocrlf=false to keep configure
+# parseable on Windows hosts). If it does exist, just check out the pinned
+# ref — no auto-fetch, so releases stay reproducible.
+#
+# The TCL source tree is treated as read-only. The actual WASM build runs in
+# $TCL_BUILD_DIR (inside magic), driven by
+# toolchains/emscripten/build-tcl-wasm.sh.
+ensure_tcl_built() {
+  local TCL_REF_FILE="$SCRIPT_DIR/tcl.ref"
+  if [ -f "$TCL_REF_FILE" ]; then
+    # shellcheck source=/dev/null
+    . "$TCL_REF_FILE"
+  fi
+  : "${TCL_REPO_URL:=https://github.com/intubun/tcl.git}"
+  : "${TCL_REF:=main}"
 
-cat toolchains/emscripten/defs.mak >> defs.mak
+  if [ ! -d "$TCL_REPO/.git" ]; then
+    echo "=== cloning $TCL_REPO_URL into $TCL_REPO ==="
+    git -c core.autocrlf=false clone "$TCL_REPO_URL" "$TCL_REPO"
+  fi
 
-# --- build -------------------------------------------------------------------
-emmake make depend
-emmake make -j"$(ncpu)" modules libs
-emmake make techs
-emmake make mains
+  ( cd "$TCL_REPO"
+    current_sha=$(git rev-parse HEAD 2>/dev/null || echo "")
+    if [ "$current_sha" != "$TCL_REF" ]; then
+      git fetch --quiet origin
+      git checkout --quiet --detach "$TCL_REF"
+    fi
+    echo "Using TCL at $(git rev-parse HEAD) ($TCL_REPO_URL)"
+  )
 
-# --- copy artifacts ----------------------------------------------------------
-cp magic/magic.js   "$SCRIPT_DIR/"
-cp magic/magic.wasm "$SCRIPT_DIR/"
-echo "Copied magic.js and magic.wasm to npm/"
+  # Build TCL for WASM if it hasn't been built yet. The presence of
+  # tclConfig.sh in the install prefix is the canonical "TCL is built" marker.
+  if [ ! -f "$TCL_WASM_PREFIX/lib/tclConfig.sh" ]; then
+    echo "=== building TCL for WASM into $TCL_BUILD_DIR (one-time) ==="
+    bash "$REPO_ROOT/toolchains/emscripten/build-tcl-wasm.sh" \
+      --src="$TCL_REPO" --out="$TCL_BUILD_DIR"
+  fi
+}
+
+# --- build a single variant --------------------------------------------------
+# Each variant gets a fresh configure run because the two configurations
+# select different code paths (MAGIC_WRAPPER on/off, MAGIC_NO_TK, link flags),
+# so the object cache from one variant is not compatible with the other.
+build_variant() {
+  local variant=$1
+  local out_dir="$SCRIPT_DIR/$variant"
+
+  echo
+  echo "==============================================================="
+  echo "=== building variant: $variant"
+  echo "==============================================================="
+
+  cd "$REPO_ROOT"
+
+  # Full clean — distclean removes the generated defs.mak and module objects.
+  if [ -f defs.mak ]; then
+    emmake make distclean || true
+  fi
+  rm -f defs.mak database/database.h
+
+  # Strip Windows CRLF line endings (no-op on Linux-native files).
+  sed_strip_cr configure
+  find scripts/ -type f -print0 | while IFS= read -r -d '' f; do sed_strip_cr "$f"; done
+
+  if [ "$variant" = "tcl" ]; then
+    ensure_tcl_built
+    CFLAGS="--std=c17 -D_DEFAULT_SOURCE=1 -DEMSCRIPTEN=1${EXTRA_CFLAGS}" \
+      emconfigure ./configure \
+        --without-cairo --without-opengl --without-x --without-tk \
+        --with-tcl="$TCL_WASM_PREFIX/lib" \
+        --with-tclincls="$TCL_WASM_PREFIX/include" \
+        --with-tcllibs="$TCL_WASM_PREFIX/lib" \
+        --disable-readline --disable-compression \
+        --host=asmjs-unknown-emscripten \
+        --target=asmjs-unknown-emscripten
+  else
+    CFLAGS="--std=c17 -D_DEFAULT_SOURCE=1 -DEMSCRIPTEN=1${EXTRA_CFLAGS}" \
+      emconfigure ./configure \
+        --without-cairo --without-opengl --without-x \
+        --without-tk --without-tcl \
+        --disable-readline --disable-compression \
+        --host=asmjs-unknown-emscripten \
+        --target=asmjs-unknown-emscripten
+  fi
+
+  cat toolchains/emscripten/defs.mak >> defs.mak
+
+  emmake make depend
+  emmake make -j"$(ncpu)" modules libs
+  emmake make techs
+  emmake make mains
+
+  mkdir -p "$out_dir"
+  cp magic/magic.js   "$out_dir/"
+  cp magic/magic.wasm "$out_dir/"
+  echo "Copied magic.js + magic.wasm into npm/$variant/"
+}
+
+case "$OPT_VARIANT" in
+  tcl|notcl) build_variant "$OPT_VARIANT" ;;
+  both)      build_variant notcl
+             build_variant tcl ;;
+esac
 
 # --- optional test -----------------------------------------------------------
-# Runs the same smoke test that CI runs (see .github/workflows/main.yml).
+# Runs the same smoke test that CI runs (see .github/workflows/main-wasm.yml).
 if [ $OPT_TEST -eq 1 ]; then
   cd "$SCRIPT_DIR"
   npm run test
diff --git a/npm/examples/helpers.js b/npm/examples/helpers.js
index 23772c0b..9092fb6c 100644
--- a/npm/examples/helpers.js
+++ b/npm/examples/helpers.js
@@ -1,11 +1,14 @@
 // Shared utilities for Magic WASM examples.
-import createMagicModule from '../magic.js';
+//
+// These examples drive the non-TCL variant (legacy magic command parser).
+// For Tcl-eval semantics, see examples/smoke-tcl.mjs.
+import createMagicModule from '../notcl/magic.js';
 import { readFileSync } from 'node:fs';
 import { fileURLToPath } from 'node:url';
 import { dirname, resolve, basename } from 'node:path';
 
