diff --git a/okhttp/src/main/java/com/squareup/okhttp/Dispatcher.java b/okhttp/src/main/java/com/squareup/okhttp/Dispatcher.java
new file mode 100644
index 000000000..924ace5c9
--- /dev/null
+++ b/okhttp/src/main/java/com/squareup/okhttp/Dispatcher.java
@@ -0,0 +1,138 @@
+/*
+ * Copyright (C) 2013 Square, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.squareup.okhttp;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.net.HttpURLConnection;
+import java.util.ArrayList;
+import java.util.LinkedHashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.concurrent.LinkedBlockingQueue;
+import java.util.concurrent.ThreadPoolExecutor;
+import java.util.concurrent.TimeUnit;
+
+class Dispatcher {
+  // TODO: thread pool size should be configurable; possibly configurable per host.
+  private final ThreadPoolExecutor executorService = new ThreadPoolExecutor(
+      8, 8, 60, TimeUnit.SECONDS, new LinkedBlockingQueue<Runnable>());
+  private final Map<Object, List<Job>> enqueuedJobs = new LinkedHashMap<Object, List<Job>>();
+
+  public synchronized void enqueue(
+      HttpURLConnection connection, Request request, Response.Receiver responseReceiver) {
+    Job job = new Job(connection, request, responseReceiver);
+    List<Job> jobsForTag = enqueuedJobs.get(request.tag());
+    if (jobsForTag == null) {
+      jobsForTag = new ArrayList<Job>(2);
+      enqueuedJobs.put(request.tag(), jobsForTag);
+    }
+    jobsForTag.add(job);
+    executorService.execute(job);
+  }
+
+  public synchronized void cancel(Object tag) {
+    List<Job> jobs = enqueuedJobs.remove(tag);
+    if (jobs == null) return;
+    for (Job job : jobs) {
+      executorService.remove(job);
+    }
+  }
+
+  private synchronized void finished(Job job) {
+    List<Job> jobs = enqueuedJobs.get(job.request.tag());
+    if (jobs != null) jobs.remove(job);
+  }
+
+  public class Job implements Runnable {
+    private final HttpURLConnection connection;
+    private final Request request;
+    private final Response.Receiver responseReceiver;
+
+    public Job(HttpURLConnection connection, Request request, Response.Receiver responseReceiver) {
+      this.connection = connection;
+      this.request = request;
+      this.responseReceiver = responseReceiver;
+    }
+
+    @Override public void run() {
+      try {
+        sendRequest();
+        Response response = readResponse();
+        responseReceiver.onResponse(response);
+      } catch (IOException e) {
+        responseReceiver.onFailure(new Failure.Builder()
+            .request(request)
+            .exception(e)
+            .build());
+      } finally {
+        connection.disconnect();
+        finished(this);
+      }
+    }
+
+    private HttpURLConnection sendRequest()
+        throws IOException {
+      for (int i = 0; i < request.headerCount(); i++) {
+        connection.addRequestProperty(request.headerName(i), request.headerValue(i));
+      }
+      Request.Body body = request.body();
+      if (body != null) {
+        connection.setDoOutput(true);
+        body.writeTo(connection.getOutputStream());
+      }
+      return connection;
+    }
+
+    private Response readResponse() throws IOException {
+      int responseCode = connection.getResponseCode();
+      Response.Builder responseBuilder = new Response.Builder(request, responseCode);
+
+      for (int i = 0; true; i++) {
+        String name = connection.getHeaderFieldKey(i);
+        if (name == null) break;
+        String value = connection.getHeaderField(i);
+        responseBuilder.addHeader(name, value);
+      }
+
+      responseBuilder.body(new RealResponseBody(connection, connection.getInputStream()));
+      // TODO: set redirectedBy
+      return responseBuilder.build();
+    }
+  }
+
+  static class RealResponseBody extends Response.Body {
+    private final HttpURLConnection connection;
+    private final InputStream in;
+
+    RealResponseBody(HttpURLConnection connection, InputStream in) {
+      this.connection = connection;
+      this.in = in;
+    }
+
+    @Override public String contentType() {
+      return connection.getHeaderField("Content-Type");
+    }
+
+    @Override public long contentLength() {
+      return connection.getContentLength(); // TODO: getContentLengthLong
+    }
+
+    @Override public InputStream byteStream() throws IOException {
+      return in;
+    }
+  }
+}
diff --git a/okhttp/src/main/java/com/squareup/okhttp/Failure.java b/okhttp/src/main/java/com/squareup/okhttp/Failure.java
new file mode 100644
index 000000000..b40133b60
--- /dev/null
+++ b/okhttp/src/main/java/com/squareup/okhttp/Failure.java
@@ -0,0 +1,59 @@
+/*
+ * Copyright (C) 2013 Square, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.squareup.okhttp;
+
+/**
+ * A failure attempting to retrieve an HTTP response.
