chore(release): 0.4.0 [skip ci]

feat: add support for counting tokens

README.md

@@ -105,9 +105,38 @@ The primary use case for working with the Anthropic API is to create a message i
 > [!NOTE]
 > The following examples assume that you have already created an instance of the `AnthropicApiClient` class named `client`. You can also find these snippets in the examples directory.
 
+### Count Message Tokens
+
+The `AnthropicApiClient` exposes a method named `CountMessageTokensAsync` that can be used to count the number of tokens in a message. The method requires a `CountMessageTokensRequest` instance as a parameter.
+
+```csharp
+using AnthropicClient;
+using AnthropicClient.Models;
+
+var response = await client.CountMessageTokensAsync(new CountMessageTokensRequest(
+  AnthropicModels.Claude3Haiku,
+  [
+    new(
+      MessageRole.User, 
+      [new TextContent("Please write a haiku about the ocean.")]
+    )
+  ]
+));
+
+if (response.IsFailure)
+{
+  Console.WriteLine("Failed to count message tokens");
+  Console.WriteLine("Error Type: {0}", response.Error.Error.Type);
+  Console.WriteLine("Error Message: {0}", response.Error.Error.Message);
+  return;
+}
+
+Console.WriteLine("Token Count: {0}", response.Value.InputTokens);
+```
+
 ### Create a message
 
-The `AnthropicApiClient` exposes a single method named `CreateMessageAsync` that can be used to create a message. The method requires a `MessageRequest` or a `StreamMessageRequest` instance as a parameter. The `MessageRequest` class is used to create a message whose response is not streamed and the `StreamMessageRequest` class is used to create a message whose response is streamed. The `MessageRequest` instance's properties can be set to configure how the message is created.
+The `AnthropicApiClient` exposes a method named `CreateMessageAsync` that can be used to create a message. The method requires a `MessageRequest` or a `StreamMessageRequest` instance as a parameter. The `MessageRequest` class is used to create a message whose response is not streamed and the `StreamMessageRequest` class is used to create a message whose response is streamed. The `MessageRequest` instance's properties can be set to configure how the message is created.
 
 #### Non-Streaming
 
@@ -694,22 +723,7 @@ foreach (var content in response.Value.Content)
 
 ### Prompt Caching
 
-Anthropic has recently introduced a feature called [Prompt Caching](https://docs.anthropic.com/en/docs/build-with-claude/prompt-caching) that allows you to cache all or part of the prompt you send to the model. This can be used to improve the performance of your application by reducing latency and token usage. This feature is covered in depth in [Anthropic's API Documentation](https://docs.anthropic.com/en/docs/build-with-claude/prompt-caching).
+Anthropic provides a feature called [Prompt Caching](https://docs.anthropic.com/en/docs/build-with-claude/prompt-caching) that allows you to cache all or part of the prompt you send to the model. This can be used to improve the performance of your application by reducing latency and token usage. This feature is covered in depth in [Anthropic's API Documentation](https://docs.anthropic.com/en/docs/build-with-claude/prompt-caching).
-
-> [!NOTE]
-> This feature is in beta and requires you to set an `anthropic-beta` header on your requests to use it.
-> The value of the header should be `prompt-caching-2024-07-31`.
-
-When using this library you can opt-in to prompt caching by adding the required header to the `HttpClient` instance you provide to the `AnthropicApiClient` constructor.
-
-```csharp
-using AnthropicClient;
-
-var httpClient = new HttpClient();
-httpClient.DefaultRequestHeaders.Add("anthropic-beta", "prompt-caching-2024-07-31");
-
-var client = new AnthropicApiClient(apiKey, httpClient);
-```
 
 Prompt caching can be used to cache all parts of the prompt including system messages, user messages, and tools. You should refer to the [Anthropic API Documentation](https://docs.anthropic.com/en/docs/build-with-claude/prompt-caching) for specifics on limitations and requirements for using prompt caching. This library aims to make using prompt caching convenient and give you complete control over what parts of the prompt are cached. Currently there is only one type of cache control available - `EphemeralCacheControl`.
 
@@ -850,22 +864,7 @@ foreach (var content in response.Value.Content)
 
 ### PDF Support
 
-Anthropic has recently introduced a feature called [PDF Support](https://docs.anthropic.com/en/docs/build-with-claude/pdf-support) that allows Claude to support PDF input and understand both text and visual content within documents. . This feature is covered in depth in [Anthropic's API Documentation](https://docs.anthropic.com/en/docs/build-with-claude/pdf-support).
+Anthropic provides a feature called [PDF Support](https://docs.anthropic.com/en/docs/build-with-claude/pdf-support) that allows Claude to support PDF input and understand both text and visual content within documents. This feature is covered in depth in [Anthropic's API Documentation](https://docs.anthropic.com/en/docs/build-with-claude/pdf-support).
-
-> [!NOTE]
-> This feature is in beta and requires you to set an `anthropic-beta` header on your requests to use it.
-> The value of the header should be `pdfs-2024-09-25`.
-
-When using this library you can opt-in to PDF support by adding the required header to the `HttpClient` instance you provide to the `AnthropicApiClient` constructor.
-
-```csharp
-using AnthropicClient;
-
-var httpClient = new HttpClient();
-httpClient.DefaultRequestHeaders.Add("anthropic-beta", "pdfs-2024-09-25");
-
-var client = new AnthropicApiClient(apiKey, httpClient);
-```
 
 PDF support can be used to provide a PDF document as input to the model. This can be used to provide additional context to the model or to ask for additional information from the model. This library aims to make using PDF support convenient by allowing you to provide the PDF document you want Anthropic's models to consider for use when creating a message.
 
@@ -885,11 +884,6 @@ var request = new MessageRequest(
   ]
 );
 
-var httpClient = new HttpClient();
-httpClient.DefaultRequestHeaders.Add("anthropic-beta", "pdfs-2024-09-25");
-
-var client = new AnthropicApiClient(apiKey, httpClient);
-
 var response = await client.CreateMessageAsync(request);
 
 if (response.IsSuccess is false)

docs/api/AnthropicClient.Models.AnthropicModels.html

@@ -154,12 +154,74 @@ Class AnthropicModels  <a class="header-action link-secondary" title="View sourc
 
 
 
-  <h3 id="AnthropicClient_Models_AnthropicModels_Claude35Sonnet" data-uid="AnthropicClient.Models.AnthropicModels.Claude35Sonnet">
+  <h3 id="AnthropicClient_Models_AnthropicModels_Claude35Haiku20241022" data-uid="AnthropicClient.Models.AnthropicModels.Claude35Haiku20241022">
-  Claude35Sonnet
+  Claude35Haiku20241022
-  <a class="header-action link-secondary" title="View source" href="https://github.com/StevanFreeborn/anthropic-client/blob/main/src/AnthropicClient/Models/AnthropicModels.cs/#L21"><i class="bi bi-code-slash"></i></a>
+  <a class="header-action link-secondary" title="View source" href="https://github.com/StevanFreeborn/anthropic-client/blob/main/src/AnthropicClient/Models/AnthropicModels.cs/#L66"><i class="bi bi-code-slash"></i></a>
   </h3>
 