 export const EXAMPLES_DIR = dirname(fileURLToPath(import.meta.url));
-export const wasmBinary   = readFileSync(resolve(EXAMPLES_DIR, '../magic.wasm'));
+export const wasmBinary   = readFileSync(resolve(EXAMPLES_DIR, '../notcl/magic.wasm'));
 export const DEFAULT_TECH = 'scmos';
 export const DEFAULT_MAG  = resolve(EXAMPLES_DIR, 'min.mag');
 export const DEFAULT_OUT  = resolve(EXAMPLES_DIR, 'output');
diff --git a/npm/examples/smoke-tcl.mjs b/npm/examples/smoke-tcl.mjs
new file mode 100644
index 00000000..6a007b74
--- /dev/null
+++ b/npm/examples/smoke-tcl.mjs
@@ -0,0 +1,39 @@
+// Smoke-test that confirms the TCL interpreter is live inside magic.wasm.
+//
+// In wrapper mode magic_wasm_run_command routes its argument to
+// Tcl_EvalEx(magicinterp, ...). So:
+//   - pure Tcl (`set x 42; puts ...`) should work
+//   - magic commands are available as ::magic:: ensemble commands too
+//
+// Run: node npm/examples/smoke-tcl.mjs
+
+// Pull in the TCL-enabled variant explicitly via the /tcl subpath export.
+import createMagic from '../tcl.js';
+
+const m = await createMagic();
+
+const status = m.init();
+if (status !== 0) {
+  console.error(`magic_wasm_init failed: ${status}`);
+  process.exit(1);
+}
+console.log('magic_wasm_init: OK');
+
+function runTcl(label, command) {
+  const rc = m.runCommand(command);
+  console.log(`[rc=${rc}] ${label}: ${command}`);
+  return rc;
+}
+
+// 1. Pure Tcl arithmetic — proves the TCL interp is parsing.
+runTcl('tcl-set',  'set tcl_smoke_x 42');
+runTcl('tcl-expr', 'set tcl_smoke_y [expr {$tcl_smoke_x * 2}]');
+
+// 2. Tcl introspection — magic should publish a Tclmagic package.
+runTcl('tcl-info', 'puts "tcl_version=$tcl_version  patchlevel=$tcl_patchLevel"');
+runTcl('tcl-pkgs', 'puts "packages=[package names]"');
+
+// 3. A real magic command via the wrapper.
+runTcl('magic-help', 'magic::help');
+
+console.log('done');
diff --git a/npm/index.js b/npm/index.js
index 9cb6e61b..517eba91 100644
--- a/npm/index.js
+++ b/npm/index.js
@@ -1,14 +1,24 @@
-import MagicModuleFactory from './magic.js';
+// Default entry point: the non-TCL build.
+//
+// This preserves the original API and behavior of magic-vlsi-wasm. Magic
+// commands ("tech load sky130A", "load /work/inv", …) are dispatched through
+// magic's legacy parser; no Tcl interpreter is involved.
+//
+// For the TCL-enabled build (commands are evaluated by Tcl_EvalEx, exposing
+// the full Tcl 9 runtime alongside the ::magic:: command ensemble), import
+// from "magic-vlsi-wasm/tcl" instead.
+
+import MagicModuleFactory from './notcl/magic.js';
 
 async function createMagic(options = {}) {
   const module = await MagicModuleFactory(options);
 
   const init       = module.cwrap('magic_wasm_init',        'number', []);
-  const runCommand = module.cwrap('magic_wasm_run_command',  'number', ['string']);
-  const sourceFile = module.cwrap('magic_wasm_source_file',  'number', ['string']);
-  const update     = module.cwrap('magic_wasm_update',       null,     []);
+  const runCommand = module.cwrap('magic_wasm_run_command', 'number', ['string']);
+  const sourceFile = module.cwrap('magic_wasm_source_file', 'number', ['string']);
+  const update     = module.cwrap('magic_wasm_update',      null,     []);
 
-  return { init, runCommand, sourceFile, update, FS: module.FS };
+  return { init, runCommand, sourceFile, update, FS: module.FS, variant: 'notcl' };
 }
 
 export { createMagic };
diff --git a/npm/notcl.js b/npm/notcl.js
new file mode 100644
index 00000000..689cac3a
--- /dev/null
+++ b/npm/notcl.js
@@ -0,0 +1,6 @@
+// Explicit non-TCL entry point: import from "magic-vlsi-wasm/notcl".
+// Identical to the default `magic-vlsi-wasm` import — exists so callers can
+// be explicit about which variant they want.
+
+export { createMagic } from './index.js';
+export { default } from './index.js';
diff --git a/npm/package.json b/npm/package.json
index d4a82e17..e10338dc 100644
--- a/npm/package.json
+++ b/npm/package.json
@@ -1,34 +1,38 @@
 {
   "name": "magic-vlsi-wasm",
   "version": "0.0.0-dev",
-  "description": "Magic VLSI Layout Tool — headless WebAssembly build",
+  "description": "Magic VLSI Layout Tool — headless WebAssembly build (TCL + non-TCL variants)",
   "type": "module",
   "main": "index.js",
   "types": "index.d.ts",
   "exports": {
-    ".": {
-      "import": "./index.js",
-      "types": "./index.d.ts"
-    }
+    ".":       { "import": "./index.js", "types": "./index.d.ts" },
+    "./tcl":   { "import": "./tcl.js",   "types": "./index.d.ts" },
+    "./notcl": { "import": "./notcl.js", "types": "./index.d.ts" }
   },
   "files": [
     "index.js",
     "index.d.ts",
-    "magic.js",
-    "magic.wasm",
+    "tcl.js",
+    "notcl.js",
+    "tcl/magic.js",
+    "tcl/magic.wasm",
+    "notcl/magic.js",
+    "notcl/magic.wasm",
     "examples/",
     "LICENSE",
     "README.md"
   ],
   "scripts": {
-    "example":  "node examples/extract.js",
-    "test":     "node examples/all.js",
-    "test:gds": "node examples/gds.js",
-    "test:drc": "node examples/drc.js",
-    "test:cif": "node examples/cif.js"
+    "example":   "node examples/extract.js",
+    "test":      "node examples/all.js",
+    "test:tcl":  "node examples/smoke-tcl.mjs",
+    "test:gds":  "node examples/gds.js",
+    "test:drc":  "node examples/drc.js",
+    "test:cif":  "node examples/cif.js"
   },
 
