diff --git a/Makefile.wasi b/Makefile.wasi
new file mode 100644
index 0000000..bb0da20
--- /dev/null
+++ b/Makefile.wasi
@@ -0,0 +1,103 @@
+WASI_SDK_PATH ?= /opt/wasi-sdk
+ADAPTER ?= wasi_snapshot_preview1.reactor.wasm
+
+CC = $(WASI_SDK_PATH)/bin/clang
+HOST_CC = gcc
+
+# Component build flags
+CFLAGS = -Oz \
+         --target=wasm32-wasi \
+         -D_WASI_EMULATED_SIGNAL \
+         -Ibuild -Igenerated -I. \
+         -mllvm -wasm-enable-sjlj
+
+LDFLAGS = -mexec-model=reactor \
+          -Wl,--export=cabi_realloc \
+          -Wl,--export=__wasm_call_ctors \
+          -lwasi-emulated-signal \
+          -lwasi-emulated-process-clocks \
+          -lsetjmp \
+          -lm
+
+# CLI build flags (for tests)
+CLI_CFLAGS = -Oz -mllvm -wasm-enable-sjlj \
+             --target=wasm32-wasip2 \
+             -Ibuild -I.
+
+CLI_LDFLAGS = -lm -lsetjmp
+
+BUILD_DIR = build
+GEN_DIR = generated
+
+CORE_WASM = $(BUILD_DIR)/core.wasm
+COMPONENT_WASM = $(BUILD_DIR)/microquickjs.component.wasm
+CLI_WASM = $(BUILD_DIR)/mqjs.wasm
+
+SRCS = glue.c \
+       mquickjs.c \
+       cutils.c \
+       dtoa.c \
+       libm.c \
+       $(GEN_DIR)/microquickjs.c
+
+OBJS = $(patsubst %.c, $(BUILD_DIR)/%.o, $(notdir $(SRCS)))
+
+all: $(COMPONENT_WASM) $(CLI_WASM)
+
+$(BUILD_DIR):
+	mkdir -p $(BUILD_DIR)
+
+# Header generation
+$(BUILD_DIR)/mqjs_stdlib.h: mqjs_stdlib.c mquickjs_build.c cutils.c | $(BUILD_DIR)
+	$(HOST_CC) -O2 -I. -o $(BUILD_DIR)/mqjs_stdlib_native $^ -lm
+	./$(BUILD_DIR)/mqjs_stdlib_native -m32 > $@
+
+$(BUILD_DIR)/mquickjs_atom.h: mqjs_stdlib.c mquickjs_build.c cutils.c | $(BUILD_DIR)
+	$(HOST_CC) -O2 -I. -o $(BUILD_DIR)/mqjs_stdlib_native $^ -lm
+	./$(BUILD_DIR)/mqjs_stdlib_native -a -m32 > $@
+
+# Component Object Compilation
+$(BUILD_DIR)/%.o: %.c | $(BUILD_DIR)
+	$(CC) $(CFLAGS) -c -o $@ $<
+
+$(BUILD_DIR)/microquickjs.o: $(GEN_DIR)/microquickjs.c | $(BUILD_DIR)
+	$(CC) $(CFLAGS) -c -o $@ $<
+
+# Core WASM
+$(CORE_WASM): $(OBJS) $(GEN_DIR)/microquickjs_component_type.o
+	$(CC) $(CFLAGS) -o $@ $^ $(LDFLAGS)
+
+# Component composition
+$(COMPONENT_WASM): $(CORE_WASM)
+	wasm-tools component embed ./microquickjs.wit --world microquickjs $(CORE_WASM) -o $(BUILD_DIR)/embedded.wasm
+	wasm-tools component new --skip-validation --adapt wasi_snapshot_preview1=$(ADAPTER) $(BUILD_DIR)/embedded.wasm -o $@
+
+# CLI WASM (wasip2)
+CLI_SRCS = mqjs.c mquickjs.c dtoa.c libm.c cutils.c readline_tty_wasi.c readline.c
+CLI_OBJS = $(patsubst %.c, $(BUILD_DIR)/%_cli.o, $(CLI_SRCS))
+
+$(BUILD_DIR)/%_cli.o: %.c | $(BUILD_DIR)
+	$(CC) $(CLI_CFLAGS) -c -o $@ $<
+
+$(CLI_WASM): $(CLI_OBJS)
+	$(CC) $(CLI_CFLAGS) -o $@ $^ $(CLI_LDFLAGS)
+
+# Dependencies
+$(BUILD_DIR)/glue.o: glue.c $(BUILD_DIR)/mqjs_stdlib.h
+$(BUILD_DIR)/mquickjs.o: mquickjs.c $(BUILD_DIR)/mquickjs_atom.h
+$(BUILD_DIR)/mquickjs_cli.o: mquickjs.c $(BUILD_DIR)/mquickjs_atom.h
+$(BUILD_DIR)/mqjs_cli.o: mqjs.c $(BUILD_DIR)/mqjs_stdlib.h
+
+test: $(CLI_WASM)
+	wasmtime run -W all-proposals=y --wasi cli=y $(CLI_WASM) tests/test_closure.js
+	wasmtime run -W all-proposals=y --wasi cli=y $(CLI_WASM) tests/test_language.js
+	wasmtime run -W all-proposals=y --wasi cli=y $(CLI_WASM) tests/test_loop.js