-  <div class="markdown level1 summary"><p>The Claude-3.5 Sonnet model.</p>
+  <div class="markdown level1 summary"><p>The Claude 3.5 Haiku model.</p>
+</div>
+  <div class="markdown level1 conceptual"></div>
+
+  <div class="codewrapper">
+    <pre><code class="lang-csharp hljs">public const string Claude35Haiku20241022 = &quot;claude-3-5-haiku-20241022&quot;</code></pre>
+  </div>
+
+
+
+
+  <h4 class="section">Field Value</h4>
+  <dl class="parameters">
+    <dt><a class="xref" href="https://learn.microsoft.com/dotnet/api/system.string">string</a></dt>
+    <dd></dd>
+  </dl>
+
+
+
+
+
+
+
+
+
+
+  <h3 id="AnthropicClient_Models_AnthropicModels_Claude35HaikuLatest" data-uid="AnthropicClient.Models.AnthropicModels.Claude35HaikuLatest">
+  Claude35HaikuLatest
+  <a class="header-action link-secondary" title="View source" href="https://github.com/StevanFreeborn/anthropic-client/blob/main/src/AnthropicClient/Models/AnthropicModels.cs/#L71"><i class="bi bi-code-slash"></i></a>
+  </h3>
+
+  <div class="markdown level1 summary"><p>The Claude 3.5 Haiku model.</p>
+</div>
+  <div class="markdown level1 conceptual"></div>
+
+  <div class="codewrapper">
+    <pre><code class="lang-csharp hljs">public const string Claude35HaikuLatest = &quot;claude-3-5-haiku-latest&quot;</code></pre>
+  </div>
+
+
+
+
+  <h4 class="section">Field Value</h4>
+  <dl class="parameters">
+    <dt><a class="xref" href="https://learn.microsoft.com/dotnet/api/system.string">string</a></dt>
+    <dd></dd>
+  </dl>
+
+
+
+
+
+
+
+
+
+
+  <h3 id="AnthropicClient_Models_AnthropicModels_Claude35Sonnet" data-uid="AnthropicClient.Models.AnthropicModels.Claude35Sonnet">
+  Claude35Sonnet
+  <a class="header-action link-secondary" title="View source" href="https://github.com/StevanFreeborn/anthropic-client/blob/main/src/AnthropicClient/Models/AnthropicModels.cs/#L36"><i class="bi bi-code-slash"></i></a>
+  </h3>
+
+  <div class="markdown level1 summary"><p>The Claude 3.5 Sonnet model.</p>
 </div>
   <div class="markdown level1 conceptual"></div>
 
@@ -185,12 +247,105 @@ Class AnthropicModels  <a class="header-action link-secondary" title="View sourc
 
 
 
-  <h3 id="AnthropicClient_Models_AnthropicModels_Claude3Haiku" data-uid="AnthropicClient.Models.AnthropicModels.Claude3Haiku">
+  <h3 id="AnthropicClient_Models_AnthropicModels_Claude35Sonnet20240620" data-uid="AnthropicClient.Models.AnthropicModels.Claude35Sonnet20240620">
-  Claude3Haiku
+  Claude35Sonnet20240620
-  <a class="header-action link-secondary" title="View source" href="https://github.com/StevanFreeborn/anthropic-client/blob/main/src/AnthropicClient/Models/AnthropicModels.cs/#L26"><i class="bi bi-code-slash"></i></a>
+  <a class="header-action link-secondary" title="View source" href="https://github.com/StevanFreeborn/anthropic-client/blob/main/src/AnthropicClient/Models/AnthropicModels.cs/#L41"><i class="bi bi-code-slash"></i></a>
   </h3>
 
-  <div class="markdown level1 summary"><p>The Claude-3 Haiku model.</p>
+  <div class="markdown level1 summary"><p>The Claude 3.5 Sonnet model.</p>
+</div>
+  <div class="markdown level1 conceptual"></div>
+
+  <div class="codewrapper">
+    <pre><code class="lang-csharp hljs">public const string Claude35Sonnet20240620 = &quot;claude-3-5-sonnet-20240620&quot;</code></pre>
+  </div>
+
+
+
+
+  <h4 class="section">Field Value</h4>
+  <dl class="parameters">
+    <dt><a class="xref" href="https://learn.microsoft.com/dotnet/api/system.string">string</a></dt>
+    <dd></dd>
+  </dl>
+
+
+
+
+
+
+
+
+
+
+  <h3 id="AnthropicClient_Models_AnthropicModels_Claude35Sonnet20241022" data-uid="AnthropicClient.Models.AnthropicModels.Claude35Sonnet20241022">
+  Claude35Sonnet20241022
+  <a class="header-action link-secondary" title="View source" href="https://github.com/StevanFreeborn/anthropic-client/blob/main/src/AnthropicClient/Models/AnthropicModels.cs/#L46"><i class="bi bi-code-slash"></i></a>
+  </h3>
+
+  <div class="markdown level1 summary"><p>The Claude 3.5 Sonnet model.</p>
+</div>
+  <div class="markdown level1 conceptual"></div>
+
+  <div class="codewrapper">
+    <pre><code class="lang-csharp hljs">public const string Claude35Sonnet20241022 = &quot;claude-3-5-sonnet-20241022&quot;</code></pre>
+  </div>
+
+
+
+
+  <h4 class="section">Field Value</h4>
+  <dl class="parameters">
+    <dt><a class="xref" href="https://learn.microsoft.com/dotnet/api/system.string">string</a></dt>
+    <dd></dd>
+  </dl>
+
+
+
+
+
+
+
+
+
+
+  <h3 id="AnthropicClient_Models_AnthropicModels_Claude35SonnetLatest" data-uid="AnthropicClient.Models.AnthropicModels.Claude35SonnetLatest">
+  Claude35SonnetLatest
+  <a class="header-action link-secondary" title="View source" href="https://github.com/StevanFreeborn/anthropic-client/blob/main/src/AnthropicClient/Models/AnthropicModels.cs/#L51"><i class="bi bi-code-slash"></i></a>
+  </h3>
+
+  <div class="markdown level1 summary"><p>The Claude 3.5 Sonnet model.</p>
+</div>
+  <div class="markdown level1 conceptual"></div>
+
+  <div class="codewrapper">
+    <pre><code class="lang-csharp hljs">public const string Claude35SonnetLatest = &quot;claude-3-5-sonnet-latest&quot;</code></pre>
+  </div>
+
+
+
+
+  <h4 class="section">Field Value</h4>
+  <dl class="parameters">
+    <dt><a class="xref" href="https://learn.microsoft.com/dotnet/api/system.string">string</a></dt>
+    <dd></dd>
+  </dl>
+
+
+
+
+
+
+
+
+
+
+  <h3 id="AnthropicClient_Models_AnthropicModels_Claude3Haiku" data-uid="AnthropicClient.Models.AnthropicModels.Claude3Haiku">
+  Claude3Haiku
+  <a class="header-action link-secondary" title="View source" href="https://github.com/StevanFreeborn/anthropic-client/blob/main/src/AnthropicClient/Models/AnthropicModels.cs/#L56"><i class="bi bi-code-slash"></i></a>
+  </h3>
+
+  <div class="markdown level1 summary"><p>The Claude 3 Haiku model.</p>
 </div>
   <div class="markdown level1 conceptual"></div>
 
@@ -216,12 +371,43 @@ Class AnthropicModels  <a class="header-action link-secondary" title="View sourc
 
 
 
+  <h3 id="AnthropicClient_Models_AnthropicModels_Claude3Haiku20240307" data-uid="AnthropicClient.Models.AnthropicModels.Claude3Haiku20240307">
+  Claude3Haiku20240307
+  <a class="header-action link-secondary" title="View source" href="https://github.com/StevanFreeborn/anthropic-client/blob/main/src/AnthropicClient/Models/AnthropicModels.cs/#L61"><i class="bi bi-code-slash"></i></a>
+  </h3>
+
+  <div class="markdown level1 summary"><p>The Claude 3 Haiku model.</p>
+</div>
+  <div class="markdown level1 conceptual"></div>
+
+  <div class="codewrapper">
+    <pre><code class="lang-csharp hljs">public const string Claude3Haiku20240307 = &quot;claude-3-haiku-20240307&quot;</code></pre>
+  </div>
+
+
+
+
+  <h4 class="section">Field Value</h4>
+  <dl class="parameters">
+    <dt><a class="xref" href="https://learn.microsoft.com/dotnet/api/system.string">string</a></dt>
+    <dd></dd>
+  </dl>
+
+
+
+
+
+
+
+
+
+
   <h3 id="AnthropicClient_Models_AnthropicModels_Claude3Opus" data-uid="AnthropicClient.Models.AnthropicModels.Claude3Opus">
   Claude3Opus
   <a class="header-action link-secondary" title="View source" href="https://github.com/StevanFreeborn/anthropic-client/blob/main/src/AnthropicClient/Models/AnthropicModels.cs/#L11"><i class="bi bi-code-slash"></i></a>
   </h3>
 