-  "keywords": ["magic", "vlsi", "eda", "wasm", "webassembly", "layout"],
+  "keywords": ["magic", "vlsi", "eda", "wasm", "webassembly", "layout", "tcl"],
   "license": "HPND",
   "engines": {
     "node": ">=18"
diff --git a/npm/tcl.js b/npm/tcl.js
new file mode 100644
index 00000000..f2b0cebb
--- /dev/null
+++ b/npm/tcl.js
@@ -0,0 +1,33 @@
+// TCL-enabled entry point: import from "magic-vlsi-wasm/tcl".
+//
+// In this variant magic.wasm embeds a full Tcl 9 interpreter (from
+// intubun/tcl, pinned via magic/npm/tcl.ref) and `runCommand(str)` calls
+// Tcl_EvalEx(magicinterp, str, ...).  Pure Tcl works:
+//
+//     await magic.runCommand('set x 42');
+//     await magic.runCommand('puts $tcl_version');
+//
+// Magic commands are exposed as the ::magic:: ensemble:
+//
+//     await magic.runCommand('magic::tech load sky130A');
+//     await magic.runCommand('magic::load /work/inv');
+//
+// (Bare command names like "tech load …" are not imported into the global
+// namespace by this build — invoke them with the ::magic:: prefix, or set
+// up `namespace import ::magic::*` yourself after init().)
+
+import MagicModuleFactory from './tcl/magic.js';
+
+async function createMagic(options = {}) {
+  const module = await MagicModuleFactory(options);
+
+  const init       = module.cwrap('magic_wasm_init',        'number', []);
+  const runCommand = module.cwrap('magic_wasm_run_command', 'number', ['string']);
+  const sourceFile = module.cwrap('magic_wasm_source_file', 'number', ['string']);
+  const update     = module.cwrap('magic_wasm_update',      null,     []);
+
+  return { init, runCommand, sourceFile, update, FS: module.FS, variant: 'tcl' };
+}
+
+export { createMagic };
+export default createMagic;
diff --git a/npm/tcl.ref b/npm/tcl.ref
new file mode 100644
index 00000000..e14c074c
--- /dev/null
+++ b/npm/tcl.ref
@@ -0,0 +1,16 @@
+# Pin for the TCL fork that the WASM build links against.
+#
+# Format: shell-style "VAR=VALUE" lines (no spaces around =).
+# Lines starting with # or blank lines are ignored.
+#
+# To take a newer TCL release into magic-wasm:
+#   1. Update TCL_REF below to the desired commit SHA (or tag/branch).
+#   2. Bump magic/VERSION as usual.
+#   3. Commit + push. CI rebuilds and republishes.
+#
+# Or use the `update-tcl` GitHub Actions workflow (workflow_dispatch only) to
+# fetch a target ref from intubun/tcl and open a PR that just rewrites this
+# file — you review and merge.
+
+TCL_REPO_URL=https://github.com/intubun/tcl.git
+TCL_REF=84b23291b0dd811d642abef4ec7a55473c3eccb3
diff --git a/scripts/configure b/scripts/configure
index fcb86a0e..1a24752f 100755
--- a/scripts/configure
+++ b/scripts/configure
@@ -6276,6 +6276,7 @@ magic_with_tk_libraries=""
 
 usingOGL=1
 usingTcl=1
+usingTk=1
 usingOA=0
 usingCairo=1
 usingPython3=1
@@ -7254,10 +7255,12 @@ if test "${with_tcl+set}" = set; then :
   magic_with_tcl=$withval
   if test "$withval" = "no" -o "$withval" = "NO"; then
     usingTcl=
+    usingTk=
   elif test $usingScheme ; then
     echo Attempt to enable both Tcl and Scheme interpreters.
     echo Disabling Tcl, and using Scheme instead.
     usingTcl=
+    usingTk=
   fi
 
 fi
@@ -7268,6 +7271,9 @@ fi
 # Check whether --with-tk was given.
 if test "${with_tk+set}" = set; then :
   withval=$with_tk; magic_with_tk=$withval
+  if test "$withval" = "no" -o "$withval" = "NO"; then
+    usingTk=
+  fi
 fi
 
 
@@ -7397,7 +7403,7 @@ fi
 # Find the Tk build configuration file "tkConfig.sh"
 # -----------------------------------------------------------------------
 
-if test $usingTcl ; then
+if test $usingTk ; then
 
   { $as_echo "$as_me:${as_lineno-$LINENO}: checking for tkConfig.sh" >&5
 $as_echo_n "checking for tkConfig.sh... " >&6; }
@@ -7477,8 +7483,8 @@ $as_echo "${tk_config_sh}" >&6; }
 
   if test "x$tk_config_sh" = "x" ; then
     echo "can't find Tk configuration script \"tkConfig.sh\""
-    echo "Reverting to non-Tcl compilation"
-    usingTcl=
+    echo "Reverting to non-Tk compilation"
+    usingTk=
   fi
 fi
 
@@ -7488,7 +7494,9 @@ fi
 
 if test $usingTcl ; then
   . $tcl_config_sh
-  . $tk_config_sh
+  if test $usingTk ; then
+    . $tk_config_sh
+  fi
 
   # Should probably trust the config file contents, but this configure
   # file checks the Tcl and Tk include and lib directories.  Since
@@ -7504,21 +7512,24 @@ if test $usingTcl ; then
 
   tmpstr=${TCL_LIB_SPEC#*-L}
   TCL_LIB_DIR=${tmpstr% -l*}
-  tmpstr=${TK_LIB_SPEC#*-L}
-  TK_LIB_DIR=${tmpstr% -l*}
   TCL_INC_DIR=${TCL_INCLUDE_SPEC#*-I}
-  TK_INC_DIR=${TK_INCLUDE_SPEC#*-I}
+  if test $usingTk ; then
+    tmpstr=${TK_LIB_SPEC#*-L}
+    TK_LIB_DIR=${tmpstr% -l*}
+    TK_INC_DIR=${TK_INCLUDE_SPEC#*-I}
 