+ *
+ * <h3>Warning: Experimental OkHttp 2.0 API</h3>
+ * This class is in beta. APIs are subject to change!
+ */
+public class Failure {
+  private final Request request;
+  private final Throwable exception;
+
+  private Failure(Builder builder) {
+    this.request = builder.request;
+    this.exception = builder.exception;
+  }
+
+  public Request request() {
+    return request;
+  }
+
+  public Throwable exception() {
+    return exception;
+  }
+
+  public static class Builder {
+    private Request request;
+    private Throwable exception;
+
+    public Builder request(Request request) {
+      this.request = request;
+      return this;
+    }
+
+    public Builder exception(Throwable exception) {
+      this.exception = exception;
+      return this;
+    }
+
+    public Failure build() {
+      return new Failure(this);
+    }
+  }
+}
diff --git a/okhttp/src/main/java/com/squareup/okhttp/OkHttpClient.java b/okhttp/src/main/java/com/squareup/okhttp/OkHttpClient.java
index 4e147f2a5..921b61aaa 100644
--- a/okhttp/src/main/java/com/squareup/okhttp/OkHttpClient.java
+++ b/okhttp/src/main/java/com/squareup/okhttp/OkHttpClient.java
@@ -59,6 +59,7 @@ public final class OkHttpClient implements URLStreamHandlerFactory {
   private boolean followProtocolRedirects = true;
   private int connectTimeout;
   private int readTimeout;
+  private Dispatcher dispatcher = new Dispatcher();
 
   public OkHttpClient() {
     this.failedRoutes = Collections.synchronizedSet(new LinkedHashSet<Route>());
@@ -311,6 +312,24 @@ public final class OkHttpClient implements URLStreamHandlerFactory {
     return transports;
   }
 
+  /**
+   * Schedules {@code request} to be executed.
+   */
+  public void enqueue(Request request, Response.Receiver responseReceiver) {
+    // Create the HttpURLConnection immediately so the enqueued job gets the current settings of
+    // this client. Otherwise changes to this client (socket factory, redirect policy, etc.) may
+    // incorrectly be reflected in the request when it is dispatched later.
+    dispatcher.enqueue(open(request.url()), request, responseReceiver);
+  }
+
+  /**
+   * Cancels all scheduled tasks tagged with {@code tag}. Requests that are already
+   * in flight might not be canceled.
+   */
+  public void cancel(Object tag) {
+    dispatcher.cancel(tag);
+  }
+
   public HttpURLConnection open(URL url) {
     String protocol = url.getProtocol();
     OkHttpClient copy = copyWithDefaults();
diff --git a/okhttp/src/main/java/com/squareup/okhttp/Request.java b/okhttp/src/main/java/com/squareup/okhttp/Request.java
new file mode 100644
index 000000000..73617716f
--- /dev/null
+++ b/okhttp/src/main/java/com/squareup/okhttp/Request.java
@@ -0,0 +1,193 @@
+/*
+ * Copyright (C) 2013 Square, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.squareup.okhttp;
+
+import com.squareup.okhttp.internal.http.RawHeaders;
+import java.io.IOException;
+import java.io.OutputStream;
+import java.net.MalformedURLException;
+import java.net.URL;
+import java.util.List;
+import java.util.Set;
+
+/**
+ * An HTTP request. Instances of this class are immutable if their {@link #body}
+ * is null or itself immutable.
