diff --git a/.gitignore b/.gitignore
index e7284854..ccc31b9a 100644
--- a/.gitignore
+++ b/.gitignore
@@ -22,7 +22,6 @@
 *.exp
 *.class
 *.wasm
-/swoole_compiler
 /tpc
 tests/**/*.diff
 tests/**/*.exp
@@ -30,3 +29,4 @@ tests/**/*.log
 tests/**/*.out
 tests/**/*.php
 tests/**/*.sh
+/browser/node_modules/
diff --git a/phpunit/src/Build/WasiToolchainTest.php b/phpunit/src/Build/WasiToolchainTest.php
index b79007a8..0b491b9a 100644
--- a/phpunit/src/Build/WasiToolchainTest.php
+++ b/phpunit/src/Build/WasiToolchainTest.php
@@ -29,16 +29,18 @@ final class WasiToolchainTest extends TestCase
 
     public function testDetectsSupportedToolsOnlyFromPath(): void
     {
-        $this->installFakeTools(22, 47, 'wasm32-unknown-wasip1');
+        $this->installFakeTools(22, 47, 1, 'wasm32-unknown-wasip2');
         putenv('PATH=' . $this->directory);
 
         $tools = (new WasiToolchain())->detect();
 
-        $this->assertSame($this->directory . '/clang++', $tools['clang++']);
+        $this->assertSame($this->directory . '/wasm32-wasip2-clang++', $tools['clang++']);
         $this->assertSame($this->directory . '/wasmtime', $tools['wasmtime']);
-        $this->assertSame('wasm32-unknown-wasip1', $tools['target']);
+        $this->assertSame($this->directory . '/jco', $tools['jco']);
+        $this->assertSame('wasm32-unknown-wasip2', $tools['target']);
         $this->assertSame('22.0.0', $tools['clang-version']);
         $this->assertSame('47.0.0', $tools['wasmtime-version']);
+        $this->assertSame('1.0.0', $tools['jco-version']);
     }
 
     public function testRejectsMissingTool(): void
@@ -46,40 +48,42 @@ final class WasiToolchainTest extends TestCase
         putenv('PATH=' . $this->directory);
 
         $this->expectException(RuntimeException::class);
-        $this->expectExceptionMessage('`clang` was not found in PATH');
+        $this->expectExceptionMessage('`wasm32-wasip2-clang` was not found in PATH');
         (new WasiToolchain())->detect();
     }
 
     public function testRejectsOldLlvm(): void
     {
-        $this->installFakeTools(21, 47, 'wasm32-unknown-wasip1');
+        $this->installFakeTools(21, 47, 1, 'wasm32-unknown-wasip2');
         putenv('PATH=' . $this->directory);
 
         $this->expectException(RuntimeException::class);
-        $this->expectExceptionMessage('`clang` 21 is too old');
+        $this->expectExceptionMessage('`wasm32-wasip2-clang` 21 is too old');
         (new WasiToolchain())->detect();
     }
 
     public function testRejectsNonWasiClangTarget(): void
     {
-        $this->installFakeTools(22, 47, 'x86_64-unknown-linux-gnu');
+        $this->installFakeTools(22, 47, 1, 'x86_64-unknown-linux-gnu');
         putenv('PATH=' . $this->directory);
 
         $this->expectException(RuntimeException::class);
-        $this->expectExceptionMessage('not configured for wasm32-wasi');
+        $this->expectExceptionMessage('not configured for wasm32-unknown-wasip2');
         (new WasiToolchain())->detect();
     }
 