-  if test "$TCL_VERSION" = "7.6" -a "$TK_VERSION" = "4.2" ; then
-    :
-  elif test "$TCL_VERSION" = "7.5" -a "$TK_VERSION" = "4.1" ; then
-    :
-  elif test "$TCL_VERSION" = "$TK_VERSION" ; then
-    :
-  else
-    echo "Mismatched Tcl/Tk versions ($TCL_VERSION != $TK_VERSION)"
-    echo "Reverting to non-Tcl compile"
-    usingTcl=
+    if test "$TCL_VERSION" = "7.6" -a "$TK_VERSION" = "4.2" ; then
+      :
+    elif test "$TCL_VERSION" = "7.5" -a "$TK_VERSION" = "4.1" ; then
+      :
+    elif test "$TCL_VERSION" = "$TK_VERSION" ; then
+      :
+    else
+      echo "Mismatched Tcl/Tk versions ($TCL_VERSION != $TK_VERSION)"
+      echo "Reverting to non-Tcl compile"
+      usingTcl=
+      usingTk=
+    fi
   fi
 fi
 
@@ -7551,14 +7562,14 @@ if test $usingTcl ; then
   fi
 fi
 
-if test $usingTcl ; then
+if test $usingTk ; then
   if test "x${magic_with_tk_includes}" != "x" ; then
     if test -r "${magic_with_tk_includes}/tk.h" ; then
       TK_INC_DIR=${magic_with_tk_includes}
     else
       echo "Can't find tk.h in \"${magic_with_tk_includes}\""
-      echo "Reverting to non-Tcl compile"
-      usingTcl=
+      echo "Reverting to non-Tk compile"
+      usingTk=
     fi
   else
     for dir in \
@@ -7575,8 +7586,8 @@ if test $usingTcl ; then
     done
     if test "x${TK_INC_DIR}" = "x" ; then
       echo "Can't find tk.h header file"
-      echo "Reverting to non-Tcl compile"
-      usingTcl=
+      echo "Reverting to non-Tk compile"
+      usingTk=
     fi
   fi
 fi
@@ -7599,14 +7610,14 @@ if test $usingTcl ; then
   if test "x${TCL_LIB_SPEC}" = "x" ; then
      TCL_LIB_SPEC="-l${TCL_LIB_NAME}"
   fi
-  if test "x${TK_LIB_SPEC}" = "x" ; then
+  if test $usingTk -a "x${TK_LIB_SPEC}" = "x" ; then
      TK_LIB_SPEC="-l${TK_LIB_NAME}"
   fi
 
 # Find the version of "wish" that corresponds to TCL_EXEC_PREFIX
 # We really ought to run "ldd" to confirm that the linked libraries match.
 
-  if test "x${magic_with_wish_binary}" = "x" ; then
+  if test $usingTk -a "x${magic_with_wish_binary}" = "x" ; then
     { $as_echo "$as_me:${as_lineno-$LINENO}: checking for wish executable" >&5
 $as_echo_n "checking for wish executable... " >&6; }
     for dir in \
@@ -7638,7 +7649,7 @@ $as_echo "no" >&6; }
       { $as_echo "$as_me:${as_lineno-$LINENO}: result: ${WISH_EXE}" >&5
 $as_echo "${WISH_EXE}" >&6; }
     fi
-  else
+  elif test $usingTk ; then
     WISH_EXE=${magic_with_wish_binary}
   fi
 
@@ -7731,7 +7742,7 @@ $as_echo "${TCLSH_EXE}" >&6; }
   fi
 fi
 
-if test $usingTcl ; then
+if test $usingTk ; then
   if test "x${magic_with_tk_libraries}" != "x" ; then
     for libname in \
      "${magic_with_tk_libraries}/${TCL_LIB_FILE}" \
@@ -7746,8 +7757,8 @@ if test $usingTcl ; then
     done
     if test "x${TK_LIB_DIR}" = "x" ; then
       echo "Can't find tk library in \"${magic_with_tk_libraries}\""
-      echo "Reverting to non-Tcl compile"
-      usingTcl=
+      echo "Reverting to non-Tk compile"
+      usingTk=
     fi
   else
     for libname in \
@@ -7762,8 +7773,8 @@ if test $usingTcl ; then
     done
     if test "x${TK_LIB_DIR}" = "x" ; then
       echo "Can't find tk library"
-      echo "Reverting to non-Tcl compile"
-      usingTcl=
+      echo "Reverting to non-Tk compile"
+      usingTk=
     fi
   fi
 fi
@@ -8638,7 +8649,12 @@ if test $usingTcl ; then
 
   extra_libs="$extra_libs \${MAGICDIR}/tcltk/libtcltk.o"
   extra_defs="$extra_defs -DTCL_DIR=\\\"\${TCLDIR}\\\""
-  stub_defs="$stub_defs -DUSE_TCL_STUBS -DUSE_TK_STUBS"
+  if test $usingTk ; then
+    stub_defs="$stub_defs -DUSE_TCL_STUBS -DUSE_TK_STUBS"
+  else
+    stub_defs="$stub_defs -DUSE_TCL_STUBS -DMAGIC_NO_TK"
+    extra_defs="$extra_defs -DMAGIC_NO_TK"
+  fi
 elif test $usingScheme ; then
   modules="$modules lisp"
   unused="$unused tcltk"
@@ -8681,7 +8697,9 @@ if test $usingTcl ; then
       gr_libs="$gr_libs -lX11"
     fi
   fi
-  gr_srcs="$gr_srcs \${TKCOMMON_SRCS}"
+  if test $usingTk ; then
+    gr_srcs="$gr_srcs \${TKCOMMON_SRCS}"
+  fi
 else
   if test $usingX11 ; then
     gr_dflags="$gr_dflags -DX11 -DXLIB"
@@ -8791,23 +8809,25 @@ if test $usingTcl ; then
 