+ *
+ * <h3>Warning: Experimental OkHttp 2.0 API</h3>
+ * This class is in beta. APIs are subject to change!
+ */
+public final class Request {
+  private final URL url;
+  private final String method;
+  private final RawHeaders headers;
+  private final Body body;
+  private final Object tag;
+
+  private Request(Builder builder) {
+    this.url = builder.url;
+    this.method = builder.method;
+    this.headers = new RawHeaders(builder.headers);
+    this.body = builder.body;
+    this.tag = builder.tag != null ? builder.tag : this;
+  }
+
+  public URL url() {
+    return url;
+  }
+
+  public String urlString() {
+    return url.toString();
+  }
+
+  public String method() {
+    return method;
+  }
+
+  public String header(String name) {
+    return headers.get(name);
+  }
+
+  public List<String> headers(String name) {
+    return headers.values(name);
+  }
+
+  public Set<String> headerNames() {
+    return headers.names();
+  }
+
+  public int headerCount() {
+    return headers.length();
+  }
+
+  public String headerName(int index) {
+    return headers.getFieldName(index);
+  }
+
+  public String headerValue(int index) {
+    return headers.getValue(index);
+  }
+
+  public Body body() {
+    return body;
+  }
+
+  public Object tag() {
+    return tag;
+  }
+
+  public abstract class Body {
+    /** Returns the Content-Type header for this body, or null if the content type is unknown. */
+    public String contentType() {
+      return null;
+    }
+
+    /** Returns the number of bytes in this body, or -1 if that count is unknown. */
+    public long contentLength() {
+      return -1;
+    }
+
+    public abstract void writeTo(OutputStream out) throws IOException;
+  }
+
+  public static class Builder {
+    private URL url;
+    private String method = "GET";
+    private final RawHeaders headers = new RawHeaders();
+    private Body body;
+    private Object tag;
+
+    public Builder(String url) {
+      url(url);
+    }
+
+    public Builder(URL url) {
+      url(url);
+    }
+
+    public Builder url(String url) {
+      try {
+        this.url = new URL(url);
+        return this;
+      } catch (MalformedURLException e) {
+        throw new IllegalArgumentException("Malformed URL: " + url);
+      }
+    }
+
+    public Builder url(URL url) {
+      if (url == null) throw new IllegalStateException("url == null");
+      this.url = url;
+      return this;
+    }
+
+    /**
+     * Sets the header named {@code name} to {@code value}. If this request
+     * already has any headers with that name, they are all replaced.
+     */
+    public Builder header(String name, String value) {
+      headers.set(name, value);
+      return this;
+    }
+
+    /**
+     * Adds a header with {@code name} and {@code value}. Prefer this method for
+     * multiply-valued headers like "Cookie".
+     */
+    public Builder addHeader(String name, String value) {
+      headers.add(name, value);
+      return this;
+    }
+
+    public Builder get() {
+      return method("GET", null);
+    }
+
+    public Builder head() {
+      return method("HEAD", null);
+    }
+
+    public Builder post(Body body) {
+      return method("POST", body);
+    }
+
+    public Builder put(Body body) {
+      return method("PUT", body);
+    }
+
+    public Builder method(String method, Body body) {
+      if (method == null || method.length() == 0) {
+        throw new IllegalArgumentException("method == null || method.length() == 0");
+      }
+      this.method = method;
+      this.body = body;
+      return this;
+    }
+
+    /**
+     * Attaches {@code tag} to the request. It can be used later to cancel the
+     * request. If the tag is unspecified or null, the request is canceled by
+     * using the request itself as the tag.