-    private function installFakeTools(int $llvmMajor, int $wasmtimeMajor, string $target): void
+    private function installFakeTools(int $llvmMajor, int $wasmtimeMajor, int $jcoMajor, string $target): void
     {
-        foreach (['clang', 'llvm-ar', 'llvm-ranlib', 'llvm-nm', 'wasm-ld'] as $tool) {
+        foreach (['wasm32-wasip2-clang', 'llvm-ar', 'llvm-ranlib', 'llvm-nm'] as $tool) {
             $this->writeExecutable($tool, "#!/bin/sh\necho 'LLVM version {$llvmMajor}.0.0'\n");
         }
+        $this->writeExecutable('wasm-component-ld', "#!/bin/sh\necho 'wasm-component-ld version 0.5.22'\n");
         $this->writeExecutable(
-            'clang++',
+            'wasm32-wasip2-clang++',
             "#!/bin/sh\nif [ \"\$1\" = '--print-target-triple' ]; then echo '{$target}'; else echo 'clang version {$llvmMajor}.0.0'; fi\n",
         );
         $this->writeExecutable('wasmtime', "#!/bin/sh\necho 'wasmtime {$wasmtimeMajor}.0.0'\n");
+        $this->writeExecutable('jco', "#!/bin/sh\necho 'jco {$jcoMajor}.0.0'\n");
     }
 
     private function writeExecutable(string $name, string $contents): void
diff --git a/phpunit/src/CompilerBaseApiTest.php b/phpunit/src/CompilerBaseApiTest.php
index 1cdf0567..4fe7b455 100644
--- a/phpunit/src/CompilerBaseApiTest.php
+++ b/phpunit/src/CompilerBaseApiTest.php
@@ -101,12 +101,12 @@ class CompilerBaseApiTest extends TestCase
 
     public function testWasiTargetDetection(): void
     {
-        foreach (['wasm32-wasi', 'wasm32-wasip1', 'wasm32-wasip1-threads'] as $target) {
+        foreach (['wasm32-wasip2', 'wasm32-unknown-wasip2'] as $target) {
             $this->setPropertyValue('targetPlatform', $target);
             $this->assertTrue($this->compiler->isWasiTarget(), $target);
         }
 
-        foreach (['', 'wasm32-unknown-unknown', 'aarch64-linux-gnu'] as $target) {
+        foreach (['', 'wasm32-wasi', 'wasm32-wasip1', 'wasm32-wasip1-threads', 'wasm32-unknown-unknown', 'aarch64-linux-gnu'] as $target) {
             $this->setPropertyValue('targetPlatform', $target);
             $this->assertFalse($this->compiler->isWasiTarget(), $target);
         }
diff --git a/phpunit/src/Generator/FiberGeneratorTest.php b/phpunit/src/Generator/FiberGeneratorTest.php
index b85efda5..e446c596 100644
--- a/phpunit/src/Generator/FiberGeneratorTest.php
+++ b/phpunit/src/Generator/FiberGeneratorTest.php
@@ -12,7 +12,7 @@ class FiberGeneratorTest extends TestCase
     {
         $compiler = CompilerTest::create(ROOT_PATH);
         $reflection = new \ReflectionClass($compiler);
-        $reflection->getProperty('targetPlatform')->setValue($compiler, 'wasm32-wasi');
+        $reflection->getProperty('targetPlatform')->setValue($compiler, 'wasm32-wasip2');
         $file = __DIR__ . '/../../code/generator-conversion-error.php';
         $compiler->addFiles([$file]);
 
diff --git a/phpunit/src/Platform/PlatformTest.php b/phpunit/src/Platform/PlatformTest.php
index 031402ee..3833cbfd 100644
--- a/phpunit/src/Platform/PlatformTest.php
+++ b/phpunit/src/Platform/PlatformTest.php
@@ -12,9 +12,9 @@ class PlatformTest extends TestCase
 {
     public function testWasiTargetProperties(): void
     {
-        $platform = new Wasi('wasm32-unknown-wasip1');
+        $platform = new Wasi('wasm32-unknown-wasip2');
 