-  <div class="markdown level1 summary"><p>The Claude-3 Opus model.</p>
+  <div class="markdown level1 summary"><p>The Claude 3 Opus model.</p>
 </div>
   <div class="markdown level1 conceptual"></div>
 
@@ -247,12 +433,74 @@ Class AnthropicModels  <a class="header-action link-secondary" title="View sourc
 
 
 
-  <h3 id="AnthropicClient_Models_AnthropicModels_Claude3Sonnet" data-uid="AnthropicClient.Models.AnthropicModels.Claude3Sonnet">
+  <h3 id="AnthropicClient_Models_AnthropicModels_Claude3Opus20241022" data-uid="AnthropicClient.Models.AnthropicModels.Claude3Opus20241022">
-  Claude3Sonnet
+  Claude3Opus20241022
   <a class="header-action link-secondary" title="View source" href="https://github.com/StevanFreeborn/anthropic-client/blob/main/src/AnthropicClient/Models/AnthropicModels.cs/#L16"><i class="bi bi-code-slash"></i></a>
   </h3>
 
-  <div class="markdown level1 summary"><p>The Claude-3 Sonnet model.</p>
+  <div class="markdown level1 summary"><p>The Claude 3 Opus model.</p>
+</div>
+  <div class="markdown level1 conceptual"></div>
+
+  <div class="codewrapper">
+    <pre><code class="lang-csharp hljs">public const string Claude3Opus20241022 = &quot;claude-3-opus-20240229&quot;</code></pre>
+  </div>
+
+
+
+
+  <h4 class="section">Field Value</h4>
+  <dl class="parameters">
+    <dt><a class="xref" href="https://learn.microsoft.com/dotnet/api/system.string">string</a></dt>
+    <dd></dd>
+  </dl>
+
+
+
+
+
+
+
+
+
+
+  <h3 id="AnthropicClient_Models_AnthropicModels_Claude3OpusLatest" data-uid="AnthropicClient.Models.AnthropicModels.Claude3OpusLatest">
+  Claude3OpusLatest
+  <a class="header-action link-secondary" title="View source" href="https://github.com/StevanFreeborn/anthropic-client/blob/main/src/AnthropicClient/Models/AnthropicModels.cs/#L21"><i class="bi bi-code-slash"></i></a>
+  </h3>
+
+  <div class="markdown level1 summary"><p>The Claude 3 Opus model.</p>
+</div>
+  <div class="markdown level1 conceptual"></div>
+
+  <div class="codewrapper">
+    <pre><code class="lang-csharp hljs">public const string Claude3OpusLatest = &quot;claude-3-opus-latest&quot;</code></pre>
+  </div>
+
+
+
+
+  <h4 class="section">Field Value</h4>
+  <dl class="parameters">
+    <dt><a class="xref" href="https://learn.microsoft.com/dotnet/api/system.string">string</a></dt>
+    <dd></dd>
+  </dl>
+
+
+
+
+
+
+
+
+
+
+  <h3 id="AnthropicClient_Models_AnthropicModels_Claude3Sonnet" data-uid="AnthropicClient.Models.AnthropicModels.Claude3Sonnet">
+  Claude3Sonnet
+  <a class="header-action link-secondary" title="View source" href="https://github.com/StevanFreeborn/anthropic-client/blob/main/src/AnthropicClient/Models/AnthropicModels.cs/#L26"><i class="bi bi-code-slash"></i></a>
+  </h3>
+
+  <div class="markdown level1 summary"><p>The Claude 3 Sonnet model.</p>
 </div>
   <div class="markdown level1 conceptual"></div>
 
@@ -278,6 +526,37 @@ Class AnthropicModels  <a class="header-action link-secondary" title="View sourc
 
 
 
+  <h3 id="AnthropicClient_Models_AnthropicModels_Claude3Sonnet20240229" data-uid="AnthropicClient.Models.AnthropicModels.Claude3Sonnet20240229">
+  Claude3Sonnet20240229
+  <a class="header-action link-secondary" title="View source" href="https://github.com/StevanFreeborn/anthropic-client/blob/main/src/AnthropicClient/Models/AnthropicModels.cs/#L31"><i class="bi bi-code-slash"></i></a>
+  </h3>
+
+  <div class="markdown level1 summary"><p>The Claude 3 Sonnet model.</p>
+</div>
+  <div class="markdown level1 conceptual"></div>
+
+  <div class="codewrapper">
+    <pre><code class="lang-csharp hljs">public const string Claude3Sonnet20240229 = &quot;claude-3-sonnet-20240229&quot;</code></pre>
+  </div>
+
+
+
+
+  <h4 class="section">Field Value</h4>
+  <dl class="parameters">
+    <dt><a class="xref" href="https://learn.microsoft.com/dotnet/api/system.string">string</a></dt>
+    <dd></dd>
+  </dl>
+
+
+
+
+
+
+
+
+
+
 </article>
 
         <div class="contribution d-print-none">

docs/index.json

@@ -32,7 +32,7 @@
   "api/AnthropicClient.Models.AnthropicModels.html": {
     "href": "api/AnthropicClient.Models.AnthropicModels.html",
     "title": "Class AnthropicModels | AnthropicClient",
-    "keywords": "Class AnthropicModels Namespace AnthropicClient.Models Assembly AnthropicClient.dll Provides constants for the Anthropic models. public static class AnthropicModels Inheritance object AnthropicModels Inherited Members object.Equals(object) object.Equals(object, object) object.GetHashCode() object.GetType() object.MemberwiseClone() object.ReferenceEquals(object, object) object.ToString() Fields Claude35Sonnet The Claude-3.5 Sonnet model. public const string Claude35Sonnet = \"claude-3-5-sonnet-20240620\" Field Value string Claude3Haiku The Claude-3 Haiku model. public const string Claude3Haiku = \"claude-3-haiku-20240307\" Field Value string Claude3Opus The Claude-3 Opus model. public const string Claude3Opus = \"claude-3-opus-20240229\" Field Value string Claude3Sonnet The Claude-3 Sonnet model. public const string Claude3Sonnet = \"claude-3-sonnet-20240229\" Field Value string"
+    "keywords": "Class AnthropicModels Namespace AnthropicClient.Models Assembly AnthropicClient.dll Provides constants for the Anthropic models. public static class AnthropicModels Inheritance object AnthropicModels Inherited Members object.Equals(object) object.Equals(object, object) object.GetHashCode() object.GetType() object.MemberwiseClone() object.ReferenceEquals(object, object) object.ToString() Fields Claude35Haiku20241022 The Claude 3.5 Haiku model. public const string Claude35Haiku20241022 = \"claude-3-5-haiku-20241022\" Field Value string Claude35HaikuLatest The Claude 3.5 Haiku model. public const string Claude35HaikuLatest = \"claude-3-5-haiku-latest\" Field Value string Claude35Sonnet The Claude 3.5 Sonnet model. public const string Claude35Sonnet = \"claude-3-5-sonnet-20240620\" Field Value string Claude35Sonnet20240620 The Claude 3.5 Sonnet model. public const string Claude35Sonnet20240620 = \"claude-3-5-sonnet-20240620\" Field Value string Claude35Sonnet20241022 The Claude 3.5 Sonnet model. public const string Claude35Sonnet20241022 = \"claude-3-5-sonnet-20241022\" Field Value string Claude35SonnetLatest The Claude 3.5 Sonnet model. public const string Claude35SonnetLatest = \"claude-3-5-sonnet-latest\" Field Value string Claude3Haiku The Claude 3 Haiku model. public const string Claude3Haiku = \"claude-3-haiku-20240307\" Field Value string Claude3Haiku20240307 The Claude 3 Haiku model. public const string Claude3Haiku20240307 = \"claude-3-haiku-20240307\" Field Value string Claude3Opus The Claude 3 Opus model. public const string Claude3Opus = \"claude-3-opus-20240229\" Field Value string Claude3Opus20241022 The Claude 3 Opus model. public const string Claude3Opus20241022 = \"claude-3-opus-20240229\" Field Value string Claude3OpusLatest The Claude 3 Opus model. public const string Claude3OpusLatest = \"claude-3-opus-latest\" Field Value string Claude3Sonnet The Claude 3 Sonnet model. public const string Claude3Sonnet = \"claude-3-sonnet-20240229\" Field Value string Claude3Sonnet20240229 The Claude 3 Sonnet model. public const string Claude3Sonnet20240229 = \"claude-3-sonnet-20240229\" Field Value string"
   },
   "api/AnthropicClient.Models.AnyToolChoice.html": {
     "href": "api/AnthropicClient.Models.AnyToolChoice.html",