+	wasmtime run -W all-proposals=y --wasi cli=y $(CLI_WASM) tests/test_builtin.js
+
+microbench: $(CLI_WASM)
+	wasmtime run -W all-proposals=y --wasi cli=y $(CLI_WASM) tests/microbench.js
+
+clean:
+	rm -rf $(BUILD_DIR) $(GEN_DIR)
+
+.PHONY: all clean test microbench
diff --git a/README.md b/README.md
index 3e53b59..584f5ff 100644
--- a/README.md
+++ b/README.md
@@ -376,3 +376,23 @@ MQuickJS is released under the MIT license.
 Unless otherwise specified, the MQuickJS sources are copyright Fabrice
 Bellard and Charlie Gordon.
 
+
+## WASI Component build
+
+Build the WASI 0.2 component using `Makefile.wasi`:
+
+```bash
+make -f Makefile.wasi
+```
+
+Run the basic tests using the `wasm32-wasip2` build binary executable:
+
+```bash
+make -f Makefile.wasi test
+```
+
+Running the QuickJS micro benchmark:
+
+```bash
+make -f Makefile.wasi microbench
+```
diff --git a/glue.c b/glue.c
new file mode 100644
index 0000000..a63433a
--- /dev/null
+++ b/glue.c
@@ -0,0 +1,285 @@
+#include <string.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <math.h>
+
+#include "mquickjs.h"
+
+// cabi_realloc is provided by wit-bindgen's generated microquickjs.c.
+void *cabi_realloc(void *ptr, size_t old_size, size_t align, size_t new_size);
+
+// WASI shim stubs
+JSValue js_date_now(JSContext *ctx, JSValue *this_val, int argc, JSValue *argv)
+    { return JS_UNDEFINED; }
+JSValue js_print(JSContext *ctx, JSValue *this_val, int argc, JSValue *argv)
+    { return JS_UNDEFINED; }
+JSValue js_performance_now(JSContext *ctx, JSValue *this_val, int argc, JSValue *argv)
+    { return JS_UNDEFINED; }
+JSValue js_gc(JSContext *ctx, JSValue *this_val, int argc, JSValue *argv)
+    { JS_GC(ctx); return JS_UNDEFINED; }
+JSValue js_load(JSContext *ctx, JSValue *this_val, int argc, JSValue *argv)
+    { return JS_UNDEFINED; }
+JSValue js_setTimeout(JSContext *ctx, JSValue *this_val, int argc, JSValue *argv)
+    { return JS_UNDEFINED; }
+JSValue js_clearTimeout(JSContext *ctx, JSValue *this_val, int argc, JSValue *argv)
+    { return JS_UNDEFINED; }
+
+#include "generated/microquickjs.h"
+#include "mqjs_stdlib.h"
+
+static uint8_t s_mem[4 * 1024 * 1024];  // 4 MiB arena
+static JSContext *s_ctx = NULL;
+
+static void ensure_context(void) {
+    if (s_ctx) return;
+    s_ctx = JS_NewContext(s_mem, sizeof(s_mem), &js_stdlib);
+}
+
+struct exports_local_microquickjs_engine_js_value_t {
+    JSValue val;
+    JSGCRef root;
+};
+
+static exports_local_microquickjs_engine_own_js_value_t
+make_own_value(JSValue val) {
+    exports_local_microquickjs_engine_js_value_t *rep = malloc(sizeof(*rep));
+    rep->val = val;
+    JS_AddGCRef(s_ctx, &rep->root);
+    rep->root.val = val;
+    return exports_local_microquickjs_engine_js_value_new(rep);
+}
+
+void exports_local_microquickjs_engine_js_value_destructor(
+    exports_local_microquickjs_engine_js_value_t *rep)
+{
+    JS_DeleteGCRef(s_ctx, &rep->root);
+    free(rep);
+}
+
+bool exports_local_microquickjs_engine_method_js_value_is_int(
+    exports_local_microquickjs_engine_borrow_js_value_t self)
+{
+    return JS_IsInt(self->val);
+}
+
+bool exports_local_microquickjs_engine_method_js_value_is_bool(
+    exports_local_microquickjs_engine_borrow_js_value_t self)
+{
