diff --git a/src/__phutil_library_map__.php b/src/__phutil_library_map__.php
--- a/src/__phutil_library_map__.php
+++ b/src/__phutil_library_map__.php
@@ -35,6 +35,7 @@
     'AphrontParameterQueryException' => 'aphront/storage/exception/AphrontParameterQueryException.php',
     'AphrontQueryException' => 'aphront/storage/exception/AphrontQueryException.php',
     'AphrontRecoverableQueryException' => 'aphront/storage/exception/AphrontRecoverableQueryException.php',
+    'AphrontRequestStream' => 'aphront/requeststream/AphrontRequestStream.php',
     'AphrontSchemaQueryException' => 'aphront/storage/exception/AphrontSchemaQueryException.php',
     'AphrontScopedUnguardedWriteCapability' => 'aphront/writeguard/AphrontScopedUnguardedWriteCapability.php',
     'AphrontWriteGuard' => 'aphront/writeguard/AphrontWriteGuard.php',
@@ -558,6 +559,7 @@
     'AphrontParameterQueryException' => 'AphrontQueryException',
     'AphrontQueryException' => 'Exception',
     'AphrontRecoverableQueryException' => 'AphrontQueryException',
+    'AphrontRequestStream' => 'Phobject',
     'AphrontSchemaQueryException' => 'AphrontQueryException',
     'AphrontScopedUnguardedWriteCapability' => 'Phobject',
     'AphrontWriteGuard' => 'Phobject',
diff --git a/src/aphront/requeststream/AphrontRequestStream.php b/src/aphront/requeststream/AphrontRequestStream.php
new file mode 100644
--- /dev/null
+++ b/src/aphront/requeststream/AphrontRequestStream.php
@@ -0,0 +1,92 @@
+<?php
+
+final class AphrontRequestStream extends Phobject {
+
+  private $encoding;
+  private $stream;
+  private $closed;
+
+  public function setEncoding($encoding) {
+    $this->encoding = $encoding;
+    return $this;
+  }
+
+  public function getEncoding() {
+    return $this->encoding;
+  }
+
+  public function readData() {
+    if ($this->closed) {
+      return null;
+    }
+
+    $stream = $this->getStream();
+    if (feof($stream)) {
+      $this->closeStream();
+      return null;
+    }
+
+    $bytes = fread($stream, 64 * 1024);
+    if ($bytes === false) {
+      throw new Exception(
+        pht('Failed to fread() from request input stream.'));
+    }
+
+    return $bytes;
+  }
+
+  private function getStream() {
+    if (!$this->stream) {
+      $this->stream = $this->newStream();
+    }
+
+    return $this->stream;
+  }
+
+  private function closeStream() {
+    $stream = $this->getStream();
+    fclose($stream);
+    $this->closed = true;
+  }
+
+  private function newStream() {
+    $stream = fopen('php://input', 'rb');
+    if (!$stream) {
+      throw new Exception(
+        pht(
+          'Failed to open stream "%s" for reading.',
+          'php://input'));
+    }
+
+    $encoding = $this->getEncoding();
+    if ($encoding === 'gzip') {
+      // This parameter is magic. Values 0-15 express a time/memory tradeoff,
+      // but the largest value (15) corresponds to only 32KB of memory and
+      // data encoded with a smaller window size than the one we pass can not
+      // be decompressed. Always pass the maximum window size.
+
+      // Additionally, you can add 16 (to enable gzip) or 32 (to enable both
+      // gzip and zlib). Add 32 to support both.
+      $zlib_window = 15 + 32;
+
+      $ok = stream_filter_append(
+        $stream,
+        'zlib.inflate',
+        STREAM_FILTER_READ,
+        array(
+          'window' => $zlib_window,
+        ));
+      if (!$ok) {
+        throw new Exception(
+          pht(
+            'Failed to append filter "%s" to input stream while processing '.
+            'a request with "%s" encoding.',
+            'zlib.inflate',
+            $encoding));
+      }
+    }
+
+    return $stream;
+  }
+
+}