+     */
+    public Builder tag(Object tag) {
+      this.tag = tag;
+      return this;
+    }
+
+    public Request build() {
+      return new Request(this);
+    }
+  }
+}
diff --git a/okhttp/src/main/java/com/squareup/okhttp/Response.java b/okhttp/src/main/java/com/squareup/okhttp/Response.java
new file mode 100644
index 000000000..4896a388b
--- /dev/null
+++ b/okhttp/src/main/java/com/squareup/okhttp/Response.java
@@ -0,0 +1,217 @@
+/*
+ * Copyright (C) 2013 Square, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.squareup.okhttp;
+
+import com.squareup.okhttp.internal.Util;
+import com.squareup.okhttp.internal.http.RawHeaders;
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.io.Reader;
+import java.util.List;
+import java.util.Set;
+
+/**
+ * An HTTP response. Instances of this class are not immutable: the response
+ * body is a one-shot value that may be consumed only once. All other properties
+ * are immutable.
+ *
+ * <h3>Warning: Experimental OkHttp 2.0 API</h3>
+ * This class is in beta. APIs are subject to change!
+ */
+public final class Response {
+  private final Request request;
+  private final int code;
+  private final RawHeaders headers;
+  private final Body body;
+  private final Response redirectedBy;
+
+  private Response(Builder builder) {
+    this.request = builder.request;
+    this.code = builder.code;
+    this.headers = new RawHeaders(builder.headers);
+    this.body = builder.body;
+    this.redirectedBy = builder.redirectedBy;
+  }
+
+  /**
+   * The wire-level request that initiated this HTTP response. This is usually
+   * <strong>not</strong> the same request instance provided to the HTTP client:
+   * <ul>
+   *     <li>It may be transformed by the HTTP client. For example, the client
+   *         may have added its own {@code Content-Encoding} header to enable
+   *         response compression.
+   *     <li>It may be the request generated in response to an HTTP redirect.
+   *         In this case the request URL may be different than the initial
+   *         request URL.
+   * </ul>
+   */
+  public Request request() {
+    return request;
+  }
+
+  public int code() {
+    return code;
+  }
+
+  public String header(String name) {
+    return header(name, null);
+  }
+
+  public String header(String name, String defaultValue) {
+    String result = headers.get(name);
+    return result != null ? result : defaultValue;
+  }
+
+  public List<String> headers(String name) {
+    return headers.values(name);
+  }
+
+  public Set<String> headerNames() {
+    return headers.names();
+  }
+
+  public int headerCount() {
+    return headers.length();
+  }
+
+  public String headerName(int index) {
+    return headers.getFieldName(index);
+  }
+
+  public String headerValue(int index) {
+    return headers.getValue(index);
+  }
+
+  public Body body() {
+    return body;
+  }
+
+  /**
+   * Returns the response for the HTTP redirect that triggered this response, or
+   * null if this response wasn't triggered by an automatic redirect. The body
+   * of the returned response should not be read because it has already been
+   * consumed by the redirecting client.
+   */
+  public Response redirectedBy() {
+    return redirectedBy;
+  }
+
+  public abstract static class Body {
+    public String contentType() {
+      return null;
+    }
+
+    public long contentLength() {
+      return -1;
+    }
+
+    public abstract InputStream byteStream() throws IOException;
+
+    public byte[] bytes() throws IOException {
+      long contentLength = contentLength();
+      if (contentLength > Integer.MAX_VALUE) {
+        throw new IOException("Cannot buffer entire body for content length: " + contentLength);
+      }
+
+      if (contentLength != -1) {
+        byte[] content = new byte[(int) contentLength];
+        InputStream in = byteStream();
+        Util.readFully(in, content);
+        if (in.read() != -1) throw new IOException("Content-Length and stream length disagree");
+        return content;
+
+      } else {
+        ByteArrayOutputStream out = new ByteArrayOutputStream();
+        Util.copy(byteStream(), out);
+        return out.toByteArray();
+      }
+    }
+
+    /**
+     * Returns the response bytes as a UTF-8 character stream. Do not call this
+     * method if the response content is not a UTF-8 character stream.
