diff --git a/src/AnthropicClient/AnthropicApiClient.cs b/src/AnthropicClient/AnthropicApiClient.cs
new file mode 100644
index 0000000..9006d24
--- /dev/null
+++ b/src/AnthropicClient/AnthropicApiClient.cs
@@ -0,0 +1,233 @@
+using System.Net.Http.Headers;
+using System.Text;
+using System.Text.Json;
+
+using AnthropicClient.Json;
+using AnthropicClient.Utils;
+using AnthropicClient.Models;
+
+namespace AnthropicClient;
+
+/// <summary>
+/// Represents a client for interacting with the Anthropic API.
+/// </summary>
+public interface IAnthropicApiClient
+{
+  /// <summary>
+  /// Creates a chat message asynchronously.
+  /// </summary>
+  /// <param name="request">The chat message request to create.</param>
+  /// <returns>A task that represents the asynchronous operation. The task result contains the chat response as an <see cref="AnthropicResult{T}"/>.</returns>
+  Task<AnthropicResult<ChatResponse>> CreateChatMessageAsync(ChatMessageRequest request);
+
+  /// <summary>
+  /// Creates a chat message asynchronously and streams the response.
+  /// </summary>
+  /// <param name="request">The chat message request to create.</param>
+  /// <returns>An asynchronous enumerable that yields the chat response line by line.</returns>
+  IAsyncEnumerable<AnthropicEvent> CreateChatMessageAsync(StreamChatMessageRequest request);
+}
+
+/// <inheritdoc cref="IAnthropicApiClient"/>
+public class AnthropicApiClient : IAnthropicApiClient
+{
+  private const string BaseUrl = "https://api.anthropic.com/v1/";
+  private const string ApiKeyHeader = "x-api-key";
+  private const string MessagesEndpoint = "messages";
+  private const string JsonContentType = "application/json";
+  private const string RequestIdHeader = "request-id";
+  private const string EventPrefix = "event:";
+  private const string DataPrefix = "data:";
+  private readonly Dictionary<string, string> _defaultHeaders = new()
+  {
+    { "anthropic-version", "2023-06-01" },
+  };
+  private readonly HttpClient _httpClient;
+
+  /// <summary>
+  /// Initializes a new instance of the <see cref="AnthropicApiClient"/> class.
+  /// </summary>
+  /// <param name="apiKey">The API key to use for the client.</param>
+  /// <param name="httpClient">The HTTP client to use for the client.</param>
+  /// <exception cref="ArgumentNullException">Thrown when the API key or HTTP client is null.</exception>
+  /// <returns>A new instance of the <see cref="AnthropicApiClient"/> class.</returns>
+  public AnthropicApiClient(string apiKey, HttpClient httpClient)
+  {
+    ArgumentValidator.ThrowIfNull(apiKey, nameof(apiKey));
+    ArgumentValidator.ThrowIfNull(httpClient, nameof(httpClient));
+
+    _httpClient = httpClient;
+    _httpClient.BaseAddress = new Uri(BaseUrl);
+    _httpClient.DefaultRequestHeaders.Add(ApiKeyHeader, apiKey);
+    _httpClient.DefaultRequestHeaders
+      .Accept
+      .Add(new MediaTypeWithQualityHeaderValue(JsonContentType));
+
+    foreach (var pair in _defaultHeaders)
+    {
+      _httpClient.DefaultRequestHeaders.Add(pair.Key, pair.Value);
+    }
+  }
+
+  /// <inheritdoc />
+  public async Task<AnthropicResult<ChatResponse>> CreateChatMessageAsync(ChatMessageRequest request)
+  {
+    var response = await SendRequestAsync(request);
+    var anthropicHeaders = new AnthropicHeaders(response.Headers);
+    var responseContent = await response.Content.ReadAsStringAsync();
+
+    if (response.IsSuccessStatusCode is false)
+    {
+      var error = Deserialize<AnthropicError>(responseContent) ?? new AnthropicError();
+      return AnthropicResult<ChatResponse>.Failure(error, anthropicHeaders);
+    }
+
+    var chatResponse = Deserialize<ChatResponse>(responseContent) ?? new ChatResponse();
+    return AnthropicResult<ChatResponse>.Success(chatResponse, anthropicHeaders);
+  }
+
+  /// <inheritdoc />
+  public async IAsyncEnumerable<AnthropicEvent> CreateChatMessageAsync(StreamChatMessageRequest request)
+  {
+    var response = await SendRequestAsync(request);
+    var anthropicHeaders = new AnthropicHeaders(response.Headers);
+
+    using var responseContent = await response.Content.ReadAsStreamAsync();
+    using var streamReader = new StreamReader(responseContent);
+
+    ChatResponse? chatResponse = null;
+    Content? content = null;
+    var toolInputJsonStringBuilder = new StringBuilder();
+    var currentEvent = new AnthropicEvent();
+
+    do
+    {
+      var line = await streamReader.ReadLineAsync();
+      
+      // I know...this is not pretty, but here is why...
