diff --git a/Justfile b/Justfile
index c907a22..4610cf8 100644
--- a/Justfile
+++ b/Justfile
@@ -54,6 +54,17 @@ build-cli: build-ffi
 build-cli-release: build-ffi-release
     cd cli && zig build -Doptimize=ReleaseSafe
 
+# Build the gossamer-launcher (wasmtime host) + cli.wasm. Replaces the
+# legacy Zig CLI once Phase 14b body-port (#42) lands. The launcher build
+# invokes ephapax to compile cli/src/Main.eph → cli.wasm in the same
+# `zig build` step, so EPHAPAX must point at a working compiler.
+build-launcher: build-ffi
+    cd cli/launcher && EPHAPAX="{{ephapax}}" zig build
+
+# Release-mode launcher + cli.wasm (used by packaging recipes).
+build-launcher-release: build-ffi-release
+    cd cli/launcher && EPHAPAX="{{ephapax}}" zig build -Doptimize=ReleaseSafe
+
 # Build everything (FFI + CLI + check)
 build: build-ffi build-cli check
 
@@ -250,11 +261,17 @@ clean:
 # Development
 # ═══════════════════════════════════════════════════════════════
 
-# Install the gossamer CLI to ~/.local/bin
-install: build-cli
-    mkdir -p ~/.local/bin
-    cp cli/zig-out/bin/gossamer ~/.local/bin/gossamer
-    @echo "  ✓ Installed gossamer to ~/.local/bin/gossamer"
+# Install the gossamer CLI to ~/.local/bin (launcher + cli.wasm)
+#
+# Lays the artefacts out so the launcher's install-prefix-relative
+# discovery (<exe_dir>/../share/gossamer/cli.wasm) finds the wasm at
+# runtime — see cli/launcher/src/main.zig:266.
+install: build-launcher
+    mkdir -p ~/.local/bin ~/.local/share/gossamer
+    cp cli/launcher/zig-out/bin/gossamer-launcher ~/.local/bin/gossamer
+    cp cli/launcher/zig-out/share/gossamer/cli.wasm ~/.local/share/gossamer/cli.wasm
+    @echo "  ✓ Installed gossamer (launcher) to ~/.local/bin/gossamer"
+    @echo "  ✓ Installed cli.wasm to ~/.local/share/gossamer/cli.wasm"
 
 # Show exported FFI symbols
 symbols:
@@ -411,11 +428,11 @@ tour:
 # ═══════════════════════════════════════════════════════════════
 
 # Build .deb package for Debian/Ubuntu
-package-deb: build-ffi-release build-cli-release
+package-deb: build-ffi-release build-launcher-release
     dpkg-buildpackage -b --no-sign --build-dir=packaging/debian
 
 # Build .rpm package for Fedora/RHEL
-package-rpm: build-ffi-release build-cli-release
+package-rpm: build-ffi-release build-launcher-release
     rpmbuild -bb packaging/rpm/gossamer.spec
 
 # Build Flatpak bundle
diff --git a/packaging/debian/gossamer.install b/packaging/debian/gossamer.install
index 9e85f85..85fe682 100644
--- a/packaging/debian/gossamer.install
+++ b/packaging/debian/gossamer.install
@@ -5,5 +5,6 @@
 # Format: <source path>  <destination directory (relative to package root)>
 
 src/interface/ffi/zig-out/lib/libgossamer.so  usr/lib/
-cli/zig-out/bin/gossamer  usr/bin/
+cli/launcher/zig-out/bin/gossamer-launcher  usr/bin/
+cli/launcher/zig-out/share/gossamer/cli.wasm  usr/share/gossamer/
 generated/abi/gossamer.h  usr/include/gossamer/
diff --git a/packaging/debian/rules b/packaging/debian/rules
index 6eee256..6ca978a 100644
--- a/packaging/debian/rules
+++ b/packaging/debian/rules
@@ -13,7 +13,7 @@
 # the default dh_auto_build heuristic (which does not know about Zig).
 override_dh_auto_build:
 	just build-ffi-release
-	just build-cli-release
+	just build-launcher-release
 