+     */
+    public Reader charStream() throws IOException {
+      // TODO: parse content-type.
+      return new InputStreamReader(byteStream(), "UTF-8");
+    }
+
+    /**
+     * Returns the response bytes as a UTF-8 string. Do not call this method if
+     * the response content is not a UTF-8 character stream.
+     */
+    public String string() throws IOException {
+      // TODO: parse content-type.
+      return new String(bytes(), "UTF-8");
+    }
+  }
+
+  public interface Receiver {
+    void onFailure(Failure failure);
+    void onResponse(Response response) throws IOException;
+  }
+
+  public static class Builder {
+    private final Request request;
+    private final int code;
+    private final RawHeaders headers = new RawHeaders();
+    private Body body;
+    private Response redirectedBy;
+
+    public Builder(Request request, int code) {
+      if (request == null) throw new IllegalArgumentException("request == null");
+      if (code <= 0) throw new IllegalArgumentException("code <= 0");
+      this.request = request;
+      this.code = code;
+    }
+
+    /**
+     * Sets the header named {@code name} to {@code value}. If this request
+     * already has any headers with that name, they are all replaced.
+     */
+    public Builder header(String name, String value) {
+      headers.set(name, value);
+      return this;
+    }
+
+    /**
+     * Adds a header with {@code name} and {@code value}. Prefer this method for
+     * multiply-valued headers like "Set-Cookie".
+     */
+    public Builder addHeader(String name, String value) {
+      headers.add(name, value);
+      return this;
+    }
+
+    public Builder body(Body body) {
+      this.body = body;
+      return this;
+    }
+
+    public Builder redirectedBy(Response redirectedBy) {
+      this.redirectedBy = redirectedBy;
+      return this;
+    }
+
+    public Response build() {
+      if (request == null) throw new IllegalStateException("Response has no request.");
+      if (code == -1) throw new IllegalStateException("Response has no code.");
+      return new Response(this);
+    }
+  }
+}
diff --git a/okhttp/src/main/java/com/squareup/okhttp/internal/http/HttpURLConnectionImpl.java b/okhttp/src/main/java/com/squareup/okhttp/internal/http/HttpURLConnectionImpl.java
index f8c5e9a98..b4cf9d68a 100644
--- a/okhttp/src/main/java/com/squareup/okhttp/internal/http/HttpURLConnectionImpl.java
+++ b/okhttp/src/main/java/com/squareup/okhttp/internal/http/HttpURLConnectionImpl.java
@@ -606,8 +606,8 @@ public class HttpURLConnectionImpl extends HttpURLConnection {
       // the list contains "http/1.1". We do this in a separate loop
       // to avoid modifying any state before we validate the input.