+      // as events are being yielded I want to also
+      // build up the complete chat response
+      // so I can yield it as a special event to make tool
+      // calling easier to handle
+      
+      // initialize chat response on message start
+      if (currentEvent.Type is EventType.MessageStart && currentEvent.Data is MessageStartEventData msgStartData)
+      {
+        chatResponse = msgStartData.Message;
+      }
+
+      // initialize content block on content block start
+      if (currentEvent.Type is EventType.ContentBlockStart && currentEvent.Data is ContentStartEventData contentStartData)
+      {
+        content = contentStartData.ContentBlock;
+      }
+
+      // update content block with deltas based on
+      // current content type and delta type
+      if (currentEvent.Type is EventType.ContentBlockDelta && currentEvent.Data is ContentDeltaEventData contentDeltaData)
+      {
+        if (content is TextContent textContent && contentDeltaData.Delta is TextDelta textDelta)
+        {
+          var newText = textContent.Text + textDelta.Text;
+          content = new TextContent(newText);
+        }
+
+        if (content is ToolUseContent toolUseContent && contentDeltaData.Delta is JsonDelta jsonDelta)
+        {
+          toolInputJsonStringBuilder.Append(jsonDelta.PartialJson);
+        }
+      }
+
+      // finalize content block on content block stop
+      // and add it to the chat response
+      if (currentEvent.Type is EventType.ContentBlockStop)
+      {
+        if (content is not null && chatResponse is not null)
+        {
+          if (content is TextContent textContent)
+          {
+            chatResponse.Content.Add(textContent);
+          }
+
+          if (content is ToolUseContent toolUseContent)
+          {
+            var input = Deserialize<Dictionary<string, object?>>(toolInputJsonStringBuilder.ToString());
+            var newToolUseContent = new ToolUseContent()
+            {
+              Id = toolUseContent.Id,
+              Name = toolUseContent.Name,
+              Input = input!,
+            };
+
+            chatResponse.Content.Add(newToolUseContent);
+          }
+
+          content = null;
+        }
+      }
+
+      // update chat response with message delta data
+      if (
+        currentEvent.Type is EventType.MessageDelta && 
+        currentEvent.Data is MessageDeltaEventData msgDeltaData &&
+        chatResponse is not null
+      )
+      {
+        chatResponse = new ChatResponse()
+        {
+          Id = chatResponse.Id,
+          Model = chatResponse.Model,
+          Role = chatResponse.Role,
+          StopReason = msgDeltaData.Delta.StopReason,
+          StopSequence = msgDeltaData.Delta.StopSequence,
+          Type = chatResponse.Type,
+          Usage = msgDeltaData.Usage,
+          Content = chatResponse.Content,
+        };
+      }
+
+      // yield chat response on message stop
+      if (currentEvent.Type is EventType.MessageStop && chatResponse is not null)
+      {
+        var eventData = new MessageCompleteEventData(chatResponse, anthropicHeaders);
+        yield return new AnthropicEvent(EventType.MessageComplete, eventData);
+        chatResponse = null;
