diff --git a/src/HttpRequest.php b/src/HttpRequest.php
index ce74cc5..12f8e44 100644
--- a/src/HttpRequest.php
+++ b/src/HttpRequest.php
@@ -41,9 +41,16 @@ class HttpRequest extends HttpMessage implements \JsonSerializable, RequestInter
 
     /**
      * @var string The URL of the request.
+     * @deprecated Use $uri instead.
      */
     protected $url;
 
+    /** @var UriInterface */
+    protected UriInterface $uri;
+
+    /** @var UriInterface|null */
+    protected UriInterface|null $proxiedToUri = null;
+
     /**
      * @var array
      */
@@ -71,7 +78,7 @@ class HttpRequest extends HttpMessage implements \JsonSerializable, RequestInter
      * Initialize an instance of the {@link HttpRequest} class.
      *
      * @param string $method The HTTP method of the request.
-     * @param string $url The URL where the request will be sent.
+     * @param string|UriInterface $url The URL where the request will be sent.
      * @param string|array $body The body of the request.
      * @param array $headers An array of http headers to be sent with the request.
      * @param array $options An array of extra options.
@@ -81,9 +88,13 @@ class HttpRequest extends HttpMessage implements \JsonSerializable, RequestInter
      * - auth: A username/password used to send basic HTTP authentication with the request.
      * - timeout: The number of seconds to wait before the request times out. A value of zero means no timeout.
      */
-    public function __construct(string $method = self::METHOD_GET, string $url = '', $body = '', array $headers = [], array $options = []) {
+    public function __construct(string $method = self::METHOD_GET, string|UriInterface $url = '', $body = '', array $headers = [], array $options = []) {
         $this->setMethod(strtoupper($method));
-        $this->setUrl($url);
+        if ($url instanceof UriInterface) {
+            $this->setUri($url);
+        } else {
+            $this->setUrl($url);
+        }
         $this->setBody($body);
         $this->setHeaders($headers);
 
@@ -184,7 +195,23 @@ public function getUrl(): string {
      * @return HttpRequest Returns `$this` for fluent calls.
      */
     public function setUrl(string $url) {
+        $uriFactory = new UriFactory();
+        $uri = $uriFactory->createUri($url);
         $this->url = $url;
+        $this->uri = $uri;
+        return $this;
+    }
+
+    /**
+     * Set the URI of the request.
+     *
+     * @param UriInterface $uri The new URI.
+     *
+     * @return static Returns `$this` for fluent calls.
+     */
+    public function setUri(UriInterface $uri): static {
+        $this->uri = $uri;
+        $this->url = (string) $uri;
         return $this;
     }
 
@@ -271,7 +298,8 @@ public function getOptions(): array {
     public function jsonSerialize(): array {
         return [
             "url" => $this->getUrl(),
-            "host" => $this->getHeader("host") ?: $this->getUri()->getHost(),
+            "proxiedToUrl" => $this->proxiedToUri !== null ? (string) $this->proxiedToUri : null,
+            "host" => $this->proxiedToUri !== null ? $this->proxiedToUri->getHost() : $this->getUri()->getHost(),
             "method" => $this->getMethod(),
         ];
     }
@@ -326,8 +354,7 @@ public function withMethod($method) {
      * @inheritDoc
      */
     public function getUri(): UriInterface {
-        $uriFactory = new UriFactory();
-        return $uriFactory->createUri($this->getUrl());
+        return $this->uri;
     }
 