       boolean containsHttp = false;
-      for (int i = 0; i < transports.length; ++i) {
-        if ("http/1.1".equals(transports[i])) {
+      for (String transport : transports) {
+        if ("http/1.1".equals(transport)) {
           containsHttp = true;
           break;
         }
@@ -620,13 +620,13 @@ public class HttpURLConnectionImpl extends HttpURLConnection {
       transportsList.addAll(this.transports);
     }
 
-    for (int i = 0; i < transports.length; ++i) {
-      if (transports[i].length() == 0) {
+    for (String transport : transports) {
+      if (transport.length() == 0) {
         throw new IllegalArgumentException("Transport list contains an empty transport");
       }
 
-      if (!transportsList.contains(transports[i])) {
-        transportsList.add(transports[i]);
+      if (!transportsList.contains(transport)) {
+        transportsList.add(transport);
       }
     }
 
diff --git a/okhttp/src/main/java/com/squareup/okhttp/internal/http/RawHeaders.java b/okhttp/src/main/java/com/squareup/okhttp/internal/http/RawHeaders.java
index eba887ec0..e5abd2cfb 100644
--- a/okhttp/src/main/java/com/squareup/okhttp/internal/http/RawHeaders.java
+++ b/okhttp/src/main/java/com/squareup/okhttp/internal/http/RawHeaders.java
@@ -32,6 +32,7 @@ import java.util.Map;
 import java.util.Map.Entry;
 import java.util.Set;
 import java.util.TreeMap;
+import java.util.TreeSet;
 
 /**
  * The HTTP status and unparsed header fields of a single HTTP message. Values
@@ -248,6 +249,15 @@ public final class RawHeaders {
     return namesAndValues.get(fieldNameIndex);
   }
 
+  /** Returns an immutable case-insensitive set of header names. */
+  public Set<String> names() {
+    TreeSet<String> result = new TreeSet<String>(String.CASE_INSENSITIVE_ORDER);
+    for (int i = 0; i < length(); i++) {
+      result.add(getFieldName(i));
+    }
+    return Collections.unmodifiableSet(result);
+  }
+
   /** Returns the value at {@code index} or null if that is out of range. */
   public String getValue(int index) {
     int valueIndex = index * 2 + 1;
@@ -267,6 +277,20 @@ public final class RawHeaders {
     return null;
   }
 
+  /** Returns an immutable list of the header values for {@code name}. */
+  public List<String> values(String name) {
+    List<String> result = null;
+    for (int i = 0; i < length(); i++) {
+      if (name.equalsIgnoreCase(getFieldName(i))) {
+        if (result == null) result = new ArrayList<String>(2);
+        result.add(getValue(i));
+      }
+    }
+    return result != null
+        ? Collections.unmodifiableList(result)
+        : Collections.<String>emptyList();
+  }
+
   /** @param fieldNames a case-insensitive set of HTTP header field names. */
   public RawHeaders getAll(Set<String> fieldNames) {
     RawHeaders result = new RawHeaders();
diff --git a/okhttp/src/test/java/com/squareup/okhttp/internal/AsyncApiTest.java b/okhttp/src/test/java/com/squareup/okhttp/internal/AsyncApiTest.java
new file mode 100644
index 000000000..6eefcf186
--- /dev/null
+++ b/okhttp/src/test/java/com/squareup/okhttp/internal/AsyncApiTest.java
@@ -0,0 +1,54 @@
+/*
+ * Copyright (C) 2013 Square, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.squareup.okhttp.internal;
+
+import com.google.mockwebserver.MockResponse;
+import com.google.mockwebserver.MockWebServer;
+import com.squareup.okhttp.OkHttpClient;
+import com.squareup.okhttp.Request;
+import org.junit.After;
+import org.junit.Test;
+
+import static org.junit.Assert.assertTrue;
+
+public final class AsyncApiTest {
+  private MockWebServer server = new MockWebServer();
+  private OkHttpClient client = new OkHttpClient();
+  private RecordingReceiver receiver = new RecordingReceiver();
+
+  @After public void tearDown() throws Exception {
+    server.shutdown();
+  }
+
+  @Test public void get() throws Exception {
+    server.enqueue(new MockResponse()
+        .setBody("abc")
+        .addHeader("Content-Type: text/plain"));
+    server.play();
+
+    Request request = new Request.Builder(server.getUrl("/"))
+        .header("User-Agent", "AsyncApiTest")
+        .build();
+    client.enqueue(request, receiver);
+
+    receiver.await(request)
+        .assertCode(200)
+        .assertContainsHeaders("Content-Type: text/plain")
+        .assertBody("abc");
+
+    assertTrue(server.takeRequest().getHeaders().contains("User-Agent: AsyncApiTest"));
+  }
+}
diff --git a/okhttp/src/test/java/com/squareup/okhttp/internal/RecordedResponse.java b/okhttp/src/test/java/com/squareup/okhttp/internal/RecordedResponse.java
new file mode 100644
index 000000000..388a27d1d
--- /dev/null
+++ b/okhttp/src/test/java/com/squareup/okhttp/internal/RecordedResponse.java
@@ -0,0 +1,64 @@
+/*
+ * Copyright (C) 2013 Square, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.squareup.okhttp.internal;
+
+import com.squareup.okhttp.Failure;
+import com.squareup.okhttp.Request;
+import com.squareup.okhttp.Response;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.fail;
+
+/**
+ * A received response or failure recorded by the response recorder.