+      }
+
+      if (line is null)
+      {
+        break;
+      }
+
+      if (line == string.Empty)
+      {
+        yield return currentEvent;
+        currentEvent = new AnthropicEvent();
+      }
+
+      if (line.StartsWith(EventPrefix))
+      {
+        var eventType = line.Substring(EventPrefix.Length).Trim();
+        currentEvent = new AnthropicEvent(eventType, currentEvent.Data);
+        continue;
+      }
+
+      if (line.StartsWith(DataPrefix))
+      {
+        var eventData = line.Substring(DataPrefix.Length).Trim();
+        var eventDataJson = Deserialize<EventData>(eventData);
+        currentEvent = new AnthropicEvent(currentEvent.Type, eventDataJson!);
+        continue;
+      }
+    } while (true);
+  }
+
+  private async Task<HttpResponseMessage> SendRequestAsync(MessageRequest request)
+  {
+    var requestContent = new StringContent(Serialize(request), Encoding.UTF8, JsonContentType);
+    return await _httpClient.PostAsync(MessagesEndpoint, requestContent);
+  }
+
+  private string Serialize<T>(T obj) => JsonSerializer.Serialize(obj, JsonSerializationOptions.DefaultOptions);
+  private T? Deserialize<T>(string json) => JsonSerializer.Deserialize<T>(json, JsonSerializationOptions.DefaultOptions);
+}
\ No newline at end of file
diff --git a/src/AnthropicClient/Client.cs b/src/AnthropicClient/Client.cs
deleted file mode 100644
index a3cf0b8..0000000
--- a/src/AnthropicClient/Client.cs
+++ /dev/null
@@ -1,154 +0,0 @@
-using System.Net.Http.Headers;
-using System.Text;
-using System.Text.Json;
-
-using AnthropicClient.Json;
-using AnthropicClient.Utils;
-using AnthropicClient.Models;
-
-namespace AnthropicClient;
-
-/// <summary>
-/// Represents a client for interacting with the Anthropic API.
-/// </summary>
-public interface IClient
-{
-  /// <summary>
-  /// Creates a chat message asynchronously.
-  /// </summary>
-  /// <param name="request">The chat message request to create.</param>
-  /// <returns>A task that represents the asynchronous operation. The task result contains the chat response as an <see cref="AnthropicResult{T}"/>.</returns>
-  Task<AnthropicResult<ChatResponse>> CreateChatMessageAsync(ChatMessageRequest request);
-
-  /// <summary>
-  /// Creates a chat message asynchronously and streams the response.
-  /// </summary>
-  /// <param name="request">The chat message request to create.</param>
-  /// <returns>An asynchronous enumerable that yields the chat response line by line.</returns>
-  IAsyncEnumerable<AnthropicEvent> CreateChatMessageAsync(StreamChatMessageRequest request);
-}
-
-/// <inheritdoc cref="IClient"/>
-public class Client : IClient
-{
-  private const string BaseUrl = "https://api.anthropic.com/v1/";
-  private const string ApiKeyHeader = "x-api-key";
-  private const string MessagesEndpoint = "messages";
-  private const string JsonContentType = "application/json";
-  private const string RequestIdHeader = "request-id";
-  private readonly Dictionary<string, string> _defaultHeaders = new()
-  {
-    { "anthropic-version", "2023-06-01" },
-  };
-  private readonly HttpClient _httpClient;
-
-  /// <summary>
-  /// Initializes a new instance of the <see cref="Client"/> class.