     /**
@@ -338,4 +365,19 @@ public function withUri(UriInterface $uri, $preserveHost = false) {
         $cloned->setUrl((string) $uri);
         return $cloned;
     }
+
+    /**
+     * @return UriInterface|null
+     */
+    public function getProxiedToUri(): ?UriInterface {
+        return $this->proxiedToUri;
+    }
+
+    /**
+     * @param UriInterface|null $proxiedToUri
+     * @return void
+     */
+    public function setProxiedToUri(?UriInterface $proxiedToUri): void {
+        $this->proxiedToUri = $proxiedToUri;
+    }
 }
diff --git a/src/HttpResponse.php b/src/HttpResponse.php
index 17ad457..856ec55 100644
--- a/src/HttpResponse.php
+++ b/src/HttpResponse.php
@@ -500,8 +500,20 @@ public function setRequest(HttpRequest $request = null)
     public function asException(): HttpResponseException
     {
         $request = $this->getRequest();
+
         if ($request !== null) {
-            $requestID = "Request \"{$request->getMethod()} {$request->getUrl()}\"";
+            $proxiedToUri = $request->getProxiedToUri();
+            $actualUri = $request->getUri();
+
+            $proxiedToUrl = $proxiedToUri !== null ? (string) $proxiedToUri : null;
+            $proxiedThroughUrl = $proxiedToUrl !== null ? (string) $actualUri : null;
+            $mainUrl = $proxiedToUrl ?? (string) $actualUri;
+
+            if ($proxiedThroughUrl !== null) {
+                $requestID = "Request \"{$request->getMethod()} {$mainUrl} (proxied through {$proxiedThroughUrl})\"";
+            } else {
+                $requestID = "Request \"{$request->getMethod()} {$mainUrl}\"";
+            }
         } else {
             $requestID = "Unknown request";
         }
diff --git a/src/MiddlewareInterface.php b/src/MiddlewareInterface.php
new file mode 100644
index 0000000..bfc5729
--- /dev/null
+++ b/src/MiddlewareInterface.php
@@ -0,0 +1,21 @@
+<?php
+namespace Garden\Http;
+
+/**
+ * An interface for middleware that processes HTTP requests and responses.
+ *
+ * Middleware can modify the request before passing it to the next handler,
+ * or modify the response after it has been processed by the next handler.
+ */
+interface MiddlewareInterface {
+
+    /**
+     * Call next to execute the next middleware or handler in the chain (next returns the response).
+     * 
+     * @param HttpRequest $request
+     * @param callable(HttpRequest): HttpResponse $next
+     *
+     * @return HttpResponse
+     */
+    public function __invoke(HttpRequest $request, callable $next): HttpResponse;
+}
diff --git a/src/ProxyMiddleware.php b/src/ProxyMiddleware.php
new file mode 100644
index 0000000..1a7c2c7
--- /dev/null
+++ b/src/ProxyMiddleware.php
@@ -0,0 +1,50 @@
+<?php
+namespace Garden\Http;
+
+use Slim\Psr7\Uri;
+
+/**
+ * Middleware to proxy requests through a proxy.
+ */
+class ProxyMiddleware implements MiddlewareInterface {
+
+
+    /**
+     * @param string $proxyHostname The hostname of the proxy to use.
+     * @param bool $downgradeScheme Whether to downgrade the scheme of the request from https to http.
+     */
+    public function __construct(protected string $proxyHostname, protected bool $downgradeScheme = true) { }
+
+    /**
+     * @inheritdoc
+     */
+    public function __invoke(HttpRequest $request, callable $next): HttpResponse
+    {
+        $this->alterRequest($request);
+        return $next($request, $next);
+    }
+
+    /**
+     * Given a url, try to replace it's base url so it routes with the cluster router.
+     *
+     * @param string $url
+     *
+     * @return void
+     */
+    protected function alterRequest(HttpRequest $request): void
+    {
+        /** @var Uri $uri */
+        $originalUri = $request->getUri();
+
+        $uri = $originalUri;
+        if ($this->downgradeScheme && $uri->getScheme() === "https") {
+            $uri = $uri->withScheme("http");
+        }
+
+        $requestUri = $uri->withHost($this->proxyHostname);
+
+        $request->setUrl($requestUri);
+        $request->setHeader("Host", $originalUri->getHost());
+        $request->setProxiedToUri($originalUri);
+    }
+}
diff --git a/tests/HttpResponseExceptionTest.php b/tests/HttpResponseExceptionTest.php
index d38dbae..c2d3ca2 100644
--- a/tests/HttpResponseExceptionTest.php
+++ b/tests/HttpResponseExceptionTest.php
@@ -30,6 +30,7 @@ public function testJsonSerialize(): void {
                 'url' => 'https://somesite.com/some/path',
                 "host" => "somesite.com",
                 'method' => 'POST',
+                'proxiedToUrl' => null,
             ],
             "response" => [
                 'statusCode' => 501,
@@ -52,6 +53,7 @@ public function testHostSiteOverrideSerialize() {
             "url" => "https://proxy-server.com/some/path",
             "host" => "proxy-server.com",
             "method" => "GET",
+            'proxiedToUrl' => null,
         ], $serialized);
     }
 