 # Override the install step to place files into the package staging tree.
 # dh_auto_install would look for a Makefile install target; we do it manually.
@@ -22,10 +22,16 @@ override_dh_auto_install:
 	install -Dm755 src/interface/ffi/zig-out/lib/libgossamer.so \
 		debian/gossamer/usr/lib/libgossamer.so
 
-	# CLI binary — goes to /usr/bin/
-	install -Dm755 cli/zig-out/bin/gossamer \
+	# CLI launcher (wasmtime host) — installed as `gossamer` so existing
+	# UX is preserved. Renames gossamer-launcher → gossamer.
+	install -Dm755 cli/launcher/zig-out/bin/gossamer-launcher \
 		debian/gossamer/usr/bin/gossamer
 
+	# Precompiled cli.wasm — discovered by the launcher at
+	# <exe_dir>/../share/gossamer/cli.wasm at runtime.
+	install -Dm644 cli/launcher/zig-out/share/gossamer/cli.wasm \
+		debian/gossamer/usr/share/gossamer/cli.wasm
+
 	# Public C header — goes to /usr/include/gossamer/
 	install -Dm644 generated/abi/gossamer.h \
 		debian/gossamer/usr/include/gossamer/gossamer.h
diff --git a/packaging/rpm/gossamer.spec b/packaging/rpm/gossamer.spec
index 47530ca..3777654 100644
--- a/packaging/rpm/gossamer.spec
+++ b/packaging/rpm/gossamer.spec
@@ -22,9 +22,16 @@ BuildRequires:  webkit2gtk4-devel >= 2.40
 BuildRequires:  gtk3-devel >= 3.22
 BuildRequires:  just
 BuildRequires:  pkg-config
+# wasmtime C API >= v44.0.1 — packaged out-of-tree for now; install
+# from https://github.com/bytecodealliance/wasmtime/releases under
+# /usr/local before building (see cli/launcher/build.zig).
+# ephapax — compiles cli/src/Main.eph → cli.wasm during the launcher
+# build. Set EPHAPAX=/path/to/ephapax if not on PATH.
 
 Requires:       webkit2gtk4 >= 2.40
 Requires:       gtk3 >= 3.22
+# wasmtime is dlopened by the launcher binary; same out-of-tree note
+# applies — /usr/local/lib/libwasmtime.so must be present at runtime.
 
 %description
 Gossamer is a webview shell framework that uses linear types to guarantee
@@ -55,8 +62,8 @@ building applications that embed the Gossamer webview shell framework.
 # Build the Zig FFI shared library in release mode.
 just build-ffi-release
 
-# Build the Gossamer CLI in release mode.
-just build-cli-release
+# Build the wasmtime-host launcher + cli.wasm in release mode.
+just build-launcher-release
 
 %install
 # Clear any stale install root.
@@ -70,10 +77,16 @@ install -Dm755 src/interface/ffi/zig-out/lib/libgossamer.so \
 install -Dm644 src/interface/ffi/zig-out/lib/libgossamer.a \
     %{buildroot}%{_libdir}/libgossamer.a
 
-# Install the CLI binary.
-install -Dm755 cli/zig-out/bin/gossamer \
+# Install the launcher binary as `gossamer` (preserving the existing
+# UX). The launcher discovers cli.wasm via the install-prefix-relative
+# path <exe_dir>/../share/gossamer/cli.wasm at runtime.
+install -Dm755 cli/launcher/zig-out/bin/gossamer-launcher \
     %{buildroot}%{_bindir}/gossamer
 
+# Install the precompiled cli.wasm into the share/gossamer prefix.
+install -Dm644 cli/launcher/zig-out/share/gossamer/cli.wasm \
+    %{buildroot}%{_datadir}/gossamer/cli.wasm
+
 # Install the public C header.
 install -Dm644 generated/abi/gossamer.h \
     %{buildroot}%{_includedir}/gossamer/gossamer.h
@@ -83,6 +96,7 @@ install -Dm644 generated/abi/gossamer.h \
 %doc README.adoc
 %{_libdir}/libgossamer.so
 %{_bindir}/gossamer
+%{_datadir}/gossamer/cli.wasm
 
 %files devel
 %{_libdir}/libgossamer.a