-  /// </summary>
-  /// <param name="apiKey">The API key to use for the client.</param>
-  /// <param name="httpClient">The HTTP client to use for the client.</param>
-  /// <exception cref="ArgumentNullException">Thrown when the API key or HTTP client is null.</exception>
-  /// <returns>A new instance of the <see cref="Client"/> class.</returns>
-  public Client(string apiKey, HttpClient httpClient)
-  {
-    ArgumentValidator.ThrowIfNull(apiKey, nameof(apiKey));
-    ArgumentValidator.ThrowIfNull(httpClient, nameof(httpClient));
-
-    _httpClient = httpClient;
-    _httpClient.BaseAddress = new Uri(BaseUrl);
-    _httpClient.DefaultRequestHeaders.Add(ApiKeyHeader, apiKey);
-    _httpClient.DefaultRequestHeaders
-      .Accept
-      .Add(new MediaTypeWithQualityHeaderValue(JsonContentType));
-
-    foreach (var pair in _defaultHeaders)
-    {
-      _httpClient.DefaultRequestHeaders.Add(pair.Key, pair.Value);
-    }
-  }
-
-  /// <inheritdoc />
-  public async Task<AnthropicResult<ChatResponse>> CreateChatMessageAsync(ChatMessageRequest request)
-  {
-    var response = await SendRequestAsync(request);
-    var requestId = GetRequestId(response);
-    var responseContent = await response.Content.ReadAsStringAsync();
-
-    if (response.IsSuccessStatusCode is false)
-    {
-      var error = Deserialize<AnthropicError>(responseContent) ?? new AnthropicError();
-      return AnthropicResult<ChatResponse>.Failure(error, requestId);
-    }
-
-    var chatResponse = Deserialize<ChatResponse>(responseContent) ?? new ChatResponse();
-    return AnthropicResult<ChatResponse>.Success(chatResponse, requestId);
-  }
-
-  /// <inheritdoc />
-  public async IAsyncEnumerable<AnthropicEvent> CreateChatMessageAsync(StreamChatMessageRequest request)
-  {
-    var response = await SendRequestAsync(request);
-    var requestId = GetRequestId(response);
-
-    using var responseContent = await response.Content.ReadAsStreamAsync();
-    using var streamReader = new StreamReader(responseContent);
-
-    var currentEvent = new AnthropicEvent();
-
-    // TODO: I'd like to emit custom events unique to this client
-    // - "content_block_complete"
-    //   - provides the complete content block that was streamed
-    //   - useful for streaming in text, but then handling tool calls with their entire input
-
-    // will need to keep track of current content so that we can build it up as relevant
-    // deltas are streamed in
-
-    // will want to capture the content block start event
-    // then continue to build this up until we get to the content block stop event
-    // at that point we should have the complete block and we should be able to yield
-    // return the complete block and reset the current content block
-    
-    // event: content_block_start
-    // data: {"type":"content_block_start","index":1,"content_block":{"type":"tool_use","id":"toolu_01T1x1fJ34qAmk2tNTrN7Up6","name":"get_weather","input":{}}}
-
-
-    do
-    {
-      var line = await streamReader.ReadLineAsync();
-      
-      if (line is null)
-      {
-        break;
-      }
-
-      if (line.StartsWith("event:"))
-      {
-        var eventType = line.Substring("event:".Length).Trim();
-        currentEvent = currentEvent with { Type = eventType };
-      }
-
-      if (line.StartsWith("data:"))
-      {
-        var eventData = line.Substring("data:".Length).Trim();
-        var eventDataJson = JsonSerializer.Deserialize<EventData>(eventData, JsonSerializationOptions.DefaultOptions);