diff --git a/tests/ProxyMiddlewareTest.php b/tests/ProxyMiddlewareTest.php
new file mode 100644
index 0000000..b13a001
--- /dev/null
+++ b/tests/ProxyMiddlewareTest.php
@@ -0,0 +1,38 @@
+<?php
+namespace Garden\Http\Tests;
+
+use Garden\Http\HttpClient;
+use Garden\Http\ProxyMiddleware;
+use PHPUnit\Framework\TestCase;
+
+/**
+ * Tests for using the HttpClient with {@link ProxyMiddleware}
+ */
+class ProxyMiddlewareTest extends TestCase {
+
+    /**
+     * Test that the proxied URI is applied correctly.
+     * 
+     * @return void
+     */
+    public function testProxiedUriIsApplied(): void {
+        $proxyHostname = "0.0.0.0:8091";
+        
+        $client = new HttpClient("https://example.com/base-url");
+        $client->addMiddleware(new ProxyMiddleware($proxyHostname, downgradeScheme: true));
+        $response = $client->get("/api?query#hash");
+        
+        $request = $response->getRequest();
+        $this->assertEquals("http://$proxyHostname/base-url/api?query#hash", $request->getUrl());
+        $this->assertEquals("example.com", $request->getHeader("Host"));
+        
+        // If we have a response exception it's message will indicate the proxied URL
+        $this->assertEquals(
+            <<<MESSAGE
+Request "GET https://example.com/base-url/api?query#hash (proxied through http://0.0.0.0:8091/base-url/api?query#hash)" failed with a response code of 404 and a standard message of "Not Found"
+MESSAGE
+,
+            $response->asException()->getMessage()
+        );
+    }
+}
diff --git a/tests/ReadmeTest.php b/tests/ReadmeTest.php
deleted file mode 100644
index c74aee6..0000000
--- a/tests/ReadmeTest.php
+++ /dev/null
@@ -1,91 +0,0 @@
-<?php
-/**
- * @author Todd Burry <todd@vanillaforums.com>
- * @copyright 2009-2018 Vanilla Forums Inc.
- * @license MIT
- */
-
-namespace Garden\Http\Tests;
-
-require_once __DIR__ . "/Fixtures/HmacMiddleware.php";
-
-use Garden\Http\HttpClient;
-use Garden\Http\HttpResponseException;
-use Garden\Http\Tests\Fixtures\HmacMiddleware;
-use PHPUnit\Framework\TestCase;
-
-/**
- * Test cases for the README.
- */
-class ReadmeTest extends TestCase
-{
-    public function testBasicExample()
-    {
-        $api = new HttpClient("http://httpbin.org");
-        $api->setThrowExceptions(true);
-        $api->setDefaultHeader("Content-Type", "application/json");
-
-        // Get some data from the API.
-        $response = $api->get("/get"); // requests off of base url
-        $data = $response->getBody(); // returns array of json decoded data
-
-        $response = $api->post("https://httpbin.org/post", ["foo" => "bar"]);
-        // Access the response like an array.
-        $posted = $response["json"]; // should be ['foo' => 'bar']
-
-        if (!$response->isSuccessful()) {
-            $this->markTestSkipped();
-        }
-        $this->assertIsArray($data);
-        $this->assertSame(["foo" => "bar"], $posted);
-    }
-
-    /**
-     * Test that exceptions can be thrown.
-     */
-    public function testExceptionsExample()
-    {
-        $this->expectException(HttpResponseException::class);
-        $this->expectExceptionCode(404);
-        $api = new HttpClient("https://httpbin.org");
-        $api->setThrowExceptions(true);
-
-        try {
-            $api->get("/status/404");
-        } catch (\Exception $ex) {
-            $code = $ex->getCode(); // should be 404
-            throw $ex;
-        }
-    }
-
-    public function testBasicAuthentication()
-    {
-        $api = new HttpClient("https://httpbin.org");
-        $api->setDefaultOption("auth", ["username", "password123"]);
-
-        // This request is made with the default authentication set above.
-        $r1 = $api->get("/basic-auth/username/password123");
-
-        // This request overrides the basic authentication.
-        $r2 = $api->get(
-            "/basic-auth/username/password",
-            [],
-            [],
-            ["auth" => ["username", "password"]]
-        );
-
-        $this->assertEquals(200, $r1->getStatusCode());
-        $this->assertEquals(200, $r2->getStatusCode());
-    }
-
-    public function testRequestMiddleware()
-    {
-        $api = new HttpClient("https://httpbin.org");
-        $middleware = new HmacMiddleware("key", "password");
-        $api->addMiddleware($middleware);
-
-        $r = $api->get("/get");
-
-        $this->assertNotEmpty($r["headers"]["Authorization"]);
-    }
-}