docs/manifest.json

@@ -694,11 +694,11 @@
       "type": "Toc",
       "source_relative_path": "api/toc.yml",
       "output": {
-        ".json": {
-          "relative_path": "api/toc.json"
-        },
         ".html": {
           "relative_path": "api/toc.html"
+        },
+        ".json": {
+          "relative_path": "api/toc.json"
         }
       },
       "version": ""
@@ -717,11 +717,11 @@
       "type": "Toc",
       "source_relative_path": "toc.yml",
       "output": {
-        ".json": {
-          "relative_path": "toc.json"
-        },
         ".html": {
           "relative_path": "toc.html"
+        },
+        ".json": {
+          "relative_path": "toc.json"
         }
       },
       "version": ""

docs/xrefmap.yml

@@ -351,30 +351,84 @@ references:
   commentId: T:AnthropicClient.Models.AnthropicModels
   fullName: AnthropicClient.Models.AnthropicModels
   nameWithType: AnthropicModels
+- uid: AnthropicClient.Models.AnthropicModels.Claude35Haiku20241022
+  name: Claude35Haiku20241022
+  href: api/AnthropicClient.Models.AnthropicModels.html#AnthropicClient_Models_AnthropicModels_Claude35Haiku20241022
+  commentId: F:AnthropicClient.Models.AnthropicModels.Claude35Haiku20241022
+  fullName: AnthropicClient.Models.AnthropicModels.Claude35Haiku20241022
+  nameWithType: AnthropicModels.Claude35Haiku20241022
+- uid: AnthropicClient.Models.AnthropicModels.Claude35HaikuLatest
+  name: Claude35HaikuLatest
+  href: api/AnthropicClient.Models.AnthropicModels.html#AnthropicClient_Models_AnthropicModels_Claude35HaikuLatest
+  commentId: F:AnthropicClient.Models.AnthropicModels.Claude35HaikuLatest
+  fullName: AnthropicClient.Models.AnthropicModels.Claude35HaikuLatest
+  nameWithType: AnthropicModels.Claude35HaikuLatest
 - uid: AnthropicClient.Models.AnthropicModels.Claude35Sonnet
   name: Claude35Sonnet
   href: api/AnthropicClient.Models.AnthropicModels.html#AnthropicClient_Models_AnthropicModels_Claude35Sonnet
   commentId: F:AnthropicClient.Models.AnthropicModels.Claude35Sonnet
   fullName: AnthropicClient.Models.AnthropicModels.Claude35Sonnet
   nameWithType: AnthropicModels.Claude35Sonnet
+- uid: AnthropicClient.Models.AnthropicModels.Claude35Sonnet20240620
+  name: Claude35Sonnet20240620
+  href: api/AnthropicClient.Models.AnthropicModels.html#AnthropicClient_Models_AnthropicModels_Claude35Sonnet20240620
+  commentId: F:AnthropicClient.Models.AnthropicModels.Claude35Sonnet20240620
+  fullName: AnthropicClient.Models.AnthropicModels.Claude35Sonnet20240620
+  nameWithType: AnthropicModels.Claude35Sonnet20240620
+- uid: AnthropicClient.Models.AnthropicModels.Claude35Sonnet20241022
+  name: Claude35Sonnet20241022
+  href: api/AnthropicClient.Models.AnthropicModels.html#AnthropicClient_Models_AnthropicModels_Claude35Sonnet20241022
+  commentId: F:AnthropicClient.Models.AnthropicModels.Claude35Sonnet20241022
+  fullName: AnthropicClient.Models.AnthropicModels.Claude35Sonnet20241022
+  nameWithType: AnthropicModels.Claude35Sonnet20241022
+- uid: AnthropicClient.Models.AnthropicModels.Claude35SonnetLatest
+  name: Claude35SonnetLatest
+  href: api/AnthropicClient.Models.AnthropicModels.html#AnthropicClient_Models_AnthropicModels_Claude35SonnetLatest
+  commentId: F:AnthropicClient.Models.AnthropicModels.Claude35SonnetLatest
+  fullName: AnthropicClient.Models.AnthropicModels.Claude35SonnetLatest
+  nameWithType: AnthropicModels.Claude35SonnetLatest
 - uid: AnthropicClient.Models.AnthropicModels.Claude3Haiku
   name: Claude3Haiku
   href: api/AnthropicClient.Models.AnthropicModels.html#AnthropicClient_Models_AnthropicModels_Claude3Haiku
   commentId: F:AnthropicClient.Models.AnthropicModels.Claude3Haiku
   fullName: AnthropicClient.Models.AnthropicModels.Claude3Haiku
   nameWithType: AnthropicModels.Claude3Haiku
+- uid: AnthropicClient.Models.AnthropicModels.Claude3Haiku20240307
+  name: Claude3Haiku20240307
+  href: api/AnthropicClient.Models.AnthropicModels.html#AnthropicClient_Models_AnthropicModels_Claude3Haiku20240307
+  commentId: F:AnthropicClient.Models.AnthropicModels.Claude3Haiku20240307
+  fullName: AnthropicClient.Models.AnthropicModels.Claude3Haiku20240307
+  nameWithType: AnthropicModels.Claude3Haiku20240307
 - uid: AnthropicClient.Models.AnthropicModels.Claude3Opus
   name: Claude3Opus
   href: api/AnthropicClient.Models.AnthropicModels.html#AnthropicClient_Models_AnthropicModels_Claude3Opus
   commentId: F:AnthropicClient.Models.AnthropicModels.Claude3Opus
   fullName: AnthropicClient.Models.AnthropicModels.Claude3Opus
   nameWithType: AnthropicModels.Claude3Opus
+- uid: AnthropicClient.Models.AnthropicModels.Claude3Opus20241022
+  name: Claude3Opus20241022
+  href: api/AnthropicClient.Models.AnthropicModels.html#AnthropicClient_Models_AnthropicModels_Claude3Opus20241022
+  commentId: F:AnthropicClient.Models.AnthropicModels.Claude3Opus20241022
+  fullName: AnthropicClient.Models.AnthropicModels.Claude3Opus20241022
+  nameWithType: AnthropicModels.Claude3Opus20241022
+- uid: AnthropicClient.Models.AnthropicModels.Claude3OpusLatest
+  name: Claude3OpusLatest
+  href: api/AnthropicClient.Models.AnthropicModels.html#AnthropicClient_Models_AnthropicModels_Claude3OpusLatest
+  commentId: F:AnthropicClient.Models.AnthropicModels.Claude3OpusLatest
+  fullName: AnthropicClient.Models.AnthropicModels.Claude3OpusLatest
+  nameWithType: AnthropicModels.Claude3OpusLatest
 - uid: AnthropicClient.Models.AnthropicModels.Claude3Sonnet
   name: Claude3Sonnet
   href: api/AnthropicClient.Models.AnthropicModels.html#AnthropicClient_Models_AnthropicModels_Claude3Sonnet
   commentId: F:AnthropicClient.Models.AnthropicModels.Claude3Sonnet
   fullName: AnthropicClient.Models.AnthropicModels.Claude3Sonnet
   nameWithType: AnthropicModels.Claude3Sonnet
+- uid: AnthropicClient.Models.AnthropicModels.Claude3Sonnet20240229
+  name: Claude3Sonnet20240229
+  href: api/AnthropicClient.Models.AnthropicModels.html#AnthropicClient_Models_AnthropicModels_Claude3Sonnet20240229
+  commentId: F:AnthropicClient.Models.AnthropicModels.Claude3Sonnet20240229
+  fullName: AnthropicClient.Models.AnthropicModels.Claude3Sonnet20240229
+  nameWithType: AnthropicModels.Claude3Sonnet20240229
 - uid: AnthropicClient.Models.AnyToolChoice
   name: AnyToolChoice
   href: api/AnthropicClient.Models.AnyToolChoice.html