-        currentEvent = currentEvent with { Data = eventDataJson! };
-      }
-
-      if (line == string.Empty)
-      {
-        yield return currentEvent;
-        currentEvent = new AnthropicEvent();
-      }
-    } while (true);
-  }
-
-  private async Task<HttpResponseMessage> SendRequestAsync(MessageRequest request)
-  {
-    var requestContent = new StringContent(Serialize(request), Encoding.UTF8, JsonContentType);
-    return await _httpClient.PostAsync(MessagesEndpoint, requestContent);
-  }
-
-  private string Serialize<T>(T obj) => JsonSerializer.Serialize(obj, JsonSerializationOptions.DefaultOptions);
-  private T? Deserialize<T>(string json) => JsonSerializer.Deserialize<T>(json, JsonSerializationOptions.DefaultOptions);
-  private string GetRequestId(HttpResponseMessage response) => response.Headers.GetValues(RequestIdHeader).FirstOrDefault() ?? string.Empty;
-}
\ No newline at end of file
diff --git a/src/AnthropicClient/Models/AnthropicEvent.cs b/src/AnthropicClient/Models/AnthropicEvent.cs
index 91bab77..2205fd3 100644
--- a/src/AnthropicClient/Models/AnthropicEvent.cs
+++ b/src/AnthropicClient/Models/AnthropicEvent.cs
@@ -2,7 +2,7 @@ using System.Text.Json.Serialization;
 
 namespace AnthropicClient.Models;
 
-public record AnthropicEvent
+public class AnthropicEvent
 {
   public string Type { get; init; } = string.Empty;
   public EventData Data { get; init; } = default!;
diff --git a/src/AnthropicClient/Models/AnthropicHeaders.cs b/src/AnthropicClient/Models/AnthropicHeaders.cs
new file mode 100644
index 0000000..0eaac8f
--- /dev/null
+++ b/src/AnthropicClient/Models/AnthropicHeaders.cs
@@ -0,0 +1,79 @@
+using System.Net.Http.Headers;
+
+namespace AnthropicClient.Models;
+
+/// <summary>
+/// Represents headers included in Anthropic API responses.
+/// </summary>
+public class AnthropicHeaders
+{
+  private const string RequestIdHeaderKey = "request-id";
+  private const string RateLimitRequestsLimitHeaderKey = "anthropic-ratelimit-requests-limit";
+  private const string RateLimitRequestsRemainingHeaderKey = "anthropic-ratelimit-requests-remaining";
+  private const string RateLimitRequestsResetHeaderKey = "anthropic-ratelimit-requests-reset";
+  private const string RateLimitTokensLimitHeaderKey = "anthropic-ratelimit-tokens-limit";
+  private const string RateLimitTokensRemainingHeaderKey = "anthropic-ratelimit-tokens-remaining";
+  private const string RateLimitTokensResetHeaderKey = "anthropic-ratelimit-tokens-reset";
+  private const string RetryAfterHeaderKey = "retry-after";
+
+  /// <summary>
+  /// Gets the request ID.
+  /// </summary>
+  public string RequestId { get; init; } = string.Empty;
+
+  /// <summary>
+  /// Gets the rate limit requests limit.
+  /// </summary>
+  public int RateLimitRequestsLimit { get; init; }
+
+  /// <summary>
+  /// Gets the rate limit requests remaining.
+  /// </summary>
+  public int RateLimitRequestsRemaining { get; init; }
+
+  /// <summary>
+  /// Gets the time of the rate limit requests reset.
+  /// </summary>
+  public DateTimeOffset RateLimitRequestsReset { get; init; }
+
+  /// <summary>
+  /// Gets the rate limit tokens limit.
+  /// </summary>
+  public int RateLimitTokensLimit { get; init; }
+
+  /// <summary>
+  /// Gets the rate limit tokens remaining.
+  /// </summary>
+  public int RateLimitTokensRemaining { get; init; }
+
+  /// <summary>
+  /// Gets the time of the rate limit tokens reset.
+  /// </summary>
+  public DateTimeOffset RateLimitTokensReset { get; init; }
+
+  /// <summary>
+  /// Gets the retry after value.