+    return JS_IsBool(self->val);
+}
+
+bool exports_local_microquickjs_engine_method_js_value_is_null(
+    exports_local_microquickjs_engine_borrow_js_value_t self)
+{
+    return JS_IsNull(self->val);
+}
+
+bool exports_local_microquickjs_engine_method_js_value_is_undefined(
+    exports_local_microquickjs_engine_borrow_js_value_t self)
+{
+    return JS_IsUndefined(self->val);
+}
+
+bool exports_local_microquickjs_engine_method_js_value_is_exception(
+    exports_local_microquickjs_engine_borrow_js_value_t self)
+{
+    return JS_IsException(self->val);
+}
+
+bool exports_local_microquickjs_engine_method_js_value_is_number(
+    exports_local_microquickjs_engine_borrow_js_value_t self)
+{
+    ensure_context();
+    return JS_IsNumber(s_ctx, self->val);
+}
+
+bool exports_local_microquickjs_engine_method_js_value_is_string(
+    exports_local_microquickjs_engine_borrow_js_value_t self)
+{
+    ensure_context();
+    return JS_IsString(s_ctx, self->val);
+}
+
+bool exports_local_microquickjs_engine_method_js_value_is_error(
+    exports_local_microquickjs_engine_borrow_js_value_t self)
+{
+    ensure_context();
+    return JS_IsError(s_ctx, self->val);
+}
+
+bool exports_local_microquickjs_engine_method_js_value_is_function(
+    exports_local_microquickjs_engine_borrow_js_value_t self)
+{
+    ensure_context();
+    return JS_IsFunction(s_ctx, self->val);
+}
+
+void exports_local_microquickjs_engine_method_js_value_to_string(
+    exports_local_microquickjs_engine_borrow_js_value_t self,
+    microquickjs_string_t *ret)
+{
+    ensure_context();
+    size_t len;
+    JSCStringBuf buf;
+    const char *cstr = JS_ToCStringLen(s_ctx, &len, self->val, &buf);
+    if (!cstr) {
+        ret->ptr = cabi_realloc(NULL, 0, 1, 1);
+        ret->ptr[0] = '\0';
+        ret->len = 0;
+    } else {
+        ret->ptr = cabi_realloc(NULL, 0, 1, len);
+        memcpy(ret->ptr, cstr, len);
+        ret->len = len;
+    }
+}
+
+int32_t exports_local_microquickjs_engine_method_js_value_to_int32(
+    exports_local_microquickjs_engine_borrow_js_value_t self)
+{
+    ensure_context();
+    int res = 0;
+    JS_ToInt32(s_ctx, &res, self->val);
+    return res;
+}
+
+double exports_local_microquickjs_engine_method_js_value_to_float64(
+    exports_local_microquickjs_engine_borrow_js_value_t self)
+{
+    ensure_context();
+    double res = 0;
+    JS_ToNumber(s_ctx, &res, self->val);
+    return res;
+}
+
+exports_local_microquickjs_engine_own_js_value_t
+exports_local_microquickjs_engine_method_js_value_get_property(
+    exports_local_microquickjs_engine_borrow_js_value_t self,
+    microquickjs_string_t *name)
+{
+    ensure_context();
+    char *cname = malloc(name->len + 1);
+    memcpy(cname, name->ptr, name->len);
+    cname[name->len] = '\0';
+    JSValue res = JS_GetPropertyStr(s_ctx, self->val, cname);
+    free(cname);
+    return make_own_value(res);
+}
+
+void exports_local_microquickjs_engine_method_js_value_set_property(
+    exports_local_microquickjs_engine_borrow_js_value_t self,
+    microquickjs_string_t *name,
+    exports_local_microquickjs_engine_borrow_js_value_t val)
+{
+    ensure_context();
+    char *cname = malloc(name->len + 1);