src/AnthropicClient/AnthropicApiClient.cs

@@ -26,6 +26,13 @@ public interface IAnthropicApiClient
   /// <param name="request">The message request to create.</param>
   /// <returns>An asynchronous enumerable that yields the response event by event.</returns>
   IAsyncEnumerable<AnthropicEvent> CreateMessageAsync(StreamMessageRequest request);
+
+  /// <summary>
+  /// Counts the tokens in a message asynchronously.
+  /// </summary>
+  /// <param name="request">The count message tokens request.</param>
+  /// <returns>A task that represents the asynchronous operation. The task result contains the response as an <see cref="AnthropicResult{T}"/> where T is <see cref="TokenCountResponse"/>.</returns>
+  Task<AnthropicResult<TokenCountResponse>> CountMessageTokensAsync(CountMessageTokensRequest request);
 }
 
 /// <inheritdoc cref="IAnthropicApiClient"/>
@@ -34,6 +41,7 @@ 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 CountTokensEndpoint = "messages/count_tokens";
   private const string JsonContentType = "application/json";
   private const string EventPrefix = "event:";
   private const string DataPrefix = "data:";
@@ -71,7 +79,7 @@ public class AnthropicApiClient : IAnthropicApiClient
   /// <inheritdoc />
   public async Task<AnthropicResult<MessageResponse>> CreateMessageAsync(MessageRequest request)
   {
-    var response = await SendRequestAsync(request);
+    var response = await SendRequestAsync(MessagesEndpoint, request);
     var anthropicHeaders = new AnthropicHeaders(response.Headers);
     var responseContent = await response.Content.ReadAsStringAsync();
 
@@ -94,7 +102,7 @@ public class AnthropicApiClient : IAnthropicApiClient
   /// <inheritdoc />
   public async IAsyncEnumerable<AnthropicEvent> CreateMessageAsync(StreamMessageRequest request)
   {
-    var response = await SendRequestAsync(request);
+    var response = await SendRequestAsync(MessagesEndpoint, request);
 
     if (response.IsSuccessStatusCode is false)
     {
@@ -255,6 +263,24 @@ public class AnthropicApiClient : IAnthropicApiClient
     } while (true);
   }
 
+  /// <inheritdoc />
+  public async Task<AnthropicResult<TokenCountResponse>> CountMessageTokensAsync(CountMessageTokensRequest request)
+  {
+    var response = await SendRequestAsync(CountTokensEndpoint, 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<TokenCountResponse>.Failure(error, anthropicHeaders);
+    }
+
+    var msgResponse = Deserialize<TokenCountResponse>(responseContent) ?? new TokenCountResponse();
+
+    return AnthropicResult<TokenCountResponse>.Success(msgResponse, anthropicHeaders);
+  }
+
   private ToolCall? GetToolCall(MessageResponse response, List<Tool> tools)
   {
     var toolUse = response.Content.OfType<ToolUseContent>().FirstOrDefault();
@@ -274,11 +300,11 @@ public class AnthropicApiClient : IAnthropicApiClient
     return new ToolCall(tool, toolUse);
   }
 
-  private async Task<HttpResponseMessage> SendRequestAsync(BaseMessageRequest request)
+  private async Task<HttpResponseMessage> SendRequestAsync<T>(string endpoint, T request)
   {
     var requestJson = Serialize(request);
     var requestContent = new StringContent(requestJson, Encoding.UTF8, JsonContentType);
-    return await _httpClient.PostAsync(MessagesEndpoint, requestContent);
+    return await _httpClient.PostAsync(endpoint, requestContent);
   }
 
   private string Serialize<T>(T obj) => JsonSerializer.Serialize(obj, JsonSerializationOptions.DefaultOptions);

src/AnthropicClient/AnthropicClient.csproj

@@ -4,7 +4,7 @@
     <TargetFramework>netstandard2.0</TargetFramework>
     <LangVersion>latest</LangVersion>
     <PackageId>AnthropicClient</PackageId>
-    <Version>0.3.0</Version>
+    <Version>0.4.0</Version>
     <Authors>Stevan Freeborn</Authors>
     <Description>Anthropic Client Library</Description>
     <PackageProjectUrl>https://anthropicclient.stevanfreeborn.com/</PackageProjectUrl>

src/AnthropicClient/CHANGELOG.md

@@ -2,6 +2,17 @@
 
 All notable changes to this project will be documented in this file. See [versionize](https://github.com/versionize/versionize) for commit guidelines.
 
+<a name="0.4.0"></a>
+## [0.4.0](https://www.github.com/StevanFreeborn/anthropic-client/releases/tag/v0.4.0) (2025-01-03)
+
+### Features
+
+* add support for count tokens endpoint ([9448220](https://www.github.com/StevanFreeborn/anthropic-client/commit/944822060cd297c5720d8a1dc366f08ca0ec79ec))
+
+### Bug Fixes
+
+* remove model id validation ([31a7097](https://www.github.com/StevanFreeborn/anthropic-client/commit/31a7097cdc9f9f60a7b6576b8bcee7a49a00552c))
+
 <a name="0.3.0"></a>
 ## [0.3.0](https://www.github.com/StevanFreeborn/anthropic-client/releases/tag/v0.3.0) (2025-01-02)
 

src/AnthropicClient/Models/AnthropicModels.cs

@@ -69,21 +69,4 @@ public static class AnthropicModels
   /// The Claude 3.5 Haiku model.
   /// </summary>
   public const string Claude35HaikuLatest = "claude-3-5-haiku-latest";
-
-  internal static bool IsValidModel(string modelId) => modelId is
-    Claude3Opus or
-    Claude3Opus20241022 or
-    Claude3OpusLatest or
-
-    Claude3Sonnet or
-    Claude3Sonnet20240229 or
-    Claude35Sonnet or
-    Claude35Sonnet20240620 or
-    Claude35Sonnet20241022 or
-    Claude35SonnetLatest or
-
-    Claude3Haiku or
-    Claude3Haiku20240307 or
-    Claude35Haiku20241022 or
-    Claude35HaikuLatest;
 }

src/AnthropicClient/Models/BaseMessageRequest.cs

@@ -126,7 +126,6 @@ public abstract class BaseMessageRequest
   /// <param name="stream">A value indicating whether the message should be streamed.</param>
   /// <param name="stopSequences">The prompt stop sequences.</param>
   /// <param name="systemMessages">The system messages to use for the request.</param>
-  /// <exception cref="ArgumentException">Thrown when the model ID is invalid.</exception>
   /// <exception cref="ArgumentNullException">Thrown when the model or messages is null.</exception>
   /// <exception cref="ArgumentException">Thrown when the messages contain no messages.</exception>
   /// <exception cref="ArgumentException">Thrown when the max tokens is less than one.</exception>
@@ -151,11 +150,6 @@ public abstract class BaseMessageRequest
     ArgumentValidator.ThrowIfNull(model, nameof(model));
     ArgumentValidator.ThrowIfNull(messages, nameof(messages));
 