+  /// </summary>
+  public int RetryAfter { get; init; }
+
+  internal AnthropicHeaders()
+  {
+  }
+
+  /// <summary>
+  /// Initializes a new instance of the <see cref="AnthropicHeaders"/> class.
+  /// </summary>
+  /// <param name="headers">The HTTP response headers.</param>
+  /// <returns>A new instance of the <see cref="AnthropicHeaders"/> class.</returns>
+  public AnthropicHeaders(HttpResponseHeaders headers)
+  {
+    RequestId = headers.GetValues(RequestIdHeaderKey).FirstOrDefault() ?? string.Empty;
+    RateLimitRequestsLimit = int.Parse(headers.GetValues(RateLimitRequestsLimitHeaderKey).FirstOrDefault() ?? "0");
+    RateLimitRequestsRemaining = int.Parse(headers.GetValues(RateLimitRequestsRemainingHeaderKey).FirstOrDefault() ?? "0");
+    RateLimitRequestsReset = DateTimeOffset.Parse(headers.GetValues(RateLimitRequestsResetHeaderKey).FirstOrDefault() ?? DateTimeOffset.MinValue.ToString());
+    RateLimitTokensLimit = int.Parse(headers.GetValues(RateLimitTokensLimitHeaderKey).FirstOrDefault() ?? "0");
+    RateLimitTokensRemaining = int.Parse(headers.GetValues(RateLimitTokensRemainingHeaderKey).FirstOrDefault() ?? "0");
+    RateLimitTokensReset = DateTimeOffset.Parse(headers.GetValues(RateLimitTokensResetHeaderKey).FirstOrDefault() ?? DateTimeOffset.MinValue.ToString());
+    RetryAfter = int.Parse(headers.GetValues(RetryAfterHeaderKey).FirstOrDefault() ?? "0");
+  }
+}
\ No newline at end of file
diff --git a/src/AnthropicClient/Models/AnthropicResult.cs b/src/AnthropicClient/Models/AnthropicResult.cs
index 1fdc4e1..19c27a9 100644
--- a/src/AnthropicClient/Models/AnthropicResult.cs
+++ b/src/AnthropicClient/Models/AnthropicResult.cs
@@ -24,7 +24,7 @@ public class AnthropicResult<T>
   /// <summary>
   /// The request ID of the operation.
   /// </summary>
-  public string RequestId { get; }
+  public AnthropicHeaders Headers { get; }
 
   /// <summary>
   /// Initializes a new instance of the <see cref="AnthropicResult{T}"/> class.
@@ -32,35 +32,35 @@ public class AnthropicResult<T>
   /// <param name="value">The value of the result.</param>
   /// <param name="error">The error of the result.</param>
   /// <param name="isSuccess">Indicates whether the operation was successful.</param>
-  /// <param name="requestId">The request ID of the operation.</param>
+  /// <param name="headers">The Anthropic headers for the result.</param>
   /// <returns>A new instance of the <see cref="AnthropicResult{T}"/> class.</returns>
-  protected AnthropicResult(T value, AnthropicError error, bool isSuccess, string requestId)
+  protected AnthropicResult(T value, AnthropicError error, bool isSuccess, AnthropicHeaders headers)
   {
     Value = value;
     Error = error;
     IsSuccess = isSuccess;
-    RequestId = requestId;
+    Headers = headers;
   }
 
   /// <summary>
   /// Creates a successful result.
   /// </summary>
   /// <param name="value">The value of the result.</param>
-  /// <param name="requestId">The request ID of the operation.</param>
+  /// <param name="headers">The Anthropic headers for the result.</param>
   /// <returns>A new instance of the <see cref="AnthropicResult{T}"/> class.</returns>
-  public static AnthropicResult<T> Success(T value, string requestId)
+  public static AnthropicResult<T> Success(T value, AnthropicHeaders headers)
   {
-    return new AnthropicResult<T>(value, null!, true, requestId);
+    return new AnthropicResult<T>(value, null!, true, headers);
   }
 
   /// <summary>
   /// Creates a failed result.