 # -----------------------------------------------------------------------
 #
-# Tk libraries and header files
+# Tk libraries and header files (skipped under --without-tk)
 #
 # -----------------------------------------------------------------------
-  if test "${TK_INC_DIR}" != "/usr/include" ; then
-    INC_SPECS="${INC_SPECS} -I${TK_INC_DIR}"
-  fi
-  if test "${TK_LIB_DIR}" = "/usr/lib" -o \
-        "${TK_LIB_DIR}" = "/usr/lib64" ; then
-    LIB_SPECS_NOSTUB="${LIB_SPECS_NOSTUB} ${TK_LIB_SPEC}"
-    LIB_SPECS="${LIB_SPECS} ${TK_STUB_LIB_SPEC}"
-  else
-    LIB_SPECS_NOSTUB="${LIB_SPECS_NOSTUB} -L${TK_LIB_DIR} ${TK_LIB_SPEC}"
-    LIB_SPECS="${LIB_SPECS} -L${TK_LIB_DIR} ${TK_STUB_LIB_SPEC}"
-    if test "x${loader_run_path}" = "x" ; then
-      loader_run_path="${TK_LIB_DIR}"
+  if test $usingTk ; then
+    if test "${TK_INC_DIR}" != "/usr/include" ; then
+      INC_SPECS="${INC_SPECS} -I${TK_INC_DIR}"
+    fi
+    if test "${TK_LIB_DIR}" = "/usr/lib" -o \
+          "${TK_LIB_DIR}" = "/usr/lib64" ; then
+      LIB_SPECS_NOSTUB="${LIB_SPECS_NOSTUB} ${TK_LIB_SPEC}"
+      LIB_SPECS="${LIB_SPECS} ${TK_STUB_LIB_SPEC}"
     else
-      loader_run_path="${TK_LIB_DIR}:${loader_run_path}"
+      LIB_SPECS_NOSTUB="${LIB_SPECS_NOSTUB} -L${TK_LIB_DIR} ${TK_LIB_SPEC}"
+      LIB_SPECS="${LIB_SPECS} -L${TK_LIB_DIR} ${TK_STUB_LIB_SPEC}"
+      if test "x${loader_run_path}" = "x" ; then
+        loader_run_path="${TK_LIB_DIR}"
+      else
+        loader_run_path="${TK_LIB_DIR}:${loader_run_path}"
+      fi
     fi
   fi
 
diff --git a/scripts/configure.in b/scripts/configure.in
index 98421feb..e2326fef 100644
--- a/scripts/configure.in
+++ b/scripts/configure.in
@@ -344,6 +344,7 @@ dnl disabled with --with-opengl=no
 
 usingOGL=1
 usingTcl=1
+usingTk=1
 usingOA=0
 usingCairo=1
 usingPython3=1
@@ -442,10 +443,12 @@ AC_ARG_WITH(tcl,
   magic_with_tcl=$withval
   if test "$withval" = "no" -o "$withval" = "NO"; then
     usingTcl=
+    usingTk=
   elif test $usingScheme ; then
     echo Attempt to enable both Tcl and Scheme interpreters.
     echo Disabling Tcl, and using Scheme instead.
     usingTcl=
+    usingTk=
   fi
 ], )
 
@@ -455,10 +458,17 @@ dnl and don't set the usingTcl variable.
 dnl
 dnl This has been broken up into a number of sections, each of which
 dnl depends independently on the setting of usingTcl.
+dnl
+dnl `usingTk` is independent of `usingTcl`: --without-tk enables
+dnl Tcl-only embedding (used by the WASM build, which has no display
+dnl server and cannot run Tk).
 dnl ----------------------------------------------------------------
 
 AC_ARG_WITH(tk,         [  --with-tk=DIR           Find tkConfig.sh in DIR],
-  magic_with_tk=$withval)
+  magic_with_tk=$withval
+  if test "$withval" = "no" -o "$withval" = "NO"; then
+    usingTk=
+  fi)
 AC_ARG_WITH(tclincls,   [  --with-tclincls=DIR     Find tcl.h in DIR],
   magic_with_tcl_includes=$withval)
 AC_ARG_WITH(tkincls,    [  --with-tkincls=DIR      Find tk.h in DIR],
@@ -564,7 +574,7 @@ fi
 # Find the Tk build configuration file "tkConfig.sh"
 # -----------------------------------------------------------------------
 
-if test $usingTcl ; then
+if test $usingTk ; then
 
   AC_MSG_CHECKING([for tkConfig.sh])
   tk_config_sh=""
@@ -642,8 +652,8 @@ if test $usingTcl ; then
 
   if test "x$tk_config_sh" = "x" ; then
     echo "can't find Tk configuration script \"tkConfig.sh\""
-    echo "Reverting to non-Tcl compilation"
-    usingTcl=
+    echo "Reverting to non-Tk compilation"
+    usingTk=
   fi
 fi
 
@@ -653,7 +663,9 @@ fi
 
 if test $usingTcl ; then
   . $tcl_config_sh
-  . $tk_config_sh
+  if test $usingTk ; then
+    . $tk_config_sh
+  fi
 
   # Should probably trust the config file contents, but this configure
   # file checks the Tcl and Tk include and lib directories.  Since
@@ -669,21 +681,24 @@ if test $usingTcl ; then
 
   tmpstr=${TCL_LIB_SPEC#*-L}
   TCL_LIB_DIR=${tmpstr% -l*}
-  tmpstr=${TK_LIB_SPEC#*-L}
-  TK_LIB_DIR=${tmpstr% -l*}
   TCL_INC_DIR=${TCL_INCLUDE_SPEC#*-I}
-  TK_INC_DIR=${TK_INCLUDE_SPEC#*-I}
+  if test $usingTk ; then
+    tmpstr=${TK_LIB_SPEC#*-L}
+    TK_LIB_DIR=${tmpstr% -l*}
+    TK_INC_DIR=${TK_INCLUDE_SPEC#*-I}
 
-  if test "$TCL_VERSION" = "7.6" -a "$TK_VERSION" = "4.2" ; then
-    :
-  elif test "$TCL_VERSION" = "7.5" -a "$TK_VERSION" = "4.1" ; then
-    :
-  elif test "$TCL_VERSION" = "$TK_VERSION" ; then
-    :
-  else
-    echo "Mismatched Tcl/Tk versions ($TCL_VERSION != $TK_VERSION)"
-    echo "Reverting to non-Tcl compile"
-    usingTcl=
+    if test "$TCL_VERSION" = "7.6" -a "$TK_VERSION" = "4.2" ; then
+      :
+    elif test "$TCL_VERSION" = "7.5" -a "$TK_VERSION" = "4.1" ; then
+      :
+    elif test "$TCL_VERSION" = "$TK_VERSION" ; then
+      :
+    else
+      echo "Mismatched Tcl/Tk versions ($TCL_VERSION != $TK_VERSION)"
+      echo "Reverting to non-Tcl compile"
+      usingTcl=
+      usingTk=
+    fi
   fi
 fi
 