-    if (AnthropicModels.IsValidModel(model) is false)
-    {
-      throw new ArgumentException($"Invalid model ID: {model}");
-    }
-
     if (messages.Count < 1)
     {
       throw new ArgumentException("Messages must contain at least one message");

src/AnthropicClient/Models/CountMessageTokensRequest.cs

@@ -0,0 +1,72 @@
+using System.Text.Json.Serialization;
+
+using AnthropicClient.Utils;
+
+namespace AnthropicClient.Models;
+
+/// <summary>
+/// Represents a request to count the number of tokens in a message.
+/// </summary>
+public class CountMessageTokensRequest
+{
+  /// <summary>
+  /// Gets the model ID to be used for the request.
+  /// </summary>
+  public string Model { get; init; } = string.Empty;
+
+  /// <summary>
+  /// Gets the messages to count the number of tokens in.
+  /// </summary>
+  public List<Message> Messages { get; init; } = [];
+
+  /// <summary>
+  /// Gets the tool choice mode to use for the request.
+  /// </summary>
+  [JsonPropertyName("tool_choice")]
+  public ToolChoice? ToolChoice { get; init; } = null;
+
+  /// <summary>
+  /// Gets the tools to use for the request.
+  /// </summary>
+  public List<Tool>? Tools { get; init; } = null;
+
+  /// <summary>
+  /// Gets the system prompt to use for the request.
+  /// </summary>
+  [JsonPropertyName("system")]
+  public List<TextContent>? SystemPrompt { get; init; } = null;
+
+  /// <summary>
+  /// Initializes a new instance of the <see cref="CountMessageTokensRequest"/> class.
+  /// </summary>
+  /// <param name="model">The model ID to use for the request.</param>
+  /// <param name="messages">The messages to count the number of tokens in.</param>
+  /// <param name="toolChoice">The tool choice mode to use for the request.</param>
+  /// <param name="tools">The tools to use for the request.</param>
+  /// <param name="systemPrompt">The system prompt to use for the request.</param>
+  /// <exception cref="ArgumentNullException">Thrown when <paramref name="model"/> or <paramref name="messages"/> is null.</exception>
+  /// <exception cref="ArgumentException">Thrown when <paramref name="messages"/> is empty.</exception>
+  /// <returns>A new instance of the <see cref="CountMessageTokensRequest"/> class.</returns>
+  public CountMessageTokensRequest(
+    string model,
+    List<Message> messages,
+    ToolChoice? toolChoice = null,
+    List<Tool>? tools = null,
+    List<TextContent>? systemPrompt = null
+  )
+  {
+    ArgumentValidator.ThrowIfNull(model, nameof(model));
+    ArgumentValidator.ThrowIfNull(messages, nameof(messages));
+
+    if (messages.Count < 1)
+    {
+      throw new ArgumentException("Messages must contain at least one message");
+    }
+
+    Model = model;
+    Messages = messages;
+    ToolChoice = toolChoice;
+    Tools = tools;
+    SystemPrompt = systemPrompt;
+  }
+}

src/AnthropicClient/Models/MessageRequest.cs

@@ -25,7 +25,6 @@ public class MessageRequest : BaseMessageRequest
   /// <param name="tools">The tools to use for the request.</param>
   /// <param name="stopSequences">The prompt stop sequences.</param>
   /// <param name="systemMessages">The system messages to include with the request.</param>
-  /// <exception cref="ArgumentException">Thrown when the model ID is invalid.</exception>
   /// <exception cref="ArgumentNullException">Thrown when the model or messages is null.</exception>
   /// <exception cref="ArgumentException">Thrown when the messages contain no messages.</exception>
   /// <exception cref="ArgumentException">Thrown when the max tokens is less than one.</exception>

src/AnthropicClient/Models/StreamMessageRequest.cs

@@ -25,7 +25,6 @@ public class StreamMessageRequest : BaseMessageRequest
   /// <param name="tools">The tools to use for the request.</param>
   /// <param name="stopSequences">The prompt stop sequences.</param>
   /// <param name="systemMessages">The system messages to include with the request.</param>
-  /// <exception cref="ArgumentException">Thrown when the model ID is invalid.</exception>
   /// <exception cref="ArgumentNullException">Thrown when the model or messages is null.</exception>
   /// <exception cref="ArgumentException">Thrown when the messages contain no messages.</exception>
   /// <exception cref="ArgumentException">Thrown when the max tokens is less than one.</exception>

src/AnthropicClient/Models/TokenCountResponse.cs

@@ -0,0 +1,15 @@
+using System.Text.Json.Serialization;
+
+namespace AnthropicClient.Models;
+
+/// <summary>
+/// Represents a response to a token count request.
+/// </summary>
+public class TokenCountResponse
+{
+  /// <summary>
+  ///  The number of input tokens counted.
+  /// </summary>
+  [JsonPropertyName("input_tokens")]
+  public int InputTokens { get; init; }
+}

tests/AnthropicClient.Tests/EndToEnd/AnthropicApiClientTests.cs

@@ -100,10 +100,7 @@ public class ClientTests(ConfigurationFixture configFixture) : EndToEndTest(conf
   [Fact]
   public async Task CreateMessageAsync_WhenSystemMessagesContainCacheControl_ItShouldUseCache()
   {
-    var httpClient = new HttpClient();
+    var client = CreateClient(new HttpClient());
-    httpClient.DefaultRequestHeaders.Add("anthropic-beta", "prompt-caching-2024-07-31");
-
-    var client = CreateClient(httpClient);
 
     var storyPath = GetTestFilePath("story.txt");
     var storyText = await File.ReadAllTextAsync(storyPath);
@@ -121,7 +118,7 @@ public class ClientTests(ConfigurationFixture configFixture) : EndToEndTest(conf
       ]
     );
 
-    var resultOne = await client.CreateMessageAsync(request);
+    var resultOne = await _client.CreateMessageAsync(request);
 
     resultOne.IsSuccess.Should().BeTrue();
     resultOne.Value.Should().BeOfType<MessageResponse>();
@@ -142,10 +139,7 @@ public class ClientTests(ConfigurationFixture configFixture) : EndToEndTest(conf
   [Fact]
   public async Task CreateMessageAsync_WhenMessagesContainCacheControl_ItShouldUseCache()
   {
-    var httpClient = new HttpClient();
+    var client = CreateClient(new HttpClient());
-    httpClient.DefaultRequestHeaders.Add("anthropic-beta", "prompt-caching-2024-07-31");
-
-    var client = CreateClient(httpClient);
 
     var storyPath = GetTestFilePath("story.txt");
     var storyText = await File.ReadAllTextAsync(storyPath);
@@ -181,10 +175,7 @@ public class ClientTests(ConfigurationFixture configFixture) : EndToEndTest(conf
   [Fact]
   public async Task CreateMessageAsync_WhenToolsContainCacheControl_ItShouldUseCache()
   {
-    var httpClient = new HttpClient();
+    var client = CreateClient(new HttpClient());
-    httpClient.DefaultRequestHeaders.Add("anthropic-beta", "prompt-caching-2024-07-31");
-
-    var client = CreateClient(httpClient);
 
     var func = (string ticker) => ticker;
 