   /// </summary>
   /// <param name="error">The error of the result.</param>
-  /// <param name="requestId">The request ID of the operation.</param>
+  /// <param name="headers">The Anthropic headers for the result.</param>
   /// <returns>A new instance of the <see cref="AnthropicResult{T}"/> class.</returns>
-  public static AnthropicResult<T> Failure(AnthropicError error, string requestId)
+  public static AnthropicResult<T> Failure(AnthropicError error, AnthropicHeaders headers)
   {
-    return new AnthropicResult<T>(default!, error, false, requestId);
+    return new AnthropicResult<T>(default!, error, false, headers);
   }
 }
diff --git a/src/AnthropicClient/Models/ContentStartEventData.cs b/src/AnthropicClient/Models/ContentStartEventData.cs
index 1edfa2e..ed2c9cf 100644
--- a/src/AnthropicClient/Models/ContentStartEventData.cs
+++ b/src/AnthropicClient/Models/ContentStartEventData.cs
@@ -7,7 +7,7 @@ public class ContentStartEventData : EventData
   public int Index { get; init; }
 
   [JsonPropertyName("content_block")]
-  public Content ContentBlock { get; init; }
+  public Content ContentBlock { get; init; } = default!;
 
   [JsonConstructor]
   internal ContentStartEventData() : base(EventType.ContentBlockStart)
diff --git a/src/AnthropicClient/Models/EventType.cs b/src/AnthropicClient/Models/EventType.cs
index a652168..48c652f 100644
--- a/src/AnthropicClient/Models/EventType.cs
+++ b/src/AnthropicClient/Models/EventType.cs
@@ -7,6 +7,7 @@ public static class EventType
   public const string MessageStart = "message_start";
   public const string MessageDelta = "message_delta";
   public const string MessageStop = "message_stop";
+  public const string MessageComplete = "message_complete";
   public const string ContentBlockStart = "content_block_start";
   public const string ContentBlockDelta = "content_block_delta";
   public const string ContentBlockStop = "content_block_stop";
diff --git a/src/AnthropicClient/Models/MessageCompleteEventData.cs b/src/AnthropicClient/Models/MessageCompleteEventData.cs
new file mode 100644
index 0000000..85218ad
--- /dev/null
+++ b/src/AnthropicClient/Models/MessageCompleteEventData.cs
@@ -0,0 +1,15 @@
+using System.Text.Json.Serialization;
+
+namespace AnthropicClient.Models;
+
+public class MessageCompleteEventData : EventData
+{
+  public AnthropicHeaders Headers { get; init; } = new();
+  public ChatResponse Message { get; init; } = new();
+
+  public MessageCompleteEventData(ChatResponse message, AnthropicHeaders headers) : base(EventType.MessageComplete)
+  {
+    Message = message;
+    Headers = headers;
+  }
+}
\ No newline at end of file
diff --git a/src/AnthropicClient/Models/MessageDeltaEventData.cs b/src/AnthropicClient/Models/MessageDeltaEventData.cs
index 240e307..b150d2e 100644
--- a/src/AnthropicClient/Models/MessageDeltaEventData.cs
+++ b/src/AnthropicClient/Models/MessageDeltaEventData.cs
@@ -4,8 +4,8 @@ namespace AnthropicClient.Models;
 
 public class MessageDeltaEventData : EventData
 {
-  public MessageDelta Delta { get; init; }
-  public ChatUsage Usage { get; init; }
+  public MessageDelta Delta { get; init; } = new();
+  public ChatUsage Usage { get; init; } = new();
 
   [JsonConstructor]
   internal MessageDeltaEventData() : base(EventType.MessageDelta)