+    memcpy(cname, name->ptr, name->len);
+    cname[name->len] = '\0';
+    JS_SetPropertyStr(s_ctx, self->val, cname, val->val);
+    free(cname);
+}
+
+exports_local_microquickjs_engine_own_js_value_t
+exports_local_microquickjs_engine_method_js_value_call(
+    exports_local_microquickjs_engine_borrow_js_value_t self,
+    exports_local_microquickjs_engine_list_borrow_js_value_t *args)
+{
+    ensure_context();
+    for (size_t i = 0; i < args->len; i++) {
+        JS_PushArg(s_ctx, args->ptr[i]->val);
+    }
+    JSValue res = JS_Call(s_ctx, (int)args->len);
+    return make_own_value(res);
+}
+
+exports_local_microquickjs_engine_own_js_value_t
+exports_local_microquickjs_engine_new_int32(int32_t val)
+{
+    ensure_context();
+    return make_own_value(JS_NewInt32(s_ctx, val));
+}
+
+exports_local_microquickjs_engine_own_js_value_t
+exports_local_microquickjs_engine_new_float64(double val)
+{
+    ensure_context();
+    return make_own_value(JS_NewFloat64(s_ctx, val));
+}
+
+exports_local_microquickjs_engine_own_js_value_t
+exports_local_microquickjs_engine_new_bool(bool val)
+{
+    ensure_context();
+    return make_own_value(JS_NewBool(val));
+}
+
+exports_local_microquickjs_engine_own_js_value_t
+exports_local_microquickjs_engine_new_string(microquickjs_string_t *val)
+{
+    ensure_context();
+    return make_own_value(JS_NewStringLen(s_ctx, (const char *)val->ptr, val->len));
+}
+
+exports_local_microquickjs_engine_own_js_value_t
+exports_local_microquickjs_engine_new_object(void)
+{
+    ensure_context();
+    return make_own_value(JS_NewObject(s_ctx));
+}
+
+exports_local_microquickjs_engine_own_js_value_t
+exports_local_microquickjs_engine_new_array(void)
+{
+    ensure_context();
+    return make_own_value(JS_NewArray(s_ctx, 0));
+}
+
+exports_local_microquickjs_engine_own_js_value_t
+exports_local_microquickjs_engine_get_global_object(void)
+{
+    ensure_context();
+    return make_own_value(JS_GetGlobalObject(s_ctx));
+}
+
+bool exports_local_microquickjs_engine_eval(
+    microquickjs_string_t *code,
+    microquickjs_string_t *ret,
+    microquickjs_string_t *err)
+{
+    ensure_context();
+    JSValue val = JS_Eval(s_ctx,
+                          (const char *)code->ptr,
+                          code->len,
+                          "<eval>",
+                          JS_EVAL_RETVAL);
+    size_t len;
+    JSCStringBuf buf;
+
+    if (JS_IsException(val)) {
+        JSValue exc = JS_GetException(s_ctx);
+        const char *cstr = JS_ToCStringLen(s_ctx, &len, exc, &buf);
+        if (!cstr) {
+            static const char unknown[] = "Error: unknown exception";
+            err->ptr = cabi_realloc(NULL, 0, 1, sizeof(unknown) - 1);
+            memcpy(err->ptr, unknown, sizeof(unknown) - 1);
+            err->len = sizeof(unknown) - 1;
+        } else {
+            err->ptr = cabi_realloc(NULL, 0, 1, len);
+            memcpy(err->ptr, cstr, len);
+            err->len = len;
+        }
+        return false;
+    }
+
+    const char *cstr = JS_ToCStringLen(s_ctx, &len, val, &buf);
+    if (!cstr) {
+        static const char undef[] = "undefined";
+        ret->ptr = cabi_realloc(NULL, 0, 1, sizeof(undef) - 1);
+        memcpy(ret->ptr, undef, sizeof(undef) - 1);
