feat: implement GetFileInfoAsync, GetFileAsync, and DeleteFileAsync

src/AnthropicClient/AnthropicApiClient.cs

@@ -385,6 +385,14 @@ public class AnthropicApiClient : IAnthropicApiClient
   public async Task<AnthropicResult<AnthropicFile>> CreateFileAsync(CreateFileRequest request, CancellationToken cancellationToken = default)
   {
     var response = await SendFileRequestAsync(FilesEndpoint, request, cancellationToken);
+
+    if (response.IsSuccessStatusCode is false)
+    {
+      var content = await response.Content.ReadAsStringAsync();
+      var error = Deserialize<AnthropicError>(content) ?? new AnthropicError();
+      return AnthropicResult<AnthropicFile>.Failure(error, new AnthropicHeaders(response.Headers));
+    }
+
     return await CreateResultAsync<AnthropicFile>(response);
   }
 
@@ -394,6 +402,14 @@ public class AnthropicApiClient : IAnthropicApiClient
     var pagingRequest = request ?? new PagingRequest();
     var endpoint = $"{FilesEndpoint}?{pagingRequest.ToQueryParameters()}";
     var response = await SendRequestAsync(endpoint, cancellationToken: cancellationToken);
+
+    if (response.IsSuccessStatusCode is false)
+    {
+      var content = await response.Content.ReadAsStringAsync();
+      var error = Deserialize<AnthropicError>(content) ?? new AnthropicError();
+      return AnthropicResult<Page<AnthropicFile>>.Failure(error, new AnthropicHeaders(response.Headers));
+    }
+
     return await CreateResultAsync<Page<AnthropicFile>>(response);
   }
 
@@ -406,6 +422,55 @@ public class AnthropicApiClient : IAnthropicApiClient
     }
   }
 
+  /// <inheritdoc/>
+  public async Task<AnthropicResult<AnthropicFile>> GetFileInfoAsync(string fileId, CancellationToken cancellationToken = default)
+  {
+    var endpoint = $"{FilesEndpoint}/{fileId}";
+    var response = await SendRequestAsync(endpoint, cancellationToken: cancellationToken);
+
+    if (response.IsSuccessStatusCode is false)
+    {
+      var content = await response.Content.ReadAsStringAsync();
+      var error = Deserialize<AnthropicError>(content) ?? new AnthropicError();
+      return AnthropicResult<AnthropicFile>.Failure(error, new AnthropicHeaders(response.Headers));
+    }
+
+    return await CreateResultAsync<AnthropicFile>(response);
+  }
+
+  /// <inheritdoc/>
+  public async Task<AnthropicResult<Stream>> GetFileAsync(string fileId, CancellationToken cancellationToken = default)
+  {
+    var endpoint = $"{FilesEndpoint}/{fileId}/content";
+    var response = await SendRequestAsync(endpoint, cancellationToken: cancellationToken);
+
+    if (response.IsSuccessStatusCode is false)
+    {
+      var content = await response.Content.ReadAsStringAsync();
+      var error = Deserialize<AnthropicError>(content) ?? new AnthropicError();
+      return AnthropicResult<Stream>.Failure(error, new AnthropicHeaders(response.Headers));
+    }
+
+    var stream = await response.Content.ReadAsStreamAsync();
+    return AnthropicResult<Stream>.Success(stream, new AnthropicHeaders(response.Headers));
+  }
+
+  /// <inheritdoc/>
+  public async Task<AnthropicResult<AnthropicFileDeleteResponse>> DeleteFileAsync(string fileId, CancellationToken cancellationToken = default)
+  {
+    var endpoint = $"{FilesEndpoint}/{fileId}";
+    var response = await SendRequestAsync(endpoint, HttpMethod.Delete, cancellationToken);
+
+    if (response.IsSuccessStatusCode is false)
+    {
+      var content = await response.Content.ReadAsStringAsync();
+      var error = Deserialize<AnthropicError>(content) ?? new AnthropicError();
+      return AnthropicResult<AnthropicFileDeleteResponse>.Failure(error, new AnthropicHeaders(response.Headers));
+    }
+
+    return await CreateResultAsync<AnthropicFileDeleteResponse>(response);
+  }
+
   private async IAsyncEnumerable<AnthropicResult<Page<T>>> GetAllPagesAsync<T>(string endpoint, int limit = 20, [EnumeratorCancellation] CancellationToken cancellationToken = default)
   {
     var pagingRequest = new PagingRequest(limit: limit);

src/AnthropicClient/IAnthropicApiClient.cs

@@ -135,4 +135,29 @@ public interface IAnthropicApiClient
   /// <param name="cancellationToken">A token to cancel the asynchronous operation.</param>
   /// <returns>An asynchronous enumerable that yields the response as an <see cref="AnthropicResult{T}"/> where T is <see cref="Page{T}"/> where T is <see cref="AnthropicFile"/>.</returns>
   IAsyncEnumerable<AnthropicResult<Page<AnthropicFile>>> ListAllFilesAsync(int limit = 20, CancellationToken cancellationToken = default);
+
+  /// <summary>
+  /// Gets a file's metadata by its ID asynchronously.
+  /// </summary>
+  /// <param name="fileId">The ID of the file to get.</param>
+  /// <param name="cancellationToken">A token to cancel the asynchronous operation.</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="AnthropicFile"/>.</returns>
+  Task<AnthropicResult<AnthropicFile>> GetFileInfoAsync(string fileId, CancellationToken cancellationToken = default);
+
+  /// <summary>
+  /// Gets a file's content by its ID asynchronously.
+  /// </summary>
+  /// <param name="fileId">The ID of the file to get the content for.</param>
+  /// <param name="cancellationToken">A token to cancel the asynchronous operation.</param>
+  /// <returns>A task that represents the asynchronous operation. The task result contains the response as an <see cref="AnthropicResult{T}"/> where T is a stream containing the file content.</returns>
+  Task<AnthropicResult<Stream>> GetFileAsync(string fileId, CancellationToken cancellationToken = default);
+
+
+  /// <summary>
+  /// Deletes a file by its ID asynchronously.
+  /// </summary>
+  /// <param name="fileId">The ID of the file to delete.</param>
+  /// <param name="cancellationToken">A token to cancel the asynchronous operation.</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="AnthropicFileDeleteResponse"/>.</returns>
+  Task<AnthropicResult<AnthropicFileDeleteResponse>> DeleteFileAsync(string fileId, CancellationToken cancellationToken = default);
 }

src/AnthropicClient/Models/AnthropicFileDeleteResponse.cs

@@ -0,0 +1,17 @@
+namespace AnthropicClient.Models;
+
+/// <summary>
+/// Represents the response from deleting a file in the Anthropic API.
+/// </summary>
+public class AnthropicFileDeleteResponse
+{
+  /// <summary>
+  /// Gets or sets the ID of the file that was deleted.
+  /// </summary>
+  public string Id { get; init; } = string.Empty;
+
+  /// <summary>
+  /// Gets or sets the response type
+  /// </summary>
+  public string Type { get; init; } = string.Empty;
+}