@@ -238,9 +229,7 @@ public class ClientTests(ConfigurationFixture configFixture) : EndToEndTest(conf
       ]
     );
 
-    var httpClient = new HttpClient();
+    var client = CreateClient(new HttpClient());
-    httpClient.DefaultRequestHeaders.Add("anthropic-beta", "pdfs-2024-09-25");
-    var client = CreateClient(httpClient);
 
     var result = await client.CreateMessageAsync(request);
 
@@ -268,9 +257,7 @@ public class ClientTests(ConfigurationFixture configFixture) : EndToEndTest(conf
     var bytes = await File.ReadAllBytesAsync(pdfPath);
     var base64Data = Convert.ToBase64String(bytes);
 
-    var httpClient = new HttpClient();
+    var client = CreateClient(new HttpClient());
-    httpClient.DefaultRequestHeaders.Add("anthropic-beta", "pdfs-2024-09-25, prompt-caching-2024-07-31");
-    var client = CreateClient(httpClient);
 
     var request = new MessageRequest(
       model: AnthropicModels.Claude35Sonnet,
@@ -299,4 +286,21 @@ public class ClientTests(ConfigurationFixture configFixture) : EndToEndTest(conf
     resultTwo.Value.Content.Should().NotBeNullOrEmpty();
     resultTwo.Value.Usage.CacheReadInputTokens.Should().BeGreaterThan(0);
   }
+
+  [Fact]
+  public async Task CountMessageTokensAsync_WhenCalled_ItShouldReturnResponse()
+  {
+    var request = new CountMessageTokensRequest(
+      model: AnthropicModels.Claude3Haiku,
+      messages: [
+        new(MessageRole.User, [new TextContent("Hello!")])
+      ]
+    );
+
+    var result = await _client.CountMessageTokensAsync(request);
+
+    result.IsSuccess.Should().BeTrue();
+    result.Value.Should().BeOfType<TokenCountResponse>();
+    result.Value.InputTokens.Should().BeGreaterThan(0);
+  }
 }

tests/AnthropicClient.Tests/Integration/AnthropicApiClientTests.cs

@@ -418,4 +418,89 @@ public class AnthropicApiClientTests : IntegrationTest
     textContent.As<TextContent>().Text.Should().Be("It is a PDF");
     textContent.As<TextContent>().Type.Should().Be("text");
   }
+
+  [Fact]
+  public async Task CountMessageTokensAsync_WhenCalled_ItShouldReturnCountTokensResponse()
+  {
+    _mockHttpMessageHandler
+      .WhenCountMessageTokensRequest()
+      .Respond(
+        HttpStatusCode.OK,
+        "application/json",
+        @"{
+          ""input_tokens"": 10
+        }"
+      );
+
+    var request = new CountMessageTokensRequest(
+      model: AnthropicModels.Claude35Sonnet,
+      messages: [
+        new(MessageRole.User, [new TextContent("Hello!")]),
+      ]
+    );
+
+    var result = await Client.CountMessageTokensAsync(request);
+
+    result.IsSuccess.Should().BeTrue();
+    result.Value.Should().BeOfType<TokenCountResponse>();
+    result.Value.InputTokens.Should().Be(10);
+  }
+
+  [Fact]
+  public async Task CountMessageTokensAsync_WhenCalledAndErrorReturned_ItShouldHandleError()
+  {
+    _mockHttpMessageHandler
+      .WhenCountMessageTokensRequest()
+      .Respond(
+        HttpStatusCode.BadRequest,
+        "application/json",
+        @"{
+          ""type"": ""error"",
+          ""error"": {
+            ""type"": ""invalid_request_error"",
+            ""message"": ""messages: roles must alternate between user and assistant, but found multiple user roles in a row""
+          }
+        }"
+      );
+
+    var request = new CountMessageTokensRequest(
+      model: AnthropicModels.Claude35Sonnet,
+      messages: [
+        new(MessageRole.User, [new TextContent("Hello!")]),
+        new(MessageRole.User, [new TextContent("Hello!")])
+      ]
+    );
+
+    var result = await Client.CountMessageTokensAsync(request);
+
+    result.IsSuccess.Should().BeFalse();
+    result.Error.Should().BeOfType<AnthropicError>();
+    result.Error.Error.Should().BeOfType<InvalidRequestError>();
+  }
+
+  [Fact]
+  public async Task CountMessageTokensAsync_WhenCalledRequestFailsAndCanNotSerializeError_ItShouldReturnUnknownError()
+  {
+    _mockHttpMessageHandler
+      .WhenCountMessageTokensRequest()
+      .Respond(
+        HttpStatusCode.BadRequest,
+        "application/json",
+        @"{}"
+      );
+
+    var request = new CountMessageTokensRequest(
+      model: AnthropicModels.Claude35Sonnet,
+      messages: [
+        new(MessageRole.User, [new TextContent("Hello!")]),
+        new(MessageRole.User, [new TextContent("Hello!")])
+      ]
+    );
+
+    var result = await Client.CountMessageTokensAsync(request);
+
+    result.IsSuccess.Should().BeFalse();
+    result.Error.Should().BeOfType<AnthropicError>();
+    result.Error.Error.Should().BeOfType<ApiError>();
+  }
 }

tests/AnthropicClient.Tests/Integration/IntegrationTest.cs

@@ -13,10 +13,18 @@ public class IntegrationTest
 
 public static class MockHttpMessageHandlerExtensions
 {
-  private static MockedRequest SetupBaseRequest(this MockHttpMessageHandler mockHttpMessageHandler)
+  private const string BaseUrl = "https://api.anthropic.com/v1";
+  private static readonly string MessagesEndpoint = $"{BaseUrl}/messages";
+  private static readonly string CountTokensEndpoint = $"{BaseUrl}/messages/count_tokens";
+
+  private static MockedRequest SetupBaseRequest(
+    this MockHttpMessageHandler mockHttpMessageHandler,
+    HttpMethod method,
+    string url
+  )
   {
     return mockHttpMessageHandler
-      .When(HttpMethod.Post, "https://api.anthropic.com/v1/messages")
+      .When(method, url)
       .WithHeaders(new Dictionary<string, string>
       {
         { "anthropic-version", "2023-06-01" },
@@ -27,14 +35,20 @@ public static class MockHttpMessageHandlerExtensions
   public static MockedRequest WhenCreateMessageRequest(this MockHttpMessageHandler mockHttpMessageHandler)
   {
     return mockHttpMessageHandler
-      .SetupBaseRequest()
+      .SetupBaseRequest(HttpMethod.Post, MessagesEndpoint)
       .WithJsonContent<MessageRequest>(r => r.Stream == false, JsonSerializationOptions.DefaultOptions);
   }
 
   public static MockedRequest WhenCreateStreamMessageRequest(this MockHttpMessageHandler mockHttpMessageHandler)
   {
     return mockHttpMessageHandler
-      .SetupBaseRequest()
+      .SetupBaseRequest(HttpMethod.Post, MessagesEndpoint)
       .WithJsonContent<StreamMessageRequest>(r => r.Stream == true, JsonSerializationOptions.DefaultOptions);
   }
+
+  public static MockedRequest WhenCountMessageTokensRequest(this MockHttpMessageHandler mockHttpMessageHandler)
+  {
+    return mockHttpMessageHandler
+      .SetupBaseRequest(HttpMethod.Post, CountTokensEndpoint);
+  }
 }