+ */
+public class RecordedResponse {
+  public final Request request;
+  public final Response response;
+  public final String body;
+  public final Failure failure;
+
+  RecordedResponse(Request request, Response response, String body, Failure failure) {
+    this.request = request;
+    this.response = response;
+    this.body = body;
+    this.failure = failure;
+  }
+
+  public RecordedResponse assertCode(int expectedCode) {
+    assertEquals(expectedCode, response.code());
+    return this;
+  }
+
+  public RecordedResponse assertContainsHeaders(String... expectedHeaders) {
+    List<String> actualHeaders = new ArrayList<String>();
+    for (int i = 0; i < response.headerCount(); i++) {
+      actualHeaders.add(response.headerName(i) + ": " + response.headerValue(i));
+    }
+    if (!actualHeaders.containsAll(Arrays.asList(expectedHeaders))) {
+      fail("Expected: " + actualHeaders + "\nto contain: " + Arrays.toString(expectedHeaders));
+    }
+    return this;
+  }
+
+  public RecordedResponse assertBody(String expectedBody) {
+    assertEquals(expectedBody, body);
+    return this;
+  }
+}
diff --git a/okhttp/src/test/java/com/squareup/okhttp/internal/RecordingReceiver.java b/okhttp/src/test/java/com/squareup/okhttp/internal/RecordingReceiver.java
new file mode 100644
index 000000000..58cd20531
--- /dev/null
+++ b/okhttp/src/test/java/com/squareup/okhttp/internal/RecordingReceiver.java
@@ -0,0 +1,65 @@
+/*
+ * Copyright (C) 2013 Square, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.squareup.okhttp.internal;
+
+import com.squareup.okhttp.Failure;
+import com.squareup.okhttp.Request;
+import com.squareup.okhttp.Response;
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.concurrent.TimeUnit;
+
+/**
+ * Records received HTTP responses so they can be later retrieved by tests.
+ */
+public class RecordingReceiver implements Response.Receiver {
+  public static final long TIMEOUT_MILLIS = TimeUnit.SECONDS.toMillis(10);
+
+  private final List<RecordedResponse> responses = new ArrayList<RecordedResponse>();
+
+  @Override public synchronized void onFailure(Failure failure) {
+    responses.add(new RecordedResponse(failure.request(), null, null, failure));
+    notifyAll();
+  }
+
+  @Override public synchronized void onResponse(Response response) throws IOException {
+    responses.add(new RecordedResponse(
+        response.request(), response, response.body().string(), null));
+    notifyAll();
+  }
+
+  /**
+   * Returns the recorded response triggered by {@code request}. Throws if the
+   * response isn't enqueued before the timeout.
+   */
+  public synchronized RecordedResponse await(Request request) throws Exception {
+    long timeoutMillis = TimeUnit.NANOSECONDS.toMillis(System.nanoTime()) + TIMEOUT_MILLIS;
+    while (true) {
+      for (RecordedResponse recordedResponse : responses) {
+        if (recordedResponse.request == request) {
+          return recordedResponse;
+        }
+      }
+
+      long nowMillis = TimeUnit.NANOSECONDS.toMillis(System.nanoTime());
+      if (nowMillis >= timeoutMillis) break;
+      wait(timeoutMillis - nowMillis);
+    }
+
+    throw new AssertionError("Timed out waiting for response to " + request);
+  }
+}