-        $this->assertSame('WASI SDK (wasm32-unknown-wasip1)', $platform->getName());
+        $this->assertSame('WASI SDK (wasm32-unknown-wasip2)', $platform->getName());
         $this->assertSame('.o', $platform->getObjectExtension());
         $this->assertSame('.wasm', $platform->getExecutableExtension());
         $this->assertSame('.a', $platform->getSharedLibraryExtension());
diff --git a/phpunit/src/WasiUnsupportedSyntaxTest.php b/phpunit/src/WasiUnsupportedSyntaxTest.php
index b6142c9a..cea5e6be 100644
--- a/phpunit/src/WasiUnsupportedSyntaxTest.php
+++ b/phpunit/src/WasiUnsupportedSyntaxTest.php
@@ -12,7 +12,7 @@ class WasiUnsupportedSyntaxTest extends TestCase
     public function testUnsupportedSyntaxFailsDuringWasiConversion(string $file, string $message): void
     {
         $compiler = CompilerTest::create(ROOT_PATH);
-        (new \ReflectionClass($compiler))->getProperty('targetPlatform')->setValue($compiler, 'wasm32-wasi');
+        (new \ReflectionClass($compiler))->getProperty('targetPlatform')->setValue($compiler, 'wasm32-wasip2');
         $source = __DIR__ . '/../code/' . $file;
         $compiler->addFiles([$source]);
         $compiler->prepareFile($source);
@@ -37,6 +37,18 @@ class WasiUnsupportedSyntaxTest extends TestCase
                 'wasi-generator-arrow.php',
                 'Fiber and Generator are not supported by the WASI target',
             ],
+            'process function' => [
+                'wasi-process.php',
+                'Function `proc_open` is not supported by the WASI target',
+            ],
+            'socket function' => [
+                'wasi-socket.php',
+                'Function `stream_socket_server` is not supported by the WASI target',
+            ],
+            'signal function' => [
+                'wasi-signal.php',
+                'Function `pcntl_signal` is not supported by the WASI target',
+            ],
         ];
     }
 }
diff --git a/src/Build/WasiToolchain.php b/src/Build/WasiToolchain.php
index e2367e8f..a07da950 100644
--- a/src/Build/WasiToolchain.php
+++ b/src/Build/WasiToolchain.php
@@ -8,34 +8,50 @@ final class WasiToolchain
 {
     public const MIN_LLVM_MAJOR = 22;
     public const MIN_WASMTIME_MAJOR = 47;
+    public const MIN_JCO_MAJOR = 1;
 
     /** @return array<string, string> */
     public function detect(): array
     {
         $tools = [];
-        foreach (['clang', 'clang++', 'llvm-ar', 'llvm-ranlib', 'llvm-nm', 'wasm-ld', 'wasmtime'] as $name) {
+        foreach ([
+            'wasm32-wasip2-clang',
+            'wasm32-wasip2-clang++',
+            'llvm-ar',
+            'llvm-ranlib',
+            'llvm-nm',
+            'wasm-component-ld',
+            'wasmtime',
+            'jco',
+        ] as $name) {
             $tools[$name] = $this->findExecutable($name);
         }
 
         $versions = [];
-        foreach (['clang', 'clang++', 'llvm-ar', 'llvm-ranlib', 'llvm-nm', 'wasm-ld'] as $name) {
+        foreach (['wasm32-wasip2-clang', 'wasm32-wasip2-clang++', 'llvm-ar', 'llvm-ranlib', 'llvm-nm'] as $name) {
             $versions[$name] = $this->requireVersion($name, $tools[$name], self::MIN_LLVM_MAJOR);
         }
+        $this->requireVersion('wasm-component-ld', $tools['wasm-component-ld'], 0);
         $versions['wasmtime'] = $this->requireVersion('wasmtime', $tools['wasmtime'], self::MIN_WASMTIME_MAJOR);
+        $versions['jco'] = $this->requireVersion('jco', $tools['jco'], self::MIN_JCO_MAJOR);
 