@@ -716,14 +731,14 @@ if test $usingTcl ; then
   fi
 fi
 
-if test $usingTcl ; then
+if test $usingTk ; then
   if test "x${magic_with_tk_includes}" != "x" ; then
     if test -r "${magic_with_tk_includes}/tk.h" ; then
       TK_INC_DIR=${magic_with_tk_includes}
     else
       echo "Can't find tk.h in \"${magic_with_tk_includes}\""
-      echo "Reverting to non-Tcl compile"
-      usingTcl=
+      echo "Reverting to non-Tk compile"
+      usingTk=
     fi
   else
     for dir in \
@@ -740,8 +755,8 @@ if test $usingTcl ; then
     done
     if test "x${TK_INC_DIR}" = "x" ; then
       echo "Can't find tk.h header file"
-      echo "Reverting to non-Tcl compile"
-      usingTcl=
+      echo "Reverting to non-Tk compile"
+      usingTk=
     fi
   fi
 fi
@@ -764,14 +779,14 @@ if test $usingTcl ; then
   if test "x${TCL_LIB_SPEC}" = "x" ; then
      TCL_LIB_SPEC="-l${TCL_LIB_NAME}"
   fi
-  if test "x${TK_LIB_SPEC}" = "x" ; then
+  if test $usingTk -a "x${TK_LIB_SPEC}" = "x" ; then
      TK_LIB_SPEC="-l${TK_LIB_NAME}"
   fi
 
 # Find the version of "wish" that corresponds to TCL_EXEC_PREFIX
 # We really ought to run "ldd" to confirm that the linked libraries match.
 
-  if test "x${magic_with_wish_binary}" = "x" ; then
+  if test $usingTk -a "x${magic_with_wish_binary}" = "x" ; then
     AC_MSG_CHECKING([for wish executable])
     for dir in \
     ${TK_EXEC_PREFIX}/bin \
@@ -800,7 +815,7 @@ if test $usingTcl ; then
     else
       AC_MSG_RESULT([${WISH_EXE}])
     fi
-  else
+  elif test $usingTk ; then
     WISH_EXE=${magic_with_wish_binary}
   fi
 
@@ -890,7 +905,7 @@ if test $usingTcl ; then
   fi
 fi
 
-if test $usingTcl ; then
+if test $usingTk ; then
   if test "x${magic_with_tk_libraries}" != "x" ; then
     for libname in \
      "${magic_with_tk_libraries}/${TCL_LIB_FILE}" \
@@ -905,8 +920,8 @@ if test $usingTcl ; then
     done
     if test "x${TK_LIB_DIR}" = "x" ; then
       echo "Can't find tk library in \"${magic_with_tk_libraries}\""
-      echo "Reverting to non-Tcl compile"
-      usingTcl=
+      echo "Reverting to non-Tk compile"
+      usingTk=
     fi
   else
     for libname in \
@@ -921,8 +936,8 @@ if test $usingTcl ; then
     done
     if test "x${TK_LIB_DIR}" = "x" ; then
       echo "Can't find tk library"
-      echo "Reverting to non-Tcl compile"
-      usingTcl=
+      echo "Reverting to non-Tk compile"
+      usingTk=
     fi
   fi
 fi
@@ -1356,7 +1371,12 @@ if test $usingTcl ; then
   AC_DEFINE(MAGIC_WRAPPER)
   extra_libs="$extra_libs \${MAGICDIR}/tcltk/libtcltk.o"
   extra_defs="$extra_defs -DTCL_DIR=\\\"\${TCLDIR}\\\""
-  stub_defs="$stub_defs -DUSE_TCL_STUBS -DUSE_TK_STUBS"
+  if test $usingTk ; then
+    stub_defs="$stub_defs -DUSE_TCL_STUBS -DUSE_TK_STUBS"
+  else
+    stub_defs="$stub_defs -DUSE_TCL_STUBS -DMAGIC_NO_TK"
+    extra_defs="$extra_defs -DMAGIC_NO_TK"
+  fi
 elif test $usingScheme ; then
   modules="$modules lisp"
   unused="$unused tcltk"
@@ -1401,7 +1421,9 @@ if test $usingTcl ; then
       gr_libs="$gr_libs -lX11"
     fi
   fi
-  gr_srcs="$gr_srcs \${TKCOMMON_SRCS}"
+  if test $usingTk ; then
+    gr_srcs="$gr_srcs \${TKCOMMON_SRCS}"
+  fi
 else
   if test $usingX11 ; then
     gr_dflags="$gr_dflags -DX11 -DXLIB"
@@ -1506,23 +1528,25 @@ if test $usingTcl ; then
 
 # -----------------------------------------------------------------------
 #
-# Tk libraries and header files
+# Tk libraries and header files (skipped under --without-tk)
 #
 # -----------------------------------------------------------------------
-  if test "${TK_INC_DIR}" != "/usr/include" ; then
-    INC_SPECS="${INC_SPECS} -I${TK_INC_DIR}"
-  fi
-  if test "${TK_LIB_DIR}" = "/usr/lib" -o \
-        "${TK_LIB_DIR}" = "/usr/lib64" ; then
-    LIB_SPECS_NOSTUB="${LIB_SPECS_NOSTUB} ${TK_LIB_SPEC}"
-    LIB_SPECS="${LIB_SPECS} ${TK_STUB_LIB_SPEC}"
-  else
-    LIB_SPECS_NOSTUB="${LIB_SPECS_NOSTUB} -L${TK_LIB_DIR} ${TK_LIB_SPEC}"
-    LIB_SPECS="${LIB_SPECS} -L${TK_LIB_DIR} ${TK_STUB_LIB_SPEC}"
-    if test "x${loader_run_path}" = "x" ; then
-      loader_run_path="${TK_LIB_DIR}"
+  if test $usingTk ; then
+    if test "${TK_INC_DIR}" != "/usr/include" ; then
+      INC_SPECS="${INC_SPECS} -I${TK_INC_DIR}"
+    fi
+    if test "${TK_LIB_DIR}" = "/usr/lib" -o \
+          "${TK_LIB_DIR}" = "/usr/lib64" ; then
+      LIB_SPECS_NOSTUB="${LIB_SPECS_NOSTUB} ${TK_LIB_SPEC}"
+      LIB_SPECS="${LIB_SPECS} ${TK_STUB_LIB_SPEC}"
     else
-      loader_run_path="${TK_LIB_DIR}:${loader_run_path}"
+      LIB_SPECS_NOSTUB="${LIB_SPECS_NOSTUB} -L${TK_LIB_DIR} ${TK_LIB_SPEC}"
+      LIB_SPECS="${LIB_SPECS} -L${TK_LIB_DIR} ${TK_STUB_LIB_SPEC}"
+      if test "x${loader_run_path}" = "x" ; then
+        loader_run_path="${TK_LIB_DIR}"
+      else
+        loader_run_path="${TK_LIB_DIR}:${loader_run_path}"
+      fi
     fi
   fi
 