diff --git a/src/AnthropicClient/Models/MessageStartEventData.cs b/src/AnthropicClient/Models/MessageStartEventData.cs
index 16b4451..ccf5c18 100644
--- a/src/AnthropicClient/Models/MessageStartEventData.cs
+++ b/src/AnthropicClient/Models/MessageStartEventData.cs
@@ -4,14 +4,14 @@ namespace AnthropicClient.Models;
 
 public class MessageStartEventData : EventData
 {
-  public ChatMessage Message { get; init; } = new();
+  public ChatResponse Message { get; init; } = new();
 
   [JsonConstructor]
   internal MessageStartEventData() : base(EventType.MessageStart)
   {
   }
 
-  public MessageStartEventData(ChatMessage message) : base(EventType.MessageStart)
+  public MessageStartEventData(ChatResponse message) : base(EventType.MessageStart)
   {
     Message = message;
   }
diff --git a/tests/AnthropicClient.Tests/EndToEnd/ClientTests.cs b/tests/AnthropicClient.Tests/EndToEnd/AnthropicApiClientTests.cs
similarity index 60%
rename from tests/AnthropicClient.Tests/EndToEnd/ClientTests.cs
rename to tests/AnthropicClient.Tests/EndToEnd/AnthropicApiClientTests.cs
index aee03d6..fe5560c 100644
--- a/tests/AnthropicClient.Tests/EndToEnd/ClientTests.cs
+++ b/tests/AnthropicClient.Tests/EndToEnd/AnthropicApiClientTests.cs
@@ -6,7 +6,7 @@ public class ClientTests(
 ) : EndToEndTest(httpClientFixture, configFixture)
 {
   [Fact]
-  public async Task CreateChatMessage_WhenCalled_ShouldReturnChatResponse()
+  public async Task CreateChatMessage_WhenCalled_ItShouldReturnChatResponse()
   {
     var request = new ChatMessageRequest(
       model: AnthropicModels.Claude3Haiku,
@@ -20,7 +20,7 @@ public class ClientTests(
   }
 
   [Fact]
-  public async Task CreateChatMessage_WhenCalledWithStreamRequest_IteratesOverChatResponse()
+  public async Task CreateChatMessage_WhenCalledWithStreamRequest_ItShouldReturnEvents()
   {
     var request = new StreamChatMessageRequest(
       model: AnthropicModels.Claude3Haiku,
@@ -38,4 +38,24 @@ public class ClientTests(
 
     events.Should().NotBeEmpty();
   }
+
+  [Fact]
+  public async Task CreateChatMessage_WhenCalledWithStreamRequest_ItShouldYieldAMessageCompleteEvent()
+  {
+    var request = new StreamChatMessageRequest(
+      model: AnthropicModels.Claude3Haiku,
+      messages: [new(MessageRole.User, [new TextContent("Hello!")])]
+    );
+
+    var response = _client.CreateChatMessageAsync(request);
+  
+    await foreach (var e in response)
+    {
+      if (e.Data is MessageCompleteEventData messageCompleteData)
+      {
+        messageCompleteData.Message.Should().NotBeNull();
+        break;
+      }
+    }
+  }
 }
\ No newline at end of file
diff --git a/tests/AnthropicClient.Tests/EndToEnd/EndToEndTest.cs b/tests/AnthropicClient.Tests/EndToEnd/EndToEndTest.cs
index c808412..b4cc22d 100644
--- a/tests/AnthropicClient.Tests/EndToEnd/EndToEndTest.cs
+++ b/tests/AnthropicClient.Tests/EndToEnd/EndToEndTest.cs
@@ -5,5 +5,5 @@ public class EndToEndTest(
   ConfigurationFixture configFixture
 ) : IClassFixture<HttpClientFixture>, IClassFixture<ConfigurationFixture>
 {
-  protected readonly Client _client = new(configFixture.AnthropicApiKey, httpClientFixture.HttpClient);
+  protected readonly AnthropicApiClient _client = new(configFixture.AnthropicApiKey, httpClientFixture.HttpClient);
 }
\ No newline at end of file