tests/AnthropicClient.Tests/Unit/Models/AnthropicModelsTests.cs

@@ -131,22 +131,4 @@ public class AnthropicModelsTests
 
     actual.Should().Be(expected);
   }
-
-  [Theory]
-  [InlineData("claude-3-opus-20240229", true)]
-  [InlineData("claude-3-opus-latest", true)]
-  [InlineData("claude-3-sonnet-20240229", true)]
-  [InlineData("claude-3-5-sonnet-20240620", true)]
-  [InlineData("claude-3-5-sonnet-20241022", true)]
-  [InlineData("claude-3-5-sonnet-latest", true)]
-  [InlineData("claude-3-haiku-20240307", true)]
-  [InlineData("claude-3-5-haiku-20241022", true)]
-  [InlineData("claude-3-5-haiku-latest", true)]
-  [InlineData("invalid", false)]
-  public void IsValidModel_WhenCalled_ItShouldReturnExpectedValue(string modelId, bool expected)
-  {
-    var actual = AnthropicModels.IsValidModel(modelId);
-
-    actual.Should().Be(expected);
-  }
 }

tests/AnthropicClient.Tests/Unit/Models/CountMessageTokensRequestTests.cs

@@ -0,0 +1,117 @@
+namespace AnthropicClient.Tests.Unit.Models;
+
+public class CountMessageTokensRequestTests : SerializationTest
+{
+  private readonly string _testJson = @"{
+    ""model"": ""claude-3-sonnet-20240229"",
+    ""system"": [{
+      ""type"": ""text"",
+      ""text"": ""test-system""
+    }],
+    ""messages"": [
+      { ""role"": ""user"", ""content"": [{ ""text"": ""Hello!"", ""type"": ""text"" }] }
+    ],
+    ""tool_choice"": { ""type"":""auto"" },
+    ""tools"": []
+  }";
+
+  [Fact]
+  public void Constructor_WhenCalled_ItShouldInitializeProperties()
+  {
+    var model = AnthropicModels.Claude3Sonnet;
+    var messages = new List<Message> { new() };
+    var systemPrompt = new List<TextContent>() { new("test-system") };
+    var toolChoice = new AutoToolChoice();
+    var tools = new List<Tool>();
+
+    var request = new CountMessageTokensRequest(
+      model: model,
+      messages: messages,
+      toolChoice: toolChoice,
+      tools: tools,
+      systemPrompt: systemPrompt
+    );
+
+    request.Model.Should().Be(model);
+    request.Messages.Should().BeSameAs(messages);
+    request.ToolChoice.Should().Be(toolChoice);
+    request.Tools.Should().BeSameAs(tools);
+    request.SystemPrompt.Should().BeSameAs(systemPrompt);
+  }
+
+  [Fact]
+  public void Constructor_WhenCalledAndModelIsNull_ItShouldThrowArgumentNullException()
+  {
+    var action = () => new CountMessageTokensRequest(
+      model: null!,
+      messages: [new()]
+    );
+
+    action.Should().Throw<ArgumentNullException>();
+  }
+
+  [Fact]
+  public void Constructor_WhenCalledAndMessagesIsNull_ItShouldThrowArgumentNullException()
+  {
+    var action = () => new CountMessageTokensRequest(
+      model: AnthropicModels.Claude3Sonnet,
+      messages: null!
+    );
+
+    action.Should().Throw<ArgumentNullException>();
+  }
+
+  [Fact]
+  public void Constructor_WhenCalledAndMessagesIsEmpty_ItShouldThrowArgumentException()
+  {
+    var action = () => new CountMessageTokensRequest(
+      model: AnthropicModels.Claude3Sonnet,
+      messages: []
+    );
+
+    action.Should().Throw<ArgumentException>();
+  }
+
+  [Fact]
+  public void JsonSerialization_WhenSerialized_ItShouldHaveExpectedShape()
+  {
+    var messages = new List<Message>()
+    {
+      new()
+      {
+        Role = MessageRole.User,
+        Content = [new TextContent("Hello!")]
+      }
+    };
+
+    var model = AnthropicModels.Claude3Sonnet;
+    var systemPrompt = new List<TextContent>() { new("test-system") };
+    var toolChoice = new AutoToolChoice();
+    var tools = new List<Tool>();
+
+    var request = new CountMessageTokensRequest(
+      model: model,
+      messages: messages,
+      toolChoice: toolChoice,
+      tools: tools,
+      systemPrompt: systemPrompt
+    );
+
+    var actual = Serialize(request);
+
+    JsonAssert.Equal(_testJson, actual);
+  }
+
+  [Fact]
+  public void JsonDeserialization_WhenDeserialized_ItShouldHaveExpectedShape()
+  {
+    var request = Deserialize<CountMessageTokensRequest>(_testJson);
+
+    request!.Model.Should().Be(AnthropicModels.Claude3Sonnet);
+    request.SystemPrompt.Should().BeEquivalentTo(new List<TextContent> { new("test-system") });
+    request.Messages.Should().HaveCount(1);
+    request.ToolChoice.Should().BeOfType<AutoToolChoice>();
+    request.ToolChoice!.Type.Should().Be("auto");
+    request.Tools.Should().HaveCount(0);
+  }
+}

tests/AnthropicClient.Tests/Unit/Models/MessageRequestTests.cs

@@ -232,14 +232,14 @@ public class MessageRequestTests : SerializationTest
   }
 
   [Fact]
-  public void Constructor_WhenCalledAndModelIsInvalid_ItShouldThrowArgumentException()
+  public void Constructor_WhenCalledAndModelIsInvalid_ItShouldNotThrowException()
   {
     var action = () => new MessageRequest(
       model: "invalid-model",
       messages: [new()]
     );
 
-    action.Should().Throw<ArgumentException>();
+    action.Should().NotThrow();
   }
 
   [Fact]

tests/AnthropicClient.Tests/Unit/Models/StreamMessageRequestTests.cs

@@ -85,14 +85,14 @@ public class StreamMessageRequestTests : SerializationTest
   }
 
   [Fact]
-  public void Constructor_WhenCalledAndModelIsInvalid_ItShouldThrowArgumentException()
+  public void Constructor_WhenCalledAndModelIsInvalid_ItShouldNotThrowException()
   {
     var action = () => new StreamMessageRequest(
       model: "invalid-model",
       messages: [new()]
     );
 
-    action.Should().Throw<ArgumentException>();
+    action.Should().NotThrow();
   }
 
   [Fact]

tests/AnthropicClient.Tests/Unit/Models/TokenCountResponseTests.cs

@@ -0,0 +1,46 @@
+namespace AnthropicClient.Tests.Unit.Models;
+
+public class TokenCountResponseTests : SerializationTest
+{
+  [Fact]
+  public void Constructor_WhenCalled_ShouldInitializeProperties()
+  {
+    var expectedTokenCount = 1;
+
+    var response = new TokenCountResponse
+    {
+      InputTokens = expectedTokenCount
+    };
+
+    response.InputTokens.Should().Be(expectedTokenCount);
+  }
+
+  [Fact]
+  public void JsonSerialization_WhenCalled_ItShouldSerializeCorrectly()
+  {
+    var expectedJson = @"{
+      ""input_tokens"": 1
+    }";
+
+    var response = new TokenCountResponse
+    {
+      InputTokens = 1
+    };
+
+    var actual = Serialize(response);
+
+    JsonAssert.Equal(expectedJson, actual);
+  }
+
+  [Fact]
+  public void JsonDeserialization_WhenCalled_ItShouldDeserializeCorrectly()
+  {
+    var json = @"{
+      ""input_tokens"": 1
+    }";
+
+    var response = Deserialize<TokenCountResponse>(json);
+
+    response!.InputTokens.Should().Be(1);
+  }
+}