+        ret->len = sizeof(undef) - 1;
+    } else {
+        ret->ptr = cabi_realloc(NULL, 0, 1, len);
+        memcpy(ret->ptr, cstr, len);
+        ret->len = len;
+    }
+    return true;
+}
diff --git a/microquickjs.wit b/microquickjs.wit
new file mode 100644
index 0000000..31e8866
--- /dev/null
+++ b/microquickjs.wit
@@ -0,0 +1,41 @@
+package local:microquickjs;
+
+interface engine {
+    resource js-value {
+        is-int:       func() -> bool;
+        is-bool:      func() -> bool;
+        is-null:      func() -> bool;
+        is-undefined: func() -> bool;
+        is-exception: func() -> bool;
+        is-number:    func() -> bool;
+        is-string:    func() -> bool;
+        is-error:     func() -> bool;
+        is-function:  func() -> bool;
+
+        to-string:  func() -> string;
+        to-int32:   func() -> s32;
+        to-float64: func() -> f64;
+
+        get-property: func(name: string) -> js-value;
+        set-property: func(name: string, val: borrow<js-value>);
+
+        call: func(args: list<borrow<js-value>>) -> js-value;
+    }
+
+    new-int32:  func(val: s32)    -> js-value;
+    new-float64: func(val: f64)   -> js-value;
+    new-bool:   func(val: bool)   -> js-value;
+    new-string: func(val: string) -> js-value;
+    new-object: func()            -> js-value;
+    new-array:  func()            -> js-value;
+
+    get-global-object: func() -> js-value;
+
+    /// Evaluate JavaScript code and return the result as a string.
+    /// Returns ok(result) on success, err(message) on syntax or runtime error.
+    eval: func(code: string) -> result<string, string>;
+}
+
+world microquickjs {
+    export engine;
+}
diff --git a/mquickjs_build.c b/mquickjs_build.c
index 6173271..9c33296 100644
--- a/mquickjs_build.c
+++ b/mquickjs_build.c
@@ -286,7 +286,7 @@ static int atom_cmp(const void *p1, const void *p2)
 
 /* js_atom_table must be properly aligned because the property hash
    table uses the low bits of the atom pointer value */
-#define ATOM_ALIGN 64
+#define ATOM_ALIGN 256
 
 static void dump_atoms(BuildContext *ctx)
 {
@@ -898,8 +898,8 @@ int build_atoms(const char *stdlib_name, const JSPropDef *global_obj,
     printf("/* this file is automatically generated - do not edit */\n\n");
     printf("#include \"mquickjs_priv.h\"\n\n");
     
-    printf("static const uint%u_t __attribute((aligned(%d))) js_stdlib_table[] = {\n",
-           JSW * 8, ATOM_ALIGN);
+    printf("const uint32_t __attribute((aligned(%d))) js_stdlib_table[] = {\n",
+           ATOM_ALIGN);
 
     dump_atoms(s);
 
diff --git a/readline_tty_wasi.c b/readline_tty_wasi.c
new file mode 100644
index 0000000..5be3d35
--- /dev/null
+++ b/readline_tty_wasi.c
@@ -0,0 +1,16 @@
+#include <stdlib.h>
+#include <stdio.h>
+#include <stdint.h>
+#include <stdarg.h>
+#include "readline_tty.h"
+
+int readline_tty_init(void) { return 80; }
+void term_printf(const char *fmt, ...) {
+    va_list ap;
+    va_start(ap, fmt);
+    vprintf(fmt, ap);
+    va_end(ap);
+}
+void term_flush(void) { fflush(stdout); }
+const char *readline_tty(ReadlineState *s, const char *prompt, BOOL multi_line) { return NULL; }
+BOOL readline_is_interrupted(void) { return 0; }