-        [$exitCode, $target, $error] = $this->run([$tools['clang++'], '--print-target-triple']);
+        [$exitCode, $target, $error] = $this->run([$tools['wasm32-wasip2-clang++'], '--print-target-triple']);
         $target = trim($target);
-        if ($exitCode !== 0 || preg_match('/^wasm32-(?:unknown-)?wasi(?:p1)?$/', $target) !== 1) {
+        if ($exitCode !== 0 || $target !== 'wasm32-unknown-wasip2') {
             $detail = trim($error) !== '' ? ': ' . trim($error) : '';
             throw new RuntimeException(
-                "clang++ from PATH is not configured for wasm32-wasi (reported target: "
+                "wasm32-wasip2-clang++ from PATH is not configured for wasm32-unknown-wasip2 (reported target: "
                 . ($target !== '' ? $target : 'unknown') . "){$detail}",
             );
         }
 
+        $tools['clang'] = $tools['wasm32-wasip2-clang'];
+        $tools['clang++'] = $tools['wasm32-wasip2-clang++'];
+        $tools['wasm-ld'] = $tools['wasm-component-ld'];
         $tools['target'] = $target;
-        $tools['clang-version'] = $versions['clang++'];
+        $tools['clang-version'] = $versions['wasm32-wasip2-clang++'];
         $tools['wasmtime-version'] = $versions['wasmtime'];
+        $tools['jco-version'] = $versions['jco'];
         return $tools;
     }
 
@@ -62,7 +78,7 @@ final class WasiToolchain
     {
         [$exitCode, $output, $error] = $this->run([$executable, '--version']);
         $versionText = trim($output . "\n" . $error);
-        if ($exitCode !== 0 || preg_match('/(?:version|wasmtime|LLD)\s+((\d+)(?:\.\d+)+)/i', $versionText, $match) !== 1) {
+        if ($exitCode !== 0 || preg_match('/\bv?((\d+)(?:\.\d+)+)\b/i', $versionText, $match) !== 1) {
             throw new RuntimeException("Unable to determine the version of WASI tool `{$name}` from PATH");
         }
         $major = (int) $match[2];
diff --git a/src/CompilerBase.php b/src/CompilerBase.php
index 7fff7db8..8e84e747 100644
--- a/src/CompilerBase.php
+++ b/src/CompilerBase.php
@@ -174,6 +174,41 @@ class CompilerBase implements PropertyAccessContext
         'stream_socket_accept',
         'popen',
     ];
+
+    /**
+     * APIs which cannot have the same semantics in Wasmtime and a browser.
+     * Keep this list at the language boundary so a WASI build never degrades
+     * into a link error or a browser-only implementation.
+     */
+    private const array WASI_UNSUPPORTED_FUNCTIONS = [
+        'exec',
+        'passthru',
+        'popen',
+        'proc_close',
+        'proc_get_status',
+        'proc_nice',
+        'proc_open',
+        'proc_terminate',
+        'shell_exec',
+        'system',
+        'fsockopen',
+        'pfsockopen',
+        'stream_socket_accept',
+        'stream_socket_client',
+        'stream_socket_enable_crypto',
+        'stream_socket_get_name',
+        'stream_socket_pair',
+        'stream_socket_recvfrom',
+        'stream_socket_sendto',
+        'stream_socket_server',
+        'stream_socket_shutdown',
+    ];
+
+    private const array WASI_UNSUPPORTED_FUNCTION_PREFIXES = [
+        'pcntl_',
+        'posix_',
+        'socket_',
+    ];
     public const int DECL_TYPE_OF_RETURN = 1;
     public const int DECL_TYPE_OF_PROPERTY = 2;
     public const int DECL_TYPE_OF_CONST = 3;
@@ -584,7 +619,24 @@ class CompilerBase implements PropertyAccessContext
     public function isWasiTarget(): bool
     {
         $target = strtolower($this->targetPlatform);
-        return str_starts_with($target, 'wasm32-wasi') || str_starts_with($target, 'wasm32-wasip1');
+        return $target === 'wasm32-unknown-wasip2' || $target === 'wasm32-wasip2';
+    }
+
+    protected function assertWasiFunctionSupported(NodeAbstract $expr, string $name): void
+    {
+        if (!$this->isWasiTarget()) {
+            return;
+        }
+
+        $name = strtolower(ltrim($name, '\\'));
+        if (in_array($name, self::WASI_UNSUPPORTED_FUNCTIONS, true)) {
+            $this->fatalError($expr, "Function `{$name}` is not supported by the WASI target");
+        }
+        foreach (self::WASI_UNSUPPORTED_FUNCTION_PREFIXES as $prefix) {
+            if (str_starts_with($name, $prefix)) {
+                $this->fatalError($expr, "Function `{$name}` is not supported by the WASI target");
+            }
+        }
     }
 