diff --git a/tcltk/Makefile b/tcltk/Makefile
index 7e29acd7..372ecdd7 100644
--- a/tcltk/Makefile
+++ b/tcltk/Makefile
@@ -41,6 +41,16 @@ BIN_FILES = \
 
 tcl-main: magicexec magicdnull magic.tcl magic.sh ext2spice.sh ext2sim.sh
 
+# In the WASM build the tcltk module ships only as libtcltk.o; there is no
+# wish-like launcher binary, no magic.sh, etc. `make mains` iterates over
+# PROGRAMS which now includes tcltk (because --with-tcl is on), so define a
+# no-op `main` to keep that loop happy. The native build still uses tcl-main
+# via `make all` → tcllibrary.
+ifeq (${MAKE_WASM},1)
+main:
+	@:
+endif
+
 install-tcl: magicexec magicdnull ${BIN_FILES} ${TCL_FILES}
 	${RM} $(DESTDIR)${INSTALL_TCLDIR}/magicexec
 	${CP} magicexec $(DESTDIR)${INSTALL_TCLDIR}/magicexec
diff --git a/tcltk/tclmagic.c b/tcltk/tclmagic.c
index dd1e3aec..b15302b9 100644
--- a/tcltk/tclmagic.c
+++ b/tcltk/tclmagic.c
@@ -178,8 +178,10 @@ TagCallback(interp, tkpath, argc, argv)
 			windCheckOnlyWindow(&w, DBWclientID);
 			if (w != NULL && !(w->w_flags & WIND_OFFSCREEN))
 			{
+#ifndef MAGIC_NO_TK
 			    Tk_Window tkwind = (Tk_Window) w->w_grdata;
 			    if (tkwind != NULL) tkpath = Tk_PathName(tkwind);
+#endif
 			}
 		    }
 		    if (tkpath == NULL)
@@ -742,8 +744,10 @@ _magic_initialize(ClientData clientData,
     /* (See graphics/grTkCommon.c)				*/
     /* (Unless "-dnull" option has been given)			*/
 
+#ifndef MAGIC_NO_TK
     if (strcmp(MainDisplayType, "NULL"))
 	RegisterTkCommands(interp);
+#endif
 
     /* Set up the console so that its menu option File->Exit	*/
     /* calls magic's exit routine first.  This should not be	*/
diff --git a/tcltk/tclmagic.h b/tcltk/tclmagic.h
index fb94dab4..bb8c3b31 100644
--- a/tcltk/tclmagic.h
+++ b/tcltk/tclmagic.h
@@ -12,7 +12,9 @@
 #ifdef MAGIC_WRAPPER
 
 #include <tcl.h>
+#ifndef MAGIC_NO_TK
 #include <tk.h>
+#endif
 
 /* Externally-defined global variables */
 
diff --git a/toolchains/emscripten/build-tcl-wasm.sh b/toolchains/emscripten/build-tcl-wasm.sh
new file mode 100644
index 00000000..88c53944
--- /dev/null
+++ b/toolchains/emscripten/build-tcl-wasm.sh
@@ -0,0 +1,142 @@
+#!/usr/bin/env bash
+# Build intubun/tcl as a static WASM library for linking into magic.wasm.
+#
+# This script does NOT modify the TCL source tree — the build is fully
+# out-of-source. configure is invoked from the build directory inside magic,
+# with the TCL source tree referenced through $0's path. All generated files
+# (Makefile, objects, tclConfig.sh, libtcl9.x.a, ...) live under $OUT.
+#
+# Outputs (under $OUT):
+#   $OUT/Makefile, *.o, tclConfig.sh, libtcl9.x.a, libtclstub.a
+#   $OUT/install/include/{tcl.h, tclDecls.h, ...}
+#   $OUT/install/lib/{libtcl9.x.a, libtclstub.a, tclConfig.sh, tcl9.x/<scripts>}
+#
+# Usage:
+#   build-tcl-wasm.sh --src=<TCL source tree> [--out=<build dir>] [--clean]
+#
+# Requirements: an activated emsdk (emcc/emconfigure/emmake on PATH), a host
+# gcc (used to build TCL's minizip helper, which runs natively), make, and a
+# git checkout of intubun/tcl pointed to by --src.
+#
+# Note on line endings: if the TCL source tree was cloned on Windows with
+# git's core.autocrlf=true, unix/configure may have CRLF line endings and
+# bash will reject it. Clone with `git -c core.autocrlf=false clone ...` to
+# avoid this; magic/npm/build.sh does that automatically.
+
+set -euo pipefail
+
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+# magic/ root is two levels up from toolchains/emscripten/.
+MAGIC_ROOT="$(cd "$SCRIPT_DIR/../.." && pwd)"
+
+TCL_SRC=""
+OUT="$MAGIC_ROOT/build-tcl-wasm"
+OPT_CLEAN=0
+for arg in "$@"; do
+  case "$arg" in
+    --src=*)   TCL_SRC=${arg#--src=} ;;
+    --out=*)   OUT=${arg#--out=}     ;;
+    --clean)   OPT_CLEAN=1           ;;
+    *) echo "Unknown option: $arg" >&2; exit 1 ;;
+  esac
+done
+
+if [ -z "$TCL_SRC" ]; then
+  echo "Error: --src=<tcl source tree> is required." >&2
+  exit 1
+fi
+if [ ! -f "$TCL_SRC/unix/configure" ]; then
+  echo "Error: $TCL_SRC/unix/configure not found — not a TCL source tree." >&2
+  exit 1
+fi
+# Detect CRLF in configure up-front so the failure mode is a useful error and
+# not a cryptic `set: pipefail: invalid option name` from bash.
+if head -1 "$TCL_SRC/unix/configure" | grep -q $'\r'; then
+  echo "Error: $TCL_SRC/unix/configure has CRLF line endings." >&2
+  echo "       Reclone intubun/tcl with: git -c core.autocrlf=false clone …" >&2
+  exit 1
+fi
+
+# Normalise to absolute paths so the generated tclConfig.sh has stable paths.
+TCL_SRC=$(cd "$TCL_SRC" && pwd)
+mkdir -p "$OUT"
+OUT=$(cd "$OUT" && pwd)
+
+if [ $OPT_CLEAN -eq 1 ]; then
+  rm -rf "$OUT"
+  mkdir -p "$OUT"
+fi
+
+command -v emcc >/dev/null 2>&1 || {
+  echo "Error: emcc not on PATH. Activate emsdk first." >&2
+  exit 1
+}
+echo "Using emcc: $(command -v emcc)"
+emcc --version | head -1
+
+ncpu() {
+  if command -v nproc >/dev/null 2>&1; then nproc
+  else echo 2
+  fi
+}
+
+cd "$OUT"
+
+# --- configure --------------------------------------------------------------
+# Standard autoconf out-of-source pattern: invoke configure from the build
+# dir via its absolute path. configure uses dirname($0) as srcdir.
+#
+# -sUSE_ZLIB=1 makes emcc inject its zlib port so configure finds zlib.h /
+# deflateSetHeader on the link line. Without it, TCL falls back to its
+# compat/zlib copy whose include path isn't picked up by tclEvent.o.
+#
+# --disable-shared      we statically link libtcl into magic.wasm.
+# --disable-load        no dynamic loading inside wasm.
+# --enable-symbols=no   release (-O2). Override CFLAGS to add -g for debug.
+if [ ! -f Makefile ]; then
+  echo "=== emconfigure ==="
+  CFLAGS="-O2 -sUSE_ZLIB=1" \
+    emconfigure "$TCL_SRC/unix/configure" \
+      --disable-shared \
+      --disable-load \
+      --enable-symbols=no \
+      --host=wasm32-unknown-emscripten \
+      --prefix="$OUT/install"
+fi
+
+# --- build ------------------------------------------------------------------
+# HOST_CC/AR/RANLIB must be native — TCL's Makefile builds a `minizip` tool
+# that runs on the host to produce the embedded zipfs resource. Without this
+# override emcc would build minizip itself as a wasm module, which crashes on
+# small stacks. HOST_OBJEXT is kept distinct from OBJEXT so host and target
+# objects don't collide.
+#
+# Archive names come from tclConfig.sh so we don't bake in a fixed version.
+TCL_LIB_FILE=$(. "$OUT/tclConfig.sh" && echo "$TCL_LIB_FILE")
+TCL_STUB_LIB_FILE=$(. "$OUT/tclConfig.sh" && echo "$TCL_STUB_LIB_FILE")
+HOST_OBJEXT=hostobj
+
+echo "=== build ($TCL_LIB_FILE, $TCL_STUB_LIB_FILE) ==="
+emmake make -j"$(ncpu)" \
+  HOST_CC=gcc HOST_AR=ar HOST_RANLIB=ranlib HOST_EXEEXT= HOST_OBJEXT="$HOST_OBJEXT" \
+  "$TCL_LIB_FILE" "$TCL_STUB_LIB_FILE"
+
+# --- install ----------------------------------------------------------------
+# install-headers populates $OUT/install/include with tcl.h + friends.
+# install-libraries copies the Tcl script library (init.tcl, encodings, ...)
+# under $OUT/install/lib/tcl9.x. We skip install-binaries because it would
+# build a tclsh executable that we don't need; we cp the static archives
+# manually so magic's configure (which scans <prefix>/lib for tclConfig.sh
+# and a libtcl*.a) finds everything in one place.
+emmake make \
+  HOST_CC=gcc HOST_AR=ar HOST_RANLIB=ranlib HOST_EXEEXT= HOST_OBJEXT="$HOST_OBJEXT" \
+  install-headers install-libraries
+
+mkdir -p "$OUT/install/lib"
+cp -f "$TCL_LIB_FILE" "$TCL_STUB_LIB_FILE" tclConfig.sh "$OUT/install/lib/"
+
+echo
+echo "=== artifacts ==="
+ls -la "$TCL_LIB_FILE" "$TCL_STUB_LIB_FILE" tclConfig.sh 2>&1 | sed 's/^/  /'
+echo "  install/lib:"
+ls -la install/lib 2>&1 | sed 's/^/    /'
diff --git a/toolchains/emscripten/defs.mak b/toolchains/emscripten/defs.mak
index dcace819..fa3d032b 100644
--- a/toolchains/emscripten/defs.mak
+++ b/toolchains/emscripten/defs.mak
@@ -24,11 +24,12 @@ TOP_EXTRA_LIBS += \
     -sWASM=1 \
     -sMODULARIZE=1 \
     -sEXPORT_ES6=1 \
+    -sUSE_ZLIB=1 \
     -sEXPORTED_FUNCTIONS=_magic_wasm_init,_magic_wasm_run_command,_magic_wasm_source_file,_magic_wasm_update \
     -sEXPORTED_RUNTIME_METHODS=cwrap,ccall,FS,setValue,getValue \
     -sALLOW_MEMORY_GROWTH=1 \
     -sINITIAL_MEMORY=33554432 \
-    -sSTACK_SIZE=5242880 \
+    -Wl,-z,stack-size=5242880 \
     -sASSERTIONS=1 \
     -sENVIRONMENT=node,web,worker \
     -sFORCE_FILESYSTEM=1 \