     public function isBuildModeBin(): bool
diff --git a/src/Parser/FunctionCallTrait.php b/src/Parser/FunctionCallTrait.php
index cc4706f7..48d6f298 100644
--- a/src/Parser/FunctionCallTrait.php
+++ b/src/Parser/FunctionCallTrait.php
@@ -78,6 +78,9 @@ trait FunctionCallTrait
         } elseif ($expr->name->getType() === 'Name' or $expr->name->getType() === 'Name_FullyQualified') {
             $name = $this->parseIdentifier($expr->name);
             $globalName = ltrim($name, '\\');
+            if ($this->isInternalFunction($globalName)) {
+                $this->assertWasiFunctionSupported($expr, $globalName);
+            }
             if (in_array($name, Constants::UNSUPPORTED_FUNCTIONS)) {
                 $this->fatalError($expr, 'Unsupported function: `' . $name . '`');
             }
diff --git a/src/Platform/Wasi.php b/src/Platform/Wasi.php
index 12913555..9765d51b 100644
--- a/src/Platform/Wasi.php
+++ b/src/Platform/Wasi.php
@@ -4,7 +4,7 @@ namespace TypePhp\Platform;
 
 final class Wasi extends UnixPlatform
 {
-    public function __construct(private readonly string $target = 'wasm32-wasi')
+    public function __construct(private readonly string $target = 'wasm32-unknown-wasip2')
     {
     }
 
diff --git a/src/Translator.php b/src/Translator.php
index f7e12f1b..bc80af2a 100644
--- a/src/Translator.php
+++ b/src/Translator.php
@@ -168,7 +168,10 @@ class Translator extends Preprocessor
             $targetPlatform = $this->climate->arguments->defined('target-platform')
                 ? (string) $this->climate->arguments->get('target-platform')
                 : '';
-            if (str_starts_with($targetPlatform, 'wasm32-wasi') || str_starts_with($targetPlatform, 'wasm32-wasip1')) {
+            if ($targetPlatform === 'wasm32-wasip1' || $targetPlatform === 'wasm32-wasi') {
+                throw new \RuntimeException('WASI Preview 1 is not supported; use wasm32-wasip2');
+            }
+            if ($targetPlatform === 'wasm32-wasip2' || $targetPlatform === 'wasm32-unknown-wasip2') {
                 $detectedTarget = getenv('TYPEPHP_WASI_TARGET');
                 $this->platform = new Wasi(
                     is_string($detectedTarget) && $detectedTarget !== '' ? $detectedTarget : $targetPlatform,
diff --git a/src/compiler.php b/src/compiler.php
index 87fb0a4a..aa6b2c5d 100644
--- a/src/compiler.php
+++ b/src/compiler.php
@@ -140,9 +140,11 @@ function compileWasmProgram(array $argv): void
     $environment['TYPEPHP_WASI_NM'] = $tools['llvm-nm'];
     $environment['TYPEPHP_WASI_LD'] = $tools['wasm-ld'];
     $environment['TYPEPHP_WASMTIME'] = $tools['wasmtime'];
+    $environment['TYPEPHP_JCO'] = $tools['jco'];
     $environment['TYPEPHP_WASI_TARGET'] = $tools['target'];
     $environment['TYPEPHP_WASI_CLANG_VERSION'] = $tools['clang-version'];
     $environment['TYPEPHP_WASMTIME_VERSION'] = $tools['wasmtime-version'];
+    $environment['TYPEPHP_JCO_VERSION'] = $tools['jco-version'];
     $environment['TYPEPHP_WASM_PROGRAM_BUILD_DIR'] = $buildDir;
 
